blob: c6786cd35b29f786336308730ab5038a51ad1604 [file] [log] [blame]
bellardfc01f7e2003-06-30 10:03:06 +00001/*
2 * QEMU System Emulator block driver
ths5fafdf22007-09-16 21:08:06 +00003 *
bellardfc01f7e2003-06-30 10:03:06 +00004 * Copyright (c) 2003 Fabrice Bellard
ths5fafdf22007-09-16 21:08:06 +00005 *
bellardfc01f7e2003-06-30 10:03:06 +00006 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
Markus Armbrustere688df62018-02-01 12:18:31 +010024
Peter Maydelld38ea872016-01-29 17:50:05 +000025#include "qemu/osdep.h"
Daniel P. Berrange0ab8ed12017-01-25 16:14:15 +000026#include "block/trace.h"
Paolo Bonzini737e1502012-12-17 18:19:44 +010027#include "block/block_int.h"
28#include "block/blockjob.h"
Kevin Wolfcd7fca92016-07-06 11:22:39 +020029#include "block/nbd.h"
Max Reitz609f45e2018-06-14 21:14:28 +020030#include "block/qdict.h"
Markus Armbrusterd49b6832015-03-17 18:29:20 +010031#include "qemu/error-report.h"
Marc Mari88d88792016-08-12 09:27:03 -040032#include "module_block.h"
Paolo Bonzini1de7afc2012-12-17 18:20:00 +010033#include "qemu/module.h"
Markus Armbrustere688df62018-02-01 12:18:31 +010034#include "qapi/error.h"
Markus Armbruster452fcdb2018-02-01 12:18:39 +010035#include "qapi/qmp/qdict.h"
Paolo Bonzini7b1b5d12012-12-17 18:19:43 +010036#include "qapi/qmp/qjson.h"
Max Reitze59a0cf2018-02-24 16:40:32 +010037#include "qapi/qmp/qnull.h"
Markus Armbrusterfc81fa12018-02-01 12:18:40 +010038#include "qapi/qmp/qstring.h"
Kevin Wolfe1d74bc2018-01-10 15:52:33 +010039#include "qapi/qobject-output-visitor.h"
40#include "qapi/qapi-visit-block-core.h"
Markus Armbrusterbfb197e2014-10-07 13:59:11 +020041#include "sysemu/block-backend.h"
Paolo Bonzini9c17d612012-12-17 18:20:04 +010042#include "sysemu/sysemu.h"
Paolo Bonzini1de7afc2012-12-17 18:20:00 +010043#include "qemu/notify.h"
Markus Armbruster922a01a2018-02-01 12:18:46 +010044#include "qemu/option.h"
Daniel P. Berrange10817bf2015-09-01 14:48:02 +010045#include "qemu/coroutine.h"
Benoît Canetc13163f2014-01-23 21:31:34 +010046#include "block/qapi.h"
Paolo Bonzini1de7afc2012-12-17 18:20:00 +010047#include "qemu/timer.h"
Veronia Bahaaf348b6d2016-03-20 19:16:19 +020048#include "qemu/cutils.h"
49#include "qemu/id.h"
bellardfc01f7e2003-06-30 10:03:06 +000050
Juan Quintela71e72a12009-07-27 16:12:56 +020051#ifdef CONFIG_BSD
bellard7674e7b2005-04-26 21:59:26 +000052#include <sys/ioctl.h>
Blue Swirl72cf2d42009-09-12 07:36:22 +000053#include <sys/queue.h>
blueswir1c5e97232009-03-07 20:06:23 +000054#ifndef __DragonFly__
bellard7674e7b2005-04-26 21:59:26 +000055#include <sys/disk.h>
56#endif
blueswir1c5e97232009-03-07 20:06:23 +000057#endif
bellard7674e7b2005-04-26 21:59:26 +000058
aliguori49dc7682009-03-08 16:26:59 +000059#ifdef _WIN32
60#include <windows.h>
61#endif
62
Stefan Hajnoczi1c9805a2011-10-13 13:08:22 +010063#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
64
Benoît Canetdc364f42014-01-23 21:31:32 +010065static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
66 QTAILQ_HEAD_INITIALIZER(graph_bdrv_states);
67
Max Reitz2c1d04e2016-01-29 16:36:11 +010068static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states =
69 QTAILQ_HEAD_INITIALIZER(all_bdrv_states);
70
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +010071static QLIST_HEAD(, BlockDriver) bdrv_drivers =
72 QLIST_HEAD_INITIALIZER(bdrv_drivers);
bellardea2384d2004-08-01 21:59:26 +000073
Max Reitz5b363932016-05-17 16:41:31 +020074static BlockDriverState *bdrv_open_inherit(const char *filename,
75 const char *reference,
76 QDict *options, int flags,
77 BlockDriverState *parent,
78 const BdrvChildRole *child_role,
79 Error **errp);
Kevin Wolff3930ed2015-04-08 13:43:47 +020080
Markus Armbrustereb852012009-10-27 18:41:44 +010081/* If non-zero, use only whitelisted block drivers */
82static int use_bdrv_whitelist;
83
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +000084#ifdef _WIN32
85static int is_windows_drive_prefix(const char *filename)
86{
87 return (((filename[0] >= 'a' && filename[0] <= 'z') ||
88 (filename[0] >= 'A' && filename[0] <= 'Z')) &&
89 filename[1] == ':');
90}
91
92int is_windows_drive(const char *filename)
93{
94 if (is_windows_drive_prefix(filename) &&
95 filename[2] == '\0')
96 return 1;
97 if (strstart(filename, "\\\\.\\", NULL) ||
98 strstart(filename, "//./", NULL))
99 return 1;
100 return 0;
101}
102#endif
103
Kevin Wolf339064d2013-11-28 10:23:32 +0100104size_t bdrv_opt_mem_align(BlockDriverState *bs)
105{
106 if (!bs || !bs->drv) {
Denis V. Lunev459b4e62015-05-12 17:30:56 +0300107 /* page size or 4k (hdd sector size) should be on the safe side */
108 return MAX(4096, getpagesize());
Kevin Wolf339064d2013-11-28 10:23:32 +0100109 }
110
111 return bs->bl.opt_mem_alignment;
112}
113
Denis V. Lunev4196d2f2015-05-12 17:30:55 +0300114size_t bdrv_min_mem_align(BlockDriverState *bs)
115{
116 if (!bs || !bs->drv) {
Denis V. Lunev459b4e62015-05-12 17:30:56 +0300117 /* page size or 4k (hdd sector size) should be on the safe side */
118 return MAX(4096, getpagesize());
Denis V. Lunev4196d2f2015-05-12 17:30:55 +0300119 }
120
121 return bs->bl.min_mem_alignment;
122}
123
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000124/* check if the path starts with "<protocol>:" */
Max Reitz5c984152014-12-03 14:57:22 +0100125int path_has_protocol(const char *path)
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000126{
Paolo Bonzini947995c2012-05-08 16:51:48 +0200127 const char *p;
128
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000129#ifdef _WIN32
130 if (is_windows_drive(path) ||
131 is_windows_drive_prefix(path)) {
132 return 0;
133 }
Paolo Bonzini947995c2012-05-08 16:51:48 +0200134 p = path + strcspn(path, ":/\\");
135#else
136 p = path + strcspn(path, ":/");
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000137#endif
138
Paolo Bonzini947995c2012-05-08 16:51:48 +0200139 return *p == ':';
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000140}
141
bellard83f64092006-08-01 16:21:11 +0000142int path_is_absolute(const char *path)
143{
bellard21664422007-01-07 18:22:37 +0000144#ifdef _WIN32
145 /* specific case for names like: "\\.\d:" */
Paolo Bonzinif53f4da2012-05-08 16:51:47 +0200146 if (is_windows_drive(path) || is_windows_drive_prefix(path)) {
bellard21664422007-01-07 18:22:37 +0000147 return 1;
Paolo Bonzinif53f4da2012-05-08 16:51:47 +0200148 }
149 return (*path == '/' || *path == '\\');
bellard3b9f94e2007-01-07 17:27:07 +0000150#else
Paolo Bonzinif53f4da2012-05-08 16:51:47 +0200151 return (*path == '/');
bellard3b9f94e2007-01-07 17:27:07 +0000152#endif
bellard83f64092006-08-01 16:21:11 +0000153}
154
Max Reitz009b03a2019-02-01 20:29:13 +0100155/* if filename is absolute, just return its duplicate. Otherwise, build a
bellard83f64092006-08-01 16:21:11 +0000156 path to it by considering it is relative to base_path. URL are
157 supported. */
Max Reitz009b03a2019-02-01 20:29:13 +0100158char *path_combine(const char *base_path, const char *filename)
bellard83f64092006-08-01 16:21:11 +0000159{
Max Reitz009b03a2019-02-01 20:29:13 +0100160 const char *protocol_stripped = NULL;
bellard83f64092006-08-01 16:21:11 +0000161 const char *p, *p1;
Max Reitz009b03a2019-02-01 20:29:13 +0100162 char *result;
bellard83f64092006-08-01 16:21:11 +0000163 int len;
164
bellard83f64092006-08-01 16:21:11 +0000165 if (path_is_absolute(filename)) {
Max Reitz009b03a2019-02-01 20:29:13 +0100166 return g_strdup(filename);
bellard83f64092006-08-01 16:21:11 +0000167 }
Max Reitz009b03a2019-02-01 20:29:13 +0100168
169 if (path_has_protocol(base_path)) {
170 protocol_stripped = strchr(base_path, ':');
171 if (protocol_stripped) {
172 protocol_stripped++;
173 }
174 }
175 p = protocol_stripped ?: base_path;
176
177 p1 = strrchr(base_path, '/');
178#ifdef _WIN32
179 {
180 const char *p2;
181 p2 = strrchr(base_path, '\\');
182 if (!p1 || p2 > p1) {
183 p1 = p2;
184 }
185 }
186#endif
187 if (p1) {
188 p1++;
189 } else {
190 p1 = base_path;
191 }
192 if (p1 > p) {
193 p = p1;
194 }
195 len = p - base_path;
196
197 result = g_malloc(len + strlen(filename) + 1);
198 memcpy(result, base_path, len);
199 strcpy(result + len, filename);
200
201 return result;
202}
203
Max Reitz03c320d2017-05-22 21:52:16 +0200204/*
205 * Helper function for bdrv_parse_filename() implementations to remove optional
206 * protocol prefixes (especially "file:") from a filename and for putting the
207 * stripped filename into the options QDict if there is such a prefix.
208 */
209void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
210 QDict *options)
211{
212 if (strstart(filename, prefix, &filename)) {
213 /* Stripping the explicit protocol prefix may result in a protocol
214 * prefix being (wrongly) detected (if the filename contains a colon) */
215 if (path_has_protocol(filename)) {
216 QString *fat_filename;
217
218 /* This means there is some colon before the first slash; therefore,
219 * this cannot be an absolute path */
220 assert(!path_is_absolute(filename));
221
222 /* And we can thus fix the protocol detection issue by prefixing it
223 * by "./" */
224 fat_filename = qstring_from_str("./");
225 qstring_append(fat_filename, filename);
226
227 assert(!path_has_protocol(qstring_get_str(fat_filename)));
228
229 qdict_put(options, "filename", fat_filename);
230 } else {
231 /* If no protocol prefix was detected, we can use the shortened
232 * filename as-is */
233 qdict_put_str(options, "filename", filename);
234 }
235 }
236}
237
238
Kevin Wolf9c5e6592017-05-04 18:52:40 +0200239/* Returns whether the image file is opened as read-only. Note that this can
240 * return false and writing to the image file is still not possible because the
241 * image is inactivated. */
Jeff Cody93ed5242017-04-07 16:55:28 -0400242bool bdrv_is_read_only(BlockDriverState *bs)
243{
244 return bs->read_only;
245}
246
Kevin Wolf54a32bf2017-08-03 17:02:58 +0200247int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
248 bool ignore_allow_rdw, Error **errp)
Jeff Codyfe5241b2017-04-07 16:55:25 -0400249{
Jeff Codye2b82472017-04-07 16:55:26 -0400250 /* Do not set read_only if copy_on_read is enabled */
251 if (bs->copy_on_read && read_only) {
252 error_setg(errp, "Can't set node '%s' to r/o with copy-on-read enabled",
253 bdrv_get_device_or_node_name(bs));
254 return -EINVAL;
255 }
256
Jeff Codyd6fcdf02017-04-07 16:55:27 -0400257 /* Do not clear read_only if it is prohibited */
Kevin Wolf54a32bf2017-08-03 17:02:58 +0200258 if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR) &&
259 !ignore_allow_rdw)
260 {
Jeff Codyd6fcdf02017-04-07 16:55:27 -0400261 error_setg(errp, "Node '%s' is read only",
262 bdrv_get_device_or_node_name(bs));
263 return -EPERM;
264 }
265
Jeff Cody45803a02017-04-07 16:55:29 -0400266 return 0;
267}
268
Kevin Wolfeaa24102018-10-12 11:27:41 +0200269/*
270 * Called by a driver that can only provide a read-only image.
271 *
272 * Returns 0 if the node is already read-only or it could switch the node to
273 * read-only because BDRV_O_AUTO_RDONLY is set.
274 *
275 * Returns -EACCES if the node is read-write and BDRV_O_AUTO_RDONLY is not set
276 * or bdrv_can_set_read_only() forbids making the node read-only. If @errmsg
277 * is not NULL, it is used as the error message for the Error object.
278 */
279int bdrv_apply_auto_read_only(BlockDriverState *bs, const char *errmsg,
280 Error **errp)
Jeff Cody45803a02017-04-07 16:55:29 -0400281{
282 int ret = 0;
283
Kevin Wolfeaa24102018-10-12 11:27:41 +0200284 if (!(bs->open_flags & BDRV_O_RDWR)) {
285 return 0;
286 }
287 if (!(bs->open_flags & BDRV_O_AUTO_RDONLY)) {
288 goto fail;
289 }
290
291 ret = bdrv_can_set_read_only(bs, true, false, NULL);
Jeff Cody45803a02017-04-07 16:55:29 -0400292 if (ret < 0) {
Kevin Wolfeaa24102018-10-12 11:27:41 +0200293 goto fail;
Jeff Cody45803a02017-04-07 16:55:29 -0400294 }
295
Kevin Wolfeaa24102018-10-12 11:27:41 +0200296 bs->read_only = true;
297 bs->open_flags &= ~BDRV_O_RDWR;
Kevin Wolfeeae6a52018-10-09 16:57:12 +0200298
Jeff Codye2b82472017-04-07 16:55:26 -0400299 return 0;
Kevin Wolfeaa24102018-10-12 11:27:41 +0200300
301fail:
302 error_setg(errp, "%s", errmsg ?: "Image is read-only");
303 return -EACCES;
Jeff Codyfe5241b2017-04-07 16:55:25 -0400304}
305
Max Reitz645ae7d2019-02-01 20:29:14 +0100306/*
307 * If @backing is empty, this function returns NULL without setting
308 * @errp. In all other cases, NULL will only be returned with @errp
309 * set.
310 *
311 * Therefore, a return value of NULL without @errp set means that
312 * there is no backing file; if @errp is set, there is one but its
313 * absolute filename cannot be generated.
314 */
315char *bdrv_get_full_backing_filename_from_filename(const char *backed,
316 const char *backing,
317 Error **errp)
Max Reitz0a828552014-11-26 17:20:25 +0100318{
Max Reitz645ae7d2019-02-01 20:29:14 +0100319 if (backing[0] == '\0') {
320 return NULL;
321 } else if (path_has_protocol(backing) || path_is_absolute(backing)) {
322 return g_strdup(backing);
Max Reitz9f074292014-11-26 17:20:26 +0100323 } else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) {
324 error_setg(errp, "Cannot use relative backing file names for '%s'",
325 backed);
Max Reitz645ae7d2019-02-01 20:29:14 +0100326 return NULL;
Max Reitz0a828552014-11-26 17:20:25 +0100327 } else {
Max Reitz645ae7d2019-02-01 20:29:14 +0100328 return path_combine(backed, backing);
Max Reitz0a828552014-11-26 17:20:25 +0100329 }
330}
331
Max Reitz9f4793d2019-02-01 20:29:16 +0100332/*
333 * If @filename is empty or NULL, this function returns NULL without
334 * setting @errp. In all other cases, NULL will only be returned with
335 * @errp set.
336 */
337static char *bdrv_make_absolute_filename(BlockDriverState *relative_to,
338 const char *filename, Error **errp)
339{
Max Reitz8df68612019-02-01 20:29:23 +0100340 char *dir, *full_name;
Max Reitz9f4793d2019-02-01 20:29:16 +0100341
Max Reitz8df68612019-02-01 20:29:23 +0100342 if (!filename || filename[0] == '\0') {
343 return NULL;
344 } else if (path_has_protocol(filename) || path_is_absolute(filename)) {
345 return g_strdup(filename);
346 }
Max Reitz9f4793d2019-02-01 20:29:16 +0100347
Max Reitz8df68612019-02-01 20:29:23 +0100348 dir = bdrv_dirname(relative_to, errp);
349 if (!dir) {
350 return NULL;
351 }
Max Reitz9f4793d2019-02-01 20:29:16 +0100352
Max Reitz8df68612019-02-01 20:29:23 +0100353 full_name = g_strconcat(dir, filename, NULL);
354 g_free(dir);
355 return full_name;
Max Reitz9f4793d2019-02-01 20:29:16 +0100356}
357
Max Reitz6b6833c2019-02-01 20:29:15 +0100358char *bdrv_get_full_backing_filename(BlockDriverState *bs, Error **errp)
Paolo Bonzinidc5a1372012-05-08 16:51:50 +0200359{
Max Reitz9f4793d2019-02-01 20:29:16 +0100360 return bdrv_make_absolute_filename(bs, bs->backing_file, errp);
Paolo Bonzinidc5a1372012-05-08 16:51:50 +0200361}
362
Stefan Hajnoczi0eb72172015-04-28 14:27:51 +0100363void bdrv_register(BlockDriver *bdrv)
364{
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +0100365 QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
bellardea2384d2004-08-01 21:59:26 +0000366}
bellardb3380822004-03-14 21:38:54 +0000367
Markus Armbrustere4e99862014-10-07 13:59:03 +0200368BlockDriverState *bdrv_new(void)
369{
370 BlockDriverState *bs;
371 int i;
372
Markus Armbruster5839e532014-08-19 10:31:08 +0200373 bs = g_new0(BlockDriverState, 1);
Fam Zhenge4654d22013-11-13 18:29:43 +0800374 QLIST_INIT(&bs->dirty_bitmaps);
Fam Zhengfbe40ff2014-05-23 21:29:42 +0800375 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
376 QLIST_INIT(&bs->op_blockers[i]);
377 }
Stefan Hajnoczid616b222013-06-24 17:13:10 +0200378 notifier_with_return_list_init(&bs->before_write_notifiers);
Paolo Bonzini3783fa32017-06-05 14:39:02 +0200379 qemu_co_mutex_init(&bs->reqs_lock);
Paolo Bonzini21198822017-06-05 14:39:03 +0200380 qemu_mutex_init(&bs->dirty_bitmap_mutex);
Fam Zheng9fcb0252013-08-23 09:14:46 +0800381 bs->refcnt = 1;
Stefan Hajnoczidcd04222014-05-08 16:34:37 +0200382 bs->aio_context = qemu_get_aio_context();
Paolo Bonzinid7d512f2012-08-23 11:20:36 +0200383
Evgeny Yakovlev3ff2f672016-07-18 22:39:52 +0300384 qemu_co_queue_init(&bs->flush_queue);
385
Kevin Wolf0f122642018-03-28 18:29:18 +0200386 for (i = 0; i < bdrv_drain_all_count; i++) {
387 bdrv_drained_begin(bs);
388 }
389
Max Reitz2c1d04e2016-01-29 16:36:11 +0100390 QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list);
391
bellardb3380822004-03-14 21:38:54 +0000392 return bs;
393}
394
Marc Mari88d88792016-08-12 09:27:03 -0400395static BlockDriver *bdrv_do_find_format(const char *format_name)
bellardea2384d2004-08-01 21:59:26 +0000396{
397 BlockDriver *drv1;
Marc Mari88d88792016-08-12 09:27:03 -0400398
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +0100399 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
400 if (!strcmp(drv1->format_name, format_name)) {
bellardea2384d2004-08-01 21:59:26 +0000401 return drv1;
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +0100402 }
bellardea2384d2004-08-01 21:59:26 +0000403 }
Marc Mari88d88792016-08-12 09:27:03 -0400404
bellardea2384d2004-08-01 21:59:26 +0000405 return NULL;
406}
407
Marc Mari88d88792016-08-12 09:27:03 -0400408BlockDriver *bdrv_find_format(const char *format_name)
409{
410 BlockDriver *drv1;
411 int i;
412
413 drv1 = bdrv_do_find_format(format_name);
414 if (drv1) {
415 return drv1;
416 }
417
418 /* The driver isn't registered, maybe we need to load a module */
419 for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
420 if (!strcmp(block_driver_modules[i].format_name, format_name)) {
421 block_module_load_one(block_driver_modules[i].library_name);
422 break;
423 }
424 }
425
426 return bdrv_do_find_format(format_name);
427}
428
Andrey Shinkevich9ac404c2019-03-07 16:33:58 +0300429static int bdrv_format_is_whitelisted(const char *format_name, bool read_only)
Markus Armbrustereb852012009-10-27 18:41:44 +0100430{
Fam Zhengb64ec4e2013-05-29 19:35:40 +0800431 static const char *whitelist_rw[] = {
432 CONFIG_BDRV_RW_WHITELIST
433 };
434 static const char *whitelist_ro[] = {
435 CONFIG_BDRV_RO_WHITELIST
Markus Armbrustereb852012009-10-27 18:41:44 +0100436 };
437 const char **p;
438
Fam Zhengb64ec4e2013-05-29 19:35:40 +0800439 if (!whitelist_rw[0] && !whitelist_ro[0]) {
Markus Armbrustereb852012009-10-27 18:41:44 +0100440 return 1; /* no whitelist, anything goes */
Fam Zhengb64ec4e2013-05-29 19:35:40 +0800441 }
Markus Armbrustereb852012009-10-27 18:41:44 +0100442
Fam Zhengb64ec4e2013-05-29 19:35:40 +0800443 for (p = whitelist_rw; *p; p++) {
Andrey Shinkevich9ac404c2019-03-07 16:33:58 +0300444 if (!strcmp(format_name, *p)) {
Markus Armbrustereb852012009-10-27 18:41:44 +0100445 return 1;
446 }
447 }
Fam Zhengb64ec4e2013-05-29 19:35:40 +0800448 if (read_only) {
449 for (p = whitelist_ro; *p; p++) {
Andrey Shinkevich9ac404c2019-03-07 16:33:58 +0300450 if (!strcmp(format_name, *p)) {
Fam Zhengb64ec4e2013-05-29 19:35:40 +0800451 return 1;
452 }
453 }
454 }
Markus Armbrustereb852012009-10-27 18:41:44 +0100455 return 0;
456}
457
Andrey Shinkevich9ac404c2019-03-07 16:33:58 +0300458int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
459{
460 return bdrv_format_is_whitelisted(drv->format_name, read_only);
461}
462
Daniel P. Berrangee6ff69b2016-03-21 14:11:48 +0000463bool bdrv_uses_whitelist(void)
464{
465 return use_bdrv_whitelist;
466}
467
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800468typedef struct CreateCo {
469 BlockDriver *drv;
470 char *filename;
Chunyan Liu83d05212014-06-05 17:20:51 +0800471 QemuOpts *opts;
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800472 int ret;
Max Reitzcc84d902013-09-06 17:14:26 +0200473 Error *err;
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800474} CreateCo;
475
476static void coroutine_fn bdrv_create_co_entry(void *opaque)
477{
Max Reitzcc84d902013-09-06 17:14:26 +0200478 Error *local_err = NULL;
479 int ret;
480
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800481 CreateCo *cco = opaque;
482 assert(cco->drv);
483
Stefan Hajnocziefc75e22018-01-18 13:43:45 +0100484 ret = cco->drv->bdrv_co_create_opts(cco->filename, cco->opts, &local_err);
Eduardo Habkost621ff942016-06-13 18:57:56 -0300485 error_propagate(&cco->err, local_err);
Max Reitzcc84d902013-09-06 17:14:26 +0200486 cco->ret = ret;
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800487}
488
Kevin Wolf0e7e1982009-05-18 16:42:10 +0200489int bdrv_create(BlockDriver *drv, const char* filename,
Chunyan Liu83d05212014-06-05 17:20:51 +0800490 QemuOpts *opts, Error **errp)
bellardea2384d2004-08-01 21:59:26 +0000491{
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800492 int ret;
Kevin Wolf0e7e1982009-05-18 16:42:10 +0200493
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800494 Coroutine *co;
495 CreateCo cco = {
496 .drv = drv,
497 .filename = g_strdup(filename),
Chunyan Liu83d05212014-06-05 17:20:51 +0800498 .opts = opts,
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800499 .ret = NOT_DONE,
Max Reitzcc84d902013-09-06 17:14:26 +0200500 .err = NULL,
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800501 };
502
Stefan Hajnocziefc75e22018-01-18 13:43:45 +0100503 if (!drv->bdrv_co_create_opts) {
Max Reitzcc84d902013-09-06 17:14:26 +0200504 error_setg(errp, "Driver '%s' does not support image creation", drv->format_name);
Luiz Capitulino80168bf2012-10-17 16:45:25 -0300505 ret = -ENOTSUP;
506 goto out;
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800507 }
508
509 if (qemu_in_coroutine()) {
510 /* Fast-path if already in coroutine context */
511 bdrv_create_co_entry(&cco);
512 } else {
Paolo Bonzini0b8b8752016-07-04 19:10:01 +0200513 co = qemu_coroutine_create(bdrv_create_co_entry, &cco);
514 qemu_coroutine_enter(co);
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800515 while (cco.ret == NOT_DONE) {
Paolo Bonzinib47ec2c2014-07-07 15:18:01 +0200516 aio_poll(qemu_get_aio_context(), true);
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800517 }
518 }
519
520 ret = cco.ret;
Max Reitzcc84d902013-09-06 17:14:26 +0200521 if (ret < 0) {
Markus Armbruster84d18f02014-01-30 15:07:28 +0100522 if (cco.err) {
Max Reitzcc84d902013-09-06 17:14:26 +0200523 error_propagate(errp, cco.err);
524 } else {
525 error_setg_errno(errp, -ret, "Could not create image");
526 }
527 }
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800528
Luiz Capitulino80168bf2012-10-17 16:45:25 -0300529out:
530 g_free(cco.filename);
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800531 return ret;
bellardea2384d2004-08-01 21:59:26 +0000532}
533
Chunyan Liuc282e1f2014-06-05 17:21:11 +0800534int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200535{
536 BlockDriver *drv;
Max Reitzcc84d902013-09-06 17:14:26 +0200537 Error *local_err = NULL;
538 int ret;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200539
Max Reitzb65a5e12015-02-05 13:58:12 -0500540 drv = bdrv_find_protocol(filename, true, errp);
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200541 if (drv == NULL) {
Stefan Hajnoczi16905d72010-11-30 15:14:14 +0000542 return -ENOENT;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200543 }
544
Chunyan Liuc282e1f2014-06-05 17:21:11 +0800545 ret = bdrv_create(drv, filename, opts, &local_err);
Eduardo Habkost621ff942016-06-13 18:57:56 -0300546 error_propagate(errp, local_err);
Max Reitzcc84d902013-09-06 17:14:26 +0200547 return ret;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200548}
549
Ekaterina Tumanova892b7de2015-02-16 12:47:54 +0100550/**
551 * Try to get @bs's logical and physical block size.
552 * On success, store them in @bsz struct and return 0.
553 * On failure return -errno.
554 * @bs must not be empty.
555 */
556int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
557{
558 BlockDriver *drv = bs->drv;
559
560 if (drv && drv->bdrv_probe_blocksizes) {
561 return drv->bdrv_probe_blocksizes(bs, bsz);
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +0300562 } else if (drv && drv->is_filter && bs->file) {
563 return bdrv_probe_blocksizes(bs->file->bs, bsz);
Ekaterina Tumanova892b7de2015-02-16 12:47:54 +0100564 }
565
566 return -ENOTSUP;
567}
568
569/**
570 * Try to get @bs's geometry (cyls, heads, sectors).
571 * On success, store them in @geo struct and return 0.
572 * On failure return -errno.
573 * @bs must not be empty.
574 */
575int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
576{
577 BlockDriver *drv = bs->drv;
578
579 if (drv && drv->bdrv_probe_geometry) {
580 return drv->bdrv_probe_geometry(bs, geo);
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +0300581 } else if (drv && drv->is_filter && bs->file) {
582 return bdrv_probe_geometry(bs->file->bs, geo);
Ekaterina Tumanova892b7de2015-02-16 12:47:54 +0100583 }
584
585 return -ENOTSUP;
586}
587
Jim Meyeringeba25052012-05-28 09:27:54 +0200588/*
589 * Create a uniquely-named empty temporary file.
590 * Return 0 upon success, otherwise a negative errno value.
591 */
592int get_tmp_filename(char *filename, int size)
593{
bellardd5249392004-08-03 21:14:23 +0000594#ifdef _WIN32
bellard3b9f94e2007-01-07 17:27:07 +0000595 char temp_dir[MAX_PATH];
Jim Meyeringeba25052012-05-28 09:27:54 +0200596 /* GetTempFileName requires that its output buffer (4th param)
597 have length MAX_PATH or greater. */
598 assert(size >= MAX_PATH);
599 return (GetTempPath(MAX_PATH, temp_dir)
600 && GetTempFileName(temp_dir, "qem", 0, filename)
601 ? 0 : -GetLastError());
bellardd5249392004-08-03 21:14:23 +0000602#else
bellardea2384d2004-08-01 21:59:26 +0000603 int fd;
blueswir17ccfb2e2008-09-14 06:45:34 +0000604 const char *tmpdir;
aurel320badc1e2008-03-10 00:05:34 +0000605 tmpdir = getenv("TMPDIR");
Amit Shah69bef792014-02-26 15:12:37 +0530606 if (!tmpdir) {
607 tmpdir = "/var/tmp";
608 }
Jim Meyeringeba25052012-05-28 09:27:54 +0200609 if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) {
610 return -EOVERFLOW;
611 }
bellardea2384d2004-08-01 21:59:26 +0000612 fd = mkstemp(filename);
Dunrong Huangfe235a02012-09-05 21:26:22 +0800613 if (fd < 0) {
614 return -errno;
615 }
616 if (close(fd) != 0) {
617 unlink(filename);
Jim Meyeringeba25052012-05-28 09:27:54 +0200618 return -errno;
619 }
620 return 0;
bellardd5249392004-08-03 21:14:23 +0000621#endif
Jim Meyeringeba25052012-05-28 09:27:54 +0200622}
bellardea2384d2004-08-01 21:59:26 +0000623
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200624/*
625 * Detect host devices. By convention, /dev/cdrom[N] is always
626 * recognized as a host CDROM.
627 */
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200628static BlockDriver *find_hdev_driver(const char *filename)
629{
Christoph Hellwig508c7cb2009-06-15 14:04:22 +0200630 int score_max = 0, score;
631 BlockDriver *drv = NULL, *d;
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200632
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +0100633 QLIST_FOREACH(d, &bdrv_drivers, list) {
Christoph Hellwig508c7cb2009-06-15 14:04:22 +0200634 if (d->bdrv_probe_device) {
635 score = d->bdrv_probe_device(filename);
636 if (score > score_max) {
637 score_max = score;
638 drv = d;
639 }
640 }
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200641 }
642
Christoph Hellwig508c7cb2009-06-15 14:04:22 +0200643 return drv;
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200644}
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200645
Marc Mari88d88792016-08-12 09:27:03 -0400646static BlockDriver *bdrv_do_find_protocol(const char *protocol)
647{
648 BlockDriver *drv1;
649
650 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
651 if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) {
652 return drv1;
653 }
654 }
655
656 return NULL;
657}
658
Kevin Wolf98289622013-07-10 15:47:39 +0200659BlockDriver *bdrv_find_protocol(const char *filename,
Max Reitzb65a5e12015-02-05 13:58:12 -0500660 bool allow_protocol_prefix,
661 Error **errp)
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200662{
663 BlockDriver *drv1;
664 char protocol[128];
665 int len;
666 const char *p;
Marc Mari88d88792016-08-12 09:27:03 -0400667 int i;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200668
Kevin Wolf66f82ce2010-04-14 14:17:38 +0200669 /* TODO Drivers without bdrv_file_open must be specified explicitly */
670
Christoph Hellwig39508e72010-06-23 12:25:17 +0200671 /*
672 * XXX(hch): we really should not let host device detection
673 * override an explicit protocol specification, but moving this
674 * later breaks access to device names with colons in them.
675 * Thanks to the brain-dead persistent naming schemes on udev-
676 * based Linux systems those actually are quite common.
677 */
678 drv1 = find_hdev_driver(filename);
679 if (drv1) {
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200680 return drv1;
681 }
Christoph Hellwig39508e72010-06-23 12:25:17 +0200682
Kevin Wolf98289622013-07-10 15:47:39 +0200683 if (!path_has_protocol(filename) || !allow_protocol_prefix) {
Max Reitzef810432014-12-02 18:32:42 +0100684 return &bdrv_file;
Christoph Hellwig39508e72010-06-23 12:25:17 +0200685 }
Kevin Wolf98289622013-07-10 15:47:39 +0200686
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000687 p = strchr(filename, ':');
688 assert(p != NULL);
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200689 len = p - filename;
690 if (len > sizeof(protocol) - 1)
691 len = sizeof(protocol) - 1;
692 memcpy(protocol, filename, len);
693 protocol[len] = '\0';
Marc Mari88d88792016-08-12 09:27:03 -0400694
695 drv1 = bdrv_do_find_protocol(protocol);
696 if (drv1) {
697 return drv1;
698 }
699
700 for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
701 if (block_driver_modules[i].protocol_name &&
702 !strcmp(block_driver_modules[i].protocol_name, protocol)) {
703 block_module_load_one(block_driver_modules[i].library_name);
704 break;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200705 }
706 }
Max Reitzb65a5e12015-02-05 13:58:12 -0500707
Marc Mari88d88792016-08-12 09:27:03 -0400708 drv1 = bdrv_do_find_protocol(protocol);
709 if (!drv1) {
710 error_setg(errp, "Unknown protocol '%s'", protocol);
711 }
712 return drv1;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200713}
714
Markus Armbrusterc6684242014-11-20 16:27:10 +0100715/*
716 * Guess image format by probing its contents.
717 * This is not a good idea when your image is raw (CVE-2008-2004), but
718 * we do it anyway for backward compatibility.
719 *
720 * @buf contains the image's first @buf_size bytes.
Kevin Wolf7cddd372014-11-20 16:27:11 +0100721 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
722 * but can be smaller if the image file is smaller)
Markus Armbrusterc6684242014-11-20 16:27:10 +0100723 * @filename is its filename.
724 *
725 * For all block drivers, call the bdrv_probe() method to get its
726 * probing score.
727 * Return the first block driver with the highest probing score.
728 */
Kevin Wolf38f3ef52014-11-20 16:27:12 +0100729BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
730 const char *filename)
Markus Armbrusterc6684242014-11-20 16:27:10 +0100731{
732 int score_max = 0, score;
733 BlockDriver *drv = NULL, *d;
734
735 QLIST_FOREACH(d, &bdrv_drivers, list) {
736 if (d->bdrv_probe) {
737 score = d->bdrv_probe(buf, buf_size, filename);
738 if (score > score_max) {
739 score_max = score;
740 drv = d;
741 }
742 }
743 }
744
745 return drv;
746}
747
Kevin Wolf5696c6e2017-02-17 18:39:24 +0100748static int find_image_format(BlockBackend *file, const char *filename,
Max Reitz34b5d2c2013-09-05 14:45:29 +0200749 BlockDriver **pdrv, Error **errp)
bellardea2384d2004-08-01 21:59:26 +0000750{
Markus Armbrusterc6684242014-11-20 16:27:10 +0100751 BlockDriver *drv;
Kevin Wolf7cddd372014-11-20 16:27:11 +0100752 uint8_t buf[BLOCK_PROBE_BUF_SIZE];
Kevin Wolff500a6d2012-11-12 17:35:27 +0100753 int ret = 0;
Nicholas Bellingerf8ea0b02010-05-17 09:45:57 -0700754
Kevin Wolf08a00552010-06-01 18:37:31 +0200755 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
Kevin Wolf5696c6e2017-02-17 18:39:24 +0100756 if (blk_is_sg(file) || !blk_is_inserted(file) || blk_getlength(file) == 0) {
Max Reitzef810432014-12-02 18:32:42 +0100757 *pdrv = &bdrv_raw;
Stefan Weilc98ac352010-07-21 21:51:51 +0200758 return ret;
Nicholas A. Bellinger1a396852010-05-27 08:56:28 -0700759 }
Nicholas Bellingerf8ea0b02010-05-17 09:45:57 -0700760
Kevin Wolf5696c6e2017-02-17 18:39:24 +0100761 ret = blk_pread(file, 0, buf, sizeof(buf));
bellard83f64092006-08-01 16:21:11 +0000762 if (ret < 0) {
Max Reitz34b5d2c2013-09-05 14:45:29 +0200763 error_setg_errno(errp, -ret, "Could not read image for determining its "
764 "format");
Stefan Weilc98ac352010-07-21 21:51:51 +0200765 *pdrv = NULL;
766 return ret;
bellard83f64092006-08-01 16:21:11 +0000767 }
768
Markus Armbrusterc6684242014-11-20 16:27:10 +0100769 drv = bdrv_probe_all(buf, ret, filename);
Stefan Weilc98ac352010-07-21 21:51:51 +0200770 if (!drv) {
Max Reitz34b5d2c2013-09-05 14:45:29 +0200771 error_setg(errp, "Could not determine image format: No compatible "
772 "driver found");
Stefan Weilc98ac352010-07-21 21:51:51 +0200773 ret = -ENOENT;
774 }
775 *pdrv = drv;
776 return ret;
bellardea2384d2004-08-01 21:59:26 +0000777}
778
Stefan Hajnoczi51762282010-04-19 16:56:41 +0100779/**
780 * Set the current 'total_sectors' value
Markus Armbruster65a9bb22014-06-26 13:23:17 +0200781 * Return 0 on success, -errno on error.
Stefan Hajnoczi51762282010-04-19 16:56:41 +0100782 */
Kevin Wolf3d9f2d22018-06-26 13:55:20 +0200783int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
Stefan Hajnoczi51762282010-04-19 16:56:41 +0100784{
785 BlockDriver *drv = bs->drv;
786
Max Reitzd470ad42017-11-10 21:31:09 +0100787 if (!drv) {
788 return -ENOMEDIUM;
789 }
790
Nicholas Bellinger396759a2010-05-17 09:46:04 -0700791 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
Dimitris Aragiorgisb192af82015-06-23 13:44:56 +0300792 if (bdrv_is_sg(bs))
Nicholas Bellinger396759a2010-05-17 09:46:04 -0700793 return 0;
794
Stefan Hajnoczi51762282010-04-19 16:56:41 +0100795 /* query actual device if possible, otherwise just trust the hint */
796 if (drv->bdrv_getlength) {
797 int64_t length = drv->bdrv_getlength(bs);
798 if (length < 0) {
799 return length;
800 }
Fam Zheng7e382002013-11-06 19:48:06 +0800801 hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE);
Stefan Hajnoczi51762282010-04-19 16:56:41 +0100802 }
803
804 bs->total_sectors = hint;
805 return 0;
806}
807
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100808/**
Kevin Wolfcddff5b2015-11-16 16:43:27 +0100809 * Combines a QDict of new block driver @options with any missing options taken
810 * from @old_options, so that leaving out an option defaults to its old value.
811 */
812static void bdrv_join_options(BlockDriverState *bs, QDict *options,
813 QDict *old_options)
814{
815 if (bs->drv && bs->drv->bdrv_join_options) {
816 bs->drv->bdrv_join_options(options, old_options);
817 } else {
818 qdict_join(options, old_options, false);
819 }
820}
821
Alberto Garcia543770b2018-09-06 12:37:09 +0300822static BlockdevDetectZeroesOptions bdrv_parse_detect_zeroes(QemuOpts *opts,
823 int open_flags,
824 Error **errp)
825{
826 Error *local_err = NULL;
827 char *value = qemu_opt_get_del(opts, "detect-zeroes");
828 BlockdevDetectZeroesOptions detect_zeroes =
829 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup, value,
830 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, &local_err);
831 g_free(value);
832 if (local_err) {
833 error_propagate(errp, local_err);
834 return detect_zeroes;
835 }
836
837 if (detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
838 !(open_flags & BDRV_O_UNMAP))
839 {
840 error_setg(errp, "setting detect-zeroes to unmap is not allowed "
841 "without setting discard operation to unmap");
842 }
843
844 return detect_zeroes;
845}
846
Kevin Wolfcddff5b2015-11-16 16:43:27 +0100847/**
Paolo Bonzini9e8f1832013-02-08 14:06:11 +0100848 * Set open flags for a given discard mode
849 *
850 * Return 0 on success, -1 if the discard mode was invalid.
851 */
852int bdrv_parse_discard_flags(const char *mode, int *flags)
853{
854 *flags &= ~BDRV_O_UNMAP;
855
856 if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) {
857 /* do nothing */
858 } else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) {
859 *flags |= BDRV_O_UNMAP;
860 } else {
861 return -1;
862 }
863
864 return 0;
865}
866
867/**
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100868 * Set open flags for a given cache mode
869 *
870 * Return 0 on success, -1 if the cache mode was invalid.
871 */
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100872int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough)
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100873{
874 *flags &= ~BDRV_O_CACHE_MASK;
875
876 if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100877 *writethrough = false;
878 *flags |= BDRV_O_NOCACHE;
Stefan Hajnoczi92196b22011-08-04 12:26:52 +0100879 } else if (!strcmp(mode, "directsync")) {
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100880 *writethrough = true;
Stefan Hajnoczi92196b22011-08-04 12:26:52 +0100881 *flags |= BDRV_O_NOCACHE;
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100882 } else if (!strcmp(mode, "writeback")) {
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100883 *writethrough = false;
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100884 } else if (!strcmp(mode, "unsafe")) {
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100885 *writethrough = false;
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100886 *flags |= BDRV_O_NO_FLUSH;
887 } else if (!strcmp(mode, "writethrough")) {
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100888 *writethrough = true;
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100889 } else {
890 return -1;
891 }
892
893 return 0;
894}
895
Kevin Wolfb5411552017-01-17 15:56:16 +0100896static char *bdrv_child_get_parent_desc(BdrvChild *c)
897{
898 BlockDriverState *parent = c->opaque;
899 return g_strdup(bdrv_get_device_or_node_name(parent));
900}
901
Kevin Wolf20018e12016-05-23 18:46:59 +0200902static void bdrv_child_cb_drained_begin(BdrvChild *child)
903{
904 BlockDriverState *bs = child->opaque;
Kevin Wolf6cd5c9d2018-05-29 17:17:45 +0200905 bdrv_do_drained_begin_quiesce(bs, NULL, false);
Kevin Wolf20018e12016-05-23 18:46:59 +0200906}
907
Kevin Wolf89bd0302018-03-22 14:11:20 +0100908static bool bdrv_child_cb_drained_poll(BdrvChild *child)
909{
910 BlockDriverState *bs = child->opaque;
Kevin Wolf6cd5c9d2018-05-29 17:17:45 +0200911 return bdrv_drain_poll(bs, false, NULL, false);
Kevin Wolf89bd0302018-03-22 14:11:20 +0100912}
913
Kevin Wolf20018e12016-05-23 18:46:59 +0200914static void bdrv_child_cb_drained_end(BdrvChild *child)
915{
916 BlockDriverState *bs = child->opaque;
917 bdrv_drained_end(bs);
918}
919
Kevin Wolfd736f112017-12-18 16:05:48 +0100920static void bdrv_child_cb_attach(BdrvChild *child)
921{
922 BlockDriverState *bs = child->opaque;
923 bdrv_apply_subtree_drain(child, bs);
924}
925
926static void bdrv_child_cb_detach(BdrvChild *child)
927{
928 BlockDriverState *bs = child->opaque;
929 bdrv_unapply_subtree_drain(child, bs);
930}
931
Kevin Wolf38701b62017-05-04 18:52:39 +0200932static int bdrv_child_cb_inactivate(BdrvChild *child)
933{
934 BlockDriverState *bs = child->opaque;
935 assert(bs->open_flags & BDRV_O_INACTIVE);
936 return 0;
937}
938
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200939/*
Kevin Wolf73176be2016-03-07 13:02:15 +0100940 * Returns the options and flags that a temporary snapshot should get, based on
941 * the originally requested flags (the originally requested image will have
942 * flags like a backing file)
Kevin Wolfb1e6fc02014-05-06 12:11:42 +0200943 */
Kevin Wolf73176be2016-03-07 13:02:15 +0100944static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options,
945 int parent_flags, QDict *parent_options)
Kevin Wolfb1e6fc02014-05-06 12:11:42 +0200946{
Kevin Wolf73176be2016-03-07 13:02:15 +0100947 *child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY;
948
949 /* For temporary files, unconditional cache=unsafe is fine */
Kevin Wolf73176be2016-03-07 13:02:15 +0100950 qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
951 qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on");
Kevin Wolf41869042016-06-16 12:59:30 +0200952
Alberto Garciaf87a0e22016-09-15 17:53:02 +0300953 /* Copy the read-only option from the parent */
954 qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
955
Kevin Wolf41869042016-06-16 12:59:30 +0200956 /* aio=native doesn't work for cache.direct=off, so disable it for the
957 * temporary snapshot */
958 *child_flags &= ~BDRV_O_NATIVE_AIO;
Kevin Wolfb1e6fc02014-05-06 12:11:42 +0200959}
960
961/*
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200962 * Returns the options and flags that bs->file should get if a protocol driver
963 * is expected, based on the given options and flags for the parent BDS
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200964 */
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200965static void bdrv_inherited_options(int *child_flags, QDict *child_options,
966 int parent_flags, QDict *parent_options)
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200967{
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200968 int flags = parent_flags;
969
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200970 /* Enable protocol handling, disable format probing for bs->file */
971 flags |= BDRV_O_PROTOCOL;
972
Kevin Wolf91a097e2015-05-08 17:49:53 +0200973 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
974 * the parent. */
975 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
976 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
Fam Zheng5a9347c2017-05-03 00:35:37 +0800977 qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE);
Kevin Wolf91a097e2015-05-08 17:49:53 +0200978
Alberto Garciaf87a0e22016-09-15 17:53:02 +0300979 /* Inherit the read-only option from the parent if it's not set */
980 qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
Kevin Wolfe35bdc12018-10-05 18:57:40 +0200981 qdict_copy_default(child_options, parent_options, BDRV_OPT_AUTO_READ_ONLY);
Alberto Garciaf87a0e22016-09-15 17:53:02 +0300982
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200983 /* Our block drivers take care to send flushes and respect unmap policy,
Kevin Wolf91a097e2015-05-08 17:49:53 +0200984 * so we can default to enable both on lower layers regardless of the
985 * corresponding parent options. */
Kevin Wolf818584a2016-09-12 18:03:18 +0200986 qdict_set_default_str(child_options, BDRV_OPT_DISCARD, "unmap");
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200987
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200988 /* Clear flags that only apply to the top layer */
Daniel P. Berrangeabb06c52016-03-21 14:11:42 +0000989 flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ |
990 BDRV_O_NO_IO);
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200991
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200992 *child_flags = flags;
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200993}
994
Kevin Wolff3930ed2015-04-08 13:43:47 +0200995const BdrvChildRole child_file = {
Kevin Wolf6cd5c9d2018-05-29 17:17:45 +0200996 .parent_is_bds = true,
Kevin Wolfb5411552017-01-17 15:56:16 +0100997 .get_parent_desc = bdrv_child_get_parent_desc,
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200998 .inherit_options = bdrv_inherited_options,
Kevin Wolf20018e12016-05-23 18:46:59 +0200999 .drained_begin = bdrv_child_cb_drained_begin,
Kevin Wolf89bd0302018-03-22 14:11:20 +01001000 .drained_poll = bdrv_child_cb_drained_poll,
Kevin Wolf20018e12016-05-23 18:46:59 +02001001 .drained_end = bdrv_child_cb_drained_end,
Kevin Wolfd736f112017-12-18 16:05:48 +01001002 .attach = bdrv_child_cb_attach,
1003 .detach = bdrv_child_cb_detach,
Kevin Wolf38701b62017-05-04 18:52:39 +02001004 .inactivate = bdrv_child_cb_inactivate,
Kevin Wolff3930ed2015-04-08 13:43:47 +02001005};
1006
1007/*
Kevin Wolf8e2160e2015-04-29 17:29:39 +02001008 * Returns the options and flags that bs->file should get if the use of formats
1009 * (and not only protocols) is permitted for it, based on the given options and
1010 * flags for the parent BDS
Kevin Wolff3930ed2015-04-08 13:43:47 +02001011 */
Kevin Wolf8e2160e2015-04-29 17:29:39 +02001012static void bdrv_inherited_fmt_options(int *child_flags, QDict *child_options,
1013 int parent_flags, QDict *parent_options)
Kevin Wolff3930ed2015-04-08 13:43:47 +02001014{
Kevin Wolf8e2160e2015-04-29 17:29:39 +02001015 child_file.inherit_options(child_flags, child_options,
1016 parent_flags, parent_options);
1017
Daniel P. Berrangeabb06c52016-03-21 14:11:42 +00001018 *child_flags &= ~(BDRV_O_PROTOCOL | BDRV_O_NO_IO);
Kevin Wolff3930ed2015-04-08 13:43:47 +02001019}
1020
1021const BdrvChildRole child_format = {
Kevin Wolf6cd5c9d2018-05-29 17:17:45 +02001022 .parent_is_bds = true,
Kevin Wolfb5411552017-01-17 15:56:16 +01001023 .get_parent_desc = bdrv_child_get_parent_desc,
Kevin Wolf8e2160e2015-04-29 17:29:39 +02001024 .inherit_options = bdrv_inherited_fmt_options,
Kevin Wolf20018e12016-05-23 18:46:59 +02001025 .drained_begin = bdrv_child_cb_drained_begin,
Kevin Wolf89bd0302018-03-22 14:11:20 +01001026 .drained_poll = bdrv_child_cb_drained_poll,
Kevin Wolf20018e12016-05-23 18:46:59 +02001027 .drained_end = bdrv_child_cb_drained_end,
Kevin Wolfd736f112017-12-18 16:05:48 +01001028 .attach = bdrv_child_cb_attach,
1029 .detach = bdrv_child_cb_detach,
Kevin Wolf38701b62017-05-04 18:52:39 +02001030 .inactivate = bdrv_child_cb_inactivate,
Kevin Wolff3930ed2015-04-08 13:43:47 +02001031};
1032
Kevin Wolfdb95dbb2017-02-08 11:28:52 +01001033static void bdrv_backing_attach(BdrvChild *c)
1034{
1035 BlockDriverState *parent = c->opaque;
1036 BlockDriverState *backing_hd = c->bs;
1037
1038 assert(!parent->backing_blocker);
1039 error_setg(&parent->backing_blocker,
1040 "node is used as backing hd of '%s'",
1041 bdrv_get_device_or_node_name(parent));
1042
Max Reitzf30c66b2019-02-01 20:29:05 +01001043 bdrv_refresh_filename(backing_hd);
1044
Kevin Wolfdb95dbb2017-02-08 11:28:52 +01001045 parent->open_flags &= ~BDRV_O_NO_BACKING;
1046 pstrcpy(parent->backing_file, sizeof(parent->backing_file),
1047 backing_hd->filename);
1048 pstrcpy(parent->backing_format, sizeof(parent->backing_format),
1049 backing_hd->drv ? backing_hd->drv->format_name : "");
1050
1051 bdrv_op_block_all(backing_hd, parent->backing_blocker);
1052 /* Otherwise we won't be able to commit or stream */
1053 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET,
1054 parent->backing_blocker);
1055 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_STREAM,
1056 parent->backing_blocker);
1057 /*
1058 * We do backup in 3 ways:
1059 * 1. drive backup
1060 * The target bs is new opened, and the source is top BDS
1061 * 2. blockdev backup
1062 * Both the source and the target are top BDSes.
1063 * 3. internal backup(used for block replication)
1064 * Both the source and the target are backing file
1065 *
1066 * In case 1 and 2, neither the source nor the target is the backing file.
1067 * In case 3, we will block the top BDS, so there is only one block job
1068 * for the top BDS and its backing chain.
1069 */
1070 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_SOURCE,
1071 parent->backing_blocker);
1072 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET,
1073 parent->backing_blocker);
Kevin Wolfd736f112017-12-18 16:05:48 +01001074
1075 bdrv_child_cb_attach(c);
Kevin Wolfdb95dbb2017-02-08 11:28:52 +01001076}
1077
1078static void bdrv_backing_detach(BdrvChild *c)
1079{
1080 BlockDriverState *parent = c->opaque;
1081
1082 assert(parent->backing_blocker);
1083 bdrv_op_unblock_all(c->bs, parent->backing_blocker);
1084 error_free(parent->backing_blocker);
1085 parent->backing_blocker = NULL;
Kevin Wolfd736f112017-12-18 16:05:48 +01001086
1087 bdrv_child_cb_detach(c);
Kevin Wolfdb95dbb2017-02-08 11:28:52 +01001088}
1089
Kevin Wolf317fc442014-04-25 13:27:34 +02001090/*
Kevin Wolf8e2160e2015-04-29 17:29:39 +02001091 * Returns the options and flags that bs->backing should get, based on the
1092 * given options and flags for the parent BDS
Kevin Wolf317fc442014-04-25 13:27:34 +02001093 */
Kevin Wolf8e2160e2015-04-29 17:29:39 +02001094static void bdrv_backing_options(int *child_flags, QDict *child_options,
1095 int parent_flags, QDict *parent_options)
Kevin Wolf317fc442014-04-25 13:27:34 +02001096{
Kevin Wolf8e2160e2015-04-29 17:29:39 +02001097 int flags = parent_flags;
1098
Kevin Wolfb8816a42016-03-04 14:52:32 +01001099 /* The cache mode is inherited unmodified for backing files; except WCE,
1100 * which is only applied on the top level (BlockBackend) */
Kevin Wolf91a097e2015-05-08 17:49:53 +02001101 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
1102 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
Fam Zheng5a9347c2017-05-03 00:35:37 +08001103 qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE);
Kevin Wolf91a097e2015-05-08 17:49:53 +02001104
Kevin Wolf317fc442014-04-25 13:27:34 +02001105 /* backing files always opened read-only */
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001106 qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on");
Kevin Wolfe35bdc12018-10-05 18:57:40 +02001107 qdict_set_default_str(child_options, BDRV_OPT_AUTO_READ_ONLY, "off");
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001108 flags &= ~BDRV_O_COPY_ON_READ;
Kevin Wolf317fc442014-04-25 13:27:34 +02001109
1110 /* snapshot=on is handled on the top layer */
Kevin Wolf8bfea152014-04-11 19:16:36 +02001111 flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY);
Kevin Wolf317fc442014-04-25 13:27:34 +02001112
Kevin Wolf8e2160e2015-04-29 17:29:39 +02001113 *child_flags = flags;
Kevin Wolf317fc442014-04-25 13:27:34 +02001114}
1115
Kevin Wolf6858eba2017-06-29 19:32:21 +02001116static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base,
1117 const char *filename, Error **errp)
1118{
1119 BlockDriverState *parent = c->opaque;
Alberto Garciae94d3db2018-11-12 16:00:34 +02001120 bool read_only = bdrv_is_read_only(parent);
Kevin Wolf6858eba2017-06-29 19:32:21 +02001121 int ret;
1122
Alberto Garciae94d3db2018-11-12 16:00:34 +02001123 if (read_only) {
1124 ret = bdrv_reopen_set_read_only(parent, false, errp);
Kevin Wolf61f09ce2017-09-19 16:22:54 +02001125 if (ret < 0) {
1126 return ret;
1127 }
1128 }
1129
Kevin Wolf6858eba2017-06-29 19:32:21 +02001130 ret = bdrv_change_backing_file(parent, filename,
1131 base->drv ? base->drv->format_name : "");
1132 if (ret < 0) {
Kevin Wolf64730692017-11-06 17:52:58 +01001133 error_setg_errno(errp, -ret, "Could not update backing file link");
Kevin Wolf6858eba2017-06-29 19:32:21 +02001134 }
1135
Alberto Garciae94d3db2018-11-12 16:00:34 +02001136 if (read_only) {
1137 bdrv_reopen_set_read_only(parent, true, NULL);
Kevin Wolf61f09ce2017-09-19 16:22:54 +02001138 }
1139
Kevin Wolf6858eba2017-06-29 19:32:21 +02001140 return ret;
1141}
1142
Kevin Wolf91ef3822016-12-20 16:23:46 +01001143const BdrvChildRole child_backing = {
Kevin Wolf6cd5c9d2018-05-29 17:17:45 +02001144 .parent_is_bds = true,
Kevin Wolfb5411552017-01-17 15:56:16 +01001145 .get_parent_desc = bdrv_child_get_parent_desc,
Kevin Wolfdb95dbb2017-02-08 11:28:52 +01001146 .attach = bdrv_backing_attach,
1147 .detach = bdrv_backing_detach,
Kevin Wolf8e2160e2015-04-29 17:29:39 +02001148 .inherit_options = bdrv_backing_options,
Kevin Wolf20018e12016-05-23 18:46:59 +02001149 .drained_begin = bdrv_child_cb_drained_begin,
Kevin Wolf89bd0302018-03-22 14:11:20 +01001150 .drained_poll = bdrv_child_cb_drained_poll,
Kevin Wolf20018e12016-05-23 18:46:59 +02001151 .drained_end = bdrv_child_cb_drained_end,
Kevin Wolf38701b62017-05-04 18:52:39 +02001152 .inactivate = bdrv_child_cb_inactivate,
Kevin Wolf6858eba2017-06-29 19:32:21 +02001153 .update_filename = bdrv_backing_update_filename,
Kevin Wolff3930ed2015-04-08 13:43:47 +02001154};
1155
Kevin Wolf7b272452012-11-12 17:05:39 +01001156static int bdrv_open_flags(BlockDriverState *bs, int flags)
1157{
Kevin Wolf61de4c62016-03-18 17:46:45 +01001158 int open_flags = flags;
Kevin Wolf7b272452012-11-12 17:05:39 +01001159
1160 /*
1161 * Clear flags that are internal to the block layer before opening the
1162 * image.
1163 */
Kevin Wolf20cca272014-06-04 14:33:27 +02001164 open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL);
Kevin Wolf7b272452012-11-12 17:05:39 +01001165
Kevin Wolf7b272452012-11-12 17:05:39 +01001166 return open_flags;
1167}
1168
Kevin Wolf91a097e2015-05-08 17:49:53 +02001169static void update_flags_from_options(int *flags, QemuOpts *opts)
1170{
Alberto Garcia2a3d4332018-11-12 16:00:48 +02001171 *flags &= ~(BDRV_O_CACHE_MASK | BDRV_O_RDWR | BDRV_O_AUTO_RDONLY);
Kevin Wolf91a097e2015-05-08 17:49:53 +02001172
Alberto Garcia57f9db92018-09-06 12:37:06 +03001173 if (qemu_opt_get_bool_del(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) {
Kevin Wolf91a097e2015-05-08 17:49:53 +02001174 *flags |= BDRV_O_NO_FLUSH;
1175 }
1176
Alberto Garcia57f9db92018-09-06 12:37:06 +03001177 if (qemu_opt_get_bool_del(opts, BDRV_OPT_CACHE_DIRECT, false)) {
Kevin Wolf91a097e2015-05-08 17:49:53 +02001178 *flags |= BDRV_O_NOCACHE;
1179 }
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001180
Alberto Garcia57f9db92018-09-06 12:37:06 +03001181 if (!qemu_opt_get_bool_del(opts, BDRV_OPT_READ_ONLY, false)) {
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001182 *flags |= BDRV_O_RDWR;
1183 }
1184
Kevin Wolfe35bdc12018-10-05 18:57:40 +02001185 if (qemu_opt_get_bool_del(opts, BDRV_OPT_AUTO_READ_ONLY, false)) {
1186 *flags |= BDRV_O_AUTO_RDONLY;
1187 }
Kevin Wolf91a097e2015-05-08 17:49:53 +02001188}
1189
1190static void update_options_from_flags(QDict *options, int flags)
1191{
Kevin Wolf91a097e2015-05-08 17:49:53 +02001192 if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) {
Eric Blake46f5ac22017-04-27 16:58:17 -05001193 qdict_put_bool(options, BDRV_OPT_CACHE_DIRECT, flags & BDRV_O_NOCACHE);
Kevin Wolf91a097e2015-05-08 17:49:53 +02001194 }
1195 if (!qdict_haskey(options, BDRV_OPT_CACHE_NO_FLUSH)) {
Eric Blake46f5ac22017-04-27 16:58:17 -05001196 qdict_put_bool(options, BDRV_OPT_CACHE_NO_FLUSH,
1197 flags & BDRV_O_NO_FLUSH);
Kevin Wolf91a097e2015-05-08 17:49:53 +02001198 }
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001199 if (!qdict_haskey(options, BDRV_OPT_READ_ONLY)) {
Eric Blake46f5ac22017-04-27 16:58:17 -05001200 qdict_put_bool(options, BDRV_OPT_READ_ONLY, !(flags & BDRV_O_RDWR));
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001201 }
Kevin Wolfe35bdc12018-10-05 18:57:40 +02001202 if (!qdict_haskey(options, BDRV_OPT_AUTO_READ_ONLY)) {
1203 qdict_put_bool(options, BDRV_OPT_AUTO_READ_ONLY,
1204 flags & BDRV_O_AUTO_RDONLY);
1205 }
Kevin Wolf91a097e2015-05-08 17:49:53 +02001206}
1207
Kevin Wolf636ea372014-01-24 14:11:52 +01001208static void bdrv_assign_node_name(BlockDriverState *bs,
1209 const char *node_name,
1210 Error **errp)
Benoît Canet6913c0c2014-01-23 21:31:33 +01001211{
Jeff Cody15489c72015-10-12 19:36:50 -04001212 char *gen_node_name = NULL;
Benoît Canet6913c0c2014-01-23 21:31:33 +01001213
Jeff Cody15489c72015-10-12 19:36:50 -04001214 if (!node_name) {
1215 node_name = gen_node_name = id_generate(ID_BLOCK);
1216 } else if (!id_wellformed(node_name)) {
1217 /*
1218 * Check for empty string or invalid characters, but not if it is
1219 * generated (generated names use characters not available to the user)
1220 */
Kevin Wolf9aebf3b2014-09-25 09:54:02 +02001221 error_setg(errp, "Invalid node name");
Kevin Wolf636ea372014-01-24 14:11:52 +01001222 return;
Benoît Canet6913c0c2014-01-23 21:31:33 +01001223 }
1224
Benoît Canet0c5e94e2014-02-12 17:15:07 +01001225 /* takes care of avoiding namespaces collisions */
Markus Armbruster7f06d472014-10-07 13:59:12 +02001226 if (blk_by_name(node_name)) {
Benoît Canet0c5e94e2014-02-12 17:15:07 +01001227 error_setg(errp, "node-name=%s is conflicting with a device id",
1228 node_name);
Jeff Cody15489c72015-10-12 19:36:50 -04001229 goto out;
Benoît Canet0c5e94e2014-02-12 17:15:07 +01001230 }
1231
Benoît Canet6913c0c2014-01-23 21:31:33 +01001232 /* takes care of avoiding duplicates node names */
1233 if (bdrv_find_node(node_name)) {
1234 error_setg(errp, "Duplicate node name");
Jeff Cody15489c72015-10-12 19:36:50 -04001235 goto out;
Benoît Canet6913c0c2014-01-23 21:31:33 +01001236 }
1237
Kevin Wolf824808d2018-07-04 13:28:29 +02001238 /* Make sure that the node name isn't truncated */
1239 if (strlen(node_name) >= sizeof(bs->node_name)) {
1240 error_setg(errp, "Node name too long");
1241 goto out;
1242 }
1243
Benoît Canet6913c0c2014-01-23 21:31:33 +01001244 /* copy node name into the bs and insert it into the graph list */
1245 pstrcpy(bs->node_name, sizeof(bs->node_name), node_name);
1246 QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list);
Jeff Cody15489c72015-10-12 19:36:50 -04001247out:
1248 g_free(gen_node_name);
Benoît Canet6913c0c2014-01-23 21:31:33 +01001249}
1250
Kevin Wolf01a56502017-01-18 15:51:56 +01001251static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv,
1252 const char *node_name, QDict *options,
1253 int open_flags, Error **errp)
1254{
1255 Error *local_err = NULL;
Kevin Wolf0f122642018-03-28 18:29:18 +02001256 int i, ret;
Kevin Wolf01a56502017-01-18 15:51:56 +01001257
1258 bdrv_assign_node_name(bs, node_name, &local_err);
1259 if (local_err) {
1260 error_propagate(errp, local_err);
1261 return -EINVAL;
1262 }
1263
1264 bs->drv = drv;
Kevin Wolf680c7f92017-01-18 17:16:41 +01001265 bs->read_only = !(bs->open_flags & BDRV_O_RDWR);
Kevin Wolf01a56502017-01-18 15:51:56 +01001266 bs->opaque = g_malloc0(drv->instance_size);
1267
1268 if (drv->bdrv_file_open) {
1269 assert(!drv->bdrv_needs_filename || bs->filename[0]);
1270 ret = drv->bdrv_file_open(bs, options, open_flags, &local_err);
Kevin Wolf680c7f92017-01-18 17:16:41 +01001271 } else if (drv->bdrv_open) {
Kevin Wolf01a56502017-01-18 15:51:56 +01001272 ret = drv->bdrv_open(bs, options, open_flags, &local_err);
Kevin Wolf680c7f92017-01-18 17:16:41 +01001273 } else {
1274 ret = 0;
Kevin Wolf01a56502017-01-18 15:51:56 +01001275 }
1276
1277 if (ret < 0) {
1278 if (local_err) {
1279 error_propagate(errp, local_err);
1280 } else if (bs->filename[0]) {
1281 error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename);
1282 } else {
1283 error_setg_errno(errp, -ret, "Could not open image");
1284 }
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001285 goto open_failed;
Kevin Wolf01a56502017-01-18 15:51:56 +01001286 }
1287
1288 ret = refresh_total_sectors(bs, bs->total_sectors);
1289 if (ret < 0) {
1290 error_setg_errno(errp, -ret, "Could not refresh total sector count");
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001291 return ret;
Kevin Wolf01a56502017-01-18 15:51:56 +01001292 }
1293
1294 bdrv_refresh_limits(bs, &local_err);
1295 if (local_err) {
1296 error_propagate(errp, local_err);
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001297 return -EINVAL;
Kevin Wolf01a56502017-01-18 15:51:56 +01001298 }
1299
1300 assert(bdrv_opt_mem_align(bs) != 0);
1301 assert(bdrv_min_mem_align(bs) != 0);
1302 assert(is_power_of_2(bs->bl.request_alignment));
1303
Kevin Wolf0f122642018-03-28 18:29:18 +02001304 for (i = 0; i < bs->quiesce_counter; i++) {
1305 if (drv->bdrv_co_drain_begin) {
1306 drv->bdrv_co_drain_begin(bs);
1307 }
1308 }
1309
Kevin Wolf01a56502017-01-18 15:51:56 +01001310 return 0;
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001311open_failed:
1312 bs->drv = NULL;
1313 if (bs->file != NULL) {
1314 bdrv_unref_child(bs, bs->file);
1315 bs->file = NULL;
1316 }
Kevin Wolf01a56502017-01-18 15:51:56 +01001317 g_free(bs->opaque);
1318 bs->opaque = NULL;
Kevin Wolf01a56502017-01-18 15:51:56 +01001319 return ret;
1320}
1321
Kevin Wolf680c7f92017-01-18 17:16:41 +01001322BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
1323 int flags, Error **errp)
1324{
1325 BlockDriverState *bs;
1326 int ret;
1327
1328 bs = bdrv_new();
1329 bs->open_flags = flags;
1330 bs->explicit_options = qdict_new();
1331 bs->options = qdict_new();
1332 bs->opaque = NULL;
1333
1334 update_options_from_flags(bs->options, flags);
1335
1336 ret = bdrv_open_driver(bs, drv, node_name, bs->options, flags, errp);
1337 if (ret < 0) {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02001338 qobject_unref(bs->explicit_options);
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001339 bs->explicit_options = NULL;
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02001340 qobject_unref(bs->options);
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001341 bs->options = NULL;
Kevin Wolf680c7f92017-01-18 17:16:41 +01001342 bdrv_unref(bs);
1343 return NULL;
1344 }
1345
1346 return bs;
1347}
1348
Kevin Wolfc5f30142016-10-06 11:33:17 +02001349QemuOptsList bdrv_runtime_opts = {
Kevin Wolf18edf282015-04-07 17:12:56 +02001350 .name = "bdrv_common",
1351 .head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head),
1352 .desc = {
1353 {
1354 .name = "node-name",
1355 .type = QEMU_OPT_STRING,
1356 .help = "Node name of the block device node",
1357 },
Kevin Wolf62392eb2015-04-24 16:38:02 +02001358 {
1359 .name = "driver",
1360 .type = QEMU_OPT_STRING,
1361 .help = "Block driver to use for the node",
1362 },
Kevin Wolf91a097e2015-05-08 17:49:53 +02001363 {
Kevin Wolf91a097e2015-05-08 17:49:53 +02001364 .name = BDRV_OPT_CACHE_DIRECT,
1365 .type = QEMU_OPT_BOOL,
1366 .help = "Bypass software writeback cache on the host",
1367 },
1368 {
1369 .name = BDRV_OPT_CACHE_NO_FLUSH,
1370 .type = QEMU_OPT_BOOL,
1371 .help = "Ignore flush requests",
1372 },
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001373 {
1374 .name = BDRV_OPT_READ_ONLY,
1375 .type = QEMU_OPT_BOOL,
1376 .help = "Node is opened in read-only mode",
1377 },
Kevin Wolf692e01a2016-09-12 21:00:41 +02001378 {
Kevin Wolfe35bdc12018-10-05 18:57:40 +02001379 .name = BDRV_OPT_AUTO_READ_ONLY,
1380 .type = QEMU_OPT_BOOL,
1381 .help = "Node can become read-only if opening read-write fails",
1382 },
1383 {
Kevin Wolf692e01a2016-09-12 21:00:41 +02001384 .name = "detect-zeroes",
1385 .type = QEMU_OPT_STRING,
1386 .help = "try to optimize zero writes (off, on, unmap)",
1387 },
Kevin Wolf818584a2016-09-12 18:03:18 +02001388 {
Alberto Garcia415bbca2018-10-03 13:23:13 +03001389 .name = BDRV_OPT_DISCARD,
Kevin Wolf818584a2016-09-12 18:03:18 +02001390 .type = QEMU_OPT_STRING,
1391 .help = "discard operation (ignore/off, unmap/on)",
1392 },
Fam Zheng5a9347c2017-05-03 00:35:37 +08001393 {
1394 .name = BDRV_OPT_FORCE_SHARE,
1395 .type = QEMU_OPT_BOOL,
1396 .help = "always accept other writers (default: off)",
1397 },
Kevin Wolf18edf282015-04-07 17:12:56 +02001398 { /* end of list */ }
1399 },
1400};
1401
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02001402/*
Kevin Wolf57915332010-04-14 15:24:50 +02001403 * Common part for opening disk images and files
Kevin Wolfb6ad4912013-03-15 10:35:04 +01001404 *
1405 * Removes all processed options from *options.
Kevin Wolf57915332010-04-14 15:24:50 +02001406 */
Kevin Wolf5696c6e2017-02-17 18:39:24 +01001407static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
Kevin Wolf82dc8b42016-01-11 19:07:50 +01001408 QDict *options, Error **errp)
Kevin Wolf57915332010-04-14 15:24:50 +02001409{
1410 int ret, open_flags;
Kevin Wolf035fccd2013-04-09 14:34:19 +02001411 const char *filename;
Kevin Wolf62392eb2015-04-24 16:38:02 +02001412 const char *driver_name = NULL;
Benoît Canet6913c0c2014-01-23 21:31:33 +01001413 const char *node_name = NULL;
Kevin Wolf818584a2016-09-12 18:03:18 +02001414 const char *discard;
Kevin Wolf18edf282015-04-07 17:12:56 +02001415 QemuOpts *opts;
Kevin Wolf62392eb2015-04-24 16:38:02 +02001416 BlockDriver *drv;
Max Reitz34b5d2c2013-09-05 14:45:29 +02001417 Error *local_err = NULL;
Kevin Wolf57915332010-04-14 15:24:50 +02001418
Paolo Bonzini64058752012-05-08 16:51:49 +02001419 assert(bs->file == NULL);
Kevin Wolf707ff822013-03-06 12:20:31 +01001420 assert(options != NULL && bs->options != options);
Kevin Wolf57915332010-04-14 15:24:50 +02001421
Kevin Wolf62392eb2015-04-24 16:38:02 +02001422 opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
1423 qemu_opts_absorb_qdict(opts, options, &local_err);
1424 if (local_err) {
1425 error_propagate(errp, local_err);
1426 ret = -EINVAL;
1427 goto fail_opts;
1428 }
1429
Alberto Garcia9b7e8692016-09-15 17:53:01 +03001430 update_flags_from_options(&bs->open_flags, opts);
1431
Kevin Wolf62392eb2015-04-24 16:38:02 +02001432 driver_name = qemu_opt_get(opts, "driver");
1433 drv = bdrv_find_format(driver_name);
1434 assert(drv != NULL);
1435
Fam Zheng5a9347c2017-05-03 00:35:37 +08001436 bs->force_share = qemu_opt_get_bool(opts, BDRV_OPT_FORCE_SHARE, false);
1437
1438 if (bs->force_share && (bs->open_flags & BDRV_O_RDWR)) {
1439 error_setg(errp,
1440 BDRV_OPT_FORCE_SHARE
1441 "=on can only be used with read-only images");
1442 ret = -EINVAL;
1443 goto fail_opts;
1444 }
1445
Kevin Wolf45673672013-04-22 17:48:40 +02001446 if (file != NULL) {
Max Reitzf30c66b2019-02-01 20:29:05 +01001447 bdrv_refresh_filename(blk_bs(file));
Kevin Wolf5696c6e2017-02-17 18:39:24 +01001448 filename = blk_bs(file)->filename;
Kevin Wolf45673672013-04-22 17:48:40 +02001449 } else {
Markus Armbruster129c7d12017-03-30 19:43:12 +02001450 /*
1451 * Caution: while qdict_get_try_str() is fine, getting
1452 * non-string types would require more care. When @options
1453 * come from -blockdev or blockdev_add, its members are typed
1454 * according to the QAPI schema, but when they come from
1455 * -drive, they're all QString.
1456 */
Kevin Wolf45673672013-04-22 17:48:40 +02001457 filename = qdict_get_try_str(options, "filename");
1458 }
1459
Max Reitz4a008242017-04-13 18:06:24 +02001460 if (drv->bdrv_needs_filename && (!filename || !filename[0])) {
Kevin Wolf765003d2014-02-03 14:49:42 +01001461 error_setg(errp, "The '%s' block driver requires a file name",
1462 drv->format_name);
Kevin Wolf18edf282015-04-07 17:12:56 +02001463 ret = -EINVAL;
1464 goto fail_opts;
1465 }
1466
Kevin Wolf82dc8b42016-01-11 19:07:50 +01001467 trace_bdrv_open_common(bs, filename ?: "", bs->open_flags,
1468 drv->format_name);
Kevin Wolf62392eb2015-04-24 16:38:02 +02001469
Kevin Wolf82dc8b42016-01-11 19:07:50 +01001470 bs->read_only = !(bs->open_flags & BDRV_O_RDWR);
Fam Zhengb64ec4e2013-05-29 19:35:40 +08001471
1472 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
Kevin Wolf8be25de2019-01-22 13:15:31 +01001473 if (!bs->read_only && bdrv_is_whitelisted(drv, true)) {
1474 ret = bdrv_apply_auto_read_only(bs, NULL, NULL);
1475 } else {
1476 ret = -ENOTSUP;
1477 }
1478 if (ret < 0) {
1479 error_setg(errp,
1480 !bs->read_only && bdrv_is_whitelisted(drv, true)
1481 ? "Driver '%s' can only be used for read-only devices"
1482 : "Driver '%s' is not whitelisted",
1483 drv->format_name);
1484 goto fail_opts;
1485 }
Fam Zhengb64ec4e2013-05-29 19:35:40 +08001486 }
Kevin Wolf57915332010-04-14 15:24:50 +02001487
Paolo Bonzinid3faa132017-06-05 14:38:50 +02001488 /* bdrv_new() and bdrv_close() make it so */
1489 assert(atomic_read(&bs->copy_on_read) == 0);
1490
Kevin Wolf82dc8b42016-01-11 19:07:50 +01001491 if (bs->open_flags & BDRV_O_COPY_ON_READ) {
Kevin Wolf0ebd24e2013-09-19 15:12:18 +02001492 if (!bs->read_only) {
1493 bdrv_enable_copy_on_read(bs);
1494 } else {
1495 error_setg(errp, "Can't use copy-on-read on read-only device");
Kevin Wolf18edf282015-04-07 17:12:56 +02001496 ret = -EINVAL;
1497 goto fail_opts;
Kevin Wolf0ebd24e2013-09-19 15:12:18 +02001498 }
Stefan Hajnoczi53fec9d2011-11-28 16:08:47 +00001499 }
1500
Alberto Garcia415bbca2018-10-03 13:23:13 +03001501 discard = qemu_opt_get(opts, BDRV_OPT_DISCARD);
Kevin Wolf818584a2016-09-12 18:03:18 +02001502 if (discard != NULL) {
1503 if (bdrv_parse_discard_flags(discard, &bs->open_flags) != 0) {
1504 error_setg(errp, "Invalid discard option");
1505 ret = -EINVAL;
1506 goto fail_opts;
1507 }
1508 }
1509
Alberto Garcia543770b2018-09-06 12:37:09 +03001510 bs->detect_zeroes =
1511 bdrv_parse_detect_zeroes(opts, bs->open_flags, &local_err);
1512 if (local_err) {
1513 error_propagate(errp, local_err);
1514 ret = -EINVAL;
1515 goto fail_opts;
Kevin Wolf692e01a2016-09-12 21:00:41 +02001516 }
1517
Kevin Wolfc2ad1b02013-03-18 16:40:51 +01001518 if (filename != NULL) {
1519 pstrcpy(bs->filename, sizeof(bs->filename), filename);
1520 } else {
1521 bs->filename[0] = '\0';
1522 }
Max Reitz91af7012014-07-18 20:24:56 +02001523 pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename);
Kevin Wolf57915332010-04-14 15:24:50 +02001524
Kevin Wolf66f82ce2010-04-14 14:17:38 +02001525 /* Open the image, either directly or using a protocol */
Kevin Wolf82dc8b42016-01-11 19:07:50 +01001526 open_flags = bdrv_open_flags(bs, bs->open_flags);
Kevin Wolf01a56502017-01-18 15:51:56 +01001527 node_name = qemu_opt_get(opts, "node-name");
Kevin Wolf66f82ce2010-04-14 14:17:38 +02001528
Kevin Wolf01a56502017-01-18 15:51:56 +01001529 assert(!drv->bdrv_file_open || file == NULL);
1530 ret = bdrv_open_driver(bs, drv, node_name, options, open_flags, errp);
Kevin Wolf57915332010-04-14 15:24:50 +02001531 if (ret < 0) {
Kevin Wolf01a56502017-01-18 15:51:56 +01001532 goto fail_opts;
Kevin Wolf57915332010-04-14 15:24:50 +02001533 }
1534
Kevin Wolf18edf282015-04-07 17:12:56 +02001535 qemu_opts_del(opts);
Kevin Wolf57915332010-04-14 15:24:50 +02001536 return 0;
1537
Kevin Wolf18edf282015-04-07 17:12:56 +02001538fail_opts:
1539 qemu_opts_del(opts);
Kevin Wolf57915332010-04-14 15:24:50 +02001540 return ret;
1541}
1542
Kevin Wolf5e5c4f62014-05-26 11:45:08 +02001543static QDict *parse_json_filename(const char *filename, Error **errp)
1544{
1545 QObject *options_obj;
1546 QDict *options;
1547 int ret;
1548
1549 ret = strstart(filename, "json:", &filename);
1550 assert(ret);
1551
Markus Armbruster5577fff2017-02-28 22:26:59 +01001552 options_obj = qobject_from_json(filename, errp);
Kevin Wolf5e5c4f62014-05-26 11:45:08 +02001553 if (!options_obj) {
Markus Armbruster5577fff2017-02-28 22:26:59 +01001554 error_prepend(errp, "Could not parse the JSON options: ");
Kevin Wolf5e5c4f62014-05-26 11:45:08 +02001555 return NULL;
1556 }
1557
Max Reitz7dc847e2018-02-24 16:40:29 +01001558 options = qobject_to(QDict, options_obj);
Markus Armbrusterca6b6e12017-02-17 21:38:18 +01001559 if (!options) {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02001560 qobject_unref(options_obj);
Kevin Wolf5e5c4f62014-05-26 11:45:08 +02001561 error_setg(errp, "Invalid JSON object given");
1562 return NULL;
1563 }
1564
Kevin Wolf5e5c4f62014-05-26 11:45:08 +02001565 qdict_flatten(options);
1566
1567 return options;
1568}
1569
Kevin Wolfde3b53f2015-10-29 15:24:41 +01001570static void parse_json_protocol(QDict *options, const char **pfilename,
1571 Error **errp)
1572{
1573 QDict *json_options;
1574 Error *local_err = NULL;
1575
1576 /* Parse json: pseudo-protocol */
1577 if (!*pfilename || !g_str_has_prefix(*pfilename, "json:")) {
1578 return;
1579 }
1580
1581 json_options = parse_json_filename(*pfilename, &local_err);
1582 if (local_err) {
1583 error_propagate(errp, local_err);
1584 return;
1585 }
1586
1587 /* Options given in the filename have lower priority than options
1588 * specified directly */
1589 qdict_join(options, json_options, false);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02001590 qobject_unref(json_options);
Kevin Wolfde3b53f2015-10-29 15:24:41 +01001591 *pfilename = NULL;
1592}
1593
Kevin Wolf57915332010-04-14 15:24:50 +02001594/*
Kevin Wolff54120f2014-05-26 11:09:59 +02001595 * Fills in default options for opening images and converts the legacy
1596 * filename/flags pair to option QDict entries.
Max Reitz53a29512015-03-19 14:53:16 -04001597 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1598 * block driver has been specified explicitly.
Kevin Wolff54120f2014-05-26 11:09:59 +02001599 */
Kevin Wolfde3b53f2015-10-29 15:24:41 +01001600static int bdrv_fill_options(QDict **options, const char *filename,
Max Reitz053e1572015-08-26 19:47:51 +02001601 int *flags, Error **errp)
Kevin Wolff54120f2014-05-26 11:09:59 +02001602{
1603 const char *drvname;
Max Reitz53a29512015-03-19 14:53:16 -04001604 bool protocol = *flags & BDRV_O_PROTOCOL;
Kevin Wolff54120f2014-05-26 11:09:59 +02001605 bool parse_filename = false;
Max Reitz053e1572015-08-26 19:47:51 +02001606 BlockDriver *drv = NULL;
Kevin Wolff54120f2014-05-26 11:09:59 +02001607 Error *local_err = NULL;
Kevin Wolff54120f2014-05-26 11:09:59 +02001608
Markus Armbruster129c7d12017-03-30 19:43:12 +02001609 /*
1610 * Caution: while qdict_get_try_str() is fine, getting non-string
1611 * types would require more care. When @options come from
1612 * -blockdev or blockdev_add, its members are typed according to
1613 * the QAPI schema, but when they come from -drive, they're all
1614 * QString.
1615 */
Max Reitz53a29512015-03-19 14:53:16 -04001616 drvname = qdict_get_try_str(*options, "driver");
Max Reitz053e1572015-08-26 19:47:51 +02001617 if (drvname) {
1618 drv = bdrv_find_format(drvname);
1619 if (!drv) {
1620 error_setg(errp, "Unknown driver '%s'", drvname);
1621 return -ENOENT;
1622 }
1623 /* If the user has explicitly specified the driver, this choice should
1624 * override the BDRV_O_PROTOCOL flag */
1625 protocol = drv->bdrv_file_open;
Max Reitz53a29512015-03-19 14:53:16 -04001626 }
1627
1628 if (protocol) {
1629 *flags |= BDRV_O_PROTOCOL;
1630 } else {
1631 *flags &= ~BDRV_O_PROTOCOL;
1632 }
1633
Kevin Wolf91a097e2015-05-08 17:49:53 +02001634 /* Translate cache options from flags into options */
1635 update_options_from_flags(*options, *flags);
1636
Kevin Wolff54120f2014-05-26 11:09:59 +02001637 /* Fetch the file name from the options QDict if necessary */
Kevin Wolf17b005f2014-05-27 10:50:29 +02001638 if (protocol && filename) {
Kevin Wolff54120f2014-05-26 11:09:59 +02001639 if (!qdict_haskey(*options, "filename")) {
Eric Blake46f5ac22017-04-27 16:58:17 -05001640 qdict_put_str(*options, "filename", filename);
Kevin Wolff54120f2014-05-26 11:09:59 +02001641 parse_filename = true;
1642 } else {
1643 error_setg(errp, "Can't specify 'file' and 'filename' options at "
1644 "the same time");
1645 return -EINVAL;
1646 }
1647 }
1648
1649 /* Find the right block driver */
Markus Armbruster129c7d12017-03-30 19:43:12 +02001650 /* See cautionary note on accessing @options above */
Kevin Wolff54120f2014-05-26 11:09:59 +02001651 filename = qdict_get_try_str(*options, "filename");
Kevin Wolff54120f2014-05-26 11:09:59 +02001652
Max Reitz053e1572015-08-26 19:47:51 +02001653 if (!drvname && protocol) {
1654 if (filename) {
1655 drv = bdrv_find_protocol(filename, parse_filename, errp);
1656 if (!drv) {
Kevin Wolff54120f2014-05-26 11:09:59 +02001657 return -EINVAL;
1658 }
Max Reitz053e1572015-08-26 19:47:51 +02001659
1660 drvname = drv->format_name;
Eric Blake46f5ac22017-04-27 16:58:17 -05001661 qdict_put_str(*options, "driver", drvname);
Max Reitz053e1572015-08-26 19:47:51 +02001662 } else {
1663 error_setg(errp, "Must specify either driver or file");
1664 return -EINVAL;
Kevin Wolff54120f2014-05-26 11:09:59 +02001665 }
1666 }
1667
Kevin Wolf17b005f2014-05-27 10:50:29 +02001668 assert(drv || !protocol);
Kevin Wolff54120f2014-05-26 11:09:59 +02001669
1670 /* Driver-specific filename parsing */
Kevin Wolf17b005f2014-05-27 10:50:29 +02001671 if (drv && drv->bdrv_parse_filename && parse_filename) {
Kevin Wolff54120f2014-05-26 11:09:59 +02001672 drv->bdrv_parse_filename(filename, *options, &local_err);
1673 if (local_err) {
1674 error_propagate(errp, local_err);
1675 return -EINVAL;
1676 }
1677
1678 if (!drv->bdrv_needs_filename) {
1679 qdict_del(*options, "filename");
1680 }
1681 }
1682
1683 return 0;
1684}
1685
Kevin Wolf3121fb42017-09-14 14:42:12 +02001686static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q,
1687 uint64_t perm, uint64_t shared,
Fam Zhengc1cef672017-03-14 10:30:50 +08001688 GSList *ignore_children, Error **errp);
1689static void bdrv_child_abort_perm_update(BdrvChild *c);
1690static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared);
1691
Kevin Wolf148eb132017-09-14 14:32:04 +02001692typedef struct BlockReopenQueueEntry {
1693 bool prepared;
Kevin Wolf69b736e2019-03-05 17:18:22 +01001694 bool perms_checked;
Kevin Wolf148eb132017-09-14 14:32:04 +02001695 BDRVReopenState state;
1696 QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry;
1697} BlockReopenQueueEntry;
1698
1699/*
1700 * Return the flags that @bs will have after the reopens in @q have
1701 * successfully completed. If @q is NULL (or @bs is not contained in @q),
1702 * return the current flags.
1703 */
1704static int bdrv_reopen_get_flags(BlockReopenQueue *q, BlockDriverState *bs)
1705{
1706 BlockReopenQueueEntry *entry;
1707
1708 if (q != NULL) {
1709 QSIMPLEQ_FOREACH(entry, q, entry) {
1710 if (entry->state.bs == bs) {
1711 return entry->state.flags;
1712 }
1713 }
1714 }
1715
1716 return bs->open_flags;
1717}
1718
1719/* Returns whether the image file can be written to after the reopen queue @q
1720 * has been successfully applied, or right now if @q is NULL. */
Max Reitzcc022142018-06-06 21:37:00 +02001721static bool bdrv_is_writable_after_reopen(BlockDriverState *bs,
1722 BlockReopenQueue *q)
Kevin Wolf148eb132017-09-14 14:32:04 +02001723{
1724 int flags = bdrv_reopen_get_flags(q, bs);
1725
1726 return (flags & (BDRV_O_RDWR | BDRV_O_INACTIVE)) == BDRV_O_RDWR;
1727}
1728
Max Reitzcc022142018-06-06 21:37:00 +02001729/*
1730 * Return whether the BDS can be written to. This is not necessarily
1731 * the same as !bdrv_is_read_only(bs), as inactivated images may not
1732 * be written to but do not count as read-only images.
1733 */
1734bool bdrv_is_writable(BlockDriverState *bs)
1735{
1736 return bdrv_is_writable_after_reopen(bs, NULL);
1737}
1738
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001739static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs,
Kevin Wolfe0995dc2017-09-14 12:47:11 +02001740 BdrvChild *c, const BdrvChildRole *role,
1741 BlockReopenQueue *reopen_queue,
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001742 uint64_t parent_perm, uint64_t parent_shared,
1743 uint64_t *nperm, uint64_t *nshared)
1744{
1745 if (bs->drv && bs->drv->bdrv_child_perm) {
Kevin Wolfe0995dc2017-09-14 12:47:11 +02001746 bs->drv->bdrv_child_perm(bs, c, role, reopen_queue,
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001747 parent_perm, parent_shared,
1748 nperm, nshared);
1749 }
Kevin Wolfe0995dc2017-09-14 12:47:11 +02001750 /* TODO Take force_share from reopen_queue */
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001751 if (child_bs && child_bs->force_share) {
1752 *nshared = BLK_PERM_ALL;
1753 }
1754}
1755
Kevin Wolf33a610c2016-12-15 13:04:20 +01001756/*
1757 * Check whether permissions on this node can be changed in a way that
1758 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1759 * permissions of all its parents. This involves checking whether all necessary
1760 * permission changes to child nodes can be performed.
1761 *
1762 * A call to this function must always be followed by a call to bdrv_set_perm()
1763 * or bdrv_abort_perm_update().
1764 */
Kevin Wolf3121fb42017-09-14 14:42:12 +02001765static int bdrv_check_perm(BlockDriverState *bs, BlockReopenQueue *q,
1766 uint64_t cumulative_perms,
Kevin Wolf46181122017-03-06 15:00:13 +01001767 uint64_t cumulative_shared_perms,
1768 GSList *ignore_children, Error **errp)
Kevin Wolf33a610c2016-12-15 13:04:20 +01001769{
1770 BlockDriver *drv = bs->drv;
1771 BdrvChild *c;
1772 int ret;
1773
1774 /* Write permissions never work with read-only images */
1775 if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) &&
Max Reitzcc022142018-06-06 21:37:00 +02001776 !bdrv_is_writable_after_reopen(bs, q))
Kevin Wolf33a610c2016-12-15 13:04:20 +01001777 {
1778 error_setg(errp, "Block node is read-only");
1779 return -EPERM;
1780 }
1781
1782 /* Check this node */
1783 if (!drv) {
1784 return 0;
1785 }
1786
1787 if (drv->bdrv_check_perm) {
1788 return drv->bdrv_check_perm(bs, cumulative_perms,
1789 cumulative_shared_perms, errp);
1790 }
1791
Kevin Wolf78e421c2016-12-20 23:25:12 +01001792 /* Drivers that never have children can omit .bdrv_child_perm() */
Kevin Wolf33a610c2016-12-15 13:04:20 +01001793 if (!drv->bdrv_child_perm) {
Kevin Wolf78e421c2016-12-20 23:25:12 +01001794 assert(QLIST_EMPTY(&bs->children));
Kevin Wolf33a610c2016-12-15 13:04:20 +01001795 return 0;
1796 }
1797
1798 /* Check all children */
1799 QLIST_FOREACH(c, &bs->children, next) {
1800 uint64_t cur_perm, cur_shared;
Kevin Wolf3121fb42017-09-14 14:42:12 +02001801 bdrv_child_perm(bs, c->bs, c, c->role, q,
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001802 cumulative_perms, cumulative_shared_perms,
1803 &cur_perm, &cur_shared);
Kevin Wolf3121fb42017-09-14 14:42:12 +02001804 ret = bdrv_child_check_perm(c, q, cur_perm, cur_shared,
1805 ignore_children, errp);
Kevin Wolf33a610c2016-12-15 13:04:20 +01001806 if (ret < 0) {
1807 return ret;
1808 }
1809 }
1810
1811 return 0;
1812}
1813
1814/*
1815 * Notifies drivers that after a previous bdrv_check_perm() call, the
1816 * permission update is not performed and any preparations made for it (e.g.
1817 * taken file locks) need to be undone.
1818 *
1819 * This function recursively notifies all child nodes.
1820 */
1821static void bdrv_abort_perm_update(BlockDriverState *bs)
1822{
1823 BlockDriver *drv = bs->drv;
1824 BdrvChild *c;
1825
1826 if (!drv) {
1827 return;
1828 }
1829
1830 if (drv->bdrv_abort_perm_update) {
1831 drv->bdrv_abort_perm_update(bs);
1832 }
1833
1834 QLIST_FOREACH(c, &bs->children, next) {
1835 bdrv_child_abort_perm_update(c);
1836 }
1837}
1838
1839static void bdrv_set_perm(BlockDriverState *bs, uint64_t cumulative_perms,
1840 uint64_t cumulative_shared_perms)
1841{
1842 BlockDriver *drv = bs->drv;
1843 BdrvChild *c;
1844
1845 if (!drv) {
1846 return;
1847 }
1848
1849 /* Update this node */
1850 if (drv->bdrv_set_perm) {
1851 drv->bdrv_set_perm(bs, cumulative_perms, cumulative_shared_perms);
1852 }
1853
Kevin Wolf78e421c2016-12-20 23:25:12 +01001854 /* Drivers that never have children can omit .bdrv_child_perm() */
Kevin Wolf33a610c2016-12-15 13:04:20 +01001855 if (!drv->bdrv_child_perm) {
Kevin Wolf78e421c2016-12-20 23:25:12 +01001856 assert(QLIST_EMPTY(&bs->children));
Kevin Wolf33a610c2016-12-15 13:04:20 +01001857 return;
1858 }
1859
1860 /* Update all children */
1861 QLIST_FOREACH(c, &bs->children, next) {
1862 uint64_t cur_perm, cur_shared;
Kevin Wolfe0995dc2017-09-14 12:47:11 +02001863 bdrv_child_perm(bs, c->bs, c, c->role, NULL,
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001864 cumulative_perms, cumulative_shared_perms,
1865 &cur_perm, &cur_shared);
Kevin Wolf33a610c2016-12-15 13:04:20 +01001866 bdrv_child_set_perm(c, cur_perm, cur_shared);
1867 }
1868}
1869
1870static void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
1871 uint64_t *shared_perm)
1872{
1873 BdrvChild *c;
1874 uint64_t cumulative_perms = 0;
1875 uint64_t cumulative_shared_perms = BLK_PERM_ALL;
1876
1877 QLIST_FOREACH(c, &bs->parents, next_parent) {
1878 cumulative_perms |= c->perm;
1879 cumulative_shared_perms &= c->shared_perm;
1880 }
1881
1882 *perm = cumulative_perms;
1883 *shared_perm = cumulative_shared_perms;
1884}
1885
Kevin Wolfd0833192017-01-16 18:26:20 +01001886static char *bdrv_child_user_desc(BdrvChild *c)
1887{
1888 if (c->role->get_parent_desc) {
1889 return c->role->get_parent_desc(c);
1890 }
1891
1892 return g_strdup("another user");
1893}
1894
Fam Zheng51761962017-05-03 00:35:36 +08001895char *bdrv_perm_names(uint64_t perm)
Kevin Wolfd0833192017-01-16 18:26:20 +01001896{
1897 struct perm_name {
1898 uint64_t perm;
1899 const char *name;
1900 } permissions[] = {
1901 { BLK_PERM_CONSISTENT_READ, "consistent read" },
1902 { BLK_PERM_WRITE, "write" },
1903 { BLK_PERM_WRITE_UNCHANGED, "write unchanged" },
1904 { BLK_PERM_RESIZE, "resize" },
1905 { BLK_PERM_GRAPH_MOD, "change children" },
1906 { 0, NULL }
1907 };
1908
1909 char *result = g_strdup("");
1910 struct perm_name *p;
1911
1912 for (p = permissions; p->name; p++) {
1913 if (perm & p->perm) {
1914 char *old = result;
1915 result = g_strdup_printf("%s%s%s", old, *old ? ", " : "", p->name);
1916 g_free(old);
1917 }
1918 }
1919
1920 return result;
1921}
1922
Kevin Wolf33a610c2016-12-15 13:04:20 +01001923/*
1924 * Checks whether a new reference to @bs can be added if the new user requires
Kevin Wolf46181122017-03-06 15:00:13 +01001925 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1926 * set, the BdrvChild objects in this list are ignored in the calculations;
1927 * this allows checking permission updates for an existing reference.
Kevin Wolf33a610c2016-12-15 13:04:20 +01001928 *
1929 * Needs to be followed by a call to either bdrv_set_perm() or
1930 * bdrv_abort_perm_update(). */
Kevin Wolf3121fb42017-09-14 14:42:12 +02001931static int bdrv_check_update_perm(BlockDriverState *bs, BlockReopenQueue *q,
1932 uint64_t new_used_perm,
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001933 uint64_t new_shared_perm,
Kevin Wolf46181122017-03-06 15:00:13 +01001934 GSList *ignore_children, Error **errp)
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001935{
1936 BdrvChild *c;
Kevin Wolf33a610c2016-12-15 13:04:20 +01001937 uint64_t cumulative_perms = new_used_perm;
1938 uint64_t cumulative_shared_perms = new_shared_perm;
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001939
1940 /* There is no reason why anyone couldn't tolerate write_unchanged */
1941 assert(new_shared_perm & BLK_PERM_WRITE_UNCHANGED);
1942
1943 QLIST_FOREACH(c, &bs->parents, next_parent) {
Kevin Wolf46181122017-03-06 15:00:13 +01001944 if (g_slist_find(ignore_children, c)) {
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001945 continue;
1946 }
1947
Kevin Wolfd0833192017-01-16 18:26:20 +01001948 if ((new_used_perm & c->shared_perm) != new_used_perm) {
1949 char *user = bdrv_child_user_desc(c);
1950 char *perm_names = bdrv_perm_names(new_used_perm & ~c->shared_perm);
1951 error_setg(errp, "Conflicts with use by %s as '%s', which does not "
1952 "allow '%s' on %s",
1953 user, c->name, perm_names, bdrv_get_node_name(c->bs));
1954 g_free(user);
1955 g_free(perm_names);
1956 return -EPERM;
1957 }
1958
1959 if ((c->perm & new_shared_perm) != c->perm) {
1960 char *user = bdrv_child_user_desc(c);
1961 char *perm_names = bdrv_perm_names(c->perm & ~new_shared_perm);
1962 error_setg(errp, "Conflicts with use by %s as '%s', which uses "
1963 "'%s' on %s",
1964 user, c->name, perm_names, bdrv_get_node_name(c->bs));
1965 g_free(user);
1966 g_free(perm_names);
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001967 return -EPERM;
1968 }
Kevin Wolf33a610c2016-12-15 13:04:20 +01001969
1970 cumulative_perms |= c->perm;
1971 cumulative_shared_perms &= c->shared_perm;
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001972 }
1973
Kevin Wolf3121fb42017-09-14 14:42:12 +02001974 return bdrv_check_perm(bs, q, cumulative_perms, cumulative_shared_perms,
Kevin Wolf46181122017-03-06 15:00:13 +01001975 ignore_children, errp);
Kevin Wolf33a610c2016-12-15 13:04:20 +01001976}
1977
1978/* Needs to be followed by a call to either bdrv_child_set_perm() or
1979 * bdrv_child_abort_perm_update(). */
Kevin Wolf3121fb42017-09-14 14:42:12 +02001980static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q,
1981 uint64_t perm, uint64_t shared,
Fam Zhengc1cef672017-03-14 10:30:50 +08001982 GSList *ignore_children, Error **errp)
Kevin Wolf33a610c2016-12-15 13:04:20 +01001983{
Kevin Wolf46181122017-03-06 15:00:13 +01001984 int ret;
1985
1986 ignore_children = g_slist_prepend(g_slist_copy(ignore_children), c);
Kevin Wolf3121fb42017-09-14 14:42:12 +02001987 ret = bdrv_check_update_perm(c->bs, q, perm, shared, ignore_children, errp);
Kevin Wolf46181122017-03-06 15:00:13 +01001988 g_slist_free(ignore_children);
1989
Vladimir Sementsov-Ogievskiyf962e962019-02-23 22:20:40 +03001990 if (ret < 0) {
1991 return ret;
1992 }
1993
1994 if (!c->has_backup_perm) {
1995 c->has_backup_perm = true;
1996 c->backup_perm = c->perm;
1997 c->backup_shared_perm = c->shared_perm;
1998 }
1999 /*
2000 * Note: it's OK if c->has_backup_perm was already set, as we can find the
2001 * same child twice during check_perm procedure
2002 */
2003
2004 c->perm = perm;
2005 c->shared_perm = shared;
2006
2007 return 0;
Kevin Wolf33a610c2016-12-15 13:04:20 +01002008}
2009
Fam Zhengc1cef672017-03-14 10:30:50 +08002010static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared)
Kevin Wolf33a610c2016-12-15 13:04:20 +01002011{
2012 uint64_t cumulative_perms, cumulative_shared_perms;
2013
Vladimir Sementsov-Ogievskiyf962e962019-02-23 22:20:40 +03002014 c->has_backup_perm = false;
2015
Kevin Wolf33a610c2016-12-15 13:04:20 +01002016 c->perm = perm;
2017 c->shared_perm = shared;
2018
2019 bdrv_get_cumulative_perm(c->bs, &cumulative_perms,
2020 &cumulative_shared_perms);
2021 bdrv_set_perm(c->bs, cumulative_perms, cumulative_shared_perms);
2022}
2023
Fam Zhengc1cef672017-03-14 10:30:50 +08002024static void bdrv_child_abort_perm_update(BdrvChild *c)
Kevin Wolf33a610c2016-12-15 13:04:20 +01002025{
Vladimir Sementsov-Ogievskiyf962e962019-02-23 22:20:40 +03002026 if (c->has_backup_perm) {
2027 c->perm = c->backup_perm;
2028 c->shared_perm = c->backup_shared_perm;
2029 c->has_backup_perm = false;
2030 }
2031
Kevin Wolf33a610c2016-12-15 13:04:20 +01002032 bdrv_abort_perm_update(c->bs);
2033}
2034
2035int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
2036 Error **errp)
2037{
2038 int ret;
2039
Kevin Wolf3121fb42017-09-14 14:42:12 +02002040 ret = bdrv_child_check_perm(c, NULL, perm, shared, NULL, errp);
Kevin Wolf33a610c2016-12-15 13:04:20 +01002041 if (ret < 0) {
2042 bdrv_child_abort_perm_update(c);
2043 return ret;
2044 }
2045
2046 bdrv_child_set_perm(c, perm, shared);
2047
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002048 return 0;
2049}
2050
Kevin Wolf6a1b9ee2016-12-15 11:27:32 +01002051void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c,
2052 const BdrvChildRole *role,
Kevin Wolfe0995dc2017-09-14 12:47:11 +02002053 BlockReopenQueue *reopen_queue,
Kevin Wolf6a1b9ee2016-12-15 11:27:32 +01002054 uint64_t perm, uint64_t shared,
2055 uint64_t *nperm, uint64_t *nshared)
2056{
2057 if (c == NULL) {
2058 *nperm = perm & DEFAULT_PERM_PASSTHROUGH;
2059 *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED;
2060 return;
2061 }
2062
2063 *nperm = (perm & DEFAULT_PERM_PASSTHROUGH) |
2064 (c->perm & DEFAULT_PERM_UNCHANGED);
2065 *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) |
2066 (c->shared_perm & DEFAULT_PERM_UNCHANGED);
2067}
2068
Kevin Wolf6b1a0442016-12-19 15:21:48 +01002069void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
2070 const BdrvChildRole *role,
Kevin Wolfe0995dc2017-09-14 12:47:11 +02002071 BlockReopenQueue *reopen_queue,
Kevin Wolf6b1a0442016-12-19 15:21:48 +01002072 uint64_t perm, uint64_t shared,
2073 uint64_t *nperm, uint64_t *nshared)
2074{
2075 bool backing = (role == &child_backing);
2076 assert(role == &child_backing || role == &child_file);
2077
2078 if (!backing) {
Kevin Wolf5fbfabd2017-11-30 17:38:43 +01002079 int flags = bdrv_reopen_get_flags(reopen_queue, bs);
2080
Kevin Wolf6b1a0442016-12-19 15:21:48 +01002081 /* Apart from the modifications below, the same permissions are
2082 * forwarded and left alone as for filters */
Kevin Wolfe0995dc2017-09-14 12:47:11 +02002083 bdrv_filter_default_perms(bs, c, role, reopen_queue, perm, shared,
2084 &perm, &shared);
Kevin Wolf6b1a0442016-12-19 15:21:48 +01002085
2086 /* Format drivers may touch metadata even if the guest doesn't write */
Max Reitzcc022142018-06-06 21:37:00 +02002087 if (bdrv_is_writable_after_reopen(bs, reopen_queue)) {
Kevin Wolf6b1a0442016-12-19 15:21:48 +01002088 perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
2089 }
2090
2091 /* bs->file always needs to be consistent because of the metadata. We
2092 * can never allow other users to resize or write to it. */
Kevin Wolf5fbfabd2017-11-30 17:38:43 +01002093 if (!(flags & BDRV_O_NO_IO)) {
2094 perm |= BLK_PERM_CONSISTENT_READ;
2095 }
Kevin Wolf6b1a0442016-12-19 15:21:48 +01002096 shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
2097 } else {
2098 /* We want consistent read from backing files if the parent needs it.
2099 * No other operations are performed on backing files. */
2100 perm &= BLK_PERM_CONSISTENT_READ;
2101
2102 /* If the parent can deal with changing data, we're okay with a
2103 * writable and resizable backing file. */
2104 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
2105 if (shared & BLK_PERM_WRITE) {
2106 shared = BLK_PERM_WRITE | BLK_PERM_RESIZE;
2107 } else {
2108 shared = 0;
2109 }
2110
2111 shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD |
2112 BLK_PERM_WRITE_UNCHANGED;
2113 }
2114
Kevin Wolf9c5e6592017-05-04 18:52:40 +02002115 if (bs->open_flags & BDRV_O_INACTIVE) {
2116 shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
2117 }
2118
Kevin Wolf6b1a0442016-12-19 15:21:48 +01002119 *nperm = perm;
2120 *nshared = shared;
2121}
2122
Kevin Wolf8ee03992017-03-06 13:45:28 +01002123static void bdrv_replace_child_noperm(BdrvChild *child,
2124 BlockDriverState *new_bs)
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002125{
2126 BlockDriverState *old_bs = child->bs;
Kevin Wolf0152bf42017-12-07 13:03:13 +01002127 int i;
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002128
Alberto Garcia2cad1eb2019-03-12 18:48:40 +02002129 assert(!child->frozen);
2130
Fam Zhengbb2614e2017-04-07 14:54:10 +08002131 if (old_bs && new_bs) {
2132 assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
2133 }
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002134 if (old_bs) {
Kevin Wolfd736f112017-12-18 16:05:48 +01002135 /* Detach first so that the recursive drain sections coming from @child
2136 * are already gone and we only end the drain sections that came from
2137 * elsewhere. */
2138 if (child->role->detach) {
2139 child->role->detach(child);
2140 }
Kevin Wolf36fe1332016-05-17 14:51:55 +02002141 if (old_bs->quiesce_counter && child->role->drained_end) {
Kevin Wolf0f122642018-03-28 18:29:18 +02002142 int num = old_bs->quiesce_counter;
2143 if (child->role->parent_is_bds) {
2144 num -= bdrv_drain_all_count;
2145 }
2146 assert(num >= 0);
2147 for (i = 0; i < num; i++) {
Kevin Wolf0152bf42017-12-07 13:03:13 +01002148 child->role->drained_end(child);
2149 }
Kevin Wolf36fe1332016-05-17 14:51:55 +02002150 }
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002151 QLIST_REMOVE(child, next_parent);
2152 }
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002153
2154 child->bs = new_bs;
Kevin Wolf36fe1332016-05-17 14:51:55 +02002155
2156 if (new_bs) {
2157 QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
2158 if (new_bs->quiesce_counter && child->role->drained_begin) {
Kevin Wolf0f122642018-03-28 18:29:18 +02002159 int num = new_bs->quiesce_counter;
2160 if (child->role->parent_is_bds) {
2161 num -= bdrv_drain_all_count;
2162 }
2163 assert(num >= 0);
2164 for (i = 0; i < num; i++) {
Kevin Wolf4be6a6d2018-06-29 18:01:31 +02002165 bdrv_parent_drained_begin_single(child, true);
Kevin Wolf0152bf42017-12-07 13:03:13 +01002166 }
Kevin Wolf36fe1332016-05-17 14:51:55 +02002167 }
Kevin Wolf33a610c2016-12-15 13:04:20 +01002168
Kevin Wolfd736f112017-12-18 16:05:48 +01002169 /* Attach only after starting new drained sections, so that recursive
2170 * drain sections coming from @child don't get an extra .drained_begin
2171 * callback. */
Kevin Wolfdb95dbb2017-02-08 11:28:52 +01002172 if (child->role->attach) {
2173 child->role->attach(child);
2174 }
Kevin Wolf36fe1332016-05-17 14:51:55 +02002175 }
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002176}
2177
Kevin Wolf466787f2017-03-08 14:44:07 +01002178/*
2179 * Updates @child to change its reference to point to @new_bs, including
2180 * checking and applying the necessary permisson updates both to the old node
2181 * and to @new_bs.
2182 *
2183 * NULL is passed as @new_bs for removing the reference before freeing @child.
2184 *
2185 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
2186 * function uses bdrv_set_perm() to update the permissions according to the new
2187 * reference that @new_bs gets.
2188 */
2189static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs)
Kevin Wolf8ee03992017-03-06 13:45:28 +01002190{
2191 BlockDriverState *old_bs = child->bs;
2192 uint64_t perm, shared_perm;
2193
Kevin Wolf8aecf1d2017-08-03 17:02:57 +02002194 bdrv_replace_child_noperm(child, new_bs);
2195
Kevin Wolf8ee03992017-03-06 13:45:28 +01002196 if (old_bs) {
2197 /* Update permissions for old node. This is guaranteed to succeed
2198 * because we're just taking a parent away, so we're loosening
2199 * restrictions. */
2200 bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm);
Kevin Wolf3121fb42017-09-14 14:42:12 +02002201 bdrv_check_perm(old_bs, NULL, perm, shared_perm, NULL, &error_abort);
Kevin Wolf8ee03992017-03-06 13:45:28 +01002202 bdrv_set_perm(old_bs, perm, shared_perm);
2203 }
2204
Kevin Wolf8ee03992017-03-06 13:45:28 +01002205 if (new_bs) {
Kevin Wolff54120f2014-05-26 11:09:59 +02002206 bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm);
Kevin Wolff54120f2014-05-26 11:09:59 +02002207 bdrv_set_perm(new_bs, perm, shared_perm);
Kevin Wolff54120f2014-05-26 11:09:59 +02002208 }
2209}
2210
Kevin Wolff21d96d2016-03-08 13:47:46 +01002211BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
2212 const char *child_name,
Kevin Wolf36fe1332016-05-17 14:51:55 +02002213 const BdrvChildRole *child_role,
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002214 uint64_t perm, uint64_t shared_perm,
2215 void *opaque, Error **errp)
Kevin Wolfdf581792015-06-15 11:53:47 +02002216{
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002217 BdrvChild *child;
2218 int ret;
2219
Kevin Wolf3121fb42017-09-14 14:42:12 +02002220 ret = bdrv_check_update_perm(child_bs, NULL, perm, shared_perm, NULL, errp);
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002221 if (ret < 0) {
Kevin Wolf33a610c2016-12-15 13:04:20 +01002222 bdrv_abort_perm_update(child_bs);
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002223 return NULL;
2224 }
2225
2226 child = g_new(BdrvChild, 1);
Kevin Wolfdf581792015-06-15 11:53:47 +02002227 *child = (BdrvChild) {
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002228 .bs = NULL,
2229 .name = g_strdup(child_name),
2230 .role = child_role,
2231 .perm = perm,
2232 .shared_perm = shared_perm,
2233 .opaque = opaque,
Kevin Wolfdf581792015-06-15 11:53:47 +02002234 };
2235
Kevin Wolf33a610c2016-12-15 13:04:20 +01002236 /* This performs the matching bdrv_set_perm() for the above check. */
Kevin Wolf466787f2017-03-08 14:44:07 +01002237 bdrv_replace_child(child, child_bs);
Kevin Wolfb4b059f2015-06-15 13:24:19 +02002238
2239 return child;
Kevin Wolfdf581792015-06-15 11:53:47 +02002240}
2241
Wen Congyang98292c62016-05-10 15:36:38 +08002242BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
2243 BlockDriverState *child_bs,
2244 const char *child_name,
Kevin Wolf8b2ff522016-12-20 22:21:17 +01002245 const BdrvChildRole *child_role,
2246 Error **errp)
Kevin Wolff21d96d2016-03-08 13:47:46 +01002247{
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002248 BdrvChild *child;
Kevin Wolff68c5982016-12-20 15:51:12 +01002249 uint64_t perm, shared_perm;
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002250
Kevin Wolff68c5982016-12-20 15:51:12 +01002251 bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm);
2252
2253 assert(parent_bs->drv);
Fam Zhengbb2614e2017-04-07 14:54:10 +08002254 assert(bdrv_get_aio_context(parent_bs) == bdrv_get_aio_context(child_bs));
Kevin Wolfe0995dc2017-09-14 12:47:11 +02002255 bdrv_child_perm(parent_bs, child_bs, NULL, child_role, NULL,
Fam Zhengffd1a5a2017-05-03 00:35:38 +08002256 perm, shared_perm, &perm, &shared_perm);
Kevin Wolff68c5982016-12-20 15:51:12 +01002257
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002258 child = bdrv_root_attach_child(child_bs, child_name, child_role,
Kevin Wolff68c5982016-12-20 15:51:12 +01002259 perm, shared_perm, parent_bs, errp);
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002260 if (child == NULL) {
2261 return NULL;
2262 }
2263
Kevin Wolff21d96d2016-03-08 13:47:46 +01002264 QLIST_INSERT_HEAD(&parent_bs->children, child, next);
2265 return child;
2266}
2267
Kevin Wolf3f09bfb2015-09-15 11:58:23 +02002268static void bdrv_detach_child(BdrvChild *child)
Kevin Wolf33a60402015-06-15 13:51:04 +02002269{
Kevin Wolff21d96d2016-03-08 13:47:46 +01002270 if (child->next.le_prev) {
2271 QLIST_REMOVE(child, next);
2272 child->next.le_prev = NULL;
2273 }
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002274
Kevin Wolf466787f2017-03-08 14:44:07 +01002275 bdrv_replace_child(child, NULL);
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002276
Kevin Wolf260fecf2015-04-27 13:46:22 +02002277 g_free(child->name);
Kevin Wolf33a60402015-06-15 13:51:04 +02002278 g_free(child);
2279}
2280
Kevin Wolff21d96d2016-03-08 13:47:46 +01002281void bdrv_root_unref_child(BdrvChild *child)
Kevin Wolf33a60402015-06-15 13:51:04 +02002282{
Kevin Wolf779020c2015-10-13 14:09:44 +02002283 BlockDriverState *child_bs;
2284
Kevin Wolff21d96d2016-03-08 13:47:46 +01002285 child_bs = child->bs;
2286 bdrv_detach_child(child);
2287 bdrv_unref(child_bs);
2288}
2289
2290void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
2291{
Kevin Wolf779020c2015-10-13 14:09:44 +02002292 if (child == NULL) {
2293 return;
2294 }
Kevin Wolf33a60402015-06-15 13:51:04 +02002295
2296 if (child->bs->inherits_from == parent) {
Kevin Wolf4e4bf5c2016-12-16 18:52:37 +01002297 BdrvChild *c;
2298
2299 /* Remove inherits_from only when the last reference between parent and
2300 * child->bs goes away. */
2301 QLIST_FOREACH(c, &parent->children, next) {
2302 if (c != child && c->bs == child->bs) {
2303 break;
2304 }
2305 }
2306 if (c == NULL) {
2307 child->bs->inherits_from = NULL;
2308 }
Kevin Wolf33a60402015-06-15 13:51:04 +02002309 }
2310
Kevin Wolff21d96d2016-03-08 13:47:46 +01002311 bdrv_root_unref_child(child);
Kevin Wolf33a60402015-06-15 13:51:04 +02002312}
2313
Kevin Wolf5c8cab42016-02-24 15:13:35 +01002314
2315static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load)
2316{
2317 BdrvChild *c;
2318 QLIST_FOREACH(c, &bs->parents, next_parent) {
2319 if (c->role->change_media) {
2320 c->role->change_media(c, load);
2321 }
2322 }
2323}
2324
Alberto Garcia0065c452018-10-31 18:16:37 +02002325/* Return true if you can reach parent going through child->inherits_from
2326 * recursively. If parent or child are NULL, return false */
2327static bool bdrv_inherits_from_recursive(BlockDriverState *child,
2328 BlockDriverState *parent)
2329{
2330 while (child && child != parent) {
2331 child = child->inherits_from;
2332 }
2333
2334 return child != NULL;
2335}
2336
Kevin Wolf5db15a52015-09-14 15:33:33 +02002337/*
2338 * Sets the backing file link of a BDS. A new reference is created; callers
2339 * which don't need their own reference any more must call bdrv_unref().
2340 */
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002341void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
2342 Error **errp)
Fam Zheng8d24cce2014-05-23 21:29:45 +08002343{
Alberto Garcia0065c452018-10-31 18:16:37 +02002344 bool update_inherits_from = bdrv_chain_contains(bs, backing_hd) &&
2345 bdrv_inherits_from_recursive(backing_hd, bs);
2346
Alberto Garcia2cad1eb2019-03-12 18:48:40 +02002347 if (bdrv_is_backing_chain_frozen(bs, backing_bs(bs), errp)) {
2348 return;
2349 }
2350
Kevin Wolf5db15a52015-09-14 15:33:33 +02002351 if (backing_hd) {
2352 bdrv_ref(backing_hd);
2353 }
Fam Zheng8d24cce2014-05-23 21:29:45 +08002354
Kevin Wolf760e0062015-06-17 14:55:21 +02002355 if (bs->backing) {
Kevin Wolf5db15a52015-09-14 15:33:33 +02002356 bdrv_unref_child(bs, bs->backing);
Fam Zheng826b6ca2014-05-23 21:29:47 +08002357 }
2358
Fam Zheng8d24cce2014-05-23 21:29:45 +08002359 if (!backing_hd) {
Kevin Wolf760e0062015-06-17 14:55:21 +02002360 bs->backing = NULL;
Fam Zheng8d24cce2014-05-23 21:29:45 +08002361 goto out;
2362 }
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002363
Kevin Wolf8b2ff522016-12-20 22:21:17 +01002364 bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_backing,
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002365 errp);
Alberto Garcia0065c452018-10-31 18:16:37 +02002366 /* If backing_hd was already part of bs's backing chain, and
2367 * inherits_from pointed recursively to bs then let's update it to
2368 * point directly to bs (else it will become NULL). */
2369 if (update_inherits_from) {
2370 backing_hd->inherits_from = bs;
2371 }
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002372 if (!bs->backing) {
2373 bdrv_unref(backing_hd);
2374 }
Fam Zheng826b6ca2014-05-23 21:29:47 +08002375
Fam Zheng8d24cce2014-05-23 21:29:45 +08002376out:
Kevin Wolf3baca892014-07-16 17:48:16 +02002377 bdrv_refresh_limits(bs, NULL);
Fam Zheng8d24cce2014-05-23 21:29:45 +08002378}
2379
Kevin Wolf31ca6d02013-03-28 15:29:24 +01002380/*
2381 * Opens the backing file for a BlockDriverState if not yet open
2382 *
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002383 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
2384 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2385 * itself, all options starting with "${bdref_key}." are considered part of the
2386 * BlockdevRef.
2387 *
2388 * TODO Can this be unified with bdrv_open_image()?
Kevin Wolf31ca6d02013-03-28 15:29:24 +01002389 */
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002390int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
2391 const char *bdref_key, Error **errp)
Paolo Bonzini9156df12012-10-18 16:49:17 +02002392{
Max Reitz6b6833c2019-02-01 20:29:15 +01002393 char *backing_filename = NULL;
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002394 char *bdref_key_dot;
2395 const char *reference = NULL;
Kevin Wolf317fc442014-04-25 13:27:34 +02002396 int ret = 0;
Max Reitz998c2012019-02-01 20:29:08 +01002397 bool implicit_backing = false;
Fam Zheng8d24cce2014-05-23 21:29:45 +08002398 BlockDriverState *backing_hd;
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002399 QDict *options;
2400 QDict *tmp_parent_options = NULL;
Max Reitz34b5d2c2013-09-05 14:45:29 +02002401 Error *local_err = NULL;
Paolo Bonzini9156df12012-10-18 16:49:17 +02002402
Kevin Wolf760e0062015-06-17 14:55:21 +02002403 if (bs->backing != NULL) {
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002404 goto free_exit;
Paolo Bonzini9156df12012-10-18 16:49:17 +02002405 }
2406
Kevin Wolf31ca6d02013-03-28 15:29:24 +01002407 /* NULL means an empty set of options */
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002408 if (parent_options == NULL) {
2409 tmp_parent_options = qdict_new();
2410 parent_options = tmp_parent_options;
Kevin Wolf31ca6d02013-03-28 15:29:24 +01002411 }
2412
Paolo Bonzini9156df12012-10-18 16:49:17 +02002413 bs->open_flags &= ~BDRV_O_NO_BACKING;
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002414
2415 bdref_key_dot = g_strdup_printf("%s.", bdref_key);
2416 qdict_extract_subqdict(parent_options, &options, bdref_key_dot);
2417 g_free(bdref_key_dot);
2418
Markus Armbruster129c7d12017-03-30 19:43:12 +02002419 /*
2420 * Caution: while qdict_get_try_str() is fine, getting non-string
2421 * types would require more care. When @parent_options come from
2422 * -blockdev or blockdev_add, its members are typed according to
2423 * the QAPI schema, but when they come from -drive, they're all
2424 * QString.
2425 */
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002426 reference = qdict_get_try_str(parent_options, bdref_key);
2427 if (reference || qdict_haskey(options, "file.filename")) {
Max Reitz6b6833c2019-02-01 20:29:15 +01002428 /* keep backing_filename NULL */
Kevin Wolf1cb6f502013-04-12 20:27:07 +02002429 } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002430 qobject_unref(options);
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002431 goto free_exit;
Fam Zhengdbecebd2013-09-22 20:05:06 +08002432 } else {
Max Reitz998c2012019-02-01 20:29:08 +01002433 if (qdict_size(options) == 0) {
2434 /* If the user specifies options that do not modify the
2435 * backing file's behavior, we might still consider it the
2436 * implicit backing file. But it's easier this way, and
2437 * just specifying some of the backing BDS's options is
2438 * only possible with -drive anyway (otherwise the QAPI
2439 * schema forces the user to specify everything). */
2440 implicit_backing = !strcmp(bs->auto_backing_file, bs->backing_file);
2441 }
2442
Max Reitz6b6833c2019-02-01 20:29:15 +01002443 backing_filename = bdrv_get_full_backing_filename(bs, &local_err);
Max Reitz9f074292014-11-26 17:20:26 +01002444 if (local_err) {
2445 ret = -EINVAL;
2446 error_propagate(errp, local_err);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002447 qobject_unref(options);
Max Reitz9f074292014-11-26 17:20:26 +01002448 goto free_exit;
2449 }
Paolo Bonzini9156df12012-10-18 16:49:17 +02002450 }
2451
Kevin Wolf8ee79e72014-06-04 15:09:35 +02002452 if (!bs->drv || !bs->drv->supports_backing) {
2453 ret = -EINVAL;
2454 error_setg(errp, "Driver doesn't support backing files");
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002455 qobject_unref(options);
Kevin Wolf8ee79e72014-06-04 15:09:35 +02002456 goto free_exit;
2457 }
2458
Peter Krempa6bff5972017-10-12 16:14:10 +02002459 if (!reference &&
2460 bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) {
Eric Blake46f5ac22017-04-27 16:58:17 -05002461 qdict_put_str(options, "driver", bs->backing_format);
Paolo Bonzini9156df12012-10-18 16:49:17 +02002462 }
2463
Max Reitz6b6833c2019-02-01 20:29:15 +01002464 backing_hd = bdrv_open_inherit(backing_filename, reference, options, 0, bs,
2465 &child_backing, errp);
Max Reitz5b363932016-05-17 16:41:31 +02002466 if (!backing_hd) {
Paolo Bonzini9156df12012-10-18 16:49:17 +02002467 bs->open_flags |= BDRV_O_NO_BACKING;
Markus Armbrustere43bfd92015-12-18 16:35:15 +01002468 error_prepend(errp, "Could not open backing file: ");
Max Reitz5b363932016-05-17 16:41:31 +02002469 ret = -EINVAL;
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002470 goto free_exit;
Paolo Bonzini9156df12012-10-18 16:49:17 +02002471 }
sochin.jiang5ce6bfe2017-06-26 19:04:24 +08002472 bdrv_set_aio_context(backing_hd, bdrv_get_aio_context(bs));
Kevin Wolfdf581792015-06-15 11:53:47 +02002473
Max Reitz998c2012019-02-01 20:29:08 +01002474 if (implicit_backing) {
2475 bdrv_refresh_filename(backing_hd);
2476 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file),
2477 backing_hd->filename);
2478 }
2479
Kevin Wolf5db15a52015-09-14 15:33:33 +02002480 /* Hook up the backing file link; drop our reference, bs owns the
2481 * backing_hd reference now */
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002482 bdrv_set_backing_hd(bs, backing_hd, &local_err);
Kevin Wolf5db15a52015-09-14 15:33:33 +02002483 bdrv_unref(backing_hd);
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002484 if (local_err) {
Fam Zheng8cd1a3e2017-03-17 09:56:30 +08002485 error_propagate(errp, local_err);
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002486 ret = -EINVAL;
2487 goto free_exit;
2488 }
Peter Feinerd80ac652014-01-08 19:43:25 +00002489
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002490 qdict_del(parent_options, bdref_key);
2491
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002492free_exit:
2493 g_free(backing_filename);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002494 qobject_unref(tmp_parent_options);
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002495 return ret;
Paolo Bonzini9156df12012-10-18 16:49:17 +02002496}
2497
Kevin Wolf2d6b86a2017-02-17 17:43:59 +01002498static BlockDriverState *
2499bdrv_open_child_bs(const char *filename, QDict *options, const char *bdref_key,
2500 BlockDriverState *parent, const BdrvChildRole *child_role,
2501 bool allow_none, Error **errp)
Max Reitzda557aa2013-12-20 19:28:11 +01002502{
Kevin Wolf2d6b86a2017-02-17 17:43:59 +01002503 BlockDriverState *bs = NULL;
Max Reitzda557aa2013-12-20 19:28:11 +01002504 QDict *image_options;
Max Reitzda557aa2013-12-20 19:28:11 +01002505 char *bdref_key_dot;
2506 const char *reference;
2507
Kevin Wolfdf581792015-06-15 11:53:47 +02002508 assert(child_role != NULL);
Max Reitzf67503e2014-02-18 18:33:05 +01002509
Max Reitzda557aa2013-12-20 19:28:11 +01002510 bdref_key_dot = g_strdup_printf("%s.", bdref_key);
2511 qdict_extract_subqdict(options, &image_options, bdref_key_dot);
2512 g_free(bdref_key_dot);
2513
Markus Armbruster129c7d12017-03-30 19:43:12 +02002514 /*
2515 * Caution: while qdict_get_try_str() is fine, getting non-string
2516 * types would require more care. When @options come from
2517 * -blockdev or blockdev_add, its members are typed according to
2518 * the QAPI schema, but when they come from -drive, they're all
2519 * QString.
2520 */
Max Reitzda557aa2013-12-20 19:28:11 +01002521 reference = qdict_get_try_str(options, bdref_key);
2522 if (!filename && !reference && !qdict_size(image_options)) {
Kevin Wolfb4b059f2015-06-15 13:24:19 +02002523 if (!allow_none) {
Max Reitzda557aa2013-12-20 19:28:11 +01002524 error_setg(errp, "A block device must be specified for \"%s\"",
2525 bdref_key);
Max Reitzda557aa2013-12-20 19:28:11 +01002526 }
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002527 qobject_unref(image_options);
Max Reitzda557aa2013-12-20 19:28:11 +01002528 goto done;
2529 }
2530
Max Reitz5b363932016-05-17 16:41:31 +02002531 bs = bdrv_open_inherit(filename, reference, image_options, 0,
2532 parent, child_role, errp);
2533 if (!bs) {
Kevin Wolfdf581792015-06-15 11:53:47 +02002534 goto done;
2535 }
2536
Max Reitzda557aa2013-12-20 19:28:11 +01002537done:
2538 qdict_del(options, bdref_key);
Kevin Wolf2d6b86a2017-02-17 17:43:59 +01002539 return bs;
2540}
2541
2542/*
2543 * Opens a disk image whose options are given as BlockdevRef in another block
2544 * device's options.
2545 *
2546 * If allow_none is true, no image will be opened if filename is false and no
2547 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2548 *
2549 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2550 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2551 * itself, all options starting with "${bdref_key}." are considered part of the
2552 * BlockdevRef.
2553 *
2554 * The BlockdevRef will be removed from the options QDict.
2555 */
2556BdrvChild *bdrv_open_child(const char *filename,
2557 QDict *options, const char *bdref_key,
2558 BlockDriverState *parent,
2559 const BdrvChildRole *child_role,
2560 bool allow_none, Error **errp)
2561{
Kevin Wolf8b2ff522016-12-20 22:21:17 +01002562 BdrvChild *c;
Kevin Wolf2d6b86a2017-02-17 17:43:59 +01002563 BlockDriverState *bs;
2564
2565 bs = bdrv_open_child_bs(filename, options, bdref_key, parent, child_role,
2566 allow_none, errp);
2567 if (bs == NULL) {
2568 return NULL;
2569 }
2570
Kevin Wolf8b2ff522016-12-20 22:21:17 +01002571 c = bdrv_attach_child(parent, bs, bdref_key, child_role, errp);
2572 if (!c) {
2573 bdrv_unref(bs);
2574 return NULL;
2575 }
2576
2577 return c;
Kevin Wolfb4b059f2015-06-15 13:24:19 +02002578}
2579
Kevin Wolfe1d74bc2018-01-10 15:52:33 +01002580/* TODO Future callers may need to specify parent/child_role in order for
2581 * option inheritance to work. Existing callers use it for the root node. */
2582BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp)
2583{
2584 BlockDriverState *bs = NULL;
2585 Error *local_err = NULL;
2586 QObject *obj = NULL;
2587 QDict *qdict = NULL;
2588 const char *reference = NULL;
2589 Visitor *v = NULL;
2590
2591 if (ref->type == QTYPE_QSTRING) {
2592 reference = ref->u.reference;
2593 } else {
2594 BlockdevOptions *options = &ref->u.definition;
2595 assert(ref->type == QTYPE_QDICT);
2596
2597 v = qobject_output_visitor_new(&obj);
2598 visit_type_BlockdevOptions(v, NULL, &options, &local_err);
2599 if (local_err) {
2600 error_propagate(errp, local_err);
2601 goto fail;
2602 }
2603 visit_complete(v, &obj);
2604
Max Reitz7dc847e2018-02-24 16:40:29 +01002605 qdict = qobject_to(QDict, obj);
Kevin Wolfe1d74bc2018-01-10 15:52:33 +01002606 qdict_flatten(qdict);
2607
2608 /* bdrv_open_inherit() defaults to the values in bdrv_flags (for
2609 * compatibility with other callers) rather than what we want as the
2610 * real defaults. Apply the defaults here instead. */
2611 qdict_set_default_str(qdict, BDRV_OPT_CACHE_DIRECT, "off");
2612 qdict_set_default_str(qdict, BDRV_OPT_CACHE_NO_FLUSH, "off");
2613 qdict_set_default_str(qdict, BDRV_OPT_READ_ONLY, "off");
Kevin Wolfe35bdc12018-10-05 18:57:40 +02002614 qdict_set_default_str(qdict, BDRV_OPT_AUTO_READ_ONLY, "off");
2615
Kevin Wolfe1d74bc2018-01-10 15:52:33 +01002616 }
2617
2618 bs = bdrv_open_inherit(NULL, reference, qdict, 0, NULL, NULL, errp);
2619 obj = NULL;
2620
2621fail:
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002622 qobject_unref(obj);
Kevin Wolfe1d74bc2018-01-10 15:52:33 +01002623 visit_free(v);
2624 return bs;
2625}
2626
Max Reitz66836182016-05-17 16:41:27 +02002627static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
2628 int flags,
2629 QDict *snapshot_options,
2630 Error **errp)
Kevin Wolfb9988752014-04-03 12:09:34 +02002631{
2632 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002633 char *tmp_filename = g_malloc0(PATH_MAX + 1);
Kevin Wolfb9988752014-04-03 12:09:34 +02002634 int64_t total_size;
Chunyan Liu83d05212014-06-05 17:20:51 +08002635 QemuOpts *opts = NULL;
Eric Blakeff6ed712017-04-27 16:58:18 -05002636 BlockDriverState *bs_snapshot = NULL;
Kevin Wolfb2c28322017-02-20 12:46:42 +01002637 Error *local_err = NULL;
Kevin Wolfb9988752014-04-03 12:09:34 +02002638 int ret;
2639
2640 /* if snapshot, we create a temporary backing file and open it
2641 instead of opening 'filename' directly */
2642
2643 /* Get the required size from the image */
Kevin Wolff1877432014-04-04 17:07:19 +02002644 total_size = bdrv_getlength(bs);
2645 if (total_size < 0) {
2646 error_setg_errno(errp, -total_size, "Could not get image size");
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002647 goto out;
Kevin Wolff1877432014-04-04 17:07:19 +02002648 }
Kevin Wolfb9988752014-04-03 12:09:34 +02002649
2650 /* Create the temporary image */
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002651 ret = get_tmp_filename(tmp_filename, PATH_MAX + 1);
Kevin Wolfb9988752014-04-03 12:09:34 +02002652 if (ret < 0) {
2653 error_setg_errno(errp, -ret, "Could not get temporary filename");
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002654 goto out;
Kevin Wolfb9988752014-04-03 12:09:34 +02002655 }
2656
Max Reitzef810432014-12-02 18:32:42 +01002657 opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0,
Chunyan Liuc282e1f2014-06-05 17:21:11 +08002658 &error_abort);
Markus Armbruster39101f22015-02-12 16:46:36 +01002659 qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort);
Markus Armbrustere43bfd92015-12-18 16:35:15 +01002660 ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp);
Chunyan Liu83d05212014-06-05 17:20:51 +08002661 qemu_opts_del(opts);
Kevin Wolfb9988752014-04-03 12:09:34 +02002662 if (ret < 0) {
Markus Armbrustere43bfd92015-12-18 16:35:15 +01002663 error_prepend(errp, "Could not create temporary overlay '%s': ",
2664 tmp_filename);
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002665 goto out;
Kevin Wolfb9988752014-04-03 12:09:34 +02002666 }
2667
Kevin Wolf73176be2016-03-07 13:02:15 +01002668 /* Prepare options QDict for the temporary file */
Eric Blake46f5ac22017-04-27 16:58:17 -05002669 qdict_put_str(snapshot_options, "file.driver", "file");
2670 qdict_put_str(snapshot_options, "file.filename", tmp_filename);
2671 qdict_put_str(snapshot_options, "driver", "qcow2");
Kevin Wolfb9988752014-04-03 12:09:34 +02002672
Max Reitz5b363932016-05-17 16:41:31 +02002673 bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp);
Kevin Wolf73176be2016-03-07 13:02:15 +01002674 snapshot_options = NULL;
Max Reitz5b363932016-05-17 16:41:31 +02002675 if (!bs_snapshot) {
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002676 goto out;
Kevin Wolfb9988752014-04-03 12:09:34 +02002677 }
2678
Eric Blakeff6ed712017-04-27 16:58:18 -05002679 /* bdrv_append() consumes a strong reference to bs_snapshot
2680 * (i.e. it will call bdrv_unref() on it) even on error, so in
2681 * order to be able to return one, we have to increase
2682 * bs_snapshot's refcount here */
Max Reitz66836182016-05-17 16:41:27 +02002683 bdrv_ref(bs_snapshot);
Kevin Wolfb2c28322017-02-20 12:46:42 +01002684 bdrv_append(bs_snapshot, bs, &local_err);
2685 if (local_err) {
2686 error_propagate(errp, local_err);
Eric Blakeff6ed712017-04-27 16:58:18 -05002687 bs_snapshot = NULL;
Kevin Wolfb2c28322017-02-20 12:46:42 +01002688 goto out;
2689 }
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002690
2691out:
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002692 qobject_unref(snapshot_options);
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002693 g_free(tmp_filename);
Eric Blakeff6ed712017-04-27 16:58:18 -05002694 return bs_snapshot;
Kevin Wolfb9988752014-04-03 12:09:34 +02002695}
2696
Max Reitzda557aa2013-12-20 19:28:11 +01002697/*
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002698 * Opens a disk image (raw, qcow2, vmdk, ...)
Kevin Wolfde9c0ce2013-03-15 10:35:02 +01002699 *
2700 * options is a QDict of options to pass to the block drivers, or NULL for an
2701 * empty set of options. The reference to the QDict belongs to the block layer
2702 * after the call (even on failure), so if the caller intends to reuse the
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002703 * dictionary, it needs to use qobject_ref() before calling bdrv_open.
Max Reitzf67503e2014-02-18 18:33:05 +01002704 *
2705 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2706 * If it is not NULL, the referenced BDS will be reused.
Max Reitzddf56362014-02-18 18:33:06 +01002707 *
2708 * The reference parameter may be used to specify an existing block device which
2709 * should be opened. If specified, neither options nor a filename may be given,
2710 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002711 */
Max Reitz5b363932016-05-17 16:41:31 +02002712static BlockDriverState *bdrv_open_inherit(const char *filename,
2713 const char *reference,
2714 QDict *options, int flags,
2715 BlockDriverState *parent,
2716 const BdrvChildRole *child_role,
2717 Error **errp)
bellardea2384d2004-08-01 21:59:26 +00002718{
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002719 int ret;
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002720 BlockBackend *file = NULL;
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02002721 BlockDriverState *bs;
Max Reitzce343772015-08-26 19:47:50 +02002722 BlockDriver *drv = NULL;
Alberto Garcia2f624b82018-06-29 14:37:00 +03002723 BdrvChild *child;
Kevin Wolf74fe54f2013-07-09 11:09:02 +02002724 const char *drvname;
Alberto Garcia3e8c2e52015-10-26 14:27:15 +02002725 const char *backing;
Max Reitz34b5d2c2013-09-05 14:45:29 +02002726 Error *local_err = NULL;
Kevin Wolf73176be2016-03-07 13:02:15 +01002727 QDict *snapshot_options = NULL;
Kevin Wolfb1e6fc02014-05-06 12:11:42 +02002728 int snapshot_flags = 0;
bellard712e7872005-04-28 21:09:32 +00002729
Kevin Wolff3930ed2015-04-08 13:43:47 +02002730 assert(!child_role || !flags);
2731 assert(!child_role == !parent);
Max Reitzf67503e2014-02-18 18:33:05 +01002732
Max Reitzddf56362014-02-18 18:33:06 +01002733 if (reference) {
2734 bool options_non_empty = options ? qdict_size(options) : false;
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002735 qobject_unref(options);
Max Reitzddf56362014-02-18 18:33:06 +01002736
Max Reitzddf56362014-02-18 18:33:06 +01002737 if (filename || options_non_empty) {
2738 error_setg(errp, "Cannot reference an existing block device with "
2739 "additional options or a new filename");
Max Reitz5b363932016-05-17 16:41:31 +02002740 return NULL;
Max Reitzddf56362014-02-18 18:33:06 +01002741 }
2742
2743 bs = bdrv_lookup_bs(reference, reference, errp);
2744 if (!bs) {
Max Reitz5b363932016-05-17 16:41:31 +02002745 return NULL;
Max Reitzddf56362014-02-18 18:33:06 +01002746 }
Kevin Wolf76b22322016-04-04 17:11:13 +02002747
Max Reitzddf56362014-02-18 18:33:06 +01002748 bdrv_ref(bs);
Max Reitz5b363932016-05-17 16:41:31 +02002749 return bs;
Max Reitzddf56362014-02-18 18:33:06 +01002750 }
2751
Max Reitz5b363932016-05-17 16:41:31 +02002752 bs = bdrv_new();
Max Reitzf67503e2014-02-18 18:33:05 +01002753
Kevin Wolfde9c0ce2013-03-15 10:35:02 +01002754 /* NULL means an empty set of options */
2755 if (options == NULL) {
2756 options = qdict_new();
2757 }
2758
Kevin Wolf145f5982015-05-08 16:15:03 +02002759 /* json: syntax counts as explicit options, as if in the QDict */
Kevin Wolfde3b53f2015-10-29 15:24:41 +01002760 parse_json_protocol(options, &filename, &local_err);
2761 if (local_err) {
Kevin Wolfde3b53f2015-10-29 15:24:41 +01002762 goto fail;
2763 }
2764
Kevin Wolf145f5982015-05-08 16:15:03 +02002765 bs->explicit_options = qdict_clone_shallow(options);
2766
Kevin Wolff3930ed2015-04-08 13:43:47 +02002767 if (child_role) {
Kevin Wolfbddcec32015-04-09 18:47:50 +02002768 bs->inherits_from = parent;
Kevin Wolf8e2160e2015-04-29 17:29:39 +02002769 child_role->inherit_options(&flags, options,
2770 parent->open_flags, parent->options);
Kevin Wolff3930ed2015-04-08 13:43:47 +02002771 }
2772
Kevin Wolfde3b53f2015-10-29 15:24:41 +01002773 ret = bdrv_fill_options(&options, filename, &flags, &local_err);
Kevin Wolf462f5bc2014-05-26 11:39:55 +02002774 if (local_err) {
2775 goto fail;
2776 }
2777
Markus Armbruster129c7d12017-03-30 19:43:12 +02002778 /*
2779 * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2780 * Caution: getting a boolean member of @options requires care.
2781 * When @options come from -blockdev or blockdev_add, members are
2782 * typed according to the QAPI schema, but when they come from
2783 * -drive, they're all QString.
2784 */
Alberto Garciaf87a0e22016-09-15 17:53:02 +03002785 if (g_strcmp0(qdict_get_try_str(options, BDRV_OPT_READ_ONLY), "on") &&
2786 !qdict_get_try_bool(options, BDRV_OPT_READ_ONLY, false)) {
2787 flags |= (BDRV_O_RDWR | BDRV_O_ALLOW_RDWR);
2788 } else {
2789 flags &= ~BDRV_O_RDWR;
Alberto Garcia14499ea2016-09-15 17:53:00 +03002790 }
2791
2792 if (flags & BDRV_O_SNAPSHOT) {
2793 snapshot_options = qdict_new();
2794 bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options,
2795 flags, options);
Alberto Garciaf87a0e22016-09-15 17:53:02 +03002796 /* Let bdrv_backing_options() override "read-only" */
2797 qdict_del(options, BDRV_OPT_READ_ONLY);
Alberto Garcia14499ea2016-09-15 17:53:00 +03002798 bdrv_backing_options(&flags, options, flags, options);
2799 }
2800
Kevin Wolf62392eb2015-04-24 16:38:02 +02002801 bs->open_flags = flags;
2802 bs->options = options;
2803 options = qdict_clone_shallow(options);
2804
Kevin Wolf76c591b2014-06-04 14:19:44 +02002805 /* Find the right image format driver */
Markus Armbruster129c7d12017-03-30 19:43:12 +02002806 /* See cautionary note on accessing @options above */
Kevin Wolf76c591b2014-06-04 14:19:44 +02002807 drvname = qdict_get_try_str(options, "driver");
2808 if (drvname) {
2809 drv = bdrv_find_format(drvname);
Kevin Wolf76c591b2014-06-04 14:19:44 +02002810 if (!drv) {
2811 error_setg(errp, "Unknown driver: '%s'", drvname);
Kevin Wolf76c591b2014-06-04 14:19:44 +02002812 goto fail;
2813 }
2814 }
2815
2816 assert(drvname || !(flags & BDRV_O_PROTOCOL));
Kevin Wolf76c591b2014-06-04 14:19:44 +02002817
Markus Armbruster129c7d12017-03-30 19:43:12 +02002818 /* See cautionary note on accessing @options above */
Alberto Garcia3e8c2e52015-10-26 14:27:15 +02002819 backing = qdict_get_try_str(options, "backing");
Max Reitze59a0cf2018-02-24 16:40:32 +01002820 if (qobject_to(QNull, qdict_get(options, "backing")) != NULL ||
2821 (backing && *backing == '\0'))
2822 {
Max Reitz4f7be282018-02-24 16:40:33 +01002823 if (backing) {
2824 warn_report("Use of \"backing\": \"\" is deprecated; "
2825 "use \"backing\": null instead");
2826 }
Alberto Garcia3e8c2e52015-10-26 14:27:15 +02002827 flags |= BDRV_O_NO_BACKING;
2828 qdict_del(options, "backing");
2829 }
2830
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002831 /* Open image file without format layer. This BlockBackend is only used for
Kevin Wolf4e4bf5c2016-12-16 18:52:37 +01002832 * probing, the block drivers will do their own bdrv_open_child() for the
2833 * same BDS, which is why we put the node name back into options. */
Kevin Wolff4788ad2014-06-03 16:44:19 +02002834 if ((flags & BDRV_O_PROTOCOL) == 0) {
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002835 BlockDriverState *file_bs;
2836
2837 file_bs = bdrv_open_child_bs(filename, options, "file", bs,
2838 &child_file, true, &local_err);
Kevin Wolf1fdd6932015-06-15 14:11:51 +02002839 if (local_err) {
Max Reitz5469a2a2014-02-18 18:33:10 +01002840 goto fail;
2841 }
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002842 if (file_bs != NULL) {
Kevin Wolfdacaa162017-11-20 14:59:13 +01002843 /* Not requesting BLK_PERM_CONSISTENT_READ because we're only
2844 * looking at the header to guess the image format. This works even
2845 * in cases where a guest would not see a consistent state. */
2846 file = blk_new(0, BLK_PERM_ALL);
Kevin Wolfd7086422017-01-13 19:02:32 +01002847 blk_insert_bs(file, file_bs, &local_err);
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002848 bdrv_unref(file_bs);
Kevin Wolfd7086422017-01-13 19:02:32 +01002849 if (local_err) {
2850 goto fail;
2851 }
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002852
Eric Blake46f5ac22017-04-27 16:58:17 -05002853 qdict_put_str(options, "file", bdrv_get_node_name(file_bs));
Kevin Wolf4e4bf5c2016-12-16 18:52:37 +01002854 }
Max Reitz5469a2a2014-02-18 18:33:10 +01002855 }
2856
Kevin Wolf76c591b2014-06-04 14:19:44 +02002857 /* Image format probing */
Kevin Wolf38f3ef52014-11-20 16:27:12 +01002858 bs->probed = !drv;
Kevin Wolf76c591b2014-06-04 14:19:44 +02002859 if (!drv && file) {
Kevin Wolfcf2ab8f2016-06-20 18:24:02 +02002860 ret = find_image_format(file, filename, &drv, &local_err);
Kevin Wolf17b005f2014-05-27 10:50:29 +02002861 if (ret < 0) {
Kevin Wolf8bfea152014-04-11 19:16:36 +02002862 goto fail;
Max Reitz2a05cbe2013-12-20 19:28:10 +01002863 }
Kevin Wolf62392eb2015-04-24 16:38:02 +02002864 /*
2865 * This option update would logically belong in bdrv_fill_options(),
2866 * but we first need to open bs->file for the probing to work, while
2867 * opening bs->file already requires the (mostly) final set of options
2868 * so that cache mode etc. can be inherited.
2869 *
2870 * Adding the driver later is somewhat ugly, but it's not an option
2871 * that would ever be inherited, so it's correct. We just need to make
2872 * sure to update both bs->options (which has the full effective
2873 * options for bs) and options (which has file.* already removed).
2874 */
Eric Blake46f5ac22017-04-27 16:58:17 -05002875 qdict_put_str(bs->options, "driver", drv->format_name);
2876 qdict_put_str(options, "driver", drv->format_name);
Kevin Wolf76c591b2014-06-04 14:19:44 +02002877 } else if (!drv) {
Kevin Wolf17b005f2014-05-27 10:50:29 +02002878 error_setg(errp, "Must specify either driver or file");
Kevin Wolf8bfea152014-04-11 19:16:36 +02002879 goto fail;
Kevin Wolff500a6d2012-11-12 17:35:27 +01002880 }
2881
Max Reitz53a29512015-03-19 14:53:16 -04002882 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
2883 assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open);
2884 /* file must be NULL if a protocol BDS is about to be created
2885 * (the inverse results in an error message from bdrv_open_common()) */
2886 assert(!(flags & BDRV_O_PROTOCOL) || !file);
2887
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002888 /* Open the image */
Kevin Wolf82dc8b42016-01-11 19:07:50 +01002889 ret = bdrv_open_common(bs, file, options, &local_err);
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002890 if (ret < 0) {
Kevin Wolf8bfea152014-04-11 19:16:36 +02002891 goto fail;
Christoph Hellwig69873072010-01-20 18:13:25 +01002892 }
2893
Kevin Wolf4e4bf5c2016-12-16 18:52:37 +01002894 if (file) {
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002895 blk_unref(file);
Kevin Wolff500a6d2012-11-12 17:35:27 +01002896 file = NULL;
2897 }
2898
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002899 /* If there is a backing file, use it */
Paolo Bonzini9156df12012-10-18 16:49:17 +02002900 if ((flags & BDRV_O_NO_BACKING) == 0) {
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002901 ret = bdrv_open_backing_file(bs, options, "backing", &local_err);
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002902 if (ret < 0) {
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002903 goto close_and_fail;
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002904 }
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002905 }
2906
Alberto Garcia50196d72018-09-06 12:37:03 +03002907 /* Remove all children options and references
2908 * from bs->options and bs->explicit_options */
Alberto Garcia2f624b82018-06-29 14:37:00 +03002909 QLIST_FOREACH(child, &bs->children, next) {
2910 char *child_key_dot;
2911 child_key_dot = g_strdup_printf("%s.", child->name);
2912 qdict_extract_subqdict(bs->explicit_options, NULL, child_key_dot);
2913 qdict_extract_subqdict(bs->options, NULL, child_key_dot);
Alberto Garcia50196d72018-09-06 12:37:03 +03002914 qdict_del(bs->explicit_options, child->name);
2915 qdict_del(bs->options, child->name);
Alberto Garcia2f624b82018-06-29 14:37:00 +03002916 g_free(child_key_dot);
2917 }
2918
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002919 /* Check if any unknown options were used */
Paolo Bonzini7ad27572017-01-04 15:59:14 +01002920 if (qdict_size(options) != 0) {
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002921 const QDictEntry *entry = qdict_first(options);
Max Reitz5acd9d82014-02-18 18:33:11 +01002922 if (flags & BDRV_O_PROTOCOL) {
2923 error_setg(errp, "Block protocol '%s' doesn't support the option "
2924 "'%s'", drv->format_name, entry->key);
2925 } else {
Max Reitzd0e46a52016-03-16 19:54:34 +01002926 error_setg(errp,
2927 "Block format '%s' does not support the option '%s'",
2928 drv->format_name, entry->key);
Max Reitz5acd9d82014-02-18 18:33:11 +01002929 }
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002930
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002931 goto close_and_fail;
2932 }
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002933
Daniel P. Berrangec01c2142017-06-23 17:24:16 +01002934 bdrv_parent_cb_change_media(bs, true);
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002935
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002936 qobject_unref(options);
Alberto Garcia8961be32018-09-06 17:25:41 +03002937 options = NULL;
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02002938
2939 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
2940 * temporary snapshot afterwards. */
2941 if (snapshot_flags) {
Max Reitz66836182016-05-17 16:41:27 +02002942 BlockDriverState *snapshot_bs;
2943 snapshot_bs = bdrv_append_temp_snapshot(bs, snapshot_flags,
2944 snapshot_options, &local_err);
Kevin Wolf73176be2016-03-07 13:02:15 +01002945 snapshot_options = NULL;
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02002946 if (local_err) {
2947 goto close_and_fail;
2948 }
Max Reitz5b363932016-05-17 16:41:31 +02002949 /* We are not going to return bs but the overlay on top of it
2950 * (snapshot_bs); thus, we have to drop the strong reference to bs
2951 * (which we obtained by calling bdrv_new()). bs will not be deleted,
2952 * though, because the overlay still has a reference to it. */
2953 bdrv_unref(bs);
2954 bs = snapshot_bs;
Max Reitz66836182016-05-17 16:41:27 +02002955 }
2956
Max Reitz5b363932016-05-17 16:41:31 +02002957 return bs;
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002958
Kevin Wolf8bfea152014-04-11 19:16:36 +02002959fail:
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002960 blk_unref(file);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002961 qobject_unref(snapshot_options);
2962 qobject_unref(bs->explicit_options);
2963 qobject_unref(bs->options);
2964 qobject_unref(options);
Kevin Wolfde9c0ce2013-03-15 10:35:02 +01002965 bs->options = NULL;
Manos Pitsidianakis998cbd62017-07-14 17:35:47 +03002966 bs->explicit_options = NULL;
Max Reitz5b363932016-05-17 16:41:31 +02002967 bdrv_unref(bs);
Eduardo Habkost621ff942016-06-13 18:57:56 -03002968 error_propagate(errp, local_err);
Max Reitz5b363932016-05-17 16:41:31 +02002969 return NULL;
Kevin Wolfde9c0ce2013-03-15 10:35:02 +01002970
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002971close_and_fail:
Max Reitz5b363932016-05-17 16:41:31 +02002972 bdrv_unref(bs);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002973 qobject_unref(snapshot_options);
2974 qobject_unref(options);
Eduardo Habkost621ff942016-06-13 18:57:56 -03002975 error_propagate(errp, local_err);
Max Reitz5b363932016-05-17 16:41:31 +02002976 return NULL;
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002977}
2978
Max Reitz5b363932016-05-17 16:41:31 +02002979BlockDriverState *bdrv_open(const char *filename, const char *reference,
2980 QDict *options, int flags, Error **errp)
Kevin Wolff3930ed2015-04-08 13:43:47 +02002981{
Max Reitz5b363932016-05-17 16:41:31 +02002982 return bdrv_open_inherit(filename, reference, options, flags, NULL,
Max Reitzce343772015-08-26 19:47:50 +02002983 NULL, errp);
Kevin Wolff3930ed2015-04-08 13:43:47 +02002984}
2985
Jeff Codye971aa12012-09-20 15:13:19 -04002986/*
Alberto Garciacb828c32019-03-12 18:48:47 +02002987 * Returns true if @child can be reached recursively from @bs
2988 */
2989static bool bdrv_recurse_has_child(BlockDriverState *bs,
2990 BlockDriverState *child)
2991{
2992 BdrvChild *c;
2993
2994 if (bs == child) {
2995 return true;
2996 }
2997
2998 QLIST_FOREACH(c, &bs->children, next) {
2999 if (bdrv_recurse_has_child(c->bs, child)) {
3000 return true;
3001 }
3002 }
3003
3004 return false;
3005}
3006
3007/*
Jeff Codye971aa12012-09-20 15:13:19 -04003008 * Adds a BlockDriverState to a simple queue for an atomic, transactional
3009 * reopen of multiple devices.
3010 *
3011 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
3012 * already performed, or alternatively may be NULL a new BlockReopenQueue will
3013 * be created and initialized. This newly created BlockReopenQueue should be
3014 * passed back in for subsequent calls that are intended to be of the same
3015 * atomic 'set'.
3016 *
3017 * bs is the BlockDriverState to add to the reopen queue.
3018 *
Kevin Wolf4d2cb092015-04-10 17:50:50 +02003019 * options contains the changed options for the associated bs
3020 * (the BlockReopenQueue takes ownership)
3021 *
Jeff Codye971aa12012-09-20 15:13:19 -04003022 * flags contains the open flags for the associated bs
3023 *
3024 * returns a pointer to bs_queue, which is either the newly allocated
3025 * bs_queue, or the existing bs_queue being used.
3026 *
Kevin Wolf1a63a902017-12-06 20:24:44 +01003027 * bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
Jeff Codye971aa12012-09-20 15:13:19 -04003028 */
Kevin Wolf28518102015-05-08 17:07:31 +02003029static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
3030 BlockDriverState *bs,
3031 QDict *options,
Kevin Wolf28518102015-05-08 17:07:31 +02003032 const BdrvChildRole *role,
3033 QDict *parent_options,
Alberto Garcia077e8e22019-03-12 18:48:44 +02003034 int parent_flags,
3035 bool keep_old_opts)
Jeff Codye971aa12012-09-20 15:13:19 -04003036{
3037 assert(bs != NULL);
3038
3039 BlockReopenQueueEntry *bs_entry;
Kevin Wolf67251a32015-04-09 18:54:04 +02003040 BdrvChild *child;
Alberto Garcia9aa09dd2018-11-12 16:00:45 +02003041 QDict *old_options, *explicit_options, *options_copy;
3042 int flags;
3043 QemuOpts *opts;
Kevin Wolf67251a32015-04-09 18:54:04 +02003044
Kevin Wolf1a63a902017-12-06 20:24:44 +01003045 /* Make sure that the caller remembered to use a drained section. This is
3046 * important to avoid graph changes between the recursive queuing here and
3047 * bdrv_reopen_multiple(). */
3048 assert(bs->quiesce_counter > 0);
3049
Jeff Codye971aa12012-09-20 15:13:19 -04003050 if (bs_queue == NULL) {
3051 bs_queue = g_new0(BlockReopenQueue, 1);
3052 QSIMPLEQ_INIT(bs_queue);
3053 }
3054
Kevin Wolf4d2cb092015-04-10 17:50:50 +02003055 if (!options) {
3056 options = qdict_new();
3057 }
3058
Alberto Garcia5b7ba052016-09-15 17:53:03 +03003059 /* Check if this BlockDriverState is already in the queue */
3060 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
3061 if (bs == bs_entry->state.bs) {
3062 break;
3063 }
3064 }
3065
Kevin Wolf28518102015-05-08 17:07:31 +02003066 /*
3067 * Precedence of options:
3068 * 1. Explicitly passed in options (highest)
Alberto Garcia9aa09dd2018-11-12 16:00:45 +02003069 * 2. Retained from explicitly set options of bs
3070 * 3. Inherited from parent node
3071 * 4. Retained from effective options of bs
Kevin Wolf28518102015-05-08 17:07:31 +02003072 */
3073
Kevin Wolf145f5982015-05-08 16:15:03 +02003074 /* Old explicitly set values (don't overwrite by inherited value) */
Alberto Garcia077e8e22019-03-12 18:48:44 +02003075 if (bs_entry || keep_old_opts) {
3076 old_options = qdict_clone_shallow(bs_entry ?
3077 bs_entry->state.explicit_options :
3078 bs->explicit_options);
3079 bdrv_join_options(bs, options, old_options);
3080 qobject_unref(old_options);
Alberto Garcia5b7ba052016-09-15 17:53:03 +03003081 }
Kevin Wolf145f5982015-05-08 16:15:03 +02003082
3083 explicit_options = qdict_clone_shallow(options);
3084
Kevin Wolf28518102015-05-08 17:07:31 +02003085 /* Inherit from parent node */
3086 if (parent_options) {
Alberto Garcia9aa09dd2018-11-12 16:00:45 +02003087 flags = 0;
Kevin Wolf8e2160e2015-04-29 17:29:39 +02003088 role->inherit_options(&flags, options, parent_flags, parent_options);
Alberto Garcia9aa09dd2018-11-12 16:00:45 +02003089 } else {
3090 flags = bdrv_get_flags(bs);
Kevin Wolf28518102015-05-08 17:07:31 +02003091 }
3092
Alberto Garcia077e8e22019-03-12 18:48:44 +02003093 if (keep_old_opts) {
3094 /* Old values are used for options that aren't set yet */
3095 old_options = qdict_clone_shallow(bs->options);
3096 bdrv_join_options(bs, options, old_options);
3097 qobject_unref(old_options);
3098 }
Kevin Wolf4d2cb092015-04-10 17:50:50 +02003099
Alberto Garcia9aa09dd2018-11-12 16:00:45 +02003100 /* We have the final set of options so let's update the flags */
3101 options_copy = qdict_clone_shallow(options);
3102 opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
3103 qemu_opts_absorb_qdict(opts, options_copy, NULL);
3104 update_flags_from_options(&flags, opts);
3105 qemu_opts_del(opts);
3106 qobject_unref(options_copy);
3107
Kevin Wolffd452022017-08-03 17:02:59 +02003108 /* bdrv_open_inherit() sets and clears some additional flags internally */
Kevin Wolff1f25a22014-04-25 19:04:55 +02003109 flags &= ~BDRV_O_PROTOCOL;
Kevin Wolffd452022017-08-03 17:02:59 +02003110 if (flags & BDRV_O_RDWR) {
3111 flags |= BDRV_O_ALLOW_RDWR;
3112 }
Kevin Wolff1f25a22014-04-25 19:04:55 +02003113
Kevin Wolf1857c972017-09-14 14:53:46 +02003114 if (!bs_entry) {
3115 bs_entry = g_new0(BlockReopenQueueEntry, 1);
3116 QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry);
3117 } else {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02003118 qobject_unref(bs_entry->state.options);
3119 qobject_unref(bs_entry->state.explicit_options);
Kevin Wolf1857c972017-09-14 14:53:46 +02003120 }
3121
3122 bs_entry->state.bs = bs;
3123 bs_entry->state.options = options;
3124 bs_entry->state.explicit_options = explicit_options;
3125 bs_entry->state.flags = flags;
3126
Kevin Wolf30450252017-07-03 17:07:35 +02003127 /* This needs to be overwritten in bdrv_reopen_prepare() */
3128 bs_entry->state.perm = UINT64_MAX;
3129 bs_entry->state.shared_perm = 0;
3130
Alberto Garcia85466322019-03-12 18:48:45 +02003131 /*
3132 * If keep_old_opts is false then it means that unspecified
3133 * options must be reset to their original value. We don't allow
3134 * resetting 'backing' but we need to know if the option is
3135 * missing in order to decide if we have to return an error.
3136 */
3137 if (!keep_old_opts) {
3138 bs_entry->state.backing_missing =
3139 !qdict_haskey(options, "backing") &&
3140 !qdict_haskey(options, "backing.driver");
3141 }
3142
Kevin Wolf67251a32015-04-09 18:54:04 +02003143 QLIST_FOREACH(child, &bs->children, next) {
Alberto Garcia85466322019-03-12 18:48:45 +02003144 QDict *new_child_options = NULL;
3145 bool child_keep_old = keep_old_opts;
Kevin Wolf67251a32015-04-09 18:54:04 +02003146
Kevin Wolf4c9dfe52015-05-08 15:14:15 +02003147 /* reopen can only change the options of block devices that were
3148 * implicitly created and inherited options. For other (referenced)
3149 * block devices, a syntax like "backing.foo" results in an error. */
Kevin Wolf67251a32015-04-09 18:54:04 +02003150 if (child->bs->inherits_from != bs) {
3151 continue;
3152 }
3153
Alberto Garcia85466322019-03-12 18:48:45 +02003154 /* Check if the options contain a child reference */
3155 if (qdict_haskey(options, child->name)) {
3156 const char *childref = qdict_get_try_str(options, child->name);
3157 /*
3158 * The current child must not be reopened if the child
3159 * reference is null or points to a different node.
3160 */
3161 if (g_strcmp0(childref, child->bs->node_name)) {
3162 continue;
3163 }
3164 /*
3165 * If the child reference points to the current child then
3166 * reopen it with its existing set of options (note that
3167 * it can still inherit new options from the parent).
3168 */
3169 child_keep_old = true;
3170 } else {
3171 /* Extract child options ("child-name.*") */
3172 char *child_key_dot = g_strdup_printf("%s.", child->name);
3173 qdict_extract_subqdict(explicit_options, NULL, child_key_dot);
3174 qdict_extract_subqdict(options, &new_child_options, child_key_dot);
3175 g_free(child_key_dot);
3176 }
Kevin Wolf4c9dfe52015-05-08 15:14:15 +02003177
Alberto Garcia9aa09dd2018-11-12 16:00:45 +02003178 bdrv_reopen_queue_child(bs_queue, child->bs, new_child_options,
Alberto Garcia85466322019-03-12 18:48:45 +02003179 child->role, options, flags, child_keep_old);
Jeff Codye971aa12012-09-20 15:13:19 -04003180 }
3181
Jeff Codye971aa12012-09-20 15:13:19 -04003182 return bs_queue;
3183}
3184
Kevin Wolf28518102015-05-08 17:07:31 +02003185BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
3186 BlockDriverState *bs,
Alberto Garcia077e8e22019-03-12 18:48:44 +02003187 QDict *options, bool keep_old_opts)
Kevin Wolf28518102015-05-08 17:07:31 +02003188{
Alberto Garcia077e8e22019-03-12 18:48:44 +02003189 return bdrv_reopen_queue_child(bs_queue, bs, options, NULL, NULL, 0,
3190 keep_old_opts);
Kevin Wolf28518102015-05-08 17:07:31 +02003191}
3192
Jeff Codye971aa12012-09-20 15:13:19 -04003193/*
3194 * Reopen multiple BlockDriverStates atomically & transactionally.
3195 *
3196 * The queue passed in (bs_queue) must have been built up previous
3197 * via bdrv_reopen_queue().
3198 *
3199 * Reopens all BDS specified in the queue, with the appropriate
3200 * flags. All devices are prepared for reopen, and failure of any
Stefan Weil50d6a8a2018-07-12 21:51:20 +02003201 * device will cause all device changes to be abandoned, and intermediate
Jeff Codye971aa12012-09-20 15:13:19 -04003202 * data cleaned up.
3203 *
3204 * If all devices prepare successfully, then the changes are committed
3205 * to all devices.
3206 *
Kevin Wolf1a63a902017-12-06 20:24:44 +01003207 * All affected nodes must be drained between bdrv_reopen_queue() and
3208 * bdrv_reopen_multiple().
Jeff Codye971aa12012-09-20 15:13:19 -04003209 */
Paolo Bonzini720150f2016-10-27 12:49:02 +02003210int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp)
Jeff Codye971aa12012-09-20 15:13:19 -04003211{
3212 int ret = -1;
3213 BlockReopenQueueEntry *bs_entry, *next;
Jeff Codye971aa12012-09-20 15:13:19 -04003214
3215 assert(bs_queue != NULL);
3216
Jeff Codye971aa12012-09-20 15:13:19 -04003217 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
Kevin Wolf1a63a902017-12-06 20:24:44 +01003218 assert(bs_entry->state.bs->quiesce_counter > 0);
Kevin Wolfa4615ab2019-03-05 16:51:13 +01003219 if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, errp)) {
Jeff Codye971aa12012-09-20 15:13:19 -04003220 goto cleanup;
3221 }
3222 bs_entry->prepared = true;
3223 }
3224
Kevin Wolf69b736e2019-03-05 17:18:22 +01003225 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
3226 BDRVReopenState *state = &bs_entry->state;
3227 ret = bdrv_check_perm(state->bs, bs_queue, state->perm,
3228 state->shared_perm, NULL, errp);
3229 if (ret < 0) {
3230 goto cleanup_perm;
3231 }
Alberto Garciacb828c32019-03-12 18:48:47 +02003232 /* Check if new_backing_bs would accept the new permissions */
3233 if (state->replace_backing_bs && state->new_backing_bs) {
3234 uint64_t nperm, nshared;
3235 bdrv_child_perm(state->bs, state->new_backing_bs,
3236 NULL, &child_backing, bs_queue,
3237 state->perm, state->shared_perm,
3238 &nperm, &nshared);
3239 ret = bdrv_check_update_perm(state->new_backing_bs, NULL,
3240 nperm, nshared, NULL, errp);
3241 if (ret < 0) {
3242 goto cleanup_perm;
3243 }
3244 }
Kevin Wolf69b736e2019-03-05 17:18:22 +01003245 bs_entry->perms_checked = true;
3246 }
3247
Jeff Codye971aa12012-09-20 15:13:19 -04003248 /* If we reach this point, we have success and just need to apply the
3249 * changes
3250 */
3251 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
3252 bdrv_reopen_commit(&bs_entry->state);
3253 }
3254
3255 ret = 0;
Kevin Wolf69b736e2019-03-05 17:18:22 +01003256cleanup_perm:
3257 QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
3258 BDRVReopenState *state = &bs_entry->state;
Jeff Codye971aa12012-09-20 15:13:19 -04003259
Kevin Wolf69b736e2019-03-05 17:18:22 +01003260 if (!bs_entry->perms_checked) {
3261 continue;
3262 }
3263
3264 if (ret == 0) {
3265 bdrv_set_perm(state->bs, state->perm, state->shared_perm);
3266 } else {
3267 bdrv_abort_perm_update(state->bs);
Alberto Garciacb828c32019-03-12 18:48:47 +02003268 if (state->replace_backing_bs && state->new_backing_bs) {
3269 bdrv_abort_perm_update(state->new_backing_bs);
3270 }
Kevin Wolf69b736e2019-03-05 17:18:22 +01003271 }
3272 }
Jeff Codye971aa12012-09-20 15:13:19 -04003273cleanup:
3274 QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
Alberto Garcia1bab38e2018-06-29 14:37:01 +03003275 if (ret) {
3276 if (bs_entry->prepared) {
3277 bdrv_reopen_abort(&bs_entry->state);
3278 }
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02003279 qobject_unref(bs_entry->state.explicit_options);
Alberto Garcia4c8350f2018-06-29 14:37:02 +03003280 qobject_unref(bs_entry->state.options);
Jeff Codye971aa12012-09-20 15:13:19 -04003281 }
Alberto Garciacb828c32019-03-12 18:48:47 +02003282 if (bs_entry->state.new_backing_bs) {
3283 bdrv_unref(bs_entry->state.new_backing_bs);
3284 }
Jeff Codye971aa12012-09-20 15:13:19 -04003285 g_free(bs_entry);
3286 }
3287 g_free(bs_queue);
Alberto Garcia40840e42016-10-28 10:08:03 +03003288
Jeff Codye971aa12012-09-20 15:13:19 -04003289 return ret;
3290}
3291
Alberto Garcia6e1000a2018-11-12 16:00:33 +02003292int bdrv_reopen_set_read_only(BlockDriverState *bs, bool read_only,
3293 Error **errp)
3294{
3295 int ret;
3296 BlockReopenQueue *queue;
3297 QDict *opts = qdict_new();
3298
3299 qdict_put_bool(opts, BDRV_OPT_READ_ONLY, read_only);
3300
3301 bdrv_subtree_drained_begin(bs);
Alberto Garcia077e8e22019-03-12 18:48:44 +02003302 queue = bdrv_reopen_queue(NULL, bs, opts, true);
Alberto Garcia6e1000a2018-11-12 16:00:33 +02003303 ret = bdrv_reopen_multiple(bdrv_get_aio_context(bs), queue, errp);
3304 bdrv_subtree_drained_end(bs);
3305
3306 return ret;
3307}
3308
Kevin Wolf30450252017-07-03 17:07:35 +02003309static BlockReopenQueueEntry *find_parent_in_reopen_queue(BlockReopenQueue *q,
3310 BdrvChild *c)
3311{
3312 BlockReopenQueueEntry *entry;
3313
3314 QSIMPLEQ_FOREACH(entry, q, entry) {
3315 BlockDriverState *bs = entry->state.bs;
3316 BdrvChild *child;
3317
3318 QLIST_FOREACH(child, &bs->children, next) {
3319 if (child == c) {
3320 return entry;
3321 }
3322 }
3323 }
3324
3325 return NULL;
3326}
3327
3328static void bdrv_reopen_perm(BlockReopenQueue *q, BlockDriverState *bs,
3329 uint64_t *perm, uint64_t *shared)
3330{
3331 BdrvChild *c;
3332 BlockReopenQueueEntry *parent;
3333 uint64_t cumulative_perms = 0;
3334 uint64_t cumulative_shared_perms = BLK_PERM_ALL;
3335
3336 QLIST_FOREACH(c, &bs->parents, next_parent) {
3337 parent = find_parent_in_reopen_queue(q, c);
3338 if (!parent) {
3339 cumulative_perms |= c->perm;
3340 cumulative_shared_perms &= c->shared_perm;
3341 } else {
3342 uint64_t nperm, nshared;
3343
3344 bdrv_child_perm(parent->state.bs, bs, c, c->role, q,
3345 parent->state.perm, parent->state.shared_perm,
3346 &nperm, &nshared);
3347
3348 cumulative_perms |= nperm;
3349 cumulative_shared_perms &= nshared;
3350 }
3351 }
3352 *perm = cumulative_perms;
3353 *shared = cumulative_shared_perms;
3354}
Jeff Codye971aa12012-09-20 15:13:19 -04003355
3356/*
Alberto Garciacb828c32019-03-12 18:48:47 +02003357 * Take a BDRVReopenState and check if the value of 'backing' in the
3358 * reopen_state->options QDict is valid or not.
3359 *
3360 * If 'backing' is missing from the QDict then return 0.
3361 *
3362 * If 'backing' contains the node name of the backing file of
3363 * reopen_state->bs then return 0.
3364 *
3365 * If 'backing' contains a different node name (or is null) then check
3366 * whether the current backing file can be replaced with the new one.
3367 * If that's the case then reopen_state->replace_backing_bs is set to
3368 * true and reopen_state->new_backing_bs contains a pointer to the new
3369 * backing BlockDriverState (or NULL).
3370 *
3371 * Return 0 on success, otherwise return < 0 and set @errp.
3372 */
3373static int bdrv_reopen_parse_backing(BDRVReopenState *reopen_state,
3374 Error **errp)
3375{
3376 BlockDriverState *bs = reopen_state->bs;
3377 BlockDriverState *overlay_bs, *new_backing_bs;
3378 QObject *value;
3379 const char *str;
3380
3381 value = qdict_get(reopen_state->options, "backing");
3382 if (value == NULL) {
3383 return 0;
3384 }
3385
3386 switch (qobject_type(value)) {
3387 case QTYPE_QNULL:
3388 new_backing_bs = NULL;
3389 break;
3390 case QTYPE_QSTRING:
3391 str = qobject_get_try_str(value);
3392 new_backing_bs = bdrv_lookup_bs(NULL, str, errp);
3393 if (new_backing_bs == NULL) {
3394 return -EINVAL;
3395 } else if (bdrv_recurse_has_child(new_backing_bs, bs)) {
3396 error_setg(errp, "Making '%s' a backing file of '%s' "
3397 "would create a cycle", str, bs->node_name);
3398 return -EINVAL;
3399 }
3400 break;
3401 default:
3402 /* 'backing' does not allow any other data type */
3403 g_assert_not_reached();
3404 }
3405
3406 /*
3407 * TODO: before removing the x- prefix from x-blockdev-reopen we
3408 * should move the new backing file into the right AioContext
3409 * instead of returning an error.
3410 */
3411 if (new_backing_bs) {
3412 if (bdrv_get_aio_context(new_backing_bs) != bdrv_get_aio_context(bs)) {
3413 error_setg(errp, "Cannot use a new backing file "
3414 "with a different AioContext");
3415 return -EINVAL;
3416 }
3417 }
3418
3419 /*
3420 * Find the "actual" backing file by skipping all links that point
3421 * to an implicit node, if any (e.g. a commit filter node).
3422 */
3423 overlay_bs = bs;
3424 while (backing_bs(overlay_bs) && backing_bs(overlay_bs)->implicit) {
3425 overlay_bs = backing_bs(overlay_bs);
3426 }
3427
3428 /* If we want to replace the backing file we need some extra checks */
3429 if (new_backing_bs != backing_bs(overlay_bs)) {
3430 /* Check for implicit nodes between bs and its backing file */
3431 if (bs != overlay_bs) {
3432 error_setg(errp, "Cannot change backing link if '%s' has "
3433 "an implicit backing file", bs->node_name);
3434 return -EPERM;
3435 }
3436 /* Check if the backing link that we want to replace is frozen */
3437 if (bdrv_is_backing_chain_frozen(overlay_bs, backing_bs(overlay_bs),
3438 errp)) {
3439 return -EPERM;
3440 }
3441 reopen_state->replace_backing_bs = true;
3442 if (new_backing_bs) {
3443 bdrv_ref(new_backing_bs);
3444 reopen_state->new_backing_bs = new_backing_bs;
3445 }
3446 }
3447
3448 return 0;
3449}
3450
3451/*
Jeff Codye971aa12012-09-20 15:13:19 -04003452 * Prepares a BlockDriverState for reopen. All changes are staged in the
3453 * 'opaque' field of the BDRVReopenState, which is used and allocated by
3454 * the block driver layer .bdrv_reopen_prepare()
3455 *
3456 * bs is the BlockDriverState to reopen
3457 * flags are the new open flags
3458 * queue is the reopen queue
3459 *
3460 * Returns 0 on success, non-zero on error. On error errp will be set
3461 * as well.
3462 *
3463 * On failure, bdrv_reopen_abort() will be called to clean up any data.
3464 * It is the responsibility of the caller to then call the abort() or
3465 * commit() for any other BDS that have been left in a prepare() state
3466 *
3467 */
3468int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
3469 Error **errp)
3470{
3471 int ret = -1;
Alberto Garciae6d79c42018-11-12 16:00:47 +02003472 int old_flags;
Jeff Codye971aa12012-09-20 15:13:19 -04003473 Error *local_err = NULL;
3474 BlockDriver *drv;
Kevin Wolfccf9dc02015-05-08 17:24:56 +02003475 QemuOpts *opts;
Alberto Garcia4c8350f2018-06-29 14:37:02 +03003476 QDict *orig_reopen_opts;
Alberto Garcia593b3072018-09-06 12:37:08 +03003477 char *discard = NULL;
Jeff Cody3d8ce172017-04-07 16:55:30 -04003478 bool read_only;
Max Reitz9ad08c42018-11-16 17:45:24 +01003479 bool drv_prepared = false;
Jeff Codye971aa12012-09-20 15:13:19 -04003480
3481 assert(reopen_state != NULL);
3482 assert(reopen_state->bs->drv != NULL);
3483 drv = reopen_state->bs->drv;
3484
Alberto Garcia4c8350f2018-06-29 14:37:02 +03003485 /* This function and each driver's bdrv_reopen_prepare() remove
3486 * entries from reopen_state->options as they are processed, so
3487 * we need to make a copy of the original QDict. */
3488 orig_reopen_opts = qdict_clone_shallow(reopen_state->options);
3489
Kevin Wolfccf9dc02015-05-08 17:24:56 +02003490 /* Process generic block layer options */
3491 opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
3492 qemu_opts_absorb_qdict(opts, reopen_state->options, &local_err);
3493 if (local_err) {
3494 error_propagate(errp, local_err);
3495 ret = -EINVAL;
3496 goto error;
3497 }
3498
Alberto Garciae6d79c42018-11-12 16:00:47 +02003499 /* This was already called in bdrv_reopen_queue_child() so the flags
3500 * are up-to-date. This time we simply want to remove the options from
3501 * QemuOpts in order to indicate that they have been processed. */
3502 old_flags = reopen_state->flags;
Kevin Wolf91a097e2015-05-08 17:49:53 +02003503 update_flags_from_options(&reopen_state->flags, opts);
Alberto Garciae6d79c42018-11-12 16:00:47 +02003504 assert(old_flags == reopen_state->flags);
Kevin Wolf91a097e2015-05-08 17:49:53 +02003505
Alberto Garcia415bbca2018-10-03 13:23:13 +03003506 discard = qemu_opt_get_del(opts, BDRV_OPT_DISCARD);
Alberto Garcia593b3072018-09-06 12:37:08 +03003507 if (discard != NULL) {
3508 if (bdrv_parse_discard_flags(discard, &reopen_state->flags) != 0) {
3509 error_setg(errp, "Invalid discard option");
3510 ret = -EINVAL;
3511 goto error;
3512 }
3513 }
3514
Alberto Garcia543770b2018-09-06 12:37:09 +03003515 reopen_state->detect_zeroes =
3516 bdrv_parse_detect_zeroes(opts, reopen_state->flags, &local_err);
3517 if (local_err) {
3518 error_propagate(errp, local_err);
3519 ret = -EINVAL;
3520 goto error;
3521 }
3522
Alberto Garcia57f9db92018-09-06 12:37:06 +03003523 /* All other options (including node-name and driver) must be unchanged.
3524 * Put them back into the QDict, so that they are checked at the end
3525 * of this function. */
3526 qemu_opts_to_qdict(opts, reopen_state->options);
Kevin Wolfccf9dc02015-05-08 17:24:56 +02003527
Jeff Cody3d8ce172017-04-07 16:55:30 -04003528 /* If we are to stay read-only, do not allow permission change
3529 * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
3530 * not set, or if the BDS still has copy_on_read enabled */
3531 read_only = !(reopen_state->flags & BDRV_O_RDWR);
Kevin Wolf54a32bf2017-08-03 17:02:58 +02003532 ret = bdrv_can_set_read_only(reopen_state->bs, read_only, true, &local_err);
Jeff Cody3d8ce172017-04-07 16:55:30 -04003533 if (local_err) {
3534 error_propagate(errp, local_err);
Jeff Codye971aa12012-09-20 15:13:19 -04003535 goto error;
3536 }
3537
Kevin Wolf30450252017-07-03 17:07:35 +02003538 /* Calculate required permissions after reopening */
3539 bdrv_reopen_perm(queue, reopen_state->bs,
3540 &reopen_state->perm, &reopen_state->shared_perm);
Jeff Codye971aa12012-09-20 15:13:19 -04003541
3542 ret = bdrv_flush(reopen_state->bs);
3543 if (ret) {
Eric Blake455b0fd2015-11-10 23:51:20 -07003544 error_setg_errno(errp, -ret, "Error flushing drive");
Jeff Codye971aa12012-09-20 15:13:19 -04003545 goto error;
3546 }
3547
3548 if (drv->bdrv_reopen_prepare) {
3549 ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err);
3550 if (ret) {
3551 if (local_err != NULL) {
3552 error_propagate(errp, local_err);
3553 } else {
Max Reitzf30c66b2019-02-01 20:29:05 +01003554 bdrv_refresh_filename(reopen_state->bs);
Luiz Capitulinod8b68952013-06-10 11:29:27 -04003555 error_setg(errp, "failed while preparing to reopen image '%s'",
3556 reopen_state->bs->filename);
Jeff Codye971aa12012-09-20 15:13:19 -04003557 }
3558 goto error;
3559 }
3560 } else {
3561 /* It is currently mandatory to have a bdrv_reopen_prepare()
3562 * handler for each supported drv. */
Alberto Garcia81e5f782015-04-08 12:29:19 +03003563 error_setg(errp, "Block format '%s' used by node '%s' "
3564 "does not support reopening files", drv->format_name,
3565 bdrv_get_device_or_node_name(reopen_state->bs));
Jeff Codye971aa12012-09-20 15:13:19 -04003566 ret = -1;
3567 goto error;
3568 }
3569
Max Reitz9ad08c42018-11-16 17:45:24 +01003570 drv_prepared = true;
3571
Alberto Garciabacd9b82019-03-12 18:48:46 +02003572 /*
3573 * We must provide the 'backing' option if the BDS has a backing
3574 * file or if the image file has a backing file name as part of
3575 * its metadata. Otherwise the 'backing' option can be omitted.
3576 */
3577 if (drv->supports_backing && reopen_state->backing_missing &&
3578 (backing_bs(reopen_state->bs) || reopen_state->bs->backing_file[0])) {
Alberto Garcia85466322019-03-12 18:48:45 +02003579 error_setg(errp, "backing is missing for '%s'",
3580 reopen_state->bs->node_name);
3581 ret = -EINVAL;
3582 goto error;
3583 }
3584
Alberto Garciacb828c32019-03-12 18:48:47 +02003585 /*
3586 * Allow changing the 'backing' option. The new value can be
3587 * either a reference to an existing node (using its node name)
3588 * or NULL to simply detach the current backing file.
3589 */
3590 ret = bdrv_reopen_parse_backing(reopen_state, errp);
3591 if (ret < 0) {
3592 goto error;
3593 }
3594 qdict_del(reopen_state->options, "backing");
3595
Kevin Wolf4d2cb092015-04-10 17:50:50 +02003596 /* Options that are not handled are only okay if they are unchanged
3597 * compared to the old state. It is expected that some options are only
3598 * used for the initial open, but not reopen (e.g. filename) */
3599 if (qdict_size(reopen_state->options)) {
3600 const QDictEntry *entry = qdict_first(reopen_state->options);
3601
3602 do {
Max Reitz54fd1b02017-11-14 19:01:26 +01003603 QObject *new = entry->value;
3604 QObject *old = qdict_get(reopen_state->bs->options, entry->key);
Kevin Wolf4d2cb092015-04-10 17:50:50 +02003605
Alberto Garciadb905282018-09-06 12:37:05 +03003606 /* Allow child references (child_name=node_name) as long as they
3607 * point to the current child (i.e. everything stays the same). */
3608 if (qobject_type(new) == QTYPE_QSTRING) {
3609 BdrvChild *child;
3610 QLIST_FOREACH(child, &reopen_state->bs->children, next) {
3611 if (!strcmp(child->name, entry->key)) {
3612 break;
3613 }
3614 }
3615
3616 if (child) {
3617 const char *str = qobject_get_try_str(new);
3618 if (!strcmp(child->bs->node_name, str)) {
3619 continue; /* Found child with this name, skip option */
3620 }
3621 }
3622 }
3623
Max Reitz54fd1b02017-11-14 19:01:26 +01003624 /*
3625 * TODO: When using -drive to specify blockdev options, all values
3626 * will be strings; however, when using -blockdev, blockdev-add or
3627 * filenames using the json:{} pseudo-protocol, they will be
3628 * correctly typed.
3629 * In contrast, reopening options are (currently) always strings
3630 * (because you can only specify them through qemu-io; all other
3631 * callers do not specify any options).
3632 * Therefore, when using anything other than -drive to create a BDS,
3633 * this cannot detect non-string options as unchanged, because
3634 * qobject_is_equal() always returns false for objects of different
3635 * type. In the future, this should be remedied by correctly typing
3636 * all options. For now, this is not too big of an issue because
3637 * the user can simply omit options which cannot be changed anyway,
3638 * so they will stay unchanged.
3639 */
3640 if (!qobject_is_equal(new, old)) {
Kevin Wolf4d2cb092015-04-10 17:50:50 +02003641 error_setg(errp, "Cannot change the option '%s'", entry->key);
3642 ret = -EINVAL;
3643 goto error;
3644 }
3645 } while ((entry = qdict_next(reopen_state->options, entry)));
3646 }
3647
Jeff Codye971aa12012-09-20 15:13:19 -04003648 ret = 0;
3649
Alberto Garcia4c8350f2018-06-29 14:37:02 +03003650 /* Restore the original reopen_state->options QDict */
3651 qobject_unref(reopen_state->options);
3652 reopen_state->options = qobject_ref(orig_reopen_opts);
3653
Jeff Codye971aa12012-09-20 15:13:19 -04003654error:
Max Reitz9ad08c42018-11-16 17:45:24 +01003655 if (ret < 0 && drv_prepared) {
3656 /* drv->bdrv_reopen_prepare() has succeeded, so we need to
3657 * call drv->bdrv_reopen_abort() before signaling an error
3658 * (bdrv_reopen_multiple() will not call bdrv_reopen_abort()
3659 * when the respective bdrv_reopen_prepare() has failed) */
3660 if (drv->bdrv_reopen_abort) {
3661 drv->bdrv_reopen_abort(reopen_state);
3662 }
3663 }
Kevin Wolfccf9dc02015-05-08 17:24:56 +02003664 qemu_opts_del(opts);
Alberto Garcia4c8350f2018-06-29 14:37:02 +03003665 qobject_unref(orig_reopen_opts);
Alberto Garcia593b3072018-09-06 12:37:08 +03003666 g_free(discard);
Jeff Codye971aa12012-09-20 15:13:19 -04003667 return ret;
3668}
3669
3670/*
3671 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
3672 * makes them final by swapping the staging BlockDriverState contents into
3673 * the active BlockDriverState contents.
3674 */
3675void bdrv_reopen_commit(BDRVReopenState *reopen_state)
3676{
3677 BlockDriver *drv;
Vladimir Sementsov-Ogievskiy50bf65b2017-06-28 15:05:12 +03003678 BlockDriverState *bs;
Alberto Garcia50196d72018-09-06 12:37:03 +03003679 BdrvChild *child;
Vladimir Sementsov-Ogievskiycb9ff6c2017-06-28 15:05:13 +03003680 bool old_can_write, new_can_write;
Jeff Codye971aa12012-09-20 15:13:19 -04003681
3682 assert(reopen_state != NULL);
Vladimir Sementsov-Ogievskiy50bf65b2017-06-28 15:05:12 +03003683 bs = reopen_state->bs;
3684 drv = bs->drv;
Jeff Codye971aa12012-09-20 15:13:19 -04003685 assert(drv != NULL);
3686
Vladimir Sementsov-Ogievskiycb9ff6c2017-06-28 15:05:13 +03003687 old_can_write =
3688 !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE);
3689
Jeff Codye971aa12012-09-20 15:13:19 -04003690 /* If there are any driver level actions to take */
3691 if (drv->bdrv_reopen_commit) {
3692 drv->bdrv_reopen_commit(reopen_state);
3693 }
3694
3695 /* set BDS specific flags now */
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02003696 qobject_unref(bs->explicit_options);
Alberto Garcia4c8350f2018-06-29 14:37:02 +03003697 qobject_unref(bs->options);
Kevin Wolf145f5982015-05-08 16:15:03 +02003698
Vladimir Sementsov-Ogievskiy50bf65b2017-06-28 15:05:12 +03003699 bs->explicit_options = reopen_state->explicit_options;
Alberto Garcia4c8350f2018-06-29 14:37:02 +03003700 bs->options = reopen_state->options;
Vladimir Sementsov-Ogievskiy50bf65b2017-06-28 15:05:12 +03003701 bs->open_flags = reopen_state->flags;
3702 bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
Alberto Garcia543770b2018-09-06 12:37:09 +03003703 bs->detect_zeroes = reopen_state->detect_zeroes;
Kevin Wolf355ef4a2013-12-11 20:14:09 +01003704
Alberto Garciacb828c32019-03-12 18:48:47 +02003705 if (reopen_state->replace_backing_bs) {
3706 qdict_del(bs->explicit_options, "backing");
3707 qdict_del(bs->options, "backing");
3708 }
3709
Alberto Garcia50196d72018-09-06 12:37:03 +03003710 /* Remove child references from bs->options and bs->explicit_options.
3711 * Child options were already removed in bdrv_reopen_queue_child() */
3712 QLIST_FOREACH(child, &bs->children, next) {
3713 qdict_del(bs->explicit_options, child->name);
3714 qdict_del(bs->options, child->name);
3715 }
3716
Alberto Garciacb828c32019-03-12 18:48:47 +02003717 /*
3718 * Change the backing file if a new one was specified. We do this
3719 * after updating bs->options, so bdrv_refresh_filename() (called
3720 * from bdrv_set_backing_hd()) has the new values.
3721 */
3722 if (reopen_state->replace_backing_bs) {
3723 BlockDriverState *old_backing_bs = backing_bs(bs);
3724 assert(!old_backing_bs || !old_backing_bs->implicit);
3725 /* Abort the permission update on the backing bs we're detaching */
3726 if (old_backing_bs) {
3727 bdrv_abort_perm_update(old_backing_bs);
3728 }
3729 bdrv_set_backing_hd(bs, reopen_state->new_backing_bs, &error_abort);
3730 }
3731
Vladimir Sementsov-Ogievskiy50bf65b2017-06-28 15:05:12 +03003732 bdrv_refresh_limits(bs, NULL);
Vladimir Sementsov-Ogievskiycb9ff6c2017-06-28 15:05:13 +03003733
3734 new_can_write =
3735 !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE);
3736 if (!old_can_write && new_can_write && drv->bdrv_reopen_bitmaps_rw) {
3737 Error *local_err = NULL;
3738 if (drv->bdrv_reopen_bitmaps_rw(bs, &local_err) < 0) {
3739 /* This is not fatal, bitmaps just left read-only, so all following
3740 * writes will fail. User can remove read-only bitmaps to unblock
3741 * writes.
3742 */
3743 error_reportf_err(local_err,
3744 "%s: Failed to make dirty bitmaps writable: ",
3745 bdrv_get_node_name(bs));
3746 }
3747 }
Jeff Codye971aa12012-09-20 15:13:19 -04003748}
3749
3750/*
3751 * Abort the reopen, and delete and free the staged changes in
3752 * reopen_state
3753 */
3754void bdrv_reopen_abort(BDRVReopenState *reopen_state)
3755{
3756 BlockDriver *drv;
3757
3758 assert(reopen_state != NULL);
3759 drv = reopen_state->bs->drv;
3760 assert(drv != NULL);
3761
3762 if (drv->bdrv_reopen_abort) {
3763 drv->bdrv_reopen_abort(reopen_state);
3764 }
3765}
3766
3767
Max Reitz64dff522016-01-29 16:36:10 +01003768static void bdrv_close(BlockDriverState *bs)
bellardfc01f7e2003-06-30 10:03:06 +00003769{
Max Reitz33384422014-06-20 21:57:33 +02003770 BdrvAioNotifier *ban, *ban_next;
Alberto Garcia50a3efb2017-11-06 16:53:45 +02003771 BdrvChild *child, *next;
Max Reitz33384422014-06-20 21:57:33 +02003772
Max Reitzca9bd242016-01-29 16:36:14 +01003773 assert(!bs->job);
Max Reitz30f55fb2016-05-17 16:41:32 +02003774 assert(!bs->refcnt);
Alberto Garcia99b7e772015-09-25 16:41:44 +03003775
Paolo Bonzinifc272912015-12-23 11:48:24 +01003776 bdrv_drained_begin(bs); /* complete I/O */
Stefan Hajnoczi58fda172013-07-02 15:36:25 +02003777 bdrv_flush(bs);
Fam Zheng53ec73e2015-05-29 18:53:14 +08003778 bdrv_drain(bs); /* in case flush left pending I/O */
Paolo Bonzinifc272912015-12-23 11:48:24 +01003779
Paolo Bonzini3cbc0022012-10-19 11:36:48 +02003780 if (bs->drv) {
Vladimir Sementsov-Ogievskiy3c005292018-08-14 15:43:19 +03003781 if (bs->drv->bdrv_close) {
3782 bs->drv->bdrv_close(bs);
3783 }
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02003784 bs->drv = NULL;
bellardb3380822004-03-14 21:38:54 +00003785 }
Zhi Yong Wu98f90db2011-11-08 13:00:14 +08003786
Alberto Garcia50a3efb2017-11-06 16:53:45 +02003787 bdrv_set_backing_hd(bs, NULL, &error_abort);
3788
3789 if (bs->file != NULL) {
3790 bdrv_unref_child(bs, bs->file);
3791 bs->file = NULL;
3792 }
3793
3794 QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
3795 /* TODO Remove bdrv_unref() from drivers' close function and use
3796 * bdrv_unref_child() here */
3797 if (child->bs->inherits_from == bs) {
3798 child->bs->inherits_from = NULL;
3799 }
3800 bdrv_detach_child(child);
3801 }
3802
3803 g_free(bs->opaque);
3804 bs->opaque = NULL;
3805 atomic_set(&bs->copy_on_read, 0);
3806 bs->backing_file[0] = '\0';
3807 bs->backing_format[0] = '\0';
3808 bs->total_sectors = 0;
3809 bs->encrypted = false;
3810 bs->sg = false;
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02003811 qobject_unref(bs->options);
3812 qobject_unref(bs->explicit_options);
Alberto Garcia50a3efb2017-11-06 16:53:45 +02003813 bs->options = NULL;
3814 bs->explicit_options = NULL;
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02003815 qobject_unref(bs->full_open_options);
Alberto Garcia50a3efb2017-11-06 16:53:45 +02003816 bs->full_open_options = NULL;
3817
Vladimir Sementsov-Ogievskiycca43ae2017-06-28 15:05:16 +03003818 bdrv_release_named_dirty_bitmaps(bs);
3819 assert(QLIST_EMPTY(&bs->dirty_bitmaps));
3820
Max Reitz33384422014-06-20 21:57:33 +02003821 QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
3822 g_free(ban);
3823 }
3824 QLIST_INIT(&bs->aio_notifiers);
Paolo Bonzinifc272912015-12-23 11:48:24 +01003825 bdrv_drained_end(bs);
bellardb3380822004-03-14 21:38:54 +00003826}
3827
MORITA Kazutaka2bc93fe2010-05-28 11:44:57 +09003828void bdrv_close_all(void)
3829{
Kevin Wolfb3b52992018-05-16 13:46:37 +02003830 assert(job_next(NULL) == NULL);
Kevin Wolfcd7fca92016-07-06 11:22:39 +02003831 nbd_export_close_all();
MORITA Kazutaka2bc93fe2010-05-28 11:44:57 +09003832
Max Reitzca9bd242016-01-29 16:36:14 +01003833 /* Drop references from requests still in flight, such as canceled block
3834 * jobs whose AIO context has not been polled yet */
3835 bdrv_drain_all();
Stefan Hajnoczied78cda2014-05-08 16:34:35 +02003836
Max Reitzca9bd242016-01-29 16:36:14 +01003837 blk_remove_all_bs();
3838 blockdev_close_all_bdrv_states();
3839
Kevin Wolfa1a2af02016-04-08 18:26:37 +02003840 assert(QTAILQ_EMPTY(&all_bdrv_states));
MORITA Kazutaka2bc93fe2010-05-28 11:44:57 +09003841}
3842
Kevin Wolfd0ac0382017-03-01 17:30:41 +01003843static bool should_update_child(BdrvChild *c, BlockDriverState *to)
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003844{
Vladimir Sementsov-Ogievskiy2f30b7c2019-02-23 22:20:39 +03003845 GQueue *queue;
3846 GHashTable *found;
3847 bool ret;
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003848
Kevin Wolfd0ac0382017-03-01 17:30:41 +01003849 if (c->role->stay_at_node) {
3850 return false;
3851 }
3852
Max Reitzec9f10f2018-06-13 20:18:15 +02003853 /* If the child @c belongs to the BDS @to, replacing the current
3854 * c->bs by @to would mean to create a loop.
3855 *
3856 * Such a case occurs when appending a BDS to a backing chain.
3857 * For instance, imagine the following chain:
3858 *
3859 * guest device -> node A -> further backing chain...
3860 *
3861 * Now we create a new BDS B which we want to put on top of this
3862 * chain, so we first attach A as its backing node:
3863 *
3864 * node B
3865 * |
3866 * v
3867 * guest device -> node A -> further backing chain...
3868 *
3869 * Finally we want to replace A by B. When doing that, we want to
3870 * replace all pointers to A by pointers to B -- except for the
3871 * pointer from B because (1) that would create a loop, and (2)
3872 * that pointer should simply stay intact:
3873 *
3874 * guest device -> node B
3875 * |
3876 * v
3877 * node A -> further backing chain...
3878 *
3879 * In general, when replacing a node A (c->bs) by a node B (@to),
3880 * if A is a child of B, that means we cannot replace A by B there
3881 * because that would create a loop. Silently detaching A from B
3882 * is also not really an option. So overall just leaving A in
Vladimir Sementsov-Ogievskiy2f30b7c2019-02-23 22:20:39 +03003883 * place there is the most sensible choice.
3884 *
3885 * We would also create a loop in any cases where @c is only
3886 * indirectly referenced by @to. Prevent this by returning false
3887 * if @c is found (by breadth-first search) anywhere in the whole
3888 * subtree of @to.
3889 */
3890
3891 ret = true;
3892 found = g_hash_table_new(NULL, NULL);
3893 g_hash_table_add(found, to);
3894 queue = g_queue_new();
3895 g_queue_push_tail(queue, to);
3896
3897 while (!g_queue_is_empty(queue)) {
3898 BlockDriverState *v = g_queue_pop_head(queue);
3899 BdrvChild *c2;
3900
3901 QLIST_FOREACH(c2, &v->children, next) {
3902 if (c2 == c) {
3903 ret = false;
3904 break;
3905 }
3906
3907 if (g_hash_table_contains(found, c2->bs)) {
3908 continue;
3909 }
3910
3911 g_queue_push_tail(queue, c2->bs);
3912 g_hash_table_add(found, c2->bs);
Kevin Wolfd0ac0382017-03-01 17:30:41 +01003913 }
3914 }
3915
Vladimir Sementsov-Ogievskiy2f30b7c2019-02-23 22:20:39 +03003916 g_queue_free(queue);
3917 g_hash_table_destroy(found);
3918
3919 return ret;
Kevin Wolfd0ac0382017-03-01 17:30:41 +01003920}
3921
Kevin Wolf5fe31c22017-03-06 16:20:51 +01003922void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
3923 Error **errp)
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003924{
Kevin Wolfd0ac0382017-03-01 17:30:41 +01003925 BdrvChild *c, *next;
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003926 GSList *list = NULL, *p;
3927 uint64_t old_perm, old_shared;
3928 uint64_t perm = 0, shared = BLK_PERM_ALL;
3929 int ret;
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003930
Kevin Wolf5fe31c22017-03-06 16:20:51 +01003931 assert(!atomic_read(&from->in_flight));
3932 assert(!atomic_read(&to->in_flight));
3933
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003934 /* Make sure that @from doesn't go away until we have successfully attached
3935 * all of its parents to @to. */
3936 bdrv_ref(from);
3937
3938 /* Put all parents into @list and calculate their cumulative permissions */
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003939 QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
Max Reitzec9f10f2018-06-13 20:18:15 +02003940 assert(c->bs == from);
Kevin Wolfd0ac0382017-03-01 17:30:41 +01003941 if (!should_update_child(c, to)) {
Kevin Wolf26de9432017-01-17 13:39:34 +01003942 continue;
3943 }
Alberto Garcia2cad1eb2019-03-12 18:48:40 +02003944 if (c->frozen) {
3945 error_setg(errp, "Cannot change '%s' link to '%s'",
3946 c->name, from->node_name);
3947 goto out;
3948 }
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003949 list = g_slist_prepend(list, c);
3950 perm |= c->perm;
3951 shared &= c->shared_perm;
3952 }
3953
3954 /* Check whether the required permissions can be granted on @to, ignoring
3955 * all BdrvChild in @list so that they can't block themselves. */
Kevin Wolf3121fb42017-09-14 14:42:12 +02003956 ret = bdrv_check_update_perm(to, NULL, perm, shared, list, errp);
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003957 if (ret < 0) {
3958 bdrv_abort_perm_update(to);
3959 goto out;
3960 }
3961
3962 /* Now actually perform the change. We performed the permission check for
3963 * all elements of @list at once, so set the permissions all at once at the
3964 * very end. */
3965 for (p = list; p != NULL; p = p->next) {
3966 c = p->data;
Max Reitz9bd910e2016-06-10 20:57:46 +02003967
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003968 bdrv_ref(to);
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003969 bdrv_replace_child_noperm(c, to);
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003970 bdrv_unref(from);
3971 }
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003972
3973 bdrv_get_cumulative_perm(to, &old_perm, &old_shared);
3974 bdrv_set_perm(to, old_perm | perm, old_shared | shared);
3975
3976out:
3977 g_slist_free(list);
3978 bdrv_unref(from);
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003979}
3980
Jeff Cody8802d1f2012-02-28 15:54:06 -05003981/*
3982 * Add new bs contents at the top of an image chain while the chain is
3983 * live, while keeping required fields on the top layer.
3984 *
3985 * This will modify the BlockDriverState fields, and swap contents
3986 * between bs_new and bs_top. Both bs_new and bs_top are modified.
3987 *
Markus Armbrusterbfb197e2014-10-07 13:59:11 +02003988 * bs_new must not be attached to a BlockBackend.
Jeff Codyf6801b82012-03-27 16:30:19 -04003989 *
Jeff Cody8802d1f2012-02-28 15:54:06 -05003990 * This function does not create any image files.
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003991 *
3992 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
3993 * that's what the callers commonly need. bs_new will be referenced by the old
3994 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
3995 * reference of its own, it must call bdrv_ref().
Jeff Cody8802d1f2012-02-28 15:54:06 -05003996 */
Kevin Wolfb2c28322017-02-20 12:46:42 +01003997void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
3998 Error **errp)
Jeff Cody8802d1f2012-02-28 15:54:06 -05003999{
Kevin Wolfb2c28322017-02-20 12:46:42 +01004000 Error *local_err = NULL;
4001
Kevin Wolfb2c28322017-02-20 12:46:42 +01004002 bdrv_set_backing_hd(bs_new, bs_top, &local_err);
4003 if (local_err) {
4004 error_propagate(errp, local_err);
4005 goto out;
4006 }
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02004007
Kevin Wolf5fe31c22017-03-06 16:20:51 +01004008 bdrv_replace_node(bs_top, bs_new, &local_err);
Kevin Wolf234ac1a2017-03-02 18:43:00 +01004009 if (local_err) {
4010 error_propagate(errp, local_err);
4011 bdrv_set_backing_hd(bs_new, NULL, &error_abort);
4012 goto out;
4013 }
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02004014
4015 /* bs_new is now referenced by its new parents, we don't need the
4016 * additional reference any more. */
Kevin Wolfb2c28322017-02-20 12:46:42 +01004017out:
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02004018 bdrv_unref(bs_new);
Jeff Cody8802d1f2012-02-28 15:54:06 -05004019}
4020
Fam Zheng4f6fd342013-08-23 09:14:47 +08004021static void bdrv_delete(BlockDriverState *bs)
bellardb3380822004-03-14 21:38:54 +00004022{
Paolo Bonzini3e914652012-03-30 13:17:11 +02004023 assert(!bs->job);
Fam Zheng3718d8a2014-05-23 21:29:43 +08004024 assert(bdrv_op_blocker_is_empty(bs));
Fam Zheng4f6fd342013-08-23 09:14:47 +08004025 assert(!bs->refcnt);
Markus Armbruster18846de2010-06-29 16:58:30 +02004026
Stefan Hajnoczie1b5c522013-06-27 15:32:26 +02004027 bdrv_close(bs);
4028
Stefan Hajnoczi1b7bdbc2010-04-10 07:02:42 +01004029 /* remove from list, if necessary */
Kevin Wolf63eaaae2016-03-18 10:46:57 +01004030 if (bs->node_name[0] != '\0') {
4031 QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list);
4032 }
Max Reitz2c1d04e2016-01-29 16:36:11 +01004033 QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list);
4034
Anthony Liguori7267c092011-08-20 22:09:37 -05004035 g_free(bs);
bellardfc01f7e2003-06-30 10:03:06 +00004036}
4037
aliguorie97fc192009-04-21 23:11:50 +00004038/*
4039 * Run consistency checks on an image
4040 *
Kevin Wolfe076f332010-06-29 11:43:13 +02004041 * Returns 0 if the check could be completed (it doesn't mean that the image is
Stefan Weila1c72732011-04-28 17:20:38 +02004042 * free of errors) or -errno when an internal error occurred. The results of the
Kevin Wolfe076f332010-06-29 11:43:13 +02004043 * check are stored in res.
aliguorie97fc192009-04-21 23:11:50 +00004044 */
Paolo Bonzini2fd61632018-03-01 17:36:19 +01004045static int coroutine_fn bdrv_co_check(BlockDriverState *bs,
4046 BdrvCheckResult *res, BdrvCheckMode fix)
aliguorie97fc192009-04-21 23:11:50 +00004047{
Max Reitz908bcd52014-08-07 22:47:55 +02004048 if (bs->drv == NULL) {
4049 return -ENOMEDIUM;
4050 }
Paolo Bonzini2fd61632018-03-01 17:36:19 +01004051 if (bs->drv->bdrv_co_check == NULL) {
aliguorie97fc192009-04-21 23:11:50 +00004052 return -ENOTSUP;
4053 }
4054
Kevin Wolfe076f332010-06-29 11:43:13 +02004055 memset(res, 0, sizeof(*res));
Paolo Bonzini2fd61632018-03-01 17:36:19 +01004056 return bs->drv->bdrv_co_check(bs, res, fix);
4057}
4058
4059typedef struct CheckCo {
4060 BlockDriverState *bs;
4061 BdrvCheckResult *res;
4062 BdrvCheckMode fix;
4063 int ret;
4064} CheckCo;
4065
4066static void bdrv_check_co_entry(void *opaque)
4067{
4068 CheckCo *cco = opaque;
4069 cco->ret = bdrv_co_check(cco->bs, cco->res, cco->fix);
Kevin Wolf4720cbe2019-01-07 13:02:48 +01004070 aio_wait_kick();
Paolo Bonzini2fd61632018-03-01 17:36:19 +01004071}
4072
4073int bdrv_check(BlockDriverState *bs,
4074 BdrvCheckResult *res, BdrvCheckMode fix)
4075{
4076 Coroutine *co;
4077 CheckCo cco = {
4078 .bs = bs,
4079 .res = res,
4080 .ret = -EINPROGRESS,
4081 .fix = fix,
4082 };
4083
4084 if (qemu_in_coroutine()) {
4085 /* Fast-path if already in coroutine context */
4086 bdrv_check_co_entry(&cco);
4087 } else {
4088 co = qemu_coroutine_create(bdrv_check_co_entry, &cco);
Kevin Wolf4720cbe2019-01-07 13:02:48 +01004089 bdrv_coroutine_enter(bs, co);
Paolo Bonzini2fd61632018-03-01 17:36:19 +01004090 BDRV_POLL_WHILE(bs, cco.ret == -EINPROGRESS);
4091 }
4092
4093 return cco.ret;
aliguorie97fc192009-04-21 23:11:50 +00004094}
4095
Kevin Wolf756e6732010-01-12 12:55:17 +01004096/*
4097 * Return values:
4098 * 0 - success
4099 * -EINVAL - backing format specified, but no file
4100 * -ENOSPC - can't update the backing file because no space is left in the
4101 * image file header
4102 * -ENOTSUP - format driver doesn't support changing the backing file
4103 */
4104int bdrv_change_backing_file(BlockDriverState *bs,
4105 const char *backing_file, const char *backing_fmt)
4106{
4107 BlockDriver *drv = bs->drv;
Paolo Bonzini469ef352012-04-12 14:01:02 +02004108 int ret;
Kevin Wolf756e6732010-01-12 12:55:17 +01004109
Max Reitzd470ad42017-11-10 21:31:09 +01004110 if (!drv) {
4111 return -ENOMEDIUM;
4112 }
4113
Paolo Bonzini5f377792012-04-12 14:01:01 +02004114 /* Backing file format doesn't make sense without a backing file */
4115 if (backing_fmt && !backing_file) {
4116 return -EINVAL;
4117 }
4118
Kevin Wolf756e6732010-01-12 12:55:17 +01004119 if (drv->bdrv_change_backing_file != NULL) {
Paolo Bonzini469ef352012-04-12 14:01:02 +02004120 ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
Kevin Wolf756e6732010-01-12 12:55:17 +01004121 } else {
Paolo Bonzini469ef352012-04-12 14:01:02 +02004122 ret = -ENOTSUP;
Kevin Wolf756e6732010-01-12 12:55:17 +01004123 }
Paolo Bonzini469ef352012-04-12 14:01:02 +02004124
4125 if (ret == 0) {
4126 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
4127 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
Max Reitz998c2012019-02-01 20:29:08 +01004128 pstrcpy(bs->auto_backing_file, sizeof(bs->auto_backing_file),
4129 backing_file ?: "");
Paolo Bonzini469ef352012-04-12 14:01:02 +02004130 }
4131 return ret;
Kevin Wolf756e6732010-01-12 12:55:17 +01004132}
4133
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004134/*
4135 * Finds the image layer in the chain that has 'bs' as its backing file.
4136 *
4137 * active is the current topmost image.
4138 *
4139 * Returns NULL if bs is not found in active's image chain,
4140 * or if active == bs.
Jeff Cody4caf0fc2014-06-25 15:35:26 -04004141 *
4142 * Returns the bottommost base image if bs == NULL.
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004143 */
4144BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
4145 BlockDriverState *bs)
4146{
Kevin Wolf760e0062015-06-17 14:55:21 +02004147 while (active && bs != backing_bs(active)) {
4148 active = backing_bs(active);
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004149 }
4150
Jeff Cody4caf0fc2014-06-25 15:35:26 -04004151 return active;
4152}
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004153
Jeff Cody4caf0fc2014-06-25 15:35:26 -04004154/* Given a BDS, searches for the base layer. */
4155BlockDriverState *bdrv_find_base(BlockDriverState *bs)
4156{
4157 return bdrv_find_overlay(bs, NULL);
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004158}
4159
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004160/*
Alberto Garcia2cad1eb2019-03-12 18:48:40 +02004161 * Return true if at least one of the backing links between @bs and
4162 * @base is frozen. @errp is set if that's the case.
4163 */
4164bool bdrv_is_backing_chain_frozen(BlockDriverState *bs, BlockDriverState *base,
4165 Error **errp)
4166{
4167 BlockDriverState *i;
4168
4169 for (i = bs; i != base && i->backing; i = backing_bs(i)) {
4170 if (i->backing->frozen) {
4171 error_setg(errp, "Cannot change '%s' link from '%s' to '%s'",
4172 i->backing->name, i->node_name,
4173 backing_bs(i)->node_name);
4174 return true;
4175 }
4176 }
4177
4178 return false;
4179}
4180
4181/*
4182 * Freeze all backing links between @bs and @base.
4183 * If any of the links is already frozen the operation is aborted and
4184 * none of the links are modified.
4185 * Returns 0 on success. On failure returns < 0 and sets @errp.
4186 */
4187int bdrv_freeze_backing_chain(BlockDriverState *bs, BlockDriverState *base,
4188 Error **errp)
4189{
4190 BlockDriverState *i;
4191
4192 if (bdrv_is_backing_chain_frozen(bs, base, errp)) {
4193 return -EPERM;
4194 }
4195
4196 for (i = bs; i != base && i->backing; i = backing_bs(i)) {
4197 i->backing->frozen = true;
4198 }
4199
4200 return 0;
4201}
4202
4203/*
4204 * Unfreeze all backing links between @bs and @base. The caller must
4205 * ensure that all links are frozen before using this function.
4206 */
4207void bdrv_unfreeze_backing_chain(BlockDriverState *bs, BlockDriverState *base)
4208{
4209 BlockDriverState *i;
4210
4211 for (i = bs; i != base && i->backing; i = backing_bs(i)) {
4212 assert(i->backing->frozen);
4213 i->backing->frozen = false;
4214 }
4215}
4216
4217/*
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004218 * Drops images above 'base' up to and including 'top', and sets the image
4219 * above 'top' to have base as its backing file.
4220 *
4221 * Requires that the overlay to 'top' is opened r/w, so that the backing file
4222 * information in 'bs' can be properly updated.
4223 *
4224 * E.g., this will convert the following chain:
4225 * bottom <- base <- intermediate <- top <- active
4226 *
4227 * to
4228 *
4229 * bottom <- base <- active
4230 *
4231 * It is allowed for bottom==base, in which case it converts:
4232 *
4233 * base <- intermediate <- top <- active
4234 *
4235 * to
4236 *
4237 * base <- active
4238 *
Jeff Cody54e26902014-06-25 15:40:10 -04004239 * If backing_file_str is non-NULL, it will be used when modifying top's
4240 * overlay image metadata.
4241 *
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004242 * Error conditions:
4243 * if active == top, that is considered an error
4244 *
4245 */
Kevin Wolfbde70712017-06-27 20:36:18 +02004246int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
4247 const char *backing_file_str)
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004248{
Alberto Garcia6bd858b2018-10-31 18:16:38 +02004249 BlockDriverState *explicit_top = top;
4250 bool update_inherits_from;
Kevin Wolf61f09ce2017-09-19 16:22:54 +02004251 BdrvChild *c, *next;
Kevin Wolf12fa4af2017-02-17 20:42:32 +01004252 Error *local_err = NULL;
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004253 int ret = -EIO;
4254
Kevin Wolf6858eba2017-06-29 19:32:21 +02004255 bdrv_ref(top);
4256
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004257 if (!top->drv || !base->drv) {
4258 goto exit;
4259 }
4260
Kevin Wolf5db15a52015-09-14 15:33:33 +02004261 /* Make sure that base is in the backing chain of top */
4262 if (!bdrv_chain_contains(top, base)) {
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004263 goto exit;
4264 }
4265
Alberto Garcia2cad1eb2019-03-12 18:48:40 +02004266 /* This function changes all links that point to top and makes
4267 * them point to base. Check that none of them is frozen. */
4268 QLIST_FOREACH(c, &top->parents, next_parent) {
4269 if (c->frozen) {
4270 goto exit;
4271 }
4272 }
4273
Alberto Garcia6bd858b2018-10-31 18:16:38 +02004274 /* If 'base' recursively inherits from 'top' then we should set
4275 * base->inherits_from to top->inherits_from after 'top' and all
4276 * other intermediate nodes have been dropped.
4277 * If 'top' is an implicit node (e.g. "commit_top") we should skip
4278 * it because no one inherits from it. We use explicit_top for that. */
4279 while (explicit_top && explicit_top->implicit) {
4280 explicit_top = backing_bs(explicit_top);
4281 }
4282 update_inherits_from = bdrv_inherits_from_recursive(base, explicit_top);
4283
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004284 /* success - we can delete the intermediate states, and link top->base */
Kevin Wolfbde70712017-06-27 20:36:18 +02004285 /* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once
4286 * we've figured out how they should work. */
Max Reitzf30c66b2019-02-01 20:29:05 +01004287 if (!backing_file_str) {
4288 bdrv_refresh_filename(base);
4289 backing_file_str = base->filename;
4290 }
Kevin Wolf61f09ce2017-09-19 16:22:54 +02004291
4292 QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) {
4293 /* Check whether we are allowed to switch c from top to base */
4294 GSList *ignore_children = g_slist_prepend(NULL, c);
4295 bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
4296 ignore_children, &local_err);
Fam Zheng2c860e72018-03-15 11:51:57 +08004297 g_slist_free(ignore_children);
Kevin Wolf61f09ce2017-09-19 16:22:54 +02004298 if (local_err) {
4299 ret = -EPERM;
4300 error_report_err(local_err);
Kevin Wolf6858eba2017-06-29 19:32:21 +02004301 goto exit;
4302 }
Kevin Wolf12fa4af2017-02-17 20:42:32 +01004303
Kevin Wolf61f09ce2017-09-19 16:22:54 +02004304 /* If so, update the backing file path in the image file */
4305 if (c->role->update_filename) {
4306 ret = c->role->update_filename(c, base, backing_file_str,
4307 &local_err);
4308 if (ret < 0) {
4309 bdrv_abort_perm_update(base);
4310 error_report_err(local_err);
4311 goto exit;
4312 }
4313 }
4314
4315 /* Do the actual switch in the in-memory graph.
4316 * Completes bdrv_check_update_perm() transaction internally. */
4317 bdrv_ref(base);
4318 bdrv_replace_child(c, base);
4319 bdrv_unref(top);
Kevin Wolf12fa4af2017-02-17 20:42:32 +01004320 }
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004321
Alberto Garcia6bd858b2018-10-31 18:16:38 +02004322 if (update_inherits_from) {
4323 base->inherits_from = explicit_top->inherits_from;
4324 }
4325
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004326 ret = 0;
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004327exit:
Kevin Wolf6858eba2017-06-29 19:32:21 +02004328 bdrv_unref(top);
Jeff Cody6ebdcee2012-09-27 13:29:12 -04004329 return ret;
4330}
4331
bellard83f64092006-08-01 16:21:11 +00004332/**
Fam Zheng4a1d5e12011-07-12 19:56:39 +08004333 * Length of a allocated file in bytes. Sparse files are counted by actual
4334 * allocated space. Return < 0 if error or unknown.
4335 */
4336int64_t bdrv_get_allocated_file_size(BlockDriverState *bs)
4337{
4338 BlockDriver *drv = bs->drv;
4339 if (!drv) {
4340 return -ENOMEDIUM;
4341 }
4342 if (drv->bdrv_get_allocated_file_size) {
4343 return drv->bdrv_get_allocated_file_size(bs);
4344 }
4345 if (bs->file) {
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02004346 return bdrv_get_allocated_file_size(bs->file->bs);
Fam Zheng4a1d5e12011-07-12 19:56:39 +08004347 }
4348 return -ENOTSUP;
4349}
4350
Stefan Hajnoczi90880ff2017-07-05 13:57:30 +01004351/*
4352 * bdrv_measure:
4353 * @drv: Format driver
4354 * @opts: Creation options for new image
4355 * @in_bs: Existing image containing data for new image (may be NULL)
4356 * @errp: Error object
4357 * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo())
4358 * or NULL on error
4359 *
4360 * Calculate file size required to create a new image.
4361 *
4362 * If @in_bs is given then space for allocated clusters and zero clusters
4363 * from that image are included in the calculation. If @opts contains a
4364 * backing file that is shared by @in_bs then backing clusters may be omitted
4365 * from the calculation.
4366 *
4367 * If @in_bs is NULL then the calculation includes no allocated clusters
4368 * unless a preallocation option is given in @opts.
4369 *
4370 * Note that @in_bs may use a different BlockDriver from @drv.
4371 *
4372 * If an error occurs the @errp pointer is set.
4373 */
4374BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
4375 BlockDriverState *in_bs, Error **errp)
4376{
4377 if (!drv->bdrv_measure) {
4378 error_setg(errp, "Block driver '%s' does not support size measurement",
4379 drv->format_name);
4380 return NULL;
4381 }
4382
4383 return drv->bdrv_measure(opts, in_bs, errp);
4384}
4385
Fam Zheng4a1d5e12011-07-12 19:56:39 +08004386/**
Markus Armbruster65a9bb22014-06-26 13:23:17 +02004387 * Return number of sectors on success, -errno on error.
bellard83f64092006-08-01 16:21:11 +00004388 */
Markus Armbruster65a9bb22014-06-26 13:23:17 +02004389int64_t bdrv_nb_sectors(BlockDriverState *bs)
bellard83f64092006-08-01 16:21:11 +00004390{
4391 BlockDriver *drv = bs->drv;
Markus Armbruster65a9bb22014-06-26 13:23:17 +02004392
bellard83f64092006-08-01 16:21:11 +00004393 if (!drv)
bellard19cb3732006-08-19 11:45:59 +00004394 return -ENOMEDIUM;
Stefan Hajnoczi51762282010-04-19 16:56:41 +01004395
Kevin Wolfb94a2612013-10-29 12:18:58 +01004396 if (drv->has_variable_length) {
4397 int ret = refresh_total_sectors(bs, bs->total_sectors);
4398 if (ret < 0) {
4399 return ret;
Stefan Hajnoczi46a4e4e2011-03-29 20:04:41 +01004400 }
bellard83f64092006-08-01 16:21:11 +00004401 }
Markus Armbruster65a9bb22014-06-26 13:23:17 +02004402 return bs->total_sectors;
4403}
4404
4405/**
4406 * Return length in bytes on success, -errno on error.
4407 * The length is always a multiple of BDRV_SECTOR_SIZE.
4408 */
4409int64_t bdrv_getlength(BlockDriverState *bs)
4410{
4411 int64_t ret = bdrv_nb_sectors(bs);
4412
Fam Zheng4a9c9ea2015-05-15 16:36:05 +08004413 ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret;
Markus Armbruster65a9bb22014-06-26 13:23:17 +02004414 return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE;
bellardfc01f7e2003-06-30 10:03:06 +00004415}
4416
bellard19cb3732006-08-19 11:45:59 +00004417/* return 0 as number of sectors if no device present or error */
ths96b8f132007-12-17 01:35:20 +00004418void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
bellardfc01f7e2003-06-30 10:03:06 +00004419{
Markus Armbruster65a9bb22014-06-26 13:23:17 +02004420 int64_t nb_sectors = bdrv_nb_sectors(bs);
4421
4422 *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors;
bellardfc01f7e2003-06-30 10:03:06 +00004423}
bellardcf989512004-02-16 21:56:36 +00004424
Eric Blake54115412016-06-23 16:37:26 -06004425bool bdrv_is_sg(BlockDriverState *bs)
ths985a03b2007-12-24 16:10:43 +00004426{
4427 return bs->sg;
4428}
4429
Eric Blake54115412016-06-23 16:37:26 -06004430bool bdrv_is_encrypted(BlockDriverState *bs)
bellardea2384d2004-08-01 21:59:26 +00004431{
Kevin Wolf760e0062015-06-17 14:55:21 +02004432 if (bs->backing && bs->backing->bs->encrypted) {
Eric Blake54115412016-06-23 16:37:26 -06004433 return true;
Kevin Wolf760e0062015-06-17 14:55:21 +02004434 }
bellardea2384d2004-08-01 21:59:26 +00004435 return bs->encrypted;
4436}
4437
Markus Armbrusterf8d6bba2012-06-13 10:11:48 +02004438const char *bdrv_get_format_name(BlockDriverState *bs)
bellardea2384d2004-08-01 21:59:26 +00004439{
Markus Armbrusterf8d6bba2012-06-13 10:11:48 +02004440 return bs->drv ? bs->drv->format_name : NULL;
bellardea2384d2004-08-01 21:59:26 +00004441}
4442
Stefan Hajnocziada42402014-08-27 12:08:55 +01004443static int qsort_strcmp(const void *a, const void *b)
4444{
Max Reitzceff5bd2016-10-12 22:49:05 +02004445 return strcmp(*(char *const *)a, *(char *const *)b);
Stefan Hajnocziada42402014-08-27 12:08:55 +01004446}
4447
ths5fafdf22007-09-16 21:08:06 +00004448void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
Andrey Shinkevich9ac404c2019-03-07 16:33:58 +03004449 void *opaque, bool read_only)
bellardea2384d2004-08-01 21:59:26 +00004450{
4451 BlockDriver *drv;
Jeff Codye855e4f2014-04-28 18:29:54 -04004452 int count = 0;
Stefan Hajnocziada42402014-08-27 12:08:55 +01004453 int i;
Jeff Codye855e4f2014-04-28 18:29:54 -04004454 const char **formats = NULL;
bellardea2384d2004-08-01 21:59:26 +00004455
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +01004456 QLIST_FOREACH(drv, &bdrv_drivers, list) {
Jeff Codye855e4f2014-04-28 18:29:54 -04004457 if (drv->format_name) {
4458 bool found = false;
4459 int i = count;
Andrey Shinkevich9ac404c2019-03-07 16:33:58 +03004460
4461 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, read_only)) {
4462 continue;
4463 }
4464
Jeff Codye855e4f2014-04-28 18:29:54 -04004465 while (formats && i && !found) {
4466 found = !strcmp(formats[--i], drv->format_name);
4467 }
4468
4469 if (!found) {
Markus Armbruster5839e532014-08-19 10:31:08 +02004470 formats = g_renew(const char *, formats, count + 1);
Jeff Codye855e4f2014-04-28 18:29:54 -04004471 formats[count++] = drv->format_name;
Jeff Codye855e4f2014-04-28 18:29:54 -04004472 }
4473 }
bellardea2384d2004-08-01 21:59:26 +00004474 }
Stefan Hajnocziada42402014-08-27 12:08:55 +01004475
Max Reitzeb0df692016-10-12 22:49:06 +02004476 for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); i++) {
4477 const char *format_name = block_driver_modules[i].format_name;
4478
4479 if (format_name) {
4480 bool found = false;
4481 int j = count;
4482
Andrey Shinkevich9ac404c2019-03-07 16:33:58 +03004483 if (use_bdrv_whitelist &&
4484 !bdrv_format_is_whitelisted(format_name, read_only)) {
4485 continue;
4486 }
4487
Max Reitzeb0df692016-10-12 22:49:06 +02004488 while (formats && j && !found) {
4489 found = !strcmp(formats[--j], format_name);
4490 }
4491
4492 if (!found) {
4493 formats = g_renew(const char *, formats, count + 1);
4494 formats[count++] = format_name;
4495 }
4496 }
4497 }
4498
Stefan Hajnocziada42402014-08-27 12:08:55 +01004499 qsort(formats, count, sizeof(formats[0]), qsort_strcmp);
4500
4501 for (i = 0; i < count; i++) {
4502 it(opaque, formats[i]);
4503 }
4504
Jeff Codye855e4f2014-04-28 18:29:54 -04004505 g_free(formats);
bellardea2384d2004-08-01 21:59:26 +00004506}
4507
Benoît Canetdc364f42014-01-23 21:31:32 +01004508/* This function is to find a node in the bs graph */
4509BlockDriverState *bdrv_find_node(const char *node_name)
4510{
4511 BlockDriverState *bs;
4512
4513 assert(node_name);
4514
4515 QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
4516 if (!strcmp(node_name, bs->node_name)) {
4517 return bs;
4518 }
4519 }
4520 return NULL;
4521}
4522
Benoît Canetc13163f2014-01-23 21:31:34 +01004523/* Put this QMP function here so it can access the static graph_bdrv_states. */
Alberto Garciad5a8ee62015-04-17 14:52:43 +03004524BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp)
Benoît Canetc13163f2014-01-23 21:31:34 +01004525{
4526 BlockDeviceInfoList *list, *entry;
4527 BlockDriverState *bs;
4528
4529 list = NULL;
4530 QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
Kevin Wolfc83f9fb2016-03-03 11:37:48 +01004531 BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, errp);
Alberto Garciad5a8ee62015-04-17 14:52:43 +03004532 if (!info) {
4533 qapi_free_BlockDeviceInfoList(list);
4534 return NULL;
4535 }
Benoît Canetc13163f2014-01-23 21:31:34 +01004536 entry = g_malloc0(sizeof(*entry));
Alberto Garciad5a8ee62015-04-17 14:52:43 +03004537 entry->value = info;
Benoît Canetc13163f2014-01-23 21:31:34 +01004538 entry->next = list;
4539 list = entry;
4540 }
4541
4542 return list;
4543}
4544
Vladimir Sementsov-Ogievskiy5d3b4e92018-12-21 20:09:07 +03004545#define QAPI_LIST_ADD(list, element) do { \
4546 typeof(list) _tmp = g_new(typeof(*(list)), 1); \
4547 _tmp->value = (element); \
4548 _tmp->next = (list); \
4549 (list) = _tmp; \
4550} while (0)
4551
4552typedef struct XDbgBlockGraphConstructor {
4553 XDbgBlockGraph *graph;
4554 GHashTable *graph_nodes;
4555} XDbgBlockGraphConstructor;
4556
4557static XDbgBlockGraphConstructor *xdbg_graph_new(void)
4558{
4559 XDbgBlockGraphConstructor *gr = g_new(XDbgBlockGraphConstructor, 1);
4560
4561 gr->graph = g_new0(XDbgBlockGraph, 1);
4562 gr->graph_nodes = g_hash_table_new(NULL, NULL);
4563
4564 return gr;
4565}
4566
4567static XDbgBlockGraph *xdbg_graph_finalize(XDbgBlockGraphConstructor *gr)
4568{
4569 XDbgBlockGraph *graph = gr->graph;
4570
4571 g_hash_table_destroy(gr->graph_nodes);
4572 g_free(gr);
4573
4574 return graph;
4575}
4576
4577static uintptr_t xdbg_graph_node_num(XDbgBlockGraphConstructor *gr, void *node)
4578{
4579 uintptr_t ret = (uintptr_t)g_hash_table_lookup(gr->graph_nodes, node);
4580
4581 if (ret != 0) {
4582 return ret;
4583 }
4584
4585 /*
4586 * Start counting from 1, not 0, because 0 interferes with not-found (NULL)
4587 * answer of g_hash_table_lookup.
4588 */
4589 ret = g_hash_table_size(gr->graph_nodes) + 1;
4590 g_hash_table_insert(gr->graph_nodes, node, (void *)ret);
4591
4592 return ret;
4593}
4594
4595static void xdbg_graph_add_node(XDbgBlockGraphConstructor *gr, void *node,
4596 XDbgBlockGraphNodeType type, const char *name)
4597{
4598 XDbgBlockGraphNode *n;
4599
4600 n = g_new0(XDbgBlockGraphNode, 1);
4601
4602 n->id = xdbg_graph_node_num(gr, node);
4603 n->type = type;
4604 n->name = g_strdup(name);
4605
4606 QAPI_LIST_ADD(gr->graph->nodes, n);
4607}
4608
4609static void xdbg_graph_add_edge(XDbgBlockGraphConstructor *gr, void *parent,
4610 const BdrvChild *child)
4611{
4612 typedef struct {
4613 unsigned int flag;
4614 BlockPermission num;
4615 } PermissionMap;
4616
4617 static const PermissionMap permissions[] = {
4618 { BLK_PERM_CONSISTENT_READ, BLOCK_PERMISSION_CONSISTENT_READ },
4619 { BLK_PERM_WRITE, BLOCK_PERMISSION_WRITE },
4620 { BLK_PERM_WRITE_UNCHANGED, BLOCK_PERMISSION_WRITE_UNCHANGED },
4621 { BLK_PERM_RESIZE, BLOCK_PERMISSION_RESIZE },
4622 { BLK_PERM_GRAPH_MOD, BLOCK_PERMISSION_GRAPH_MOD },
4623 { 0, 0 }
4624 };
4625 const PermissionMap *p;
4626 XDbgBlockGraphEdge *edge;
4627
4628 QEMU_BUILD_BUG_ON(1UL << (ARRAY_SIZE(permissions) - 1) != BLK_PERM_ALL + 1);
4629
4630 edge = g_new0(XDbgBlockGraphEdge, 1);
4631
4632 edge->parent = xdbg_graph_node_num(gr, parent);
4633 edge->child = xdbg_graph_node_num(gr, child->bs);
4634 edge->name = g_strdup(child->name);
4635
4636 for (p = permissions; p->flag; p++) {
4637 if (p->flag & child->perm) {
4638 QAPI_LIST_ADD(edge->perm, p->num);
4639 }
4640 if (p->flag & child->shared_perm) {
4641 QAPI_LIST_ADD(edge->shared_perm, p->num);
4642 }
4643 }
4644
4645 QAPI_LIST_ADD(gr->graph->edges, edge);
4646}
4647
4648
4649XDbgBlockGraph *bdrv_get_xdbg_block_graph(Error **errp)
4650{
4651 BlockBackend *blk;
4652 BlockJob *job;
4653 BlockDriverState *bs;
4654 BdrvChild *child;
4655 XDbgBlockGraphConstructor *gr = xdbg_graph_new();
4656
4657 for (blk = blk_all_next(NULL); blk; blk = blk_all_next(blk)) {
4658 char *allocated_name = NULL;
4659 const char *name = blk_name(blk);
4660
4661 if (!*name) {
4662 name = allocated_name = blk_get_attached_dev_id(blk);
4663 }
4664 xdbg_graph_add_node(gr, blk, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND,
4665 name);
4666 g_free(allocated_name);
4667 if (blk_root(blk)) {
4668 xdbg_graph_add_edge(gr, blk, blk_root(blk));
4669 }
4670 }
4671
4672 for (job = block_job_next(NULL); job; job = block_job_next(job)) {
4673 GSList *el;
4674
4675 xdbg_graph_add_node(gr, job, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB,
4676 job->job.id);
4677 for (el = job->nodes; el; el = el->next) {
4678 xdbg_graph_add_edge(gr, job, (BdrvChild *)el->data);
4679 }
4680 }
4681
4682 QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
4683 xdbg_graph_add_node(gr, bs, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_DRIVER,
4684 bs->node_name);
4685 QLIST_FOREACH(child, &bs->children, next) {
4686 xdbg_graph_add_edge(gr, bs, child);
4687 }
4688 }
4689
4690 return xdbg_graph_finalize(gr);
4691}
4692
Benoît Canet12d3ba82014-01-23 21:31:35 +01004693BlockDriverState *bdrv_lookup_bs(const char *device,
4694 const char *node_name,
4695 Error **errp)
4696{
Markus Armbruster7f06d472014-10-07 13:59:12 +02004697 BlockBackend *blk;
4698 BlockDriverState *bs;
Benoît Canet12d3ba82014-01-23 21:31:35 +01004699
Benoît Canet12d3ba82014-01-23 21:31:35 +01004700 if (device) {
Markus Armbruster7f06d472014-10-07 13:59:12 +02004701 blk = blk_by_name(device);
Benoît Canet12d3ba82014-01-23 21:31:35 +01004702
Markus Armbruster7f06d472014-10-07 13:59:12 +02004703 if (blk) {
Alberto Garcia9f4ed6f2015-10-26 16:46:49 +02004704 bs = blk_bs(blk);
4705 if (!bs) {
Max Reitz5433c242015-10-19 17:53:29 +02004706 error_setg(errp, "Device '%s' has no medium", device);
Max Reitz5433c242015-10-19 17:53:29 +02004707 }
4708
Alberto Garcia9f4ed6f2015-10-26 16:46:49 +02004709 return bs;
Benoît Canet12d3ba82014-01-23 21:31:35 +01004710 }
Benoît Canet12d3ba82014-01-23 21:31:35 +01004711 }
4712
Benoît Canetdd67fa52014-02-12 17:15:06 +01004713 if (node_name) {
4714 bs = bdrv_find_node(node_name);
Benoît Canet12d3ba82014-01-23 21:31:35 +01004715
Benoît Canetdd67fa52014-02-12 17:15:06 +01004716 if (bs) {
4717 return bs;
4718 }
Benoît Canet12d3ba82014-01-23 21:31:35 +01004719 }
4720
Benoît Canetdd67fa52014-02-12 17:15:06 +01004721 error_setg(errp, "Cannot find device=%s nor node_name=%s",
4722 device ? device : "",
4723 node_name ? node_name : "");
4724 return NULL;
Benoît Canet12d3ba82014-01-23 21:31:35 +01004725}
4726
Jeff Cody5a6684d2014-06-25 15:40:09 -04004727/* If 'base' is in the same chain as 'top', return true. Otherwise,
4728 * return false. If either argument is NULL, return false. */
4729bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
4730{
4731 while (top && top != base) {
Kevin Wolf760e0062015-06-17 14:55:21 +02004732 top = backing_bs(top);
Jeff Cody5a6684d2014-06-25 15:40:09 -04004733 }
4734
4735 return top != NULL;
4736}
4737
Fam Zheng04df7652014-10-31 11:32:54 +08004738BlockDriverState *bdrv_next_node(BlockDriverState *bs)
4739{
4740 if (!bs) {
4741 return QTAILQ_FIRST(&graph_bdrv_states);
4742 }
4743 return QTAILQ_NEXT(bs, node_list);
4744}
4745
Kevin Wolf0f122642018-03-28 18:29:18 +02004746BlockDriverState *bdrv_next_all_states(BlockDriverState *bs)
4747{
4748 if (!bs) {
4749 return QTAILQ_FIRST(&all_bdrv_states);
4750 }
4751 return QTAILQ_NEXT(bs, bs_list);
4752}
4753
Fam Zheng20a9e772014-10-31 11:32:55 +08004754const char *bdrv_get_node_name(const BlockDriverState *bs)
4755{
4756 return bs->node_name;
4757}
4758
Kevin Wolf1f0c4612016-03-22 18:38:44 +01004759const char *bdrv_get_parent_name(const BlockDriverState *bs)
Kevin Wolf4c265bf2016-02-26 10:22:16 +01004760{
4761 BdrvChild *c;
4762 const char *name;
4763
4764 /* If multiple parents have a name, just pick the first one. */
4765 QLIST_FOREACH(c, &bs->parents, next_parent) {
4766 if (c->role->get_name) {
4767 name = c->role->get_name(c);
4768 if (name && *name) {
4769 return name;
4770 }
4771 }
4772 }
4773
4774 return NULL;
4775}
4776
Markus Armbruster7f06d472014-10-07 13:59:12 +02004777/* TODO check what callers really want: bs->node_name or blk_name() */
Markus Armbrusterbfb197e2014-10-07 13:59:11 +02004778const char *bdrv_get_device_name(const BlockDriverState *bs)
bellardea2384d2004-08-01 21:59:26 +00004779{
Kevin Wolf4c265bf2016-02-26 10:22:16 +01004780 return bdrv_get_parent_name(bs) ?: "";
bellardea2384d2004-08-01 21:59:26 +00004781}
4782
Alberto Garcia9b2aa842015-04-08 12:29:18 +03004783/* This can be used to identify nodes that might not have a device
4784 * name associated. Since node and device names live in the same
4785 * namespace, the result is unambiguous. The exception is if both are
4786 * absent, then this returns an empty (non-null) string. */
4787const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
4788{
Kevin Wolf4c265bf2016-02-26 10:22:16 +01004789 return bdrv_get_parent_name(bs) ?: bs->node_name;
Alberto Garcia9b2aa842015-04-08 12:29:18 +03004790}
4791
Markus Armbrusterc8433282012-06-05 16:49:24 +02004792int bdrv_get_flags(BlockDriverState *bs)
4793{
4794 return bs->open_flags;
4795}
4796
Peter Lieven3ac21622013-06-28 12:47:42 +02004797int bdrv_has_zero_init_1(BlockDriverState *bs)
4798{
4799 return 1;
4800}
4801
Kevin Wolff2feebb2010-04-14 17:30:35 +02004802int bdrv_has_zero_init(BlockDriverState *bs)
4803{
Max Reitzd470ad42017-11-10 21:31:09 +01004804 if (!bs->drv) {
4805 return 0;
4806 }
Kevin Wolff2feebb2010-04-14 17:30:35 +02004807
Paolo Bonzini11212d82013-09-04 19:00:27 +02004808 /* If BS is a copy on write image, it is initialized to
4809 the contents of the base image, which may not be zeroes. */
Kevin Wolf760e0062015-06-17 14:55:21 +02004810 if (bs->backing) {
Paolo Bonzini11212d82013-09-04 19:00:27 +02004811 return 0;
4812 }
Kevin Wolf336c1c12010-07-28 11:26:29 +02004813 if (bs->drv->bdrv_has_zero_init) {
4814 return bs->drv->bdrv_has_zero_init(bs);
Kevin Wolff2feebb2010-04-14 17:30:35 +02004815 }
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +03004816 if (bs->file && bs->drv->is_filter) {
4817 return bdrv_has_zero_init(bs->file->bs);
4818 }
Kevin Wolff2feebb2010-04-14 17:30:35 +02004819
Peter Lieven3ac21622013-06-28 12:47:42 +02004820 /* safe default */
4821 return 0;
Kevin Wolff2feebb2010-04-14 17:30:35 +02004822}
4823
Peter Lieven4ce78692013-10-24 12:06:54 +02004824bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
4825{
4826 BlockDriverInfo bdi;
4827
Kevin Wolf760e0062015-06-17 14:55:21 +02004828 if (bs->backing) {
Peter Lieven4ce78692013-10-24 12:06:54 +02004829 return false;
4830 }
4831
4832 if (bdrv_get_info(bs, &bdi) == 0) {
4833 return bdi.unallocated_blocks_are_zero;
4834 }
4835
4836 return false;
4837}
4838
4839bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
4840{
Denis V. Lunev2f0342e2016-07-14 16:33:26 +03004841 if (!(bs->open_flags & BDRV_O_UNMAP)) {
Peter Lieven4ce78692013-10-24 12:06:54 +02004842 return false;
4843 }
4844
Eric Blakee24d8132018-01-26 13:34:39 -06004845 return bs->supported_zero_flags & BDRV_REQ_MAY_UNMAP;
Peter Lieven4ce78692013-10-24 12:06:54 +02004846}
4847
ths5fafdf22007-09-16 21:08:06 +00004848void bdrv_get_backing_filename(BlockDriverState *bs,
bellard83f64092006-08-01 16:21:11 +00004849 char *filename, int filename_size)
bellardea2384d2004-08-01 21:59:26 +00004850{
Kevin Wolf3574c602011-10-26 11:02:11 +02004851 pstrcpy(filename, filename_size, bs->backing_file);
bellardea2384d2004-08-01 21:59:26 +00004852}
4853
bellardfaea38e2006-08-05 21:31:00 +00004854int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
4855{
4856 BlockDriver *drv = bs->drv;
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +03004857 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
4858 if (!drv) {
bellard19cb3732006-08-19 11:45:59 +00004859 return -ENOMEDIUM;
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +03004860 }
4861 if (!drv->bdrv_get_info) {
4862 if (bs->file && drv->is_filter) {
4863 return bdrv_get_info(bs->file->bs, bdi);
4864 }
bellardfaea38e2006-08-05 21:31:00 +00004865 return -ENOTSUP;
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +03004866 }
bellardfaea38e2006-08-05 21:31:00 +00004867 memset(bdi, 0, sizeof(*bdi));
4868 return drv->bdrv_get_info(bs, bdi);
4869}
4870
Andrey Shinkevich1bf6e9c2019-02-08 18:06:06 +03004871ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs,
4872 Error **errp)
Max Reitzeae041f2013-10-09 10:46:16 +02004873{
4874 BlockDriver *drv = bs->drv;
4875 if (drv && drv->bdrv_get_specific_info) {
Andrey Shinkevich1bf6e9c2019-02-08 18:06:06 +03004876 return drv->bdrv_get_specific_info(bs, errp);
Max Reitzeae041f2013-10-09 10:46:16 +02004877 }
4878 return NULL;
4879}
4880
Eric Blakea31939e2015-11-18 01:52:54 -07004881void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event)
Kevin Wolf8b9b0cc2010-03-15 17:27:00 +01004882{
Kevin Wolfbf736fe2013-06-05 15:17:55 +02004883 if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
Kevin Wolf8b9b0cc2010-03-15 17:27:00 +01004884 return;
4885 }
4886
Kevin Wolfbf736fe2013-06-05 15:17:55 +02004887 bs->drv->bdrv_debug_event(bs, event);
Kevin Wolf41c695c2012-12-06 14:32:58 +01004888}
Kevin Wolf8b9b0cc2010-03-15 17:27:00 +01004889
Kevin Wolf41c695c2012-12-06 14:32:58 +01004890int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
4891 const char *tag)
4892{
4893 while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) {
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02004894 bs = bs->file ? bs->file->bs : NULL;
Kevin Wolf41c695c2012-12-06 14:32:58 +01004895 }
4896
4897 if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) {
4898 return bs->drv->bdrv_debug_breakpoint(bs, event, tag);
4899 }
4900
4901 return -ENOTSUP;
4902}
4903
Fam Zheng4cc70e92013-11-20 10:01:54 +08004904int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
4905{
4906 while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) {
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02004907 bs = bs->file ? bs->file->bs : NULL;
Fam Zheng4cc70e92013-11-20 10:01:54 +08004908 }
4909
4910 if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) {
4911 return bs->drv->bdrv_debug_remove_breakpoint(bs, tag);
4912 }
4913
4914 return -ENOTSUP;
4915}
4916
Kevin Wolf41c695c2012-12-06 14:32:58 +01004917int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
4918{
Max Reitz938789e2014-03-10 23:44:08 +01004919 while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) {
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02004920 bs = bs->file ? bs->file->bs : NULL;
Kevin Wolf41c695c2012-12-06 14:32:58 +01004921 }
4922
4923 if (bs && bs->drv && bs->drv->bdrv_debug_resume) {
4924 return bs->drv->bdrv_debug_resume(bs, tag);
4925 }
4926
4927 return -ENOTSUP;
4928}
4929
4930bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag)
4931{
4932 while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) {
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02004933 bs = bs->file ? bs->file->bs : NULL;
Kevin Wolf41c695c2012-12-06 14:32:58 +01004934 }
4935
4936 if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) {
4937 return bs->drv->bdrv_debug_is_suspended(bs, tag);
4938 }
4939
4940 return false;
Kevin Wolf8b9b0cc2010-03-15 17:27:00 +01004941}
4942
Jeff Codyb1b1d782012-10-16 15:49:09 -04004943/* backing_file can either be relative, or absolute, or a protocol. If it is
4944 * relative, it must be relative to the chain. So, passing in bs->filename
4945 * from a BDS as backing_file should not be done, as that may be relative to
4946 * the CWD rather than the chain. */
Marcelo Tosattie8a6bb92012-01-18 14:40:51 +00004947BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
4948 const char *backing_file)
4949{
Jeff Codyb1b1d782012-10-16 15:49:09 -04004950 char *filename_full = NULL;
4951 char *backing_file_full = NULL;
4952 char *filename_tmp = NULL;
4953 int is_protocol = 0;
4954 BlockDriverState *curr_bs = NULL;
4955 BlockDriverState *retval = NULL;
4956
4957 if (!bs || !bs->drv || !backing_file) {
Marcelo Tosattie8a6bb92012-01-18 14:40:51 +00004958 return NULL;
4959 }
4960
Jeff Codyb1b1d782012-10-16 15:49:09 -04004961 filename_full = g_malloc(PATH_MAX);
4962 backing_file_full = g_malloc(PATH_MAX);
Jeff Codyb1b1d782012-10-16 15:49:09 -04004963
4964 is_protocol = path_has_protocol(backing_file);
4965
Kevin Wolf760e0062015-06-17 14:55:21 +02004966 for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) {
Jeff Codyb1b1d782012-10-16 15:49:09 -04004967
4968 /* If either of the filename paths is actually a protocol, then
4969 * compare unmodified paths; otherwise make paths relative */
4970 if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
Max Reitz6b6833c2019-02-01 20:29:15 +01004971 char *backing_file_full_ret;
4972
Jeff Codyb1b1d782012-10-16 15:49:09 -04004973 if (strcmp(backing_file, curr_bs->backing_file) == 0) {
Kevin Wolf760e0062015-06-17 14:55:21 +02004974 retval = curr_bs->backing->bs;
Jeff Codyb1b1d782012-10-16 15:49:09 -04004975 break;
4976 }
Jeff Cody418661e2017-01-25 20:08:20 -05004977 /* Also check against the full backing filename for the image */
Max Reitz6b6833c2019-02-01 20:29:15 +01004978 backing_file_full_ret = bdrv_get_full_backing_filename(curr_bs,
4979 NULL);
4980 if (backing_file_full_ret) {
4981 bool equal = strcmp(backing_file, backing_file_full_ret) == 0;
4982 g_free(backing_file_full_ret);
4983 if (equal) {
Jeff Cody418661e2017-01-25 20:08:20 -05004984 retval = curr_bs->backing->bs;
4985 break;
4986 }
Jeff Cody418661e2017-01-25 20:08:20 -05004987 }
Marcelo Tosattie8a6bb92012-01-18 14:40:51 +00004988 } else {
Jeff Codyb1b1d782012-10-16 15:49:09 -04004989 /* If not an absolute filename path, make it relative to the current
4990 * image's filename path */
Max Reitz2d9158c2019-02-01 20:29:17 +01004991 filename_tmp = bdrv_make_absolute_filename(curr_bs, backing_file,
4992 NULL);
4993 /* We are going to compare canonicalized absolute pathnames */
4994 if (!filename_tmp || !realpath(filename_tmp, filename_full)) {
4995 g_free(filename_tmp);
Jeff Codyb1b1d782012-10-16 15:49:09 -04004996 continue;
4997 }
Max Reitz2d9158c2019-02-01 20:29:17 +01004998 g_free(filename_tmp);
Jeff Codyb1b1d782012-10-16 15:49:09 -04004999
5000 /* We need to make sure the backing filename we are comparing against
5001 * is relative to the current image filename (or absolute) */
Max Reitz2d9158c2019-02-01 20:29:17 +01005002 filename_tmp = bdrv_get_full_backing_filename(curr_bs, NULL);
5003 if (!filename_tmp || !realpath(filename_tmp, backing_file_full)) {
5004 g_free(filename_tmp);
Jeff Codyb1b1d782012-10-16 15:49:09 -04005005 continue;
5006 }
Max Reitz2d9158c2019-02-01 20:29:17 +01005007 g_free(filename_tmp);
Jeff Codyb1b1d782012-10-16 15:49:09 -04005008
5009 if (strcmp(backing_file_full, filename_full) == 0) {
Kevin Wolf760e0062015-06-17 14:55:21 +02005010 retval = curr_bs->backing->bs;
Jeff Codyb1b1d782012-10-16 15:49:09 -04005011 break;
5012 }
Marcelo Tosattie8a6bb92012-01-18 14:40:51 +00005013 }
5014 }
5015
Jeff Codyb1b1d782012-10-16 15:49:09 -04005016 g_free(filename_full);
5017 g_free(backing_file_full);
Jeff Codyb1b1d782012-10-16 15:49:09 -04005018 return retval;
Marcelo Tosattie8a6bb92012-01-18 14:40:51 +00005019}
5020
bellardea2384d2004-08-01 21:59:26 +00005021void bdrv_init(void)
5022{
Anthony Liguori5efa9d52009-05-09 17:03:42 -05005023 module_call_init(MODULE_INIT_BLOCK);
bellardea2384d2004-08-01 21:59:26 +00005024}
pbrookce1a14d2006-08-07 02:38:06 +00005025
Markus Armbrustereb852012009-10-27 18:41:44 +01005026void bdrv_init_with_whitelist(void)
5027{
5028 use_bdrv_whitelist = 1;
5029 bdrv_init();
5030}
5031
Paolo Bonzini2b148f32018-03-01 17:36:18 +01005032static void coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs,
5033 Error **errp)
Anthony Liguori0f154232011-11-14 15:09:45 -06005034{
Kevin Wolf4417ab72017-05-04 18:52:37 +02005035 BdrvChild *child, *parent;
Kevin Wolf9c5e6592017-05-04 18:52:40 +02005036 uint64_t perm, shared_perm;
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01005037 Error *local_err = NULL;
5038 int ret;
Vladimir Sementsov-Ogievskiy9c98f142018-10-29 16:23:17 -04005039 BdrvDirtyBitmap *bm;
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01005040
Kevin Wolf3456a8d2014-03-11 10:58:39 +01005041 if (!bs->drv) {
5042 return;
Anthony Liguori0f154232011-11-14 15:09:45 -06005043 }
Kevin Wolf3456a8d2014-03-11 10:58:39 +01005044
Kevin Wolf04c01a52016-01-13 15:56:06 +01005045 if (!(bs->open_flags & BDRV_O_INACTIVE)) {
Alexey Kardashevskiy7ea2d262014-10-09 13:50:46 +11005046 return;
5047 }
Alexey Kardashevskiy7ea2d262014-10-09 13:50:46 +11005048
Vladimir Sementsov-Ogievskiy16e977d2017-01-31 14:23:08 +03005049 QLIST_FOREACH(child, &bs->children, next) {
Paolo Bonzini2b148f32018-03-01 17:36:18 +01005050 bdrv_co_invalidate_cache(child->bs, &local_err);
Fam Zheng0d1c5c92016-05-11 10:45:33 +08005051 if (local_err) {
Fam Zheng0d1c5c92016-05-11 10:45:33 +08005052 error_propagate(errp, local_err);
5053 return;
5054 }
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01005055 }
Fam Zheng0d1c5c92016-05-11 10:45:33 +08005056
Kevin Wolfdafe0962017-11-16 13:00:01 +01005057 /*
5058 * Update permissions, they may differ for inactive nodes.
5059 *
5060 * Note that the required permissions of inactive images are always a
5061 * subset of the permissions required after activating the image. This
5062 * allows us to just get the permissions upfront without restricting
5063 * drv->bdrv_invalidate_cache().
5064 *
5065 * It also means that in error cases, we don't have to try and revert to
5066 * the old permissions (which is an operation that could fail, too). We can
5067 * just keep the extended permissions for the next time that an activation
5068 * of the image is tried.
5069 */
Vladimir Sementsov-Ogievskiy16e977d2017-01-31 14:23:08 +03005070 bs->open_flags &= ~BDRV_O_INACTIVE;
Kevin Wolfdafe0962017-11-16 13:00:01 +01005071 bdrv_get_cumulative_perm(bs, &perm, &shared_perm);
5072 ret = bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, &local_err);
5073 if (ret < 0) {
5074 bs->open_flags |= BDRV_O_INACTIVE;
5075 error_propagate(errp, local_err);
5076 return;
5077 }
5078 bdrv_set_perm(bs, perm, shared_perm);
5079
Paolo Bonzini2b148f32018-03-01 17:36:18 +01005080 if (bs->drv->bdrv_co_invalidate_cache) {
5081 bs->drv->bdrv_co_invalidate_cache(bs, &local_err);
Fam Zheng0d1c5c92016-05-11 10:45:33 +08005082 if (local_err) {
5083 bs->open_flags |= BDRV_O_INACTIVE;
5084 error_propagate(errp, local_err);
5085 return;
5086 }
Kevin Wolf3456a8d2014-03-11 10:58:39 +01005087 }
5088
Vladimir Sementsov-Ogievskiy9c98f142018-10-29 16:23:17 -04005089 for (bm = bdrv_dirty_bitmap_next(bs, NULL); bm;
5090 bm = bdrv_dirty_bitmap_next(bs, bm))
5091 {
5092 bdrv_dirty_bitmap_set_migration(bm, false);
5093 }
5094
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01005095 ret = refresh_total_sectors(bs, bs->total_sectors);
5096 if (ret < 0) {
Kevin Wolf04c01a52016-01-13 15:56:06 +01005097 bs->open_flags |= BDRV_O_INACTIVE;
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01005098 error_setg_errno(errp, -ret, "Could not refresh total sector count");
5099 return;
5100 }
Kevin Wolf4417ab72017-05-04 18:52:37 +02005101
5102 QLIST_FOREACH(parent, &bs->parents, next_parent) {
5103 if (parent->role->activate) {
5104 parent->role->activate(parent, &local_err);
5105 if (local_err) {
Kevin Wolf78fc3b32019-01-31 15:16:10 +01005106 bs->open_flags |= BDRV_O_INACTIVE;
Kevin Wolf4417ab72017-05-04 18:52:37 +02005107 error_propagate(errp, local_err);
5108 return;
5109 }
5110 }
5111 }
Anthony Liguori0f154232011-11-14 15:09:45 -06005112}
5113
Paolo Bonzini2b148f32018-03-01 17:36:18 +01005114typedef struct InvalidateCacheCo {
5115 BlockDriverState *bs;
5116 Error **errp;
5117 bool done;
5118} InvalidateCacheCo;
5119
5120static void coroutine_fn bdrv_invalidate_cache_co_entry(void *opaque)
5121{
5122 InvalidateCacheCo *ico = opaque;
5123 bdrv_co_invalidate_cache(ico->bs, ico->errp);
5124 ico->done = true;
Kevin Wolf4720cbe2019-01-07 13:02:48 +01005125 aio_wait_kick();
Paolo Bonzini2b148f32018-03-01 17:36:18 +01005126}
5127
5128void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
5129{
5130 Coroutine *co;
5131 InvalidateCacheCo ico = {
5132 .bs = bs,
5133 .done = false,
5134 .errp = errp
5135 };
5136
5137 if (qemu_in_coroutine()) {
5138 /* Fast-path if already in coroutine context */
5139 bdrv_invalidate_cache_co_entry(&ico);
5140 } else {
5141 co = qemu_coroutine_create(bdrv_invalidate_cache_co_entry, &ico);
Kevin Wolf4720cbe2019-01-07 13:02:48 +01005142 bdrv_coroutine_enter(bs, co);
Paolo Bonzini2b148f32018-03-01 17:36:18 +01005143 BDRV_POLL_WHILE(bs, !ico.done);
5144 }
5145}
5146
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01005147void bdrv_invalidate_cache_all(Error **errp)
Anthony Liguori0f154232011-11-14 15:09:45 -06005148{
Kevin Wolf7c8eece2016-03-22 18:58:50 +01005149 BlockDriverState *bs;
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01005150 Error *local_err = NULL;
Kevin Wolf88be7b42016-05-20 18:49:07 +02005151 BdrvNextIterator it;
Anthony Liguori0f154232011-11-14 15:09:45 -06005152
Kevin Wolf88be7b42016-05-20 18:49:07 +02005153 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
Stefan Hajnoczied78cda2014-05-08 16:34:35 +02005154 AioContext *aio_context = bdrv_get_aio_context(bs);
5155
5156 aio_context_acquire(aio_context);
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01005157 bdrv_invalidate_cache(bs, &local_err);
Stefan Hajnoczied78cda2014-05-08 16:34:35 +02005158 aio_context_release(aio_context);
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01005159 if (local_err) {
5160 error_propagate(errp, local_err);
Max Reitz5e003f12017-11-10 18:25:45 +01005161 bdrv_next_cleanup(&it);
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01005162 return;
5163 }
Anthony Liguori0f154232011-11-14 15:09:45 -06005164 }
5165}
5166
Kevin Wolf9e372712018-11-23 15:11:14 +01005167static bool bdrv_has_bds_parent(BlockDriverState *bs, bool only_active)
5168{
5169 BdrvChild *parent;
5170
5171 QLIST_FOREACH(parent, &bs->parents, next_parent) {
5172 if (parent->role->parent_is_bds) {
5173 BlockDriverState *parent_bs = parent->opaque;
5174 if (!only_active || !(parent_bs->open_flags & BDRV_O_INACTIVE)) {
5175 return true;
5176 }
5177 }
5178 }
5179
5180 return false;
5181}
5182
5183static int bdrv_inactivate_recurse(BlockDriverState *bs)
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01005184{
Kevin Wolfcfa1a572017-05-04 18:52:38 +02005185 BdrvChild *child, *parent;
Kevin Wolf9e372712018-11-23 15:11:14 +01005186 uint64_t perm, shared_perm;
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01005187 int ret;
5188
Max Reitzd470ad42017-11-10 21:31:09 +01005189 if (!bs->drv) {
5190 return -ENOMEDIUM;
5191 }
5192
Kevin Wolf9e372712018-11-23 15:11:14 +01005193 /* Make sure that we don't inactivate a child before its parent.
5194 * It will be covered by recursion from the yet active parent. */
5195 if (bdrv_has_bds_parent(bs, true)) {
5196 return 0;
5197 }
5198
5199 assert(!(bs->open_flags & BDRV_O_INACTIVE));
5200
5201 /* Inactivate this node */
5202 if (bs->drv->bdrv_inactivate) {
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01005203 ret = bs->drv->bdrv_inactivate(bs);
5204 if (ret < 0) {
5205 return ret;
5206 }
5207 }
5208
Kevin Wolf9e372712018-11-23 15:11:14 +01005209 QLIST_FOREACH(parent, &bs->parents, next_parent) {
5210 if (parent->role->inactivate) {
5211 ret = parent->role->inactivate(parent);
5212 if (ret < 0) {
5213 return ret;
Kevin Wolfcfa1a572017-05-04 18:52:38 +02005214 }
5215 }
Fam Zhengaad0b7a2016-05-11 10:45:35 +08005216 }
Kevin Wolf38701b62017-05-04 18:52:39 +02005217
Kevin Wolf9e372712018-11-23 15:11:14 +01005218 bs->open_flags |= BDRV_O_INACTIVE;
5219
5220 /* Update permissions, they may differ for inactive nodes */
5221 bdrv_get_cumulative_perm(bs, &perm, &shared_perm);
5222 bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, &error_abort);
5223 bdrv_set_perm(bs, perm, shared_perm);
5224
5225
5226 /* Recursively inactivate children */
Kevin Wolf38701b62017-05-04 18:52:39 +02005227 QLIST_FOREACH(child, &bs->children, next) {
Kevin Wolf9e372712018-11-23 15:11:14 +01005228 ret = bdrv_inactivate_recurse(child->bs);
Kevin Wolf38701b62017-05-04 18:52:39 +02005229 if (ret < 0) {
5230 return ret;
5231 }
5232 }
5233
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01005234 return 0;
5235}
5236
5237int bdrv_inactivate_all(void)
5238{
Max Reitz79720af2016-03-16 19:54:44 +01005239 BlockDriverState *bs = NULL;
Kevin Wolf88be7b42016-05-20 18:49:07 +02005240 BdrvNextIterator it;
Fam Zhengaad0b7a2016-05-11 10:45:35 +08005241 int ret = 0;
Paolo Bonzinibd6458e2017-12-07 20:13:15 +00005242 GSList *aio_ctxs = NULL, *ctx;
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01005243
Kevin Wolf88be7b42016-05-20 18:49:07 +02005244 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
Paolo Bonzinibd6458e2017-12-07 20:13:15 +00005245 AioContext *aio_context = bdrv_get_aio_context(bs);
5246
5247 if (!g_slist_find(aio_ctxs, aio_context)) {
5248 aio_ctxs = g_slist_prepend(aio_ctxs, aio_context);
5249 aio_context_acquire(aio_context);
5250 }
Fam Zhengaad0b7a2016-05-11 10:45:35 +08005251 }
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01005252
Kevin Wolf9e372712018-11-23 15:11:14 +01005253 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
5254 /* Nodes with BDS parents are covered by recursion from the last
5255 * parent that gets inactivated. Don't inactivate them a second
5256 * time if that has already happened. */
5257 if (bdrv_has_bds_parent(bs, false)) {
5258 continue;
5259 }
5260 ret = bdrv_inactivate_recurse(bs);
5261 if (ret < 0) {
5262 bdrv_next_cleanup(&it);
5263 goto out;
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01005264 }
5265 }
5266
Fam Zhengaad0b7a2016-05-11 10:45:35 +08005267out:
Paolo Bonzinibd6458e2017-12-07 20:13:15 +00005268 for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) {
5269 AioContext *aio_context = ctx->data;
5270 aio_context_release(aio_context);
Fam Zhengaad0b7a2016-05-11 10:45:35 +08005271 }
Paolo Bonzinibd6458e2017-12-07 20:13:15 +00005272 g_slist_free(aio_ctxs);
Fam Zhengaad0b7a2016-05-11 10:45:35 +08005273
5274 return ret;
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01005275}
5276
Kevin Wolff9f05dc2011-07-15 13:50:26 +02005277/**************************************************************/
bellard19cb3732006-08-19 11:45:59 +00005278/* removable device support */
5279
5280/**
5281 * Return TRUE if the media is present
5282 */
Max Reitze031f752015-10-19 17:53:11 +02005283bool bdrv_is_inserted(BlockDriverState *bs)
bellard19cb3732006-08-19 11:45:59 +00005284{
5285 BlockDriver *drv = bs->drv;
Max Reitz28d7a782015-10-19 17:53:13 +02005286 BdrvChild *child;
Markus Armbrustera1aff5b2011-09-06 18:58:41 +02005287
Max Reitze031f752015-10-19 17:53:11 +02005288 if (!drv) {
5289 return false;
5290 }
Max Reitz28d7a782015-10-19 17:53:13 +02005291 if (drv->bdrv_is_inserted) {
5292 return drv->bdrv_is_inserted(bs);
Max Reitze031f752015-10-19 17:53:11 +02005293 }
Max Reitz28d7a782015-10-19 17:53:13 +02005294 QLIST_FOREACH(child, &bs->children, next) {
5295 if (!bdrv_is_inserted(child->bs)) {
5296 return false;
5297 }
5298 }
5299 return true;
bellard19cb3732006-08-19 11:45:59 +00005300}
5301
5302/**
bellard19cb3732006-08-19 11:45:59 +00005303 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
5304 */
Luiz Capitulinof36f3942012-02-03 16:24:53 -02005305void bdrv_eject(BlockDriverState *bs, bool eject_flag)
bellard19cb3732006-08-19 11:45:59 +00005306{
5307 BlockDriver *drv = bs->drv;
bellard19cb3732006-08-19 11:45:59 +00005308
Markus Armbruster822e1cd2011-07-20 18:23:42 +02005309 if (drv && drv->bdrv_eject) {
5310 drv->bdrv_eject(bs, eject_flag);
bellard19cb3732006-08-19 11:45:59 +00005311 }
bellard19cb3732006-08-19 11:45:59 +00005312}
5313
bellard19cb3732006-08-19 11:45:59 +00005314/**
5315 * Lock or unlock the media (if it is locked, the user won't be able
5316 * to eject it manually).
5317 */
Markus Armbruster025e8492011-09-06 18:58:47 +02005318void bdrv_lock_medium(BlockDriverState *bs, bool locked)
bellard19cb3732006-08-19 11:45:59 +00005319{
5320 BlockDriver *drv = bs->drv;
5321
Markus Armbruster025e8492011-09-06 18:58:47 +02005322 trace_bdrv_lock_medium(bs, locked);
Stefan Hajnoczib8c6d092011-03-29 20:04:40 +01005323
Markus Armbruster025e8492011-09-06 18:58:47 +02005324 if (drv && drv->bdrv_lock_medium) {
5325 drv->bdrv_lock_medium(bs, locked);
bellard19cb3732006-08-19 11:45:59 +00005326 }
5327}
ths985a03b2007-12-24 16:10:43 +00005328
Fam Zheng9fcb0252013-08-23 09:14:46 +08005329/* Get a reference to bs */
5330void bdrv_ref(BlockDriverState *bs)
5331{
5332 bs->refcnt++;
5333}
5334
5335/* Release a previously grabbed reference to bs.
5336 * If after releasing, reference count is zero, the BlockDriverState is
5337 * deleted. */
5338void bdrv_unref(BlockDriverState *bs)
5339{
Jeff Cody9a4d5ca2014-07-23 17:22:57 -04005340 if (!bs) {
5341 return;
5342 }
Fam Zheng9fcb0252013-08-23 09:14:46 +08005343 assert(bs->refcnt > 0);
5344 if (--bs->refcnt == 0) {
5345 bdrv_delete(bs);
5346 }
5347}
5348
Fam Zhengfbe40ff2014-05-23 21:29:42 +08005349struct BdrvOpBlocker {
5350 Error *reason;
5351 QLIST_ENTRY(BdrvOpBlocker) list;
5352};
5353
5354bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
5355{
5356 BdrvOpBlocker *blocker;
5357 assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
5358 if (!QLIST_EMPTY(&bs->op_blockers[op])) {
5359 blocker = QLIST_FIRST(&bs->op_blockers[op]);
Markus Armbruster4b576642018-10-17 10:26:25 +02005360 error_propagate_prepend(errp, error_copy(blocker->reason),
5361 "Node '%s' is busy: ",
5362 bdrv_get_device_or_node_name(bs));
Fam Zhengfbe40ff2014-05-23 21:29:42 +08005363 return true;
5364 }
5365 return false;
5366}
5367
5368void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason)
5369{
5370 BdrvOpBlocker *blocker;
5371 assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
5372
Markus Armbruster5839e532014-08-19 10:31:08 +02005373 blocker = g_new0(BdrvOpBlocker, 1);
Fam Zhengfbe40ff2014-05-23 21:29:42 +08005374 blocker->reason = reason;
5375 QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list);
5376}
5377
5378void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason)
5379{
5380 BdrvOpBlocker *blocker, *next;
5381 assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
5382 QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) {
5383 if (blocker->reason == reason) {
5384 QLIST_REMOVE(blocker, list);
5385 g_free(blocker);
5386 }
5387 }
5388}
5389
5390void bdrv_op_block_all(BlockDriverState *bs, Error *reason)
5391{
5392 int i;
5393 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
5394 bdrv_op_block(bs, i, reason);
5395 }
5396}
5397
5398void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason)
5399{
5400 int i;
5401 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
5402 bdrv_op_unblock(bs, i, reason);
5403 }
5404}
5405
5406bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
5407{
5408 int i;
5409
5410 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
5411 if (!QLIST_EMPTY(&bs->op_blockers[i])) {
5412 return false;
5413 }
5414 }
5415 return true;
5416}
5417
Luiz Capitulinod92ada22012-11-30 10:52:09 -02005418void bdrv_img_create(const char *filename, const char *fmt,
5419 const char *base_filename, const char *base_fmt,
Fam Zheng92172832017-04-21 20:27:01 +08005420 char *options, uint64_t img_size, int flags, bool quiet,
5421 Error **errp)
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005422{
Chunyan Liu83d05212014-06-05 17:20:51 +08005423 QemuOptsList *create_opts = NULL;
5424 QemuOpts *opts = NULL;
5425 const char *backing_fmt, *backing_file;
5426 int64_t size;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005427 BlockDriver *drv, *proto_drv;
Max Reitzcc84d902013-09-06 17:14:26 +02005428 Error *local_err = NULL;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005429 int ret = 0;
5430
5431 /* Find driver and parse its options */
5432 drv = bdrv_find_format(fmt);
5433 if (!drv) {
Luiz Capitulino71c79812012-11-30 10:52:04 -02005434 error_setg(errp, "Unknown file format '%s'", fmt);
Luiz Capitulinod92ada22012-11-30 10:52:09 -02005435 return;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005436 }
5437
Max Reitzb65a5e12015-02-05 13:58:12 -05005438 proto_drv = bdrv_find_protocol(filename, true, errp);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005439 if (!proto_drv) {
Luiz Capitulinod92ada22012-11-30 10:52:09 -02005440 return;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005441 }
5442
Max Reitzc6149722014-12-02 18:32:45 +01005443 if (!drv->create_opts) {
5444 error_setg(errp, "Format driver '%s' does not support image creation",
5445 drv->format_name);
5446 return;
5447 }
5448
5449 if (!proto_drv->create_opts) {
5450 error_setg(errp, "Protocol driver '%s' does not support image creation",
5451 proto_drv->format_name);
5452 return;
5453 }
5454
Chunyan Liuc282e1f2014-06-05 17:21:11 +08005455 create_opts = qemu_opts_append(create_opts, drv->create_opts);
5456 create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005457
5458 /* Create parameter list with default values */
Chunyan Liu83d05212014-06-05 17:20:51 +08005459 opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
Markus Armbruster39101f22015-02-12 16:46:36 +01005460 qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005461
5462 /* Parse -o options */
5463 if (options) {
Markus Armbrusterdc523cd342015-02-12 18:37:11 +01005464 qemu_opts_do_parse(opts, options, NULL, &local_err);
5465 if (local_err) {
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005466 goto out;
5467 }
5468 }
5469
5470 if (base_filename) {
Markus Armbrusterf43e47d2015-02-12 17:52:20 +01005471 qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, &local_err);
Markus Armbruster6be41942015-02-12 17:49:02 +01005472 if (local_err) {
Luiz Capitulino71c79812012-11-30 10:52:04 -02005473 error_setg(errp, "Backing file not supported for file format '%s'",
5474 fmt);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005475 goto out;
5476 }
5477 }
5478
5479 if (base_fmt) {
Markus Armbrusterf43e47d2015-02-12 17:52:20 +01005480 qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, &local_err);
Markus Armbruster6be41942015-02-12 17:49:02 +01005481 if (local_err) {
Luiz Capitulino71c79812012-11-30 10:52:04 -02005482 error_setg(errp, "Backing file format not supported for file "
5483 "format '%s'", fmt);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005484 goto out;
5485 }
5486 }
5487
Chunyan Liu83d05212014-06-05 17:20:51 +08005488 backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
5489 if (backing_file) {
5490 if (!strcmp(filename, backing_file)) {
Luiz Capitulino71c79812012-11-30 10:52:04 -02005491 error_setg(errp, "Error: Trying to create an image with the "
5492 "same filename as the backing file");
Jes Sorensen792da932010-12-16 13:52:17 +01005493 goto out;
5494 }
5495 }
5496
Chunyan Liu83d05212014-06-05 17:20:51 +08005497 backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005498
John Snow6e6e55f2017-07-17 20:34:22 -04005499 /* The size for the image must always be specified, unless we have a backing
5500 * file and we have not been forbidden from opening it. */
Eric Blakea8b42a12017-09-25 09:55:07 -05005501 size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, img_size);
John Snow6e6e55f2017-07-17 20:34:22 -04005502 if (backing_file && !(flags & BDRV_O_NO_BACKING)) {
5503 BlockDriverState *bs;
Max Reitz645ae7d2019-02-01 20:29:14 +01005504 char *full_backing;
John Snow6e6e55f2017-07-17 20:34:22 -04005505 int back_flags;
5506 QDict *backing_options = NULL;
Paolo Bonzini63090da2012-04-12 14:01:03 +02005507
Max Reitz645ae7d2019-02-01 20:29:14 +01005508 full_backing =
5509 bdrv_get_full_backing_filename_from_filename(filename, backing_file,
5510 &local_err);
John Snow6e6e55f2017-07-17 20:34:22 -04005511 if (local_err) {
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005512 goto out;
5513 }
Max Reitz645ae7d2019-02-01 20:29:14 +01005514 assert(full_backing);
John Snow6e6e55f2017-07-17 20:34:22 -04005515
5516 /* backing files always opened read-only */
5517 back_flags = flags;
5518 back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
5519
Fam Zhengcc954f02017-12-15 16:04:45 +08005520 backing_options = qdict_new();
John Snow6e6e55f2017-07-17 20:34:22 -04005521 if (backing_fmt) {
John Snow6e6e55f2017-07-17 20:34:22 -04005522 qdict_put_str(backing_options, "driver", backing_fmt);
5523 }
Fam Zhengcc954f02017-12-15 16:04:45 +08005524 qdict_put_bool(backing_options, BDRV_OPT_FORCE_SHARE, true);
John Snow6e6e55f2017-07-17 20:34:22 -04005525
5526 bs = bdrv_open(full_backing, NULL, backing_options, back_flags,
5527 &local_err);
5528 g_free(full_backing);
5529 if (!bs && size != -1) {
5530 /* Couldn't open BS, but we have a size, so it's nonfatal */
5531 warn_reportf_err(local_err,
5532 "Could not verify backing image. "
5533 "This may become an error in future versions.\n");
5534 local_err = NULL;
5535 } else if (!bs) {
5536 /* Couldn't open bs, do not have size */
5537 error_append_hint(&local_err,
5538 "Could not open backing image to determine size.\n");
5539 goto out;
5540 } else {
5541 if (size == -1) {
5542 /* Opened BS, have no size */
5543 size = bdrv_getlength(bs);
5544 if (size < 0) {
5545 error_setg_errno(errp, -size, "Could not get size of '%s'",
5546 backing_file);
5547 bdrv_unref(bs);
5548 goto out;
5549 }
5550 qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort);
5551 }
5552 bdrv_unref(bs);
5553 }
5554 } /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */
5555
5556 if (size == -1) {
5557 error_setg(errp, "Image creation needs a size parameter");
5558 goto out;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005559 }
5560
Miroslav Rezaninaf382d432013-02-13 09:09:40 +01005561 if (!quiet) {
Kővágó, Zoltánfe646692015-07-07 16:42:10 +02005562 printf("Formatting '%s', fmt=%s ", filename, fmt);
Fam Zheng43c5d8f2014-12-09 15:38:04 +08005563 qemu_opts_print(opts, " ");
Miroslav Rezaninaf382d432013-02-13 09:09:40 +01005564 puts("");
5565 }
Chunyan Liu83d05212014-06-05 17:20:51 +08005566
Chunyan Liuc282e1f2014-06-05 17:21:11 +08005567 ret = bdrv_create(drv, filename, opts, &local_err);
Chunyan Liu83d05212014-06-05 17:20:51 +08005568
Max Reitzcc84d902013-09-06 17:14:26 +02005569 if (ret == -EFBIG) {
5570 /* This is generally a better message than whatever the driver would
5571 * deliver (especially because of the cluster_size_hint), since that
5572 * is most probably not much different from "image too large". */
5573 const char *cluster_size_hint = "";
Chunyan Liu83d05212014-06-05 17:20:51 +08005574 if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) {
Max Reitzcc84d902013-09-06 17:14:26 +02005575 cluster_size_hint = " (try using a larger cluster size)";
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005576 }
Max Reitzcc84d902013-09-06 17:14:26 +02005577 error_setg(errp, "The image size is too large for file format '%s'"
5578 "%s", fmt, cluster_size_hint);
5579 error_free(local_err);
5580 local_err = NULL;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005581 }
5582
5583out:
Chunyan Liu83d05212014-06-05 17:20:51 +08005584 qemu_opts_del(opts);
5585 qemu_opts_free(create_opts);
Eduardo Habkost621ff942016-06-13 18:57:56 -03005586 error_propagate(errp, local_err);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01005587}
Stefan Hajnoczi85d126f2013-03-07 13:41:48 +01005588
5589AioContext *bdrv_get_aio_context(BlockDriverState *bs)
5590{
Stefan Hajnoczi33f2a752018-02-16 16:50:13 +00005591 return bs ? bs->aio_context : qemu_get_aio_context();
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005592}
5593
Fam Zheng052a7572017-04-10 20:09:25 +08005594void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co)
5595{
5596 aio_co_enter(bdrv_get_aio_context(bs), co);
5597}
5598
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01005599static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban)
5600{
5601 QLIST_REMOVE(ban, list);
5602 g_free(ban);
5603}
5604
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005605void bdrv_detach_aio_context(BlockDriverState *bs)
5606{
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01005607 BdrvAioNotifier *baf, *baf_tmp;
Max Reitzb97511c2016-05-17 13:38:04 +02005608 BdrvChild *child;
Max Reitz33384422014-06-20 21:57:33 +02005609
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005610 if (!bs->drv) {
5611 return;
5612 }
5613
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01005614 assert(!bs->walking_aio_notifiers);
5615 bs->walking_aio_notifiers = true;
5616 QLIST_FOREACH_SAFE(baf, &bs->aio_notifiers, list, baf_tmp) {
5617 if (baf->deleted) {
5618 bdrv_do_remove_aio_context_notifier(baf);
5619 } else {
5620 baf->detach_aio_context(baf->opaque);
5621 }
Max Reitz33384422014-06-20 21:57:33 +02005622 }
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01005623 /* Never mind iterating again to check for ->deleted. bdrv_close() will
5624 * remove remaining aio notifiers if we aren't called again.
5625 */
5626 bs->walking_aio_notifiers = false;
Max Reitz33384422014-06-20 21:57:33 +02005627
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005628 if (bs->drv->bdrv_detach_aio_context) {
5629 bs->drv->bdrv_detach_aio_context(bs);
5630 }
Max Reitzb97511c2016-05-17 13:38:04 +02005631 QLIST_FOREACH(child, &bs->children, next) {
5632 bdrv_detach_aio_context(child->bs);
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005633 }
5634
Kevin Wolfe64f25f2019-02-08 16:51:17 +01005635 if (bs->quiesce_counter) {
5636 aio_enable_external(bs->aio_context);
5637 }
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005638 bs->aio_context = NULL;
5639}
5640
5641void bdrv_attach_aio_context(BlockDriverState *bs,
5642 AioContext *new_context)
5643{
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01005644 BdrvAioNotifier *ban, *ban_tmp;
Max Reitzb97511c2016-05-17 13:38:04 +02005645 BdrvChild *child;
Max Reitz33384422014-06-20 21:57:33 +02005646
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005647 if (!bs->drv) {
5648 return;
5649 }
5650
Kevin Wolfe64f25f2019-02-08 16:51:17 +01005651 if (bs->quiesce_counter) {
5652 aio_disable_external(new_context);
5653 }
5654
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005655 bs->aio_context = new_context;
5656
Max Reitzb97511c2016-05-17 13:38:04 +02005657 QLIST_FOREACH(child, &bs->children, next) {
5658 bdrv_attach_aio_context(child->bs, new_context);
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005659 }
5660 if (bs->drv->bdrv_attach_aio_context) {
5661 bs->drv->bdrv_attach_aio_context(bs, new_context);
5662 }
Max Reitz33384422014-06-20 21:57:33 +02005663
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01005664 assert(!bs->walking_aio_notifiers);
5665 bs->walking_aio_notifiers = true;
5666 QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_tmp) {
5667 if (ban->deleted) {
5668 bdrv_do_remove_aio_context_notifier(ban);
5669 } else {
5670 ban->attached_aio_context(new_context, ban->opaque);
5671 }
Max Reitz33384422014-06-20 21:57:33 +02005672 }
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01005673 bs->walking_aio_notifiers = false;
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005674}
5675
Kevin Wolfd70d5952019-02-08 16:53:37 +01005676/* The caller must own the AioContext lock for the old AioContext of bs, but it
5677 * must not own the AioContext lock for new_context (unless new_context is
5678 * the same as the current context of bs). */
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005679void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
5680{
Kevin Wolfd70d5952019-02-08 16:53:37 +01005681 if (bdrv_get_aio_context(bs) == new_context) {
Denis Plotnikov57830a42019-02-15 16:03:25 +03005682 return;
5683 }
5684
Kevin Wolfd70d5952019-02-08 16:53:37 +01005685 bdrv_drained_begin(bs);
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005686 bdrv_detach_aio_context(bs);
5687
5688 /* This function executes in the old AioContext so acquire the new one in
5689 * case it runs in a different thread.
5690 */
5691 aio_context_acquire(new_context);
5692 bdrv_attach_aio_context(bs, new_context);
Kevin Wolfd70d5952019-02-08 16:53:37 +01005693 bdrv_drained_end(bs);
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02005694 aio_context_release(new_context);
Stefan Hajnoczi85d126f2013-03-07 13:41:48 +01005695}
Stefan Hajnoczid616b222013-06-24 17:13:10 +02005696
Max Reitz33384422014-06-20 21:57:33 +02005697void bdrv_add_aio_context_notifier(BlockDriverState *bs,
5698 void (*attached_aio_context)(AioContext *new_context, void *opaque),
5699 void (*detach_aio_context)(void *opaque), void *opaque)
5700{
5701 BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1);
5702 *ban = (BdrvAioNotifier){
5703 .attached_aio_context = attached_aio_context,
5704 .detach_aio_context = detach_aio_context,
5705 .opaque = opaque
5706 };
5707
5708 QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list);
5709}
5710
5711void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
5712 void (*attached_aio_context)(AioContext *,
5713 void *),
5714 void (*detach_aio_context)(void *),
5715 void *opaque)
5716{
5717 BdrvAioNotifier *ban, *ban_next;
5718
5719 QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
5720 if (ban->attached_aio_context == attached_aio_context &&
5721 ban->detach_aio_context == detach_aio_context &&
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01005722 ban->opaque == opaque &&
5723 ban->deleted == false)
Max Reitz33384422014-06-20 21:57:33 +02005724 {
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01005725 if (bs->walking_aio_notifiers) {
5726 ban->deleted = true;
5727 } else {
5728 bdrv_do_remove_aio_context_notifier(ban);
5729 }
Max Reitz33384422014-06-20 21:57:33 +02005730 return;
5731 }
5732 }
5733
5734 abort();
5735}
5736
Max Reitz77485432014-10-27 11:12:50 +01005737int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts,
Max Reitzd1402b52018-05-09 23:00:18 +02005738 BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
5739 Error **errp)
Max Reitz6f176b42013-09-03 10:09:50 +02005740{
Max Reitzd470ad42017-11-10 21:31:09 +01005741 if (!bs->drv) {
Max Reitzd1402b52018-05-09 23:00:18 +02005742 error_setg(errp, "Node is ejected");
Max Reitzd470ad42017-11-10 21:31:09 +01005743 return -ENOMEDIUM;
5744 }
Chunyan Liuc282e1f2014-06-05 17:21:11 +08005745 if (!bs->drv->bdrv_amend_options) {
Max Reitzd1402b52018-05-09 23:00:18 +02005746 error_setg(errp, "Block driver '%s' does not support option amendment",
5747 bs->drv->format_name);
Max Reitz6f176b42013-09-03 10:09:50 +02005748 return -ENOTSUP;
5749 }
Max Reitzd1402b52018-05-09 23:00:18 +02005750 return bs->drv->bdrv_amend_options(bs, opts, status_cb, cb_opaque, errp);
Max Reitz6f176b42013-09-03 10:09:50 +02005751}
Benoît Canetf6186f42013-10-02 14:33:48 +02005752
Benoît Canetb5042a32014-03-03 19:11:34 +01005753/* This function will be called by the bdrv_recurse_is_first_non_filter method
5754 * of block filter and by bdrv_is_first_non_filter.
5755 * It is used to test if the given bs is the candidate or recurse more in the
5756 * node graph.
Benoît Canet212a5a82014-01-23 21:31:36 +01005757 */
Benoît Canet212a5a82014-01-23 21:31:36 +01005758bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
5759 BlockDriverState *candidate)
Benoît Canetf6186f42013-10-02 14:33:48 +02005760{
Benoît Canetb5042a32014-03-03 19:11:34 +01005761 /* return false if basic checks fails */
5762 if (!bs || !bs->drv) {
5763 return false;
5764 }
5765
5766 /* the code reached a non block filter driver -> check if the bs is
5767 * the same as the candidate. It's the recursion termination condition.
5768 */
5769 if (!bs->drv->is_filter) {
5770 return bs == candidate;
5771 }
5772 /* Down this path the driver is a block filter driver */
5773
5774 /* If the block filter recursion method is defined use it to recurse down
5775 * the node graph.
5776 */
5777 if (bs->drv->bdrv_recurse_is_first_non_filter) {
Benoît Canet212a5a82014-01-23 21:31:36 +01005778 return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate);
5779 }
5780
Benoît Canetb5042a32014-03-03 19:11:34 +01005781 /* the driver is a block filter but don't allow to recurse -> return false
5782 */
5783 return false;
Benoît Canet212a5a82014-01-23 21:31:36 +01005784}
5785
5786/* This function checks if the candidate is the first non filter bs down it's
5787 * bs chain. Since we don't have pointers to parents it explore all bs chains
5788 * from the top. Some filters can choose not to pass down the recursion.
5789 */
5790bool bdrv_is_first_non_filter(BlockDriverState *candidate)
5791{
Kevin Wolf7c8eece2016-03-22 18:58:50 +01005792 BlockDriverState *bs;
Kevin Wolf88be7b42016-05-20 18:49:07 +02005793 BdrvNextIterator it;
Benoît Canet212a5a82014-01-23 21:31:36 +01005794
5795 /* walk down the bs forest recursively */
Kevin Wolf88be7b42016-05-20 18:49:07 +02005796 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
Benoît Canet212a5a82014-01-23 21:31:36 +01005797 bool perm;
5798
Benoît Canetb5042a32014-03-03 19:11:34 +01005799 /* try to recurse in this top level bs */
Kevin Wolfe6dc8a12014-02-04 11:45:31 +01005800 perm = bdrv_recurse_is_first_non_filter(bs, candidate);
Benoît Canet212a5a82014-01-23 21:31:36 +01005801
5802 /* candidate is the first non filter */
5803 if (perm) {
Max Reitz5e003f12017-11-10 18:25:45 +01005804 bdrv_next_cleanup(&it);
Benoît Canet212a5a82014-01-23 21:31:36 +01005805 return true;
5806 }
5807 }
5808
5809 return false;
Benoît Canetf6186f42013-10-02 14:33:48 +02005810}
Benoît Canet09158f02014-06-27 18:25:25 +02005811
Wen Congyange12f3782015-07-17 10:12:22 +08005812BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
5813 const char *node_name, Error **errp)
Benoît Canet09158f02014-06-27 18:25:25 +02005814{
5815 BlockDriverState *to_replace_bs = bdrv_find_node(node_name);
Stefan Hajnoczi5a7e7a02014-10-21 12:03:58 +01005816 AioContext *aio_context;
5817
Benoît Canet09158f02014-06-27 18:25:25 +02005818 if (!to_replace_bs) {
5819 error_setg(errp, "Node name '%s' not found", node_name);
5820 return NULL;
5821 }
5822
Stefan Hajnoczi5a7e7a02014-10-21 12:03:58 +01005823 aio_context = bdrv_get_aio_context(to_replace_bs);
5824 aio_context_acquire(aio_context);
5825
Benoît Canet09158f02014-06-27 18:25:25 +02005826 if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) {
Stefan Hajnoczi5a7e7a02014-10-21 12:03:58 +01005827 to_replace_bs = NULL;
5828 goto out;
Benoît Canet09158f02014-06-27 18:25:25 +02005829 }
5830
5831 /* We don't want arbitrary node of the BDS chain to be replaced only the top
5832 * most non filter in order to prevent data corruption.
5833 * Another benefit is that this tests exclude backing files which are
5834 * blocked by the backing blockers.
5835 */
Wen Congyange12f3782015-07-17 10:12:22 +08005836 if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) {
Benoît Canet09158f02014-06-27 18:25:25 +02005837 error_setg(errp, "Only top most non filter can be replaced");
Stefan Hajnoczi5a7e7a02014-10-21 12:03:58 +01005838 to_replace_bs = NULL;
5839 goto out;
Benoît Canet09158f02014-06-27 18:25:25 +02005840 }
5841
Stefan Hajnoczi5a7e7a02014-10-21 12:03:58 +01005842out:
5843 aio_context_release(aio_context);
Benoît Canet09158f02014-06-27 18:25:25 +02005844 return to_replace_bs;
5845}
Ming Lei448ad912014-07-04 18:04:33 +08005846
Max Reitz97e2f022019-02-01 20:29:27 +01005847/**
5848 * Iterates through the list of runtime option keys that are said to
5849 * be "strong" for a BDS. An option is called "strong" if it changes
5850 * a BDS's data. For example, the null block driver's "size" and
5851 * "read-zeroes" options are strong, but its "latency-ns" option is
5852 * not.
5853 *
5854 * If a key returned by this function ends with a dot, all options
5855 * starting with that prefix are strong.
5856 */
5857static const char *const *strong_options(BlockDriverState *bs,
5858 const char *const *curopt)
5859{
5860 static const char *const global_options[] = {
5861 "driver", "filename", NULL
5862 };
5863
5864 if (!curopt) {
5865 return &global_options[0];
5866 }
5867
5868 curopt++;
5869 if (curopt == &global_options[ARRAY_SIZE(global_options) - 1] && bs->drv) {
5870 curopt = bs->drv->strong_runtime_opts;
5871 }
5872
5873 return (curopt && *curopt) ? curopt : NULL;
5874}
5875
5876/**
5877 * Copies all strong runtime options from bs->options to the given
5878 * QDict. The set of strong option keys is determined by invoking
5879 * strong_options().
5880 *
5881 * Returns true iff any strong option was present in bs->options (and
5882 * thus copied to the target QDict) with the exception of "filename"
5883 * and "driver". The caller is expected to use this value to decide
5884 * whether the existence of strong options prevents the generation of
5885 * a plain filename.
5886 */
5887static bool append_strong_runtime_options(QDict *d, BlockDriverState *bs)
5888{
5889 bool found_any = false;
5890 const char *const *option_name = NULL;
5891
5892 if (!bs->drv) {
5893 return false;
5894 }
5895
5896 while ((option_name = strong_options(bs, option_name))) {
5897 bool option_given = false;
5898
5899 assert(strlen(*option_name) > 0);
5900 if ((*option_name)[strlen(*option_name) - 1] != '.') {
5901 QObject *entry = qdict_get(bs->options, *option_name);
5902 if (!entry) {
5903 continue;
5904 }
5905
5906 qdict_put_obj(d, *option_name, qobject_ref(entry));
5907 option_given = true;
5908 } else {
5909 const QDictEntry *entry;
5910 for (entry = qdict_first(bs->options); entry;
5911 entry = qdict_next(bs->options, entry))
5912 {
5913 if (strstart(qdict_entry_key(entry), *option_name, NULL)) {
5914 qdict_put_obj(d, qdict_entry_key(entry),
5915 qobject_ref(qdict_entry_value(entry)));
5916 option_given = true;
5917 }
5918 }
5919 }
5920
5921 /* While "driver" and "filename" need to be included in a JSON filename,
5922 * their existence does not prohibit generation of a plain filename. */
5923 if (!found_any && option_given &&
5924 strcmp(*option_name, "driver") && strcmp(*option_name, "filename"))
5925 {
5926 found_any = true;
5927 }
5928 }
5929
Max Reitz62a01a272019-02-01 20:29:34 +01005930 if (!qdict_haskey(d, "driver")) {
5931 /* Drivers created with bdrv_new_open_driver() may not have a
5932 * @driver option. Add it here. */
5933 qdict_put_str(d, "driver", bs->drv->format_name);
5934 }
5935
Max Reitz97e2f022019-02-01 20:29:27 +01005936 return found_any;
5937}
5938
Max Reitz90993622019-02-01 20:29:09 +01005939/* Note: This function may return false positives; it may return true
5940 * even if opening the backing file specified by bs's image header
5941 * would result in exactly bs->backing. */
5942static bool bdrv_backing_overridden(BlockDriverState *bs)
5943{
5944 if (bs->backing) {
5945 return strcmp(bs->auto_backing_file,
5946 bs->backing->bs->filename);
5947 } else {
5948 /* No backing BDS, so if the image header reports any backing
5949 * file, it must have been suppressed */
5950 return bs->auto_backing_file[0] != '\0';
5951 }
5952}
5953
Max Reitz91af7012014-07-18 20:24:56 +02005954/* Updates the following BDS fields:
5955 * - exact_filename: A filename which may be used for opening a block device
5956 * which (mostly) equals the given BDS (even without any
5957 * other options; so reading and writing must return the same
5958 * results, but caching etc. may be different)
5959 * - full_open_options: Options which, when given when opening a block device
5960 * (without a filename), result in a BDS (mostly)
5961 * equalling the given one
5962 * - filename: If exact_filename is set, it is copied here. Otherwise,
5963 * full_open_options is converted to a JSON object, prefixed with
5964 * "json:" (for use through the JSON pseudo protocol) and put here.
5965 */
5966void bdrv_refresh_filename(BlockDriverState *bs)
5967{
5968 BlockDriver *drv = bs->drv;
Max Reitze24518e2019-02-01 20:29:06 +01005969 BdrvChild *child;
Max Reitz91af7012014-07-18 20:24:56 +02005970 QDict *opts;
Max Reitz90993622019-02-01 20:29:09 +01005971 bool backing_overridden;
Max Reitz998b3a12019-02-01 20:29:28 +01005972 bool generate_json_filename; /* Whether our default implementation should
5973 fill exact_filename (false) or not (true) */
Max Reitz91af7012014-07-18 20:24:56 +02005974
5975 if (!drv) {
5976 return;
5977 }
5978
Max Reitze24518e2019-02-01 20:29:06 +01005979 /* This BDS's file name may depend on any of its children's file names, so
5980 * refresh those first */
5981 QLIST_FOREACH(child, &bs->children, next) {
5982 bdrv_refresh_filename(child->bs);
Max Reitz91af7012014-07-18 20:24:56 +02005983 }
5984
Max Reitzbb808d52019-02-01 20:29:07 +01005985 if (bs->implicit) {
5986 /* For implicit nodes, just copy everything from the single child */
5987 child = QLIST_FIRST(&bs->children);
5988 assert(QLIST_NEXT(child, next) == NULL);
5989
5990 pstrcpy(bs->exact_filename, sizeof(bs->exact_filename),
5991 child->bs->exact_filename);
5992 pstrcpy(bs->filename, sizeof(bs->filename), child->bs->filename);
5993
5994 bs->full_open_options = qobject_ref(child->bs->full_open_options);
5995
5996 return;
5997 }
5998
Max Reitz90993622019-02-01 20:29:09 +01005999 backing_overridden = bdrv_backing_overridden(bs);
6000
6001 if (bs->open_flags & BDRV_O_NO_IO) {
6002 /* Without I/O, the backing file does not change anything.
6003 * Therefore, in such a case (primarily qemu-img), we can
6004 * pretend the backing file has not been overridden even if
6005 * it technically has been. */
6006 backing_overridden = false;
6007 }
6008
Max Reitz97e2f022019-02-01 20:29:27 +01006009 /* Gather the options QDict */
6010 opts = qdict_new();
Max Reitz998b3a12019-02-01 20:29:28 +01006011 generate_json_filename = append_strong_runtime_options(opts, bs);
6012 generate_json_filename |= backing_overridden;
Max Reitz97e2f022019-02-01 20:29:27 +01006013
6014 if (drv->bdrv_gather_child_options) {
6015 /* Some block drivers may not want to present all of their children's
6016 * options, or name them differently from BdrvChild.name */
6017 drv->bdrv_gather_child_options(bs, opts, backing_overridden);
6018 } else {
6019 QLIST_FOREACH(child, &bs->children, next) {
6020 if (child->role == &child_backing && !backing_overridden) {
6021 /* We can skip the backing BDS if it has not been overridden */
6022 continue;
6023 }
6024
6025 qdict_put(opts, child->name,
6026 qobject_ref(child->bs->full_open_options));
6027 }
6028
6029 if (backing_overridden && !bs->backing) {
6030 /* Force no backing file */
6031 qdict_put_null(opts, "backing");
6032 }
6033 }
6034
6035 qobject_unref(bs->full_open_options);
6036 bs->full_open_options = opts;
6037
Max Reitz998b3a12019-02-01 20:29:28 +01006038 if (drv->bdrv_refresh_filename) {
6039 /* Obsolete information is of no use here, so drop the old file name
6040 * information before refreshing it */
6041 bs->exact_filename[0] = '\0';
6042
6043 drv->bdrv_refresh_filename(bs);
6044 } else if (bs->file) {
6045 /* Try to reconstruct valid information from the underlying file */
6046
6047 bs->exact_filename[0] = '\0';
6048
Max Reitzfb695c72019-02-01 20:29:29 +01006049 /*
6050 * We can use the underlying file's filename if:
6051 * - it has a filename,
6052 * - the file is a protocol BDS, and
6053 * - opening that file (as this BDS's format) will automatically create
6054 * the BDS tree we have right now, that is:
6055 * - the user did not significantly change this BDS's behavior with
6056 * some explicit (strong) options
6057 * - no non-file child of this BDS has been overridden by the user
6058 * Both of these conditions are represented by generate_json_filename.
6059 */
6060 if (bs->file->bs->exact_filename[0] &&
6061 bs->file->bs->drv->bdrv_file_open &&
6062 !generate_json_filename)
6063 {
Max Reitz998b3a12019-02-01 20:29:28 +01006064 strcpy(bs->exact_filename, bs->file->bs->exact_filename);
6065 }
6066 }
6067
Max Reitz91af7012014-07-18 20:24:56 +02006068 if (bs->exact_filename[0]) {
6069 pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename);
Max Reitz97e2f022019-02-01 20:29:27 +01006070 } else {
Max Reitz91af7012014-07-18 20:24:56 +02006071 QString *json = qobject_to_json(QOBJECT(bs->full_open_options));
6072 snprintf(bs->filename, sizeof(bs->filename), "json:%s",
6073 qstring_get_str(json));
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02006074 qobject_unref(json);
Max Reitz91af7012014-07-18 20:24:56 +02006075 }
6076}
Wen Congyange06018a2016-05-10 15:36:37 +08006077
Max Reitz1e89d0f2019-02-01 20:29:18 +01006078char *bdrv_dirname(BlockDriverState *bs, Error **errp)
6079{
6080 BlockDriver *drv = bs->drv;
6081
6082 if (!drv) {
6083 error_setg(errp, "Node '%s' is ejected", bs->node_name);
6084 return NULL;
6085 }
6086
6087 if (drv->bdrv_dirname) {
6088 return drv->bdrv_dirname(bs, errp);
6089 }
6090
6091 if (bs->file) {
6092 return bdrv_dirname(bs->file->bs, errp);
6093 }
6094
6095 bdrv_refresh_filename(bs);
6096 if (bs->exact_filename[0] != '\0') {
6097 return path_combine(bs->exact_filename, "");
6098 }
6099
6100 error_setg(errp, "Cannot generate a base directory for %s nodes",
6101 drv->format_name);
6102 return NULL;
6103}
6104
Wen Congyange06018a2016-05-10 15:36:37 +08006105/*
6106 * Hot add/remove a BDS's child. So the user can take a child offline when
6107 * it is broken and take a new child online
6108 */
6109void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs,
6110 Error **errp)
6111{
6112
6113 if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) {
6114 error_setg(errp, "The node %s does not support adding a child",
6115 bdrv_get_device_or_node_name(parent_bs));
6116 return;
6117 }
6118
6119 if (!QLIST_EMPTY(&child_bs->parents)) {
6120 error_setg(errp, "The node %s already has a parent",
6121 child_bs->node_name);
6122 return;
6123 }
6124
6125 parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp);
6126}
6127
6128void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp)
6129{
6130 BdrvChild *tmp;
6131
6132 if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) {
6133 error_setg(errp, "The node %s does not support removing a child",
6134 bdrv_get_device_or_node_name(parent_bs));
6135 return;
6136 }
6137
6138 QLIST_FOREACH(tmp, &parent_bs->children, next) {
6139 if (tmp == child) {
6140 break;
6141 }
6142 }
6143
6144 if (!tmp) {
6145 error_setg(errp, "The node %s does not have a child named %s",
6146 bdrv_get_device_or_node_name(parent_bs),
6147 bdrv_get_device_or_node_name(child->bs));
6148 return;
6149 }
6150
6151 parent_bs->drv->bdrv_del_child(parent_bs, child, errp);
6152}
Vladimir Sementsov-Ogievskiy67b792f2017-06-28 15:05:21 +03006153
6154bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
6155 uint32_t granularity, Error **errp)
6156{
6157 BlockDriver *drv = bs->drv;
6158
6159 if (!drv) {
6160 error_setg_errno(errp, ENOMEDIUM,
6161 "Can't store persistent bitmaps to %s",
6162 bdrv_get_device_or_node_name(bs));
6163 return false;
6164 }
6165
6166 if (!drv->bdrv_can_store_new_dirty_bitmap) {
6167 error_setg_errno(errp, ENOTSUP,
6168 "Can't store persistent bitmaps to %s",
6169 bdrv_get_device_or_node_name(bs));
6170 return false;
6171 }
6172
6173 return drv->bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp);
6174}