blob: 9d577f65bbc66f51ccc163f1ea5b29519fbe7a8e [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"
Markus Armbrusterd49b6832015-03-17 18:29:20 +010030#include "qemu/error-report.h"
Marc Mari88d88792016-08-12 09:27:03 -040031#include "module_block.h"
Paolo Bonzini1de7afc2012-12-17 18:20:00 +010032#include "qemu/module.h"
Markus Armbrustere688df62018-02-01 12:18:31 +010033#include "qapi/error.h"
Markus Armbruster452fcdb2018-02-01 12:18:39 +010034#include "qapi/qmp/qdict.h"
Paolo Bonzini7b1b5d12012-12-17 18:19:43 +010035#include "qapi/qmp/qjson.h"
Max Reitze59a0cf2018-02-24 16:40:32 +010036#include "qapi/qmp/qnull.h"
Markus Armbrusterfc81fa12018-02-01 12:18:40 +010037#include "qapi/qmp/qstring.h"
Kevin Wolfe1d74bc2018-01-10 15:52:33 +010038#include "qapi/qobject-output-visitor.h"
39#include "qapi/qapi-visit-block-core.h"
Markus Armbrusterbfb197e2014-10-07 13:59:11 +020040#include "sysemu/block-backend.h"
Paolo Bonzini9c17d612012-12-17 18:20:04 +010041#include "sysemu/sysemu.h"
Paolo Bonzini1de7afc2012-12-17 18:20:00 +010042#include "qemu/notify.h"
Markus Armbruster922a01a2018-02-01 12:18:46 +010043#include "qemu/option.h"
Daniel P. Berrange10817bf2015-09-01 14:48:02 +010044#include "qemu/coroutine.h"
Benoît Canetc13163f2014-01-23 21:31:34 +010045#include "block/qapi.h"
Paolo Bonzini1de7afc2012-12-17 18:20:00 +010046#include "qemu/timer.h"
Veronia Bahaaf348b6d2016-03-20 19:16:19 +020047#include "qemu/cutils.h"
48#include "qemu/id.h"
bellardfc01f7e2003-06-30 10:03:06 +000049
Juan Quintela71e72a12009-07-27 16:12:56 +020050#ifdef CONFIG_BSD
bellard7674e7b2005-04-26 21:59:26 +000051#include <sys/ioctl.h>
Blue Swirl72cf2d42009-09-12 07:36:22 +000052#include <sys/queue.h>
blueswir1c5e97232009-03-07 20:06:23 +000053#ifndef __DragonFly__
bellard7674e7b2005-04-26 21:59:26 +000054#include <sys/disk.h>
55#endif
blueswir1c5e97232009-03-07 20:06:23 +000056#endif
bellard7674e7b2005-04-26 21:59:26 +000057
aliguori49dc7682009-03-08 16:26:59 +000058#ifdef _WIN32
59#include <windows.h>
60#endif
61
Stefan Hajnoczi1c9805a2011-10-13 13:08:22 +010062#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
63
Benoît Canetdc364f42014-01-23 21:31:32 +010064static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
65 QTAILQ_HEAD_INITIALIZER(graph_bdrv_states);
66
Max Reitz2c1d04e2016-01-29 16:36:11 +010067static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states =
68 QTAILQ_HEAD_INITIALIZER(all_bdrv_states);
69
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +010070static QLIST_HEAD(, BlockDriver) bdrv_drivers =
71 QLIST_HEAD_INITIALIZER(bdrv_drivers);
bellardea2384d2004-08-01 21:59:26 +000072
Max Reitz5b363932016-05-17 16:41:31 +020073static BlockDriverState *bdrv_open_inherit(const char *filename,
74 const char *reference,
75 QDict *options, int flags,
76 BlockDriverState *parent,
77 const BdrvChildRole *child_role,
78 Error **errp);
Kevin Wolff3930ed2015-04-08 13:43:47 +020079
Markus Armbrustereb852012009-10-27 18:41:44 +010080/* If non-zero, use only whitelisted block drivers */
81static int use_bdrv_whitelist;
82
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +000083#ifdef _WIN32
84static int is_windows_drive_prefix(const char *filename)
85{
86 return (((filename[0] >= 'a' && filename[0] <= 'z') ||
87 (filename[0] >= 'A' && filename[0] <= 'Z')) &&
88 filename[1] == ':');
89}
90
91int is_windows_drive(const char *filename)
92{
93 if (is_windows_drive_prefix(filename) &&
94 filename[2] == '\0')
95 return 1;
96 if (strstart(filename, "\\\\.\\", NULL) ||
97 strstart(filename, "//./", NULL))
98 return 1;
99 return 0;
100}
101#endif
102
Kevin Wolf339064d2013-11-28 10:23:32 +0100103size_t bdrv_opt_mem_align(BlockDriverState *bs)
104{
105 if (!bs || !bs->drv) {
Denis V. Lunev459b4e62015-05-12 17:30:56 +0300106 /* page size or 4k (hdd sector size) should be on the safe side */
107 return MAX(4096, getpagesize());
Kevin Wolf339064d2013-11-28 10:23:32 +0100108 }
109
110 return bs->bl.opt_mem_alignment;
111}
112
Denis V. Lunev4196d2f2015-05-12 17:30:55 +0300113size_t bdrv_min_mem_align(BlockDriverState *bs)
114{
115 if (!bs || !bs->drv) {
Denis V. Lunev459b4e62015-05-12 17:30:56 +0300116 /* page size or 4k (hdd sector size) should be on the safe side */
117 return MAX(4096, getpagesize());
Denis V. Lunev4196d2f2015-05-12 17:30:55 +0300118 }
119
120 return bs->bl.min_mem_alignment;
121}
122
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000123/* check if the path starts with "<protocol>:" */
Max Reitz5c984152014-12-03 14:57:22 +0100124int path_has_protocol(const char *path)
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000125{
Paolo Bonzini947995c2012-05-08 16:51:48 +0200126 const char *p;
127
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000128#ifdef _WIN32
129 if (is_windows_drive(path) ||
130 is_windows_drive_prefix(path)) {
131 return 0;
132 }
Paolo Bonzini947995c2012-05-08 16:51:48 +0200133 p = path + strcspn(path, ":/\\");
134#else
135 p = path + strcspn(path, ":/");
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000136#endif
137
Paolo Bonzini947995c2012-05-08 16:51:48 +0200138 return *p == ':';
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000139}
140
bellard83f64092006-08-01 16:21:11 +0000141int path_is_absolute(const char *path)
142{
bellard21664422007-01-07 18:22:37 +0000143#ifdef _WIN32
144 /* specific case for names like: "\\.\d:" */
Paolo Bonzinif53f4da2012-05-08 16:51:47 +0200145 if (is_windows_drive(path) || is_windows_drive_prefix(path)) {
bellard21664422007-01-07 18:22:37 +0000146 return 1;
Paolo Bonzinif53f4da2012-05-08 16:51:47 +0200147 }
148 return (*path == '/' || *path == '\\');
bellard3b9f94e2007-01-07 17:27:07 +0000149#else
Paolo Bonzinif53f4da2012-05-08 16:51:47 +0200150 return (*path == '/');
bellard3b9f94e2007-01-07 17:27:07 +0000151#endif
bellard83f64092006-08-01 16:21:11 +0000152}
153
154/* if filename is absolute, just copy it to dest. Otherwise, build a
155 path to it by considering it is relative to base_path. URL are
156 supported. */
157void path_combine(char *dest, int dest_size,
158 const char *base_path,
159 const char *filename)
160{
161 const char *p, *p1;
162 int len;
163
164 if (dest_size <= 0)
165 return;
166 if (path_is_absolute(filename)) {
167 pstrcpy(dest, dest_size, filename);
168 } else {
Max Reitz0d54a6f2017-05-22 21:52:15 +0200169 const char *protocol_stripped = NULL;
170
171 if (path_has_protocol(base_path)) {
172 protocol_stripped = strchr(base_path, ':');
173 if (protocol_stripped) {
174 protocol_stripped++;
175 }
176 }
177 p = protocol_stripped ?: base_path;
178
bellard3b9f94e2007-01-07 17:27:07 +0000179 p1 = strrchr(base_path, '/');
180#ifdef _WIN32
181 {
182 const char *p2;
183 p2 = strrchr(base_path, '\\');
184 if (!p1 || p2 > p1)
185 p1 = p2;
186 }
187#endif
bellard83f64092006-08-01 16:21:11 +0000188 if (p1)
189 p1++;
190 else
191 p1 = base_path;
192 if (p1 > p)
193 p = p1;
194 len = p - base_path;
195 if (len > dest_size - 1)
196 len = dest_size - 1;
197 memcpy(dest, base_path, len);
198 dest[len] = '\0';
199 pstrcat(dest, dest_size, filename);
200 }
201}
202
Max Reitz03c320d2017-05-22 21:52:16 +0200203/*
204 * Helper function for bdrv_parse_filename() implementations to remove optional
205 * protocol prefixes (especially "file:") from a filename and for putting the
206 * stripped filename into the options QDict if there is such a prefix.
207 */
208void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
209 QDict *options)
210{
211 if (strstart(filename, prefix, &filename)) {
212 /* Stripping the explicit protocol prefix may result in a protocol
213 * prefix being (wrongly) detected (if the filename contains a colon) */
214 if (path_has_protocol(filename)) {
215 QString *fat_filename;
216
217 /* This means there is some colon before the first slash; therefore,
218 * this cannot be an absolute path */
219 assert(!path_is_absolute(filename));
220
221 /* And we can thus fix the protocol detection issue by prefixing it
222 * by "./" */
223 fat_filename = qstring_from_str("./");
224 qstring_append(fat_filename, filename);
225
226 assert(!path_has_protocol(qstring_get_str(fat_filename)));
227
228 qdict_put(options, "filename", fat_filename);
229 } else {
230 /* If no protocol prefix was detected, we can use the shortened
231 * filename as-is */
232 qdict_put_str(options, "filename", filename);
233 }
234 }
235}
236
237
Kevin Wolf9c5e6592017-05-04 18:52:40 +0200238/* Returns whether the image file is opened as read-only. Note that this can
239 * return false and writing to the image file is still not possible because the
240 * image is inactivated. */
Jeff Cody93ed5242017-04-07 16:55:28 -0400241bool bdrv_is_read_only(BlockDriverState *bs)
242{
243 return bs->read_only;
244}
245
Kevin Wolf54a32bf2017-08-03 17:02:58 +0200246int bdrv_can_set_read_only(BlockDriverState *bs, bool read_only,
247 bool ignore_allow_rdw, Error **errp)
Jeff Codyfe5241b2017-04-07 16:55:25 -0400248{
Jeff Codye2b82472017-04-07 16:55:26 -0400249 /* Do not set read_only if copy_on_read is enabled */
250 if (bs->copy_on_read && read_only) {
251 error_setg(errp, "Can't set node '%s' to r/o with copy-on-read enabled",
252 bdrv_get_device_or_node_name(bs));
253 return -EINVAL;
254 }
255
Jeff Codyd6fcdf02017-04-07 16:55:27 -0400256 /* Do not clear read_only if it is prohibited */
Kevin Wolf54a32bf2017-08-03 17:02:58 +0200257 if (!read_only && !(bs->open_flags & BDRV_O_ALLOW_RDWR) &&
258 !ignore_allow_rdw)
259 {
Jeff Codyd6fcdf02017-04-07 16:55:27 -0400260 error_setg(errp, "Node '%s' is read only",
261 bdrv_get_device_or_node_name(bs));
262 return -EPERM;
263 }
264
Jeff Cody45803a02017-04-07 16:55:29 -0400265 return 0;
266}
267
Kevin Wolf398e6ad2017-11-07 18:21:41 +0100268/* TODO Remove (deprecated since 2.11)
269 * Block drivers are not supposed to automatically change bs->read_only.
270 * Instead, they should just check whether they can provide what the user
271 * explicitly requested and error out if read-write is requested, but they can
272 * only provide read-only access. */
Jeff Cody45803a02017-04-07 16:55:29 -0400273int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp)
274{
275 int ret = 0;
276
Kevin Wolf54a32bf2017-08-03 17:02:58 +0200277 ret = bdrv_can_set_read_only(bs, read_only, false, errp);
Jeff Cody45803a02017-04-07 16:55:29 -0400278 if (ret < 0) {
279 return ret;
280 }
281
Jeff Codyfe5241b2017-04-07 16:55:25 -0400282 bs->read_only = read_only;
Jeff Codye2b82472017-04-07 16:55:26 -0400283 return 0;
Jeff Codyfe5241b2017-04-07 16:55:25 -0400284}
285
Max Reitz0a828552014-11-26 17:20:25 +0100286void bdrv_get_full_backing_filename_from_filename(const char *backed,
287 const char *backing,
Max Reitz9f074292014-11-26 17:20:26 +0100288 char *dest, size_t sz,
289 Error **errp)
Max Reitz0a828552014-11-26 17:20:25 +0100290{
Max Reitz9f074292014-11-26 17:20:26 +0100291 if (backing[0] == '\0' || path_has_protocol(backing) ||
292 path_is_absolute(backing))
293 {
Max Reitz0a828552014-11-26 17:20:25 +0100294 pstrcpy(dest, sz, backing);
Max Reitz9f074292014-11-26 17:20:26 +0100295 } else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) {
296 error_setg(errp, "Cannot use relative backing file names for '%s'",
297 backed);
Max Reitz0a828552014-11-26 17:20:25 +0100298 } else {
299 path_combine(dest, sz, backed, backing);
300 }
301}
302
Max Reitz9f074292014-11-26 17:20:26 +0100303void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz,
304 Error **errp)
Paolo Bonzinidc5a1372012-05-08 16:51:50 +0200305{
Max Reitz9f074292014-11-26 17:20:26 +0100306 char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename;
307
308 bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file,
309 dest, sz, errp);
Paolo Bonzinidc5a1372012-05-08 16:51:50 +0200310}
311
Stefan Hajnoczi0eb72172015-04-28 14:27:51 +0100312void bdrv_register(BlockDriver *bdrv)
313{
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +0100314 QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list);
bellardea2384d2004-08-01 21:59:26 +0000315}
bellardb3380822004-03-14 21:38:54 +0000316
Markus Armbrustere4e99862014-10-07 13:59:03 +0200317BlockDriverState *bdrv_new(void)
318{
319 BlockDriverState *bs;
320 int i;
321
Markus Armbruster5839e532014-08-19 10:31:08 +0200322 bs = g_new0(BlockDriverState, 1);
Fam Zhenge4654d22013-11-13 18:29:43 +0800323 QLIST_INIT(&bs->dirty_bitmaps);
Fam Zhengfbe40ff2014-05-23 21:29:42 +0800324 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
325 QLIST_INIT(&bs->op_blockers[i]);
326 }
Stefan Hajnoczid616b222013-06-24 17:13:10 +0200327 notifier_with_return_list_init(&bs->before_write_notifiers);
Paolo Bonzini3783fa32017-06-05 14:39:02 +0200328 qemu_co_mutex_init(&bs->reqs_lock);
Paolo Bonzini21198822017-06-05 14:39:03 +0200329 qemu_mutex_init(&bs->dirty_bitmap_mutex);
Fam Zheng9fcb0252013-08-23 09:14:46 +0800330 bs->refcnt = 1;
Stefan Hajnoczidcd04222014-05-08 16:34:37 +0200331 bs->aio_context = qemu_get_aio_context();
Paolo Bonzinid7d512f2012-08-23 11:20:36 +0200332
Evgeny Yakovlev3ff2f672016-07-18 22:39:52 +0300333 qemu_co_queue_init(&bs->flush_queue);
334
Max Reitz2c1d04e2016-01-29 16:36:11 +0100335 QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list);
336
bellardb3380822004-03-14 21:38:54 +0000337 return bs;
338}
339
Marc Mari88d88792016-08-12 09:27:03 -0400340static BlockDriver *bdrv_do_find_format(const char *format_name)
bellardea2384d2004-08-01 21:59:26 +0000341{
342 BlockDriver *drv1;
Marc Mari88d88792016-08-12 09:27:03 -0400343
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +0100344 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
345 if (!strcmp(drv1->format_name, format_name)) {
bellardea2384d2004-08-01 21:59:26 +0000346 return drv1;
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +0100347 }
bellardea2384d2004-08-01 21:59:26 +0000348 }
Marc Mari88d88792016-08-12 09:27:03 -0400349
bellardea2384d2004-08-01 21:59:26 +0000350 return NULL;
351}
352
Marc Mari88d88792016-08-12 09:27:03 -0400353BlockDriver *bdrv_find_format(const char *format_name)
354{
355 BlockDriver *drv1;
356 int i;
357
358 drv1 = bdrv_do_find_format(format_name);
359 if (drv1) {
360 return drv1;
361 }
362
363 /* The driver isn't registered, maybe we need to load a module */
364 for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
365 if (!strcmp(block_driver_modules[i].format_name, format_name)) {
366 block_module_load_one(block_driver_modules[i].library_name);
367 break;
368 }
369 }
370
371 return bdrv_do_find_format(format_name);
372}
373
Kevin Wolfe8eb8632018-02-21 11:47:43 +0100374int bdrv_is_whitelisted(BlockDriver *drv, bool read_only)
Markus Armbrustereb852012009-10-27 18:41:44 +0100375{
Fam Zhengb64ec4e2013-05-29 19:35:40 +0800376 static const char *whitelist_rw[] = {
377 CONFIG_BDRV_RW_WHITELIST
378 };
379 static const char *whitelist_ro[] = {
380 CONFIG_BDRV_RO_WHITELIST
Markus Armbrustereb852012009-10-27 18:41:44 +0100381 };
382 const char **p;
383
Fam Zhengb64ec4e2013-05-29 19:35:40 +0800384 if (!whitelist_rw[0] && !whitelist_ro[0]) {
Markus Armbrustereb852012009-10-27 18:41:44 +0100385 return 1; /* no whitelist, anything goes */
Fam Zhengb64ec4e2013-05-29 19:35:40 +0800386 }
Markus Armbrustereb852012009-10-27 18:41:44 +0100387
Fam Zhengb64ec4e2013-05-29 19:35:40 +0800388 for (p = whitelist_rw; *p; p++) {
Markus Armbrustereb852012009-10-27 18:41:44 +0100389 if (!strcmp(drv->format_name, *p)) {
390 return 1;
391 }
392 }
Fam Zhengb64ec4e2013-05-29 19:35:40 +0800393 if (read_only) {
394 for (p = whitelist_ro; *p; p++) {
395 if (!strcmp(drv->format_name, *p)) {
396 return 1;
397 }
398 }
399 }
Markus Armbrustereb852012009-10-27 18:41:44 +0100400 return 0;
401}
402
Daniel P. Berrangee6ff69b2016-03-21 14:11:48 +0000403bool bdrv_uses_whitelist(void)
404{
405 return use_bdrv_whitelist;
406}
407
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800408typedef struct CreateCo {
409 BlockDriver *drv;
410 char *filename;
Chunyan Liu83d05212014-06-05 17:20:51 +0800411 QemuOpts *opts;
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800412 int ret;
Max Reitzcc84d902013-09-06 17:14:26 +0200413 Error *err;
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800414} CreateCo;
415
416static void coroutine_fn bdrv_create_co_entry(void *opaque)
417{
Max Reitzcc84d902013-09-06 17:14:26 +0200418 Error *local_err = NULL;
419 int ret;
420
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800421 CreateCo *cco = opaque;
422 assert(cco->drv);
423
Stefan Hajnocziefc75e22018-01-18 13:43:45 +0100424 ret = cco->drv->bdrv_co_create_opts(cco->filename, cco->opts, &local_err);
Eduardo Habkost621ff942016-06-13 18:57:56 -0300425 error_propagate(&cco->err, local_err);
Max Reitzcc84d902013-09-06 17:14:26 +0200426 cco->ret = ret;
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800427}
428
Kevin Wolf0e7e1982009-05-18 16:42:10 +0200429int bdrv_create(BlockDriver *drv, const char* filename,
Chunyan Liu83d05212014-06-05 17:20:51 +0800430 QemuOpts *opts, Error **errp)
bellardea2384d2004-08-01 21:59:26 +0000431{
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800432 int ret;
Kevin Wolf0e7e1982009-05-18 16:42:10 +0200433
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800434 Coroutine *co;
435 CreateCo cco = {
436 .drv = drv,
437 .filename = g_strdup(filename),
Chunyan Liu83d05212014-06-05 17:20:51 +0800438 .opts = opts,
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800439 .ret = NOT_DONE,
Max Reitzcc84d902013-09-06 17:14:26 +0200440 .err = NULL,
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800441 };
442
Stefan Hajnocziefc75e22018-01-18 13:43:45 +0100443 if (!drv->bdrv_co_create_opts) {
Max Reitzcc84d902013-09-06 17:14:26 +0200444 error_setg(errp, "Driver '%s' does not support image creation", drv->format_name);
Luiz Capitulino80168bf2012-10-17 16:45:25 -0300445 ret = -ENOTSUP;
446 goto out;
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800447 }
448
449 if (qemu_in_coroutine()) {
450 /* Fast-path if already in coroutine context */
451 bdrv_create_co_entry(&cco);
452 } else {
Paolo Bonzini0b8b8752016-07-04 19:10:01 +0200453 co = qemu_coroutine_create(bdrv_create_co_entry, &cco);
454 qemu_coroutine_enter(co);
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800455 while (cco.ret == NOT_DONE) {
Paolo Bonzinib47ec2c2014-07-07 15:18:01 +0200456 aio_poll(qemu_get_aio_context(), true);
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800457 }
458 }
459
460 ret = cco.ret;
Max Reitzcc84d902013-09-06 17:14:26 +0200461 if (ret < 0) {
Markus Armbruster84d18f02014-01-30 15:07:28 +0100462 if (cco.err) {
Max Reitzcc84d902013-09-06 17:14:26 +0200463 error_propagate(errp, cco.err);
464 } else {
465 error_setg_errno(errp, -ret, "Could not create image");
466 }
467 }
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800468
Luiz Capitulino80168bf2012-10-17 16:45:25 -0300469out:
470 g_free(cco.filename);
Zhi Yong Wu5b7e1542012-05-07 16:50:42 +0800471 return ret;
bellardea2384d2004-08-01 21:59:26 +0000472}
473
Chunyan Liuc282e1f2014-06-05 17:21:11 +0800474int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200475{
476 BlockDriver *drv;
Max Reitzcc84d902013-09-06 17:14:26 +0200477 Error *local_err = NULL;
478 int ret;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200479
Max Reitzb65a5e12015-02-05 13:58:12 -0500480 drv = bdrv_find_protocol(filename, true, errp);
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200481 if (drv == NULL) {
Stefan Hajnoczi16905d72010-11-30 15:14:14 +0000482 return -ENOENT;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200483 }
484
Chunyan Liuc282e1f2014-06-05 17:21:11 +0800485 ret = bdrv_create(drv, filename, opts, &local_err);
Eduardo Habkost621ff942016-06-13 18:57:56 -0300486 error_propagate(errp, local_err);
Max Reitzcc84d902013-09-06 17:14:26 +0200487 return ret;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200488}
489
Ekaterina Tumanova892b7de2015-02-16 12:47:54 +0100490/**
491 * Try to get @bs's logical and physical block size.
492 * On success, store them in @bsz struct and return 0.
493 * On failure return -errno.
494 * @bs must not be empty.
495 */
496int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz)
497{
498 BlockDriver *drv = bs->drv;
499
500 if (drv && drv->bdrv_probe_blocksizes) {
501 return drv->bdrv_probe_blocksizes(bs, bsz);
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +0300502 } else if (drv && drv->is_filter && bs->file) {
503 return bdrv_probe_blocksizes(bs->file->bs, bsz);
Ekaterina Tumanova892b7de2015-02-16 12:47:54 +0100504 }
505
506 return -ENOTSUP;
507}
508
509/**
510 * Try to get @bs's geometry (cyls, heads, sectors).
511 * On success, store them in @geo struct and return 0.
512 * On failure return -errno.
513 * @bs must not be empty.
514 */
515int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo)
516{
517 BlockDriver *drv = bs->drv;
518
519 if (drv && drv->bdrv_probe_geometry) {
520 return drv->bdrv_probe_geometry(bs, geo);
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +0300521 } else if (drv && drv->is_filter && bs->file) {
522 return bdrv_probe_geometry(bs->file->bs, geo);
Ekaterina Tumanova892b7de2015-02-16 12:47:54 +0100523 }
524
525 return -ENOTSUP;
526}
527
Jim Meyeringeba25052012-05-28 09:27:54 +0200528/*
529 * Create a uniquely-named empty temporary file.
530 * Return 0 upon success, otherwise a negative errno value.
531 */
532int get_tmp_filename(char *filename, int size)
533{
bellardd5249392004-08-03 21:14:23 +0000534#ifdef _WIN32
bellard3b9f94e2007-01-07 17:27:07 +0000535 char temp_dir[MAX_PATH];
Jim Meyeringeba25052012-05-28 09:27:54 +0200536 /* GetTempFileName requires that its output buffer (4th param)
537 have length MAX_PATH or greater. */
538 assert(size >= MAX_PATH);
539 return (GetTempPath(MAX_PATH, temp_dir)
540 && GetTempFileName(temp_dir, "qem", 0, filename)
541 ? 0 : -GetLastError());
bellardd5249392004-08-03 21:14:23 +0000542#else
bellardea2384d2004-08-01 21:59:26 +0000543 int fd;
blueswir17ccfb2e2008-09-14 06:45:34 +0000544 const char *tmpdir;
aurel320badc1e2008-03-10 00:05:34 +0000545 tmpdir = getenv("TMPDIR");
Amit Shah69bef792014-02-26 15:12:37 +0530546 if (!tmpdir) {
547 tmpdir = "/var/tmp";
548 }
Jim Meyeringeba25052012-05-28 09:27:54 +0200549 if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) {
550 return -EOVERFLOW;
551 }
bellardea2384d2004-08-01 21:59:26 +0000552 fd = mkstemp(filename);
Dunrong Huangfe235a02012-09-05 21:26:22 +0800553 if (fd < 0) {
554 return -errno;
555 }
556 if (close(fd) != 0) {
557 unlink(filename);
Jim Meyeringeba25052012-05-28 09:27:54 +0200558 return -errno;
559 }
560 return 0;
bellardd5249392004-08-03 21:14:23 +0000561#endif
Jim Meyeringeba25052012-05-28 09:27:54 +0200562}
bellardea2384d2004-08-01 21:59:26 +0000563
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200564/*
565 * Detect host devices. By convention, /dev/cdrom[N] is always
566 * recognized as a host CDROM.
567 */
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200568static BlockDriver *find_hdev_driver(const char *filename)
569{
Christoph Hellwig508c7cb2009-06-15 14:04:22 +0200570 int score_max = 0, score;
571 BlockDriver *drv = NULL, *d;
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200572
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +0100573 QLIST_FOREACH(d, &bdrv_drivers, list) {
Christoph Hellwig508c7cb2009-06-15 14:04:22 +0200574 if (d->bdrv_probe_device) {
575 score = d->bdrv_probe_device(filename);
576 if (score > score_max) {
577 score_max = score;
578 drv = d;
579 }
580 }
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200581 }
582
Christoph Hellwig508c7cb2009-06-15 14:04:22 +0200583 return drv;
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200584}
Christoph Hellwigf3a5d3f2009-06-15 13:55:19 +0200585
Marc Mari88d88792016-08-12 09:27:03 -0400586static BlockDriver *bdrv_do_find_protocol(const char *protocol)
587{
588 BlockDriver *drv1;
589
590 QLIST_FOREACH(drv1, &bdrv_drivers, list) {
591 if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) {
592 return drv1;
593 }
594 }
595
596 return NULL;
597}
598
Kevin Wolf98289622013-07-10 15:47:39 +0200599BlockDriver *bdrv_find_protocol(const char *filename,
Max Reitzb65a5e12015-02-05 13:58:12 -0500600 bool allow_protocol_prefix,
601 Error **errp)
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200602{
603 BlockDriver *drv1;
604 char protocol[128];
605 int len;
606 const char *p;
Marc Mari88d88792016-08-12 09:27:03 -0400607 int i;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200608
Kevin Wolf66f82ce2010-04-14 14:17:38 +0200609 /* TODO Drivers without bdrv_file_open must be specified explicitly */
610
Christoph Hellwig39508e72010-06-23 12:25:17 +0200611 /*
612 * XXX(hch): we really should not let host device detection
613 * override an explicit protocol specification, but moving this
614 * later breaks access to device names with colons in them.
615 * Thanks to the brain-dead persistent naming schemes on udev-
616 * based Linux systems those actually are quite common.
617 */
618 drv1 = find_hdev_driver(filename);
619 if (drv1) {
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200620 return drv1;
621 }
Christoph Hellwig39508e72010-06-23 12:25:17 +0200622
Kevin Wolf98289622013-07-10 15:47:39 +0200623 if (!path_has_protocol(filename) || !allow_protocol_prefix) {
Max Reitzef810432014-12-02 18:32:42 +0100624 return &bdrv_file;
Christoph Hellwig39508e72010-06-23 12:25:17 +0200625 }
Kevin Wolf98289622013-07-10 15:47:39 +0200626
Stefan Hajnoczi9e0b22f2010-12-09 11:53:00 +0000627 p = strchr(filename, ':');
628 assert(p != NULL);
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200629 len = p - filename;
630 if (len > sizeof(protocol) - 1)
631 len = sizeof(protocol) - 1;
632 memcpy(protocol, filename, len);
633 protocol[len] = '\0';
Marc Mari88d88792016-08-12 09:27:03 -0400634
635 drv1 = bdrv_do_find_protocol(protocol);
636 if (drv1) {
637 return drv1;
638 }
639
640 for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) {
641 if (block_driver_modules[i].protocol_name &&
642 !strcmp(block_driver_modules[i].protocol_name, protocol)) {
643 block_module_load_one(block_driver_modules[i].library_name);
644 break;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200645 }
646 }
Max Reitzb65a5e12015-02-05 13:58:12 -0500647
Marc Mari88d88792016-08-12 09:27:03 -0400648 drv1 = bdrv_do_find_protocol(protocol);
649 if (!drv1) {
650 error_setg(errp, "Unknown protocol '%s'", protocol);
651 }
652 return drv1;
Christoph Hellwig84a12e62010-04-07 22:30:24 +0200653}
654
Markus Armbrusterc6684242014-11-20 16:27:10 +0100655/*
656 * Guess image format by probing its contents.
657 * This is not a good idea when your image is raw (CVE-2008-2004), but
658 * we do it anyway for backward compatibility.
659 *
660 * @buf contains the image's first @buf_size bytes.
Kevin Wolf7cddd372014-11-20 16:27:11 +0100661 * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE,
662 * but can be smaller if the image file is smaller)
Markus Armbrusterc6684242014-11-20 16:27:10 +0100663 * @filename is its filename.
664 *
665 * For all block drivers, call the bdrv_probe() method to get its
666 * probing score.
667 * Return the first block driver with the highest probing score.
668 */
Kevin Wolf38f3ef52014-11-20 16:27:12 +0100669BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
670 const char *filename)
Markus Armbrusterc6684242014-11-20 16:27:10 +0100671{
672 int score_max = 0, score;
673 BlockDriver *drv = NULL, *d;
674
675 QLIST_FOREACH(d, &bdrv_drivers, list) {
676 if (d->bdrv_probe) {
677 score = d->bdrv_probe(buf, buf_size, filename);
678 if (score > score_max) {
679 score_max = score;
680 drv = d;
681 }
682 }
683 }
684
685 return drv;
686}
687
Kevin Wolf5696c6e2017-02-17 18:39:24 +0100688static int find_image_format(BlockBackend *file, const char *filename,
Max Reitz34b5d2c2013-09-05 14:45:29 +0200689 BlockDriver **pdrv, Error **errp)
bellardea2384d2004-08-01 21:59:26 +0000690{
Markus Armbrusterc6684242014-11-20 16:27:10 +0100691 BlockDriver *drv;
Kevin Wolf7cddd372014-11-20 16:27:11 +0100692 uint8_t buf[BLOCK_PROBE_BUF_SIZE];
Kevin Wolff500a6d2012-11-12 17:35:27 +0100693 int ret = 0;
Nicholas Bellingerf8ea0b02010-05-17 09:45:57 -0700694
Kevin Wolf08a00552010-06-01 18:37:31 +0200695 /* Return the raw BlockDriver * to scsi-generic devices or empty drives */
Kevin Wolf5696c6e2017-02-17 18:39:24 +0100696 if (blk_is_sg(file) || !blk_is_inserted(file) || blk_getlength(file) == 0) {
Max Reitzef810432014-12-02 18:32:42 +0100697 *pdrv = &bdrv_raw;
Stefan Weilc98ac352010-07-21 21:51:51 +0200698 return ret;
Nicholas A. Bellinger1a396852010-05-27 08:56:28 -0700699 }
Nicholas Bellingerf8ea0b02010-05-17 09:45:57 -0700700
Kevin Wolf5696c6e2017-02-17 18:39:24 +0100701 ret = blk_pread(file, 0, buf, sizeof(buf));
bellard83f64092006-08-01 16:21:11 +0000702 if (ret < 0) {
Max Reitz34b5d2c2013-09-05 14:45:29 +0200703 error_setg_errno(errp, -ret, "Could not read image for determining its "
704 "format");
Stefan Weilc98ac352010-07-21 21:51:51 +0200705 *pdrv = NULL;
706 return ret;
bellard83f64092006-08-01 16:21:11 +0000707 }
708
Markus Armbrusterc6684242014-11-20 16:27:10 +0100709 drv = bdrv_probe_all(buf, ret, filename);
Stefan Weilc98ac352010-07-21 21:51:51 +0200710 if (!drv) {
Max Reitz34b5d2c2013-09-05 14:45:29 +0200711 error_setg(errp, "Could not determine image format: No compatible "
712 "driver found");
Stefan Weilc98ac352010-07-21 21:51:51 +0200713 ret = -ENOENT;
714 }
715 *pdrv = drv;
716 return ret;
bellardea2384d2004-08-01 21:59:26 +0000717}
718
Stefan Hajnoczi51762282010-04-19 16:56:41 +0100719/**
720 * Set the current 'total_sectors' value
Markus Armbruster65a9bb22014-06-26 13:23:17 +0200721 * Return 0 on success, -errno on error.
Stefan Hajnoczi51762282010-04-19 16:56:41 +0100722 */
723static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
724{
725 BlockDriver *drv = bs->drv;
726
Max Reitzd470ad42017-11-10 21:31:09 +0100727 if (!drv) {
728 return -ENOMEDIUM;
729 }
730
Nicholas Bellinger396759a2010-05-17 09:46:04 -0700731 /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
Dimitris Aragiorgisb192af82015-06-23 13:44:56 +0300732 if (bdrv_is_sg(bs))
Nicholas Bellinger396759a2010-05-17 09:46:04 -0700733 return 0;
734
Stefan Hajnoczi51762282010-04-19 16:56:41 +0100735 /* query actual device if possible, otherwise just trust the hint */
736 if (drv->bdrv_getlength) {
737 int64_t length = drv->bdrv_getlength(bs);
738 if (length < 0) {
739 return length;
740 }
Fam Zheng7e382002013-11-06 19:48:06 +0800741 hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE);
Stefan Hajnoczi51762282010-04-19 16:56:41 +0100742 }
743
744 bs->total_sectors = hint;
745 return 0;
746}
747
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100748/**
Kevin Wolfcddff5b2015-11-16 16:43:27 +0100749 * Combines a QDict of new block driver @options with any missing options taken
750 * from @old_options, so that leaving out an option defaults to its old value.
751 */
752static void bdrv_join_options(BlockDriverState *bs, QDict *options,
753 QDict *old_options)
754{
755 if (bs->drv && bs->drv->bdrv_join_options) {
756 bs->drv->bdrv_join_options(options, old_options);
757 } else {
758 qdict_join(options, old_options, false);
759 }
760}
761
762/**
Paolo Bonzini9e8f1832013-02-08 14:06:11 +0100763 * Set open flags for a given discard mode
764 *
765 * Return 0 on success, -1 if the discard mode was invalid.
766 */
767int bdrv_parse_discard_flags(const char *mode, int *flags)
768{
769 *flags &= ~BDRV_O_UNMAP;
770
771 if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) {
772 /* do nothing */
773 } else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) {
774 *flags |= BDRV_O_UNMAP;
775 } else {
776 return -1;
777 }
778
779 return 0;
780}
781
782/**
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100783 * Set open flags for a given cache mode
784 *
785 * Return 0 on success, -1 if the cache mode was invalid.
786 */
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100787int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough)
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100788{
789 *flags &= ~BDRV_O_CACHE_MASK;
790
791 if (!strcmp(mode, "off") || !strcmp(mode, "none")) {
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100792 *writethrough = false;
793 *flags |= BDRV_O_NOCACHE;
Stefan Hajnoczi92196b22011-08-04 12:26:52 +0100794 } else if (!strcmp(mode, "directsync")) {
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100795 *writethrough = true;
Stefan Hajnoczi92196b22011-08-04 12:26:52 +0100796 *flags |= BDRV_O_NOCACHE;
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100797 } else if (!strcmp(mode, "writeback")) {
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100798 *writethrough = false;
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100799 } else if (!strcmp(mode, "unsafe")) {
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100800 *writethrough = false;
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100801 *flags |= BDRV_O_NO_FLUSH;
802 } else if (!strcmp(mode, "writethrough")) {
Kevin Wolf53e8ae02016-03-18 15:36:58 +0100803 *writethrough = true;
Stefan Hajnoczic3993cd2011-08-04 12:26:51 +0100804 } else {
805 return -1;
806 }
807
808 return 0;
809}
810
Kevin Wolfb5411552017-01-17 15:56:16 +0100811static char *bdrv_child_get_parent_desc(BdrvChild *c)
812{
813 BlockDriverState *parent = c->opaque;
814 return g_strdup(bdrv_get_device_or_node_name(parent));
815}
816
Kevin Wolf20018e12016-05-23 18:46:59 +0200817static void bdrv_child_cb_drained_begin(BdrvChild *child)
818{
819 BlockDriverState *bs = child->opaque;
820 bdrv_drained_begin(bs);
821}
822
823static void bdrv_child_cb_drained_end(BdrvChild *child)
824{
825 BlockDriverState *bs = child->opaque;
826 bdrv_drained_end(bs);
827}
828
Kevin Wolfd736f112017-12-18 16:05:48 +0100829static void bdrv_child_cb_attach(BdrvChild *child)
830{
831 BlockDriverState *bs = child->opaque;
832 bdrv_apply_subtree_drain(child, bs);
833}
834
835static void bdrv_child_cb_detach(BdrvChild *child)
836{
837 BlockDriverState *bs = child->opaque;
838 bdrv_unapply_subtree_drain(child, bs);
839}
840
Kevin Wolf38701b62017-05-04 18:52:39 +0200841static int bdrv_child_cb_inactivate(BdrvChild *child)
842{
843 BlockDriverState *bs = child->opaque;
844 assert(bs->open_flags & BDRV_O_INACTIVE);
845 return 0;
846}
847
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200848/*
Kevin Wolf73176be2016-03-07 13:02:15 +0100849 * Returns the options and flags that a temporary snapshot should get, based on
850 * the originally requested flags (the originally requested image will have
851 * flags like a backing file)
Kevin Wolfb1e6fc02014-05-06 12:11:42 +0200852 */
Kevin Wolf73176be2016-03-07 13:02:15 +0100853static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options,
854 int parent_flags, QDict *parent_options)
Kevin Wolfb1e6fc02014-05-06 12:11:42 +0200855{
Kevin Wolf73176be2016-03-07 13:02:15 +0100856 *child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY;
857
858 /* For temporary files, unconditional cache=unsafe is fine */
Kevin Wolf73176be2016-03-07 13:02:15 +0100859 qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off");
860 qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on");
Kevin Wolf41869042016-06-16 12:59:30 +0200861
Alberto Garciaf87a0e22016-09-15 17:53:02 +0300862 /* Copy the read-only option from the parent */
863 qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
864
Kevin Wolf41869042016-06-16 12:59:30 +0200865 /* aio=native doesn't work for cache.direct=off, so disable it for the
866 * temporary snapshot */
867 *child_flags &= ~BDRV_O_NATIVE_AIO;
Kevin Wolfb1e6fc02014-05-06 12:11:42 +0200868}
869
870/*
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200871 * Returns the options and flags that bs->file should get if a protocol driver
872 * is expected, based on the given options and flags for the parent BDS
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200873 */
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200874static void bdrv_inherited_options(int *child_flags, QDict *child_options,
875 int parent_flags, QDict *parent_options)
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200876{
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200877 int flags = parent_flags;
878
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200879 /* Enable protocol handling, disable format probing for bs->file */
880 flags |= BDRV_O_PROTOCOL;
881
Kevin Wolf91a097e2015-05-08 17:49:53 +0200882 /* If the cache mode isn't explicitly set, inherit direct and no-flush from
883 * the parent. */
884 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
885 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
Fam Zheng5a9347c2017-05-03 00:35:37 +0800886 qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE);
Kevin Wolf91a097e2015-05-08 17:49:53 +0200887
Alberto Garciaf87a0e22016-09-15 17:53:02 +0300888 /* Inherit the read-only option from the parent if it's not set */
889 qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY);
890
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200891 /* Our block drivers take care to send flushes and respect unmap policy,
Kevin Wolf91a097e2015-05-08 17:49:53 +0200892 * so we can default to enable both on lower layers regardless of the
893 * corresponding parent options. */
Kevin Wolf818584a2016-09-12 18:03:18 +0200894 qdict_set_default_str(child_options, BDRV_OPT_DISCARD, "unmap");
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200895
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200896 /* Clear flags that only apply to the top layer */
Daniel P. Berrangeabb06c52016-03-21 14:11:42 +0000897 flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ |
898 BDRV_O_NO_IO);
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200899
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200900 *child_flags = flags;
Kevin Wolf0b50cc82014-04-11 21:29:52 +0200901}
902
Kevin Wolff3930ed2015-04-08 13:43:47 +0200903const BdrvChildRole child_file = {
Kevin Wolfb5411552017-01-17 15:56:16 +0100904 .get_parent_desc = bdrv_child_get_parent_desc,
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200905 .inherit_options = bdrv_inherited_options,
Kevin Wolf20018e12016-05-23 18:46:59 +0200906 .drained_begin = bdrv_child_cb_drained_begin,
907 .drained_end = bdrv_child_cb_drained_end,
Kevin Wolfd736f112017-12-18 16:05:48 +0100908 .attach = bdrv_child_cb_attach,
909 .detach = bdrv_child_cb_detach,
Kevin Wolf38701b62017-05-04 18:52:39 +0200910 .inactivate = bdrv_child_cb_inactivate,
Kevin Wolff3930ed2015-04-08 13:43:47 +0200911};
912
913/*
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200914 * Returns the options and flags that bs->file should get if the use of formats
915 * (and not only protocols) is permitted for it, based on the given options and
916 * flags for the parent BDS
Kevin Wolff3930ed2015-04-08 13:43:47 +0200917 */
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200918static void bdrv_inherited_fmt_options(int *child_flags, QDict *child_options,
919 int parent_flags, QDict *parent_options)
Kevin Wolff3930ed2015-04-08 13:43:47 +0200920{
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200921 child_file.inherit_options(child_flags, child_options,
922 parent_flags, parent_options);
923
Daniel P. Berrangeabb06c52016-03-21 14:11:42 +0000924 *child_flags &= ~(BDRV_O_PROTOCOL | BDRV_O_NO_IO);
Kevin Wolff3930ed2015-04-08 13:43:47 +0200925}
926
927const BdrvChildRole child_format = {
Kevin Wolfb5411552017-01-17 15:56:16 +0100928 .get_parent_desc = bdrv_child_get_parent_desc,
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200929 .inherit_options = bdrv_inherited_fmt_options,
Kevin Wolf20018e12016-05-23 18:46:59 +0200930 .drained_begin = bdrv_child_cb_drained_begin,
931 .drained_end = bdrv_child_cb_drained_end,
Kevin Wolfd736f112017-12-18 16:05:48 +0100932 .attach = bdrv_child_cb_attach,
933 .detach = bdrv_child_cb_detach,
Kevin Wolf38701b62017-05-04 18:52:39 +0200934 .inactivate = bdrv_child_cb_inactivate,
Kevin Wolff3930ed2015-04-08 13:43:47 +0200935};
936
Kevin Wolfdb95dbb2017-02-08 11:28:52 +0100937static void bdrv_backing_attach(BdrvChild *c)
938{
939 BlockDriverState *parent = c->opaque;
940 BlockDriverState *backing_hd = c->bs;
941
942 assert(!parent->backing_blocker);
943 error_setg(&parent->backing_blocker,
944 "node is used as backing hd of '%s'",
945 bdrv_get_device_or_node_name(parent));
946
947 parent->open_flags &= ~BDRV_O_NO_BACKING;
948 pstrcpy(parent->backing_file, sizeof(parent->backing_file),
949 backing_hd->filename);
950 pstrcpy(parent->backing_format, sizeof(parent->backing_format),
951 backing_hd->drv ? backing_hd->drv->format_name : "");
952
953 bdrv_op_block_all(backing_hd, parent->backing_blocker);
954 /* Otherwise we won't be able to commit or stream */
955 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET,
956 parent->backing_blocker);
957 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_STREAM,
958 parent->backing_blocker);
959 /*
960 * We do backup in 3 ways:
961 * 1. drive backup
962 * The target bs is new opened, and the source is top BDS
963 * 2. blockdev backup
964 * Both the source and the target are top BDSes.
965 * 3. internal backup(used for block replication)
966 * Both the source and the target are backing file
967 *
968 * In case 1 and 2, neither the source nor the target is the backing file.
969 * In case 3, we will block the top BDS, so there is only one block job
970 * for the top BDS and its backing chain.
971 */
972 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_SOURCE,
973 parent->backing_blocker);
974 bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET,
975 parent->backing_blocker);
Kevin Wolfd736f112017-12-18 16:05:48 +0100976
977 bdrv_child_cb_attach(c);
Kevin Wolfdb95dbb2017-02-08 11:28:52 +0100978}
979
980static void bdrv_backing_detach(BdrvChild *c)
981{
982 BlockDriverState *parent = c->opaque;
983
984 assert(parent->backing_blocker);
985 bdrv_op_unblock_all(c->bs, parent->backing_blocker);
986 error_free(parent->backing_blocker);
987 parent->backing_blocker = NULL;
Kevin Wolfd736f112017-12-18 16:05:48 +0100988
989 bdrv_child_cb_detach(c);
Kevin Wolfdb95dbb2017-02-08 11:28:52 +0100990}
991
Kevin Wolf317fc442014-04-25 13:27:34 +0200992/*
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200993 * Returns the options and flags that bs->backing should get, based on the
994 * given options and flags for the parent BDS
Kevin Wolf317fc442014-04-25 13:27:34 +0200995 */
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200996static void bdrv_backing_options(int *child_flags, QDict *child_options,
997 int parent_flags, QDict *parent_options)
Kevin Wolf317fc442014-04-25 13:27:34 +0200998{
Kevin Wolf8e2160e2015-04-29 17:29:39 +0200999 int flags = parent_flags;
1000
Kevin Wolfb8816a42016-03-04 14:52:32 +01001001 /* The cache mode is inherited unmodified for backing files; except WCE,
1002 * which is only applied on the top level (BlockBackend) */
Kevin Wolf91a097e2015-05-08 17:49:53 +02001003 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT);
1004 qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH);
Fam Zheng5a9347c2017-05-03 00:35:37 +08001005 qdict_copy_default(child_options, parent_options, BDRV_OPT_FORCE_SHARE);
Kevin Wolf91a097e2015-05-08 17:49:53 +02001006
Kevin Wolf317fc442014-04-25 13:27:34 +02001007 /* backing files always opened read-only */
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001008 qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on");
1009 flags &= ~BDRV_O_COPY_ON_READ;
Kevin Wolf317fc442014-04-25 13:27:34 +02001010
1011 /* snapshot=on is handled on the top layer */
Kevin Wolf8bfea152014-04-11 19:16:36 +02001012 flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY);
Kevin Wolf317fc442014-04-25 13:27:34 +02001013
Kevin Wolf8e2160e2015-04-29 17:29:39 +02001014 *child_flags = flags;
Kevin Wolf317fc442014-04-25 13:27:34 +02001015}
1016
Kevin Wolf6858eba2017-06-29 19:32:21 +02001017static int bdrv_backing_update_filename(BdrvChild *c, BlockDriverState *base,
1018 const char *filename, Error **errp)
1019{
1020 BlockDriverState *parent = c->opaque;
Kevin Wolf61f09ce2017-09-19 16:22:54 +02001021 int orig_flags = bdrv_get_flags(parent);
Kevin Wolf6858eba2017-06-29 19:32:21 +02001022 int ret;
1023
Kevin Wolf61f09ce2017-09-19 16:22:54 +02001024 if (!(orig_flags & BDRV_O_RDWR)) {
1025 ret = bdrv_reopen(parent, orig_flags | BDRV_O_RDWR, errp);
1026 if (ret < 0) {
1027 return ret;
1028 }
1029 }
1030
Kevin Wolf6858eba2017-06-29 19:32:21 +02001031 ret = bdrv_change_backing_file(parent, filename,
1032 base->drv ? base->drv->format_name : "");
1033 if (ret < 0) {
Kevin Wolf64730692017-11-06 17:52:58 +01001034 error_setg_errno(errp, -ret, "Could not update backing file link");
Kevin Wolf6858eba2017-06-29 19:32:21 +02001035 }
1036
Kevin Wolf61f09ce2017-09-19 16:22:54 +02001037 if (!(orig_flags & BDRV_O_RDWR)) {
1038 bdrv_reopen(parent, orig_flags, NULL);
1039 }
1040
Kevin Wolf6858eba2017-06-29 19:32:21 +02001041 return ret;
1042}
1043
Kevin Wolf91ef3822016-12-20 16:23:46 +01001044const BdrvChildRole child_backing = {
Kevin Wolfb5411552017-01-17 15:56:16 +01001045 .get_parent_desc = bdrv_child_get_parent_desc,
Kevin Wolfdb95dbb2017-02-08 11:28:52 +01001046 .attach = bdrv_backing_attach,
1047 .detach = bdrv_backing_detach,
Kevin Wolf8e2160e2015-04-29 17:29:39 +02001048 .inherit_options = bdrv_backing_options,
Kevin Wolf20018e12016-05-23 18:46:59 +02001049 .drained_begin = bdrv_child_cb_drained_begin,
1050 .drained_end = bdrv_child_cb_drained_end,
Kevin Wolf38701b62017-05-04 18:52:39 +02001051 .inactivate = bdrv_child_cb_inactivate,
Kevin Wolf6858eba2017-06-29 19:32:21 +02001052 .update_filename = bdrv_backing_update_filename,
Kevin Wolff3930ed2015-04-08 13:43:47 +02001053};
1054
Kevin Wolf7b272452012-11-12 17:05:39 +01001055static int bdrv_open_flags(BlockDriverState *bs, int flags)
1056{
Kevin Wolf61de4c62016-03-18 17:46:45 +01001057 int open_flags = flags;
Kevin Wolf7b272452012-11-12 17:05:39 +01001058
1059 /*
1060 * Clear flags that are internal to the block layer before opening the
1061 * image.
1062 */
Kevin Wolf20cca272014-06-04 14:33:27 +02001063 open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL);
Kevin Wolf7b272452012-11-12 17:05:39 +01001064
1065 /*
1066 * Snapshots should be writable.
1067 */
Kevin Wolf8bfea152014-04-11 19:16:36 +02001068 if (flags & BDRV_O_TEMPORARY) {
Kevin Wolf7b272452012-11-12 17:05:39 +01001069 open_flags |= BDRV_O_RDWR;
1070 }
1071
1072 return open_flags;
1073}
1074
Kevin Wolf91a097e2015-05-08 17:49:53 +02001075static void update_flags_from_options(int *flags, QemuOpts *opts)
1076{
1077 *flags &= ~BDRV_O_CACHE_MASK;
1078
Kevin Wolf91a097e2015-05-08 17:49:53 +02001079 assert(qemu_opt_find(opts, BDRV_OPT_CACHE_NO_FLUSH));
1080 if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) {
1081 *flags |= BDRV_O_NO_FLUSH;
1082 }
1083
1084 assert(qemu_opt_find(opts, BDRV_OPT_CACHE_DIRECT));
1085 if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_DIRECT, false)) {
1086 *flags |= BDRV_O_NOCACHE;
1087 }
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001088
1089 *flags &= ~BDRV_O_RDWR;
1090
1091 assert(qemu_opt_find(opts, BDRV_OPT_READ_ONLY));
1092 if (!qemu_opt_get_bool(opts, BDRV_OPT_READ_ONLY, false)) {
1093 *flags |= BDRV_O_RDWR;
1094 }
1095
Kevin Wolf91a097e2015-05-08 17:49:53 +02001096}
1097
1098static void update_options_from_flags(QDict *options, int flags)
1099{
Kevin Wolf91a097e2015-05-08 17:49:53 +02001100 if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) {
Eric Blake46f5ac22017-04-27 16:58:17 -05001101 qdict_put_bool(options, BDRV_OPT_CACHE_DIRECT, flags & BDRV_O_NOCACHE);
Kevin Wolf91a097e2015-05-08 17:49:53 +02001102 }
1103 if (!qdict_haskey(options, BDRV_OPT_CACHE_NO_FLUSH)) {
Eric Blake46f5ac22017-04-27 16:58:17 -05001104 qdict_put_bool(options, BDRV_OPT_CACHE_NO_FLUSH,
1105 flags & BDRV_O_NO_FLUSH);
Kevin Wolf91a097e2015-05-08 17:49:53 +02001106 }
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001107 if (!qdict_haskey(options, BDRV_OPT_READ_ONLY)) {
Eric Blake46f5ac22017-04-27 16:58:17 -05001108 qdict_put_bool(options, BDRV_OPT_READ_ONLY, !(flags & BDRV_O_RDWR));
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001109 }
Kevin Wolf91a097e2015-05-08 17:49:53 +02001110}
1111
Kevin Wolf636ea372014-01-24 14:11:52 +01001112static void bdrv_assign_node_name(BlockDriverState *bs,
1113 const char *node_name,
1114 Error **errp)
Benoît Canet6913c0c2014-01-23 21:31:33 +01001115{
Jeff Cody15489c72015-10-12 19:36:50 -04001116 char *gen_node_name = NULL;
Benoît Canet6913c0c2014-01-23 21:31:33 +01001117
Jeff Cody15489c72015-10-12 19:36:50 -04001118 if (!node_name) {
1119 node_name = gen_node_name = id_generate(ID_BLOCK);
1120 } else if (!id_wellformed(node_name)) {
1121 /*
1122 * Check for empty string or invalid characters, but not if it is
1123 * generated (generated names use characters not available to the user)
1124 */
Kevin Wolf9aebf3b2014-09-25 09:54:02 +02001125 error_setg(errp, "Invalid node name");
Kevin Wolf636ea372014-01-24 14:11:52 +01001126 return;
Benoît Canet6913c0c2014-01-23 21:31:33 +01001127 }
1128
Benoît Canet0c5e94e2014-02-12 17:15:07 +01001129 /* takes care of avoiding namespaces collisions */
Markus Armbruster7f06d472014-10-07 13:59:12 +02001130 if (blk_by_name(node_name)) {
Benoît Canet0c5e94e2014-02-12 17:15:07 +01001131 error_setg(errp, "node-name=%s is conflicting with a device id",
1132 node_name);
Jeff Cody15489c72015-10-12 19:36:50 -04001133 goto out;
Benoît Canet0c5e94e2014-02-12 17:15:07 +01001134 }
1135
Benoît Canet6913c0c2014-01-23 21:31:33 +01001136 /* takes care of avoiding duplicates node names */
1137 if (bdrv_find_node(node_name)) {
1138 error_setg(errp, "Duplicate node name");
Jeff Cody15489c72015-10-12 19:36:50 -04001139 goto out;
Benoît Canet6913c0c2014-01-23 21:31:33 +01001140 }
1141
1142 /* copy node name into the bs and insert it into the graph list */
1143 pstrcpy(bs->node_name, sizeof(bs->node_name), node_name);
1144 QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list);
Jeff Cody15489c72015-10-12 19:36:50 -04001145out:
1146 g_free(gen_node_name);
Benoît Canet6913c0c2014-01-23 21:31:33 +01001147}
1148
Kevin Wolf01a56502017-01-18 15:51:56 +01001149static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv,
1150 const char *node_name, QDict *options,
1151 int open_flags, Error **errp)
1152{
1153 Error *local_err = NULL;
1154 int ret;
1155
1156 bdrv_assign_node_name(bs, node_name, &local_err);
1157 if (local_err) {
1158 error_propagate(errp, local_err);
1159 return -EINVAL;
1160 }
1161
1162 bs->drv = drv;
Kevin Wolf680c7f92017-01-18 17:16:41 +01001163 bs->read_only = !(bs->open_flags & BDRV_O_RDWR);
Kevin Wolf01a56502017-01-18 15:51:56 +01001164 bs->opaque = g_malloc0(drv->instance_size);
1165
1166 if (drv->bdrv_file_open) {
1167 assert(!drv->bdrv_needs_filename || bs->filename[0]);
1168 ret = drv->bdrv_file_open(bs, options, open_flags, &local_err);
Kevin Wolf680c7f92017-01-18 17:16:41 +01001169 } else if (drv->bdrv_open) {
Kevin Wolf01a56502017-01-18 15:51:56 +01001170 ret = drv->bdrv_open(bs, options, open_flags, &local_err);
Kevin Wolf680c7f92017-01-18 17:16:41 +01001171 } else {
1172 ret = 0;
Kevin Wolf01a56502017-01-18 15:51:56 +01001173 }
1174
1175 if (ret < 0) {
1176 if (local_err) {
1177 error_propagate(errp, local_err);
1178 } else if (bs->filename[0]) {
1179 error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename);
1180 } else {
1181 error_setg_errno(errp, -ret, "Could not open image");
1182 }
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001183 goto open_failed;
Kevin Wolf01a56502017-01-18 15:51:56 +01001184 }
1185
1186 ret = refresh_total_sectors(bs, bs->total_sectors);
1187 if (ret < 0) {
1188 error_setg_errno(errp, -ret, "Could not refresh total sector count");
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001189 return ret;
Kevin Wolf01a56502017-01-18 15:51:56 +01001190 }
1191
1192 bdrv_refresh_limits(bs, &local_err);
1193 if (local_err) {
1194 error_propagate(errp, local_err);
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001195 return -EINVAL;
Kevin Wolf01a56502017-01-18 15:51:56 +01001196 }
1197
1198 assert(bdrv_opt_mem_align(bs) != 0);
1199 assert(bdrv_min_mem_align(bs) != 0);
1200 assert(is_power_of_2(bs->bl.request_alignment));
1201
1202 return 0;
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001203open_failed:
1204 bs->drv = NULL;
1205 if (bs->file != NULL) {
1206 bdrv_unref_child(bs, bs->file);
1207 bs->file = NULL;
1208 }
Kevin Wolf01a56502017-01-18 15:51:56 +01001209 g_free(bs->opaque);
1210 bs->opaque = NULL;
Kevin Wolf01a56502017-01-18 15:51:56 +01001211 return ret;
1212}
1213
Kevin Wolf680c7f92017-01-18 17:16:41 +01001214BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name,
1215 int flags, Error **errp)
1216{
1217 BlockDriverState *bs;
1218 int ret;
1219
1220 bs = bdrv_new();
1221 bs->open_flags = flags;
1222 bs->explicit_options = qdict_new();
1223 bs->options = qdict_new();
1224 bs->opaque = NULL;
1225
1226 update_options_from_flags(bs->options, flags);
1227
1228 ret = bdrv_open_driver(bs, drv, node_name, bs->options, flags, errp);
1229 if (ret < 0) {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02001230 qobject_unref(bs->explicit_options);
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001231 bs->explicit_options = NULL;
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02001232 qobject_unref(bs->options);
Manos Pitsidianakis180ca192017-07-14 17:35:48 +03001233 bs->options = NULL;
Kevin Wolf680c7f92017-01-18 17:16:41 +01001234 bdrv_unref(bs);
1235 return NULL;
1236 }
1237
1238 return bs;
1239}
1240
Kevin Wolfc5f30142016-10-06 11:33:17 +02001241QemuOptsList bdrv_runtime_opts = {
Kevin Wolf18edf282015-04-07 17:12:56 +02001242 .name = "bdrv_common",
1243 .head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head),
1244 .desc = {
1245 {
1246 .name = "node-name",
1247 .type = QEMU_OPT_STRING,
1248 .help = "Node name of the block device node",
1249 },
Kevin Wolf62392eb2015-04-24 16:38:02 +02001250 {
1251 .name = "driver",
1252 .type = QEMU_OPT_STRING,
1253 .help = "Block driver to use for the node",
1254 },
Kevin Wolf91a097e2015-05-08 17:49:53 +02001255 {
Kevin Wolf91a097e2015-05-08 17:49:53 +02001256 .name = BDRV_OPT_CACHE_DIRECT,
1257 .type = QEMU_OPT_BOOL,
1258 .help = "Bypass software writeback cache on the host",
1259 },
1260 {
1261 .name = BDRV_OPT_CACHE_NO_FLUSH,
1262 .type = QEMU_OPT_BOOL,
1263 .help = "Ignore flush requests",
1264 },
Alberto Garciaf87a0e22016-09-15 17:53:02 +03001265 {
1266 .name = BDRV_OPT_READ_ONLY,
1267 .type = QEMU_OPT_BOOL,
1268 .help = "Node is opened in read-only mode",
1269 },
Kevin Wolf692e01a2016-09-12 21:00:41 +02001270 {
1271 .name = "detect-zeroes",
1272 .type = QEMU_OPT_STRING,
1273 .help = "try to optimize zero writes (off, on, unmap)",
1274 },
Kevin Wolf818584a2016-09-12 18:03:18 +02001275 {
1276 .name = "discard",
1277 .type = QEMU_OPT_STRING,
1278 .help = "discard operation (ignore/off, unmap/on)",
1279 },
Fam Zheng5a9347c2017-05-03 00:35:37 +08001280 {
1281 .name = BDRV_OPT_FORCE_SHARE,
1282 .type = QEMU_OPT_BOOL,
1283 .help = "always accept other writers (default: off)",
1284 },
Kevin Wolf18edf282015-04-07 17:12:56 +02001285 { /* end of list */ }
1286 },
1287};
1288
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02001289/*
Kevin Wolf57915332010-04-14 15:24:50 +02001290 * Common part for opening disk images and files
Kevin Wolfb6ad4912013-03-15 10:35:04 +01001291 *
1292 * Removes all processed options from *options.
Kevin Wolf57915332010-04-14 15:24:50 +02001293 */
Kevin Wolf5696c6e2017-02-17 18:39:24 +01001294static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file,
Kevin Wolf82dc8b42016-01-11 19:07:50 +01001295 QDict *options, Error **errp)
Kevin Wolf57915332010-04-14 15:24:50 +02001296{
1297 int ret, open_flags;
Kevin Wolf035fccd2013-04-09 14:34:19 +02001298 const char *filename;
Kevin Wolf62392eb2015-04-24 16:38:02 +02001299 const char *driver_name = NULL;
Benoît Canet6913c0c2014-01-23 21:31:33 +01001300 const char *node_name = NULL;
Kevin Wolf818584a2016-09-12 18:03:18 +02001301 const char *discard;
Kevin Wolf692e01a2016-09-12 21:00:41 +02001302 const char *detect_zeroes;
Kevin Wolf18edf282015-04-07 17:12:56 +02001303 QemuOpts *opts;
Kevin Wolf62392eb2015-04-24 16:38:02 +02001304 BlockDriver *drv;
Max Reitz34b5d2c2013-09-05 14:45:29 +02001305 Error *local_err = NULL;
Kevin Wolf57915332010-04-14 15:24:50 +02001306
Paolo Bonzini64058752012-05-08 16:51:49 +02001307 assert(bs->file == NULL);
Kevin Wolf707ff822013-03-06 12:20:31 +01001308 assert(options != NULL && bs->options != options);
Kevin Wolf57915332010-04-14 15:24:50 +02001309
Kevin Wolf62392eb2015-04-24 16:38:02 +02001310 opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
1311 qemu_opts_absorb_qdict(opts, options, &local_err);
1312 if (local_err) {
1313 error_propagate(errp, local_err);
1314 ret = -EINVAL;
1315 goto fail_opts;
1316 }
1317
Alberto Garcia9b7e8692016-09-15 17:53:01 +03001318 update_flags_from_options(&bs->open_flags, opts);
1319
Kevin Wolf62392eb2015-04-24 16:38:02 +02001320 driver_name = qemu_opt_get(opts, "driver");
1321 drv = bdrv_find_format(driver_name);
1322 assert(drv != NULL);
1323
Fam Zheng5a9347c2017-05-03 00:35:37 +08001324 bs->force_share = qemu_opt_get_bool(opts, BDRV_OPT_FORCE_SHARE, false);
1325
1326 if (bs->force_share && (bs->open_flags & BDRV_O_RDWR)) {
1327 error_setg(errp,
1328 BDRV_OPT_FORCE_SHARE
1329 "=on can only be used with read-only images");
1330 ret = -EINVAL;
1331 goto fail_opts;
1332 }
1333
Kevin Wolf45673672013-04-22 17:48:40 +02001334 if (file != NULL) {
Kevin Wolf5696c6e2017-02-17 18:39:24 +01001335 filename = blk_bs(file)->filename;
Kevin Wolf45673672013-04-22 17:48:40 +02001336 } else {
Markus Armbruster129c7d12017-03-30 19:43:12 +02001337 /*
1338 * Caution: while qdict_get_try_str() is fine, getting
1339 * non-string types would require more care. When @options
1340 * come from -blockdev or blockdev_add, its members are typed
1341 * according to the QAPI schema, but when they come from
1342 * -drive, they're all QString.
1343 */
Kevin Wolf45673672013-04-22 17:48:40 +02001344 filename = qdict_get_try_str(options, "filename");
1345 }
1346
Max Reitz4a008242017-04-13 18:06:24 +02001347 if (drv->bdrv_needs_filename && (!filename || !filename[0])) {
Kevin Wolf765003d2014-02-03 14:49:42 +01001348 error_setg(errp, "The '%s' block driver requires a file name",
1349 drv->format_name);
Kevin Wolf18edf282015-04-07 17:12:56 +02001350 ret = -EINVAL;
1351 goto fail_opts;
1352 }
1353
Kevin Wolf82dc8b42016-01-11 19:07:50 +01001354 trace_bdrv_open_common(bs, filename ?: "", bs->open_flags,
1355 drv->format_name);
Kevin Wolf62392eb2015-04-24 16:38:02 +02001356
Kevin Wolf82dc8b42016-01-11 19:07:50 +01001357 bs->read_only = !(bs->open_flags & BDRV_O_RDWR);
Fam Zhengb64ec4e2013-05-29 19:35:40 +08001358
1359 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
Kevin Wolf8f94a6e2013-10-10 11:45:55 +02001360 error_setg(errp,
1361 !bs->read_only && bdrv_is_whitelisted(drv, true)
1362 ? "Driver '%s' can only be used for read-only devices"
1363 : "Driver '%s' is not whitelisted",
1364 drv->format_name);
Kevin Wolf18edf282015-04-07 17:12:56 +02001365 ret = -ENOTSUP;
1366 goto fail_opts;
Fam Zhengb64ec4e2013-05-29 19:35:40 +08001367 }
Kevin Wolf57915332010-04-14 15:24:50 +02001368
Paolo Bonzinid3faa132017-06-05 14:38:50 +02001369 /* bdrv_new() and bdrv_close() make it so */
1370 assert(atomic_read(&bs->copy_on_read) == 0);
1371
Kevin Wolf82dc8b42016-01-11 19:07:50 +01001372 if (bs->open_flags & BDRV_O_COPY_ON_READ) {
Kevin Wolf0ebd24e2013-09-19 15:12:18 +02001373 if (!bs->read_only) {
1374 bdrv_enable_copy_on_read(bs);
1375 } else {
1376 error_setg(errp, "Can't use copy-on-read on read-only device");
Kevin Wolf18edf282015-04-07 17:12:56 +02001377 ret = -EINVAL;
1378 goto fail_opts;
Kevin Wolf0ebd24e2013-09-19 15:12:18 +02001379 }
Stefan Hajnoczi53fec9d2011-11-28 16:08:47 +00001380 }
1381
Kevin Wolf818584a2016-09-12 18:03:18 +02001382 discard = qemu_opt_get(opts, "discard");
1383 if (discard != NULL) {
1384 if (bdrv_parse_discard_flags(discard, &bs->open_flags) != 0) {
1385 error_setg(errp, "Invalid discard option");
1386 ret = -EINVAL;
1387 goto fail_opts;
1388 }
1389 }
1390
Kevin Wolf692e01a2016-09-12 21:00:41 +02001391 detect_zeroes = qemu_opt_get(opts, "detect-zeroes");
1392 if (detect_zeroes) {
1393 BlockdevDetectZeroesOptions value =
Marc-André Lureauf7abe0e2017-08-24 10:46:10 +02001394 qapi_enum_parse(&BlockdevDetectZeroesOptions_lookup,
Kevin Wolf692e01a2016-09-12 21:00:41 +02001395 detect_zeroes,
Kevin Wolf692e01a2016-09-12 21:00:41 +02001396 BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF,
1397 &local_err);
1398 if (local_err) {
1399 error_propagate(errp, local_err);
1400 ret = -EINVAL;
1401 goto fail_opts;
1402 }
1403
1404 if (value == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP &&
1405 !(bs->open_flags & BDRV_O_UNMAP))
1406 {
1407 error_setg(errp, "setting detect-zeroes to unmap is not allowed "
1408 "without setting discard operation to unmap");
1409 ret = -EINVAL;
1410 goto fail_opts;
1411 }
1412
1413 bs->detect_zeroes = value;
1414 }
1415
Kevin Wolfc2ad1b02013-03-18 16:40:51 +01001416 if (filename != NULL) {
1417 pstrcpy(bs->filename, sizeof(bs->filename), filename);
1418 } else {
1419 bs->filename[0] = '\0';
1420 }
Max Reitz91af7012014-07-18 20:24:56 +02001421 pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename);
Kevin Wolf57915332010-04-14 15:24:50 +02001422
Kevin Wolf66f82ce2010-04-14 14:17:38 +02001423 /* Open the image, either directly or using a protocol */
Kevin Wolf82dc8b42016-01-11 19:07:50 +01001424 open_flags = bdrv_open_flags(bs, bs->open_flags);
Kevin Wolf01a56502017-01-18 15:51:56 +01001425 node_name = qemu_opt_get(opts, "node-name");
Kevin Wolf66f82ce2010-04-14 14:17:38 +02001426
Kevin Wolf01a56502017-01-18 15:51:56 +01001427 assert(!drv->bdrv_file_open || file == NULL);
1428 ret = bdrv_open_driver(bs, drv, node_name, options, open_flags, errp);
Kevin Wolf57915332010-04-14 15:24:50 +02001429 if (ret < 0) {
Kevin Wolf01a56502017-01-18 15:51:56 +01001430 goto fail_opts;
Kevin Wolf57915332010-04-14 15:24:50 +02001431 }
1432
Kevin Wolf18edf282015-04-07 17:12:56 +02001433 qemu_opts_del(opts);
Kevin Wolf57915332010-04-14 15:24:50 +02001434 return 0;
1435
Kevin Wolf18edf282015-04-07 17:12:56 +02001436fail_opts:
1437 qemu_opts_del(opts);
Kevin Wolf57915332010-04-14 15:24:50 +02001438 return ret;
1439}
1440
Kevin Wolf5e5c4f62014-05-26 11:45:08 +02001441static QDict *parse_json_filename(const char *filename, Error **errp)
1442{
1443 QObject *options_obj;
1444 QDict *options;
1445 int ret;
1446
1447 ret = strstart(filename, "json:", &filename);
1448 assert(ret);
1449
Markus Armbruster5577fff2017-02-28 22:26:59 +01001450 options_obj = qobject_from_json(filename, errp);
Kevin Wolf5e5c4f62014-05-26 11:45:08 +02001451 if (!options_obj) {
Markus Armbruster5577fff2017-02-28 22:26:59 +01001452 /* Work around qobject_from_json() lossage TODO fix that */
1453 if (errp && !*errp) {
1454 error_setg(errp, "Could not parse the JSON options");
1455 return NULL;
1456 }
1457 error_prepend(errp, "Could not parse the JSON options: ");
Kevin Wolf5e5c4f62014-05-26 11:45:08 +02001458 return NULL;
1459 }
1460
Max Reitz7dc847e2018-02-24 16:40:29 +01001461 options = qobject_to(QDict, options_obj);
Markus Armbrusterca6b6e12017-02-17 21:38:18 +01001462 if (!options) {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02001463 qobject_unref(options_obj);
Kevin Wolf5e5c4f62014-05-26 11:45:08 +02001464 error_setg(errp, "Invalid JSON object given");
1465 return NULL;
1466 }
1467
Kevin Wolf5e5c4f62014-05-26 11:45:08 +02001468 qdict_flatten(options);
1469
1470 return options;
1471}
1472
Kevin Wolfde3b53f2015-10-29 15:24:41 +01001473static void parse_json_protocol(QDict *options, const char **pfilename,
1474 Error **errp)
1475{
1476 QDict *json_options;
1477 Error *local_err = NULL;
1478
1479 /* Parse json: pseudo-protocol */
1480 if (!*pfilename || !g_str_has_prefix(*pfilename, "json:")) {
1481 return;
1482 }
1483
1484 json_options = parse_json_filename(*pfilename, &local_err);
1485 if (local_err) {
1486 error_propagate(errp, local_err);
1487 return;
1488 }
1489
1490 /* Options given in the filename have lower priority than options
1491 * specified directly */
1492 qdict_join(options, json_options, false);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02001493 qobject_unref(json_options);
Kevin Wolfde3b53f2015-10-29 15:24:41 +01001494 *pfilename = NULL;
1495}
1496
Kevin Wolf57915332010-04-14 15:24:50 +02001497/*
Kevin Wolff54120f2014-05-26 11:09:59 +02001498 * Fills in default options for opening images and converts the legacy
1499 * filename/flags pair to option QDict entries.
Max Reitz53a29512015-03-19 14:53:16 -04001500 * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a
1501 * block driver has been specified explicitly.
Kevin Wolff54120f2014-05-26 11:09:59 +02001502 */
Kevin Wolfde3b53f2015-10-29 15:24:41 +01001503static int bdrv_fill_options(QDict **options, const char *filename,
Max Reitz053e1572015-08-26 19:47:51 +02001504 int *flags, Error **errp)
Kevin Wolff54120f2014-05-26 11:09:59 +02001505{
1506 const char *drvname;
Max Reitz53a29512015-03-19 14:53:16 -04001507 bool protocol = *flags & BDRV_O_PROTOCOL;
Kevin Wolff54120f2014-05-26 11:09:59 +02001508 bool parse_filename = false;
Max Reitz053e1572015-08-26 19:47:51 +02001509 BlockDriver *drv = NULL;
Kevin Wolff54120f2014-05-26 11:09:59 +02001510 Error *local_err = NULL;
Kevin Wolff54120f2014-05-26 11:09:59 +02001511
Markus Armbruster129c7d12017-03-30 19:43:12 +02001512 /*
1513 * Caution: while qdict_get_try_str() is fine, getting non-string
1514 * types would require more care. When @options come from
1515 * -blockdev or blockdev_add, its members are typed according to
1516 * the QAPI schema, but when they come from -drive, they're all
1517 * QString.
1518 */
Max Reitz53a29512015-03-19 14:53:16 -04001519 drvname = qdict_get_try_str(*options, "driver");
Max Reitz053e1572015-08-26 19:47:51 +02001520 if (drvname) {
1521 drv = bdrv_find_format(drvname);
1522 if (!drv) {
1523 error_setg(errp, "Unknown driver '%s'", drvname);
1524 return -ENOENT;
1525 }
1526 /* If the user has explicitly specified the driver, this choice should
1527 * override the BDRV_O_PROTOCOL flag */
1528 protocol = drv->bdrv_file_open;
Max Reitz53a29512015-03-19 14:53:16 -04001529 }
1530
1531 if (protocol) {
1532 *flags |= BDRV_O_PROTOCOL;
1533 } else {
1534 *flags &= ~BDRV_O_PROTOCOL;
1535 }
1536
Kevin Wolf91a097e2015-05-08 17:49:53 +02001537 /* Translate cache options from flags into options */
1538 update_options_from_flags(*options, *flags);
1539
Kevin Wolff54120f2014-05-26 11:09:59 +02001540 /* Fetch the file name from the options QDict if necessary */
Kevin Wolf17b005f2014-05-27 10:50:29 +02001541 if (protocol && filename) {
Kevin Wolff54120f2014-05-26 11:09:59 +02001542 if (!qdict_haskey(*options, "filename")) {
Eric Blake46f5ac22017-04-27 16:58:17 -05001543 qdict_put_str(*options, "filename", filename);
Kevin Wolff54120f2014-05-26 11:09:59 +02001544 parse_filename = true;
1545 } else {
1546 error_setg(errp, "Can't specify 'file' and 'filename' options at "
1547 "the same time");
1548 return -EINVAL;
1549 }
1550 }
1551
1552 /* Find the right block driver */
Markus Armbruster129c7d12017-03-30 19:43:12 +02001553 /* See cautionary note on accessing @options above */
Kevin Wolff54120f2014-05-26 11:09:59 +02001554 filename = qdict_get_try_str(*options, "filename");
Kevin Wolff54120f2014-05-26 11:09:59 +02001555
Max Reitz053e1572015-08-26 19:47:51 +02001556 if (!drvname && protocol) {
1557 if (filename) {
1558 drv = bdrv_find_protocol(filename, parse_filename, errp);
1559 if (!drv) {
Kevin Wolff54120f2014-05-26 11:09:59 +02001560 return -EINVAL;
1561 }
Max Reitz053e1572015-08-26 19:47:51 +02001562
1563 drvname = drv->format_name;
Eric Blake46f5ac22017-04-27 16:58:17 -05001564 qdict_put_str(*options, "driver", drvname);
Max Reitz053e1572015-08-26 19:47:51 +02001565 } else {
1566 error_setg(errp, "Must specify either driver or file");
1567 return -EINVAL;
Kevin Wolff54120f2014-05-26 11:09:59 +02001568 }
1569 }
1570
Kevin Wolf17b005f2014-05-27 10:50:29 +02001571 assert(drv || !protocol);
Kevin Wolff54120f2014-05-26 11:09:59 +02001572
1573 /* Driver-specific filename parsing */
Kevin Wolf17b005f2014-05-27 10:50:29 +02001574 if (drv && drv->bdrv_parse_filename && parse_filename) {
Kevin Wolff54120f2014-05-26 11:09:59 +02001575 drv->bdrv_parse_filename(filename, *options, &local_err);
1576 if (local_err) {
1577 error_propagate(errp, local_err);
1578 return -EINVAL;
1579 }
1580
1581 if (!drv->bdrv_needs_filename) {
1582 qdict_del(*options, "filename");
1583 }
1584 }
1585
1586 return 0;
1587}
1588
Kevin Wolf3121fb42017-09-14 14:42:12 +02001589static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q,
1590 uint64_t perm, uint64_t shared,
Fam Zhengc1cef672017-03-14 10:30:50 +08001591 GSList *ignore_children, Error **errp);
1592static void bdrv_child_abort_perm_update(BdrvChild *c);
1593static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared);
1594
Kevin Wolf148eb132017-09-14 14:32:04 +02001595typedef struct BlockReopenQueueEntry {
1596 bool prepared;
1597 BDRVReopenState state;
1598 QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry;
1599} BlockReopenQueueEntry;
1600
1601/*
1602 * Return the flags that @bs will have after the reopens in @q have
1603 * successfully completed. If @q is NULL (or @bs is not contained in @q),
1604 * return the current flags.
1605 */
1606static int bdrv_reopen_get_flags(BlockReopenQueue *q, BlockDriverState *bs)
1607{
1608 BlockReopenQueueEntry *entry;
1609
1610 if (q != NULL) {
1611 QSIMPLEQ_FOREACH(entry, q, entry) {
1612 if (entry->state.bs == bs) {
1613 return entry->state.flags;
1614 }
1615 }
1616 }
1617
1618 return bs->open_flags;
1619}
1620
1621/* Returns whether the image file can be written to after the reopen queue @q
1622 * has been successfully applied, or right now if @q is NULL. */
1623static bool bdrv_is_writable(BlockDriverState *bs, BlockReopenQueue *q)
1624{
1625 int flags = bdrv_reopen_get_flags(q, bs);
1626
1627 return (flags & (BDRV_O_RDWR | BDRV_O_INACTIVE)) == BDRV_O_RDWR;
1628}
1629
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001630static void bdrv_child_perm(BlockDriverState *bs, BlockDriverState *child_bs,
Kevin Wolfe0995dc2017-09-14 12:47:11 +02001631 BdrvChild *c, const BdrvChildRole *role,
1632 BlockReopenQueue *reopen_queue,
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001633 uint64_t parent_perm, uint64_t parent_shared,
1634 uint64_t *nperm, uint64_t *nshared)
1635{
1636 if (bs->drv && bs->drv->bdrv_child_perm) {
Kevin Wolfe0995dc2017-09-14 12:47:11 +02001637 bs->drv->bdrv_child_perm(bs, c, role, reopen_queue,
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001638 parent_perm, parent_shared,
1639 nperm, nshared);
1640 }
Kevin Wolfe0995dc2017-09-14 12:47:11 +02001641 /* TODO Take force_share from reopen_queue */
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001642 if (child_bs && child_bs->force_share) {
1643 *nshared = BLK_PERM_ALL;
1644 }
1645}
1646
Kevin Wolf33a610c2016-12-15 13:04:20 +01001647/*
1648 * Check whether permissions on this node can be changed in a way that
1649 * @cumulative_perms and @cumulative_shared_perms are the new cumulative
1650 * permissions of all its parents. This involves checking whether all necessary
1651 * permission changes to child nodes can be performed.
1652 *
1653 * A call to this function must always be followed by a call to bdrv_set_perm()
1654 * or bdrv_abort_perm_update().
1655 */
Kevin Wolf3121fb42017-09-14 14:42:12 +02001656static int bdrv_check_perm(BlockDriverState *bs, BlockReopenQueue *q,
1657 uint64_t cumulative_perms,
Kevin Wolf46181122017-03-06 15:00:13 +01001658 uint64_t cumulative_shared_perms,
1659 GSList *ignore_children, Error **errp)
Kevin Wolf33a610c2016-12-15 13:04:20 +01001660{
1661 BlockDriver *drv = bs->drv;
1662 BdrvChild *c;
1663 int ret;
1664
1665 /* Write permissions never work with read-only images */
1666 if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) &&
Kevin Wolf148eb132017-09-14 14:32:04 +02001667 !bdrv_is_writable(bs, q))
Kevin Wolf33a610c2016-12-15 13:04:20 +01001668 {
1669 error_setg(errp, "Block node is read-only");
1670 return -EPERM;
1671 }
1672
1673 /* Check this node */
1674 if (!drv) {
1675 return 0;
1676 }
1677
1678 if (drv->bdrv_check_perm) {
1679 return drv->bdrv_check_perm(bs, cumulative_perms,
1680 cumulative_shared_perms, errp);
1681 }
1682
Kevin Wolf78e421c2016-12-20 23:25:12 +01001683 /* Drivers that never have children can omit .bdrv_child_perm() */
Kevin Wolf33a610c2016-12-15 13:04:20 +01001684 if (!drv->bdrv_child_perm) {
Kevin Wolf78e421c2016-12-20 23:25:12 +01001685 assert(QLIST_EMPTY(&bs->children));
Kevin Wolf33a610c2016-12-15 13:04:20 +01001686 return 0;
1687 }
1688
1689 /* Check all children */
1690 QLIST_FOREACH(c, &bs->children, next) {
1691 uint64_t cur_perm, cur_shared;
Kevin Wolf3121fb42017-09-14 14:42:12 +02001692 bdrv_child_perm(bs, c->bs, c, c->role, q,
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001693 cumulative_perms, cumulative_shared_perms,
1694 &cur_perm, &cur_shared);
Kevin Wolf3121fb42017-09-14 14:42:12 +02001695 ret = bdrv_child_check_perm(c, q, cur_perm, cur_shared,
1696 ignore_children, errp);
Kevin Wolf33a610c2016-12-15 13:04:20 +01001697 if (ret < 0) {
1698 return ret;
1699 }
1700 }
1701
1702 return 0;
1703}
1704
1705/*
1706 * Notifies drivers that after a previous bdrv_check_perm() call, the
1707 * permission update is not performed and any preparations made for it (e.g.
1708 * taken file locks) need to be undone.
1709 *
1710 * This function recursively notifies all child nodes.
1711 */
1712static void bdrv_abort_perm_update(BlockDriverState *bs)
1713{
1714 BlockDriver *drv = bs->drv;
1715 BdrvChild *c;
1716
1717 if (!drv) {
1718 return;
1719 }
1720
1721 if (drv->bdrv_abort_perm_update) {
1722 drv->bdrv_abort_perm_update(bs);
1723 }
1724
1725 QLIST_FOREACH(c, &bs->children, next) {
1726 bdrv_child_abort_perm_update(c);
1727 }
1728}
1729
1730static void bdrv_set_perm(BlockDriverState *bs, uint64_t cumulative_perms,
1731 uint64_t cumulative_shared_perms)
1732{
1733 BlockDriver *drv = bs->drv;
1734 BdrvChild *c;
1735
1736 if (!drv) {
1737 return;
1738 }
1739
1740 /* Update this node */
1741 if (drv->bdrv_set_perm) {
1742 drv->bdrv_set_perm(bs, cumulative_perms, cumulative_shared_perms);
1743 }
1744
Kevin Wolf78e421c2016-12-20 23:25:12 +01001745 /* Drivers that never have children can omit .bdrv_child_perm() */
Kevin Wolf33a610c2016-12-15 13:04:20 +01001746 if (!drv->bdrv_child_perm) {
Kevin Wolf78e421c2016-12-20 23:25:12 +01001747 assert(QLIST_EMPTY(&bs->children));
Kevin Wolf33a610c2016-12-15 13:04:20 +01001748 return;
1749 }
1750
1751 /* Update all children */
1752 QLIST_FOREACH(c, &bs->children, next) {
1753 uint64_t cur_perm, cur_shared;
Kevin Wolfe0995dc2017-09-14 12:47:11 +02001754 bdrv_child_perm(bs, c->bs, c, c->role, NULL,
Fam Zhengffd1a5a2017-05-03 00:35:38 +08001755 cumulative_perms, cumulative_shared_perms,
1756 &cur_perm, &cur_shared);
Kevin Wolf33a610c2016-12-15 13:04:20 +01001757 bdrv_child_set_perm(c, cur_perm, cur_shared);
1758 }
1759}
1760
1761static void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm,
1762 uint64_t *shared_perm)
1763{
1764 BdrvChild *c;
1765 uint64_t cumulative_perms = 0;
1766 uint64_t cumulative_shared_perms = BLK_PERM_ALL;
1767
1768 QLIST_FOREACH(c, &bs->parents, next_parent) {
1769 cumulative_perms |= c->perm;
1770 cumulative_shared_perms &= c->shared_perm;
1771 }
1772
1773 *perm = cumulative_perms;
1774 *shared_perm = cumulative_shared_perms;
1775}
1776
Kevin Wolfd0833192017-01-16 18:26:20 +01001777static char *bdrv_child_user_desc(BdrvChild *c)
1778{
1779 if (c->role->get_parent_desc) {
1780 return c->role->get_parent_desc(c);
1781 }
1782
1783 return g_strdup("another user");
1784}
1785
Fam Zheng51761962017-05-03 00:35:36 +08001786char *bdrv_perm_names(uint64_t perm)
Kevin Wolfd0833192017-01-16 18:26:20 +01001787{
1788 struct perm_name {
1789 uint64_t perm;
1790 const char *name;
1791 } permissions[] = {
1792 { BLK_PERM_CONSISTENT_READ, "consistent read" },
1793 { BLK_PERM_WRITE, "write" },
1794 { BLK_PERM_WRITE_UNCHANGED, "write unchanged" },
1795 { BLK_PERM_RESIZE, "resize" },
1796 { BLK_PERM_GRAPH_MOD, "change children" },
1797 { 0, NULL }
1798 };
1799
1800 char *result = g_strdup("");
1801 struct perm_name *p;
1802
1803 for (p = permissions; p->name; p++) {
1804 if (perm & p->perm) {
1805 char *old = result;
1806 result = g_strdup_printf("%s%s%s", old, *old ? ", " : "", p->name);
1807 g_free(old);
1808 }
1809 }
1810
1811 return result;
1812}
1813
Kevin Wolf33a610c2016-12-15 13:04:20 +01001814/*
1815 * Checks whether a new reference to @bs can be added if the new user requires
Kevin Wolf46181122017-03-06 15:00:13 +01001816 * @new_used_perm/@new_shared_perm as its permissions. If @ignore_children is
1817 * set, the BdrvChild objects in this list are ignored in the calculations;
1818 * this allows checking permission updates for an existing reference.
Kevin Wolf33a610c2016-12-15 13:04:20 +01001819 *
1820 * Needs to be followed by a call to either bdrv_set_perm() or
1821 * bdrv_abort_perm_update(). */
Kevin Wolf3121fb42017-09-14 14:42:12 +02001822static int bdrv_check_update_perm(BlockDriverState *bs, BlockReopenQueue *q,
1823 uint64_t new_used_perm,
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001824 uint64_t new_shared_perm,
Kevin Wolf46181122017-03-06 15:00:13 +01001825 GSList *ignore_children, Error **errp)
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001826{
1827 BdrvChild *c;
Kevin Wolf33a610c2016-12-15 13:04:20 +01001828 uint64_t cumulative_perms = new_used_perm;
1829 uint64_t cumulative_shared_perms = new_shared_perm;
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001830
1831 /* There is no reason why anyone couldn't tolerate write_unchanged */
1832 assert(new_shared_perm & BLK_PERM_WRITE_UNCHANGED);
1833
1834 QLIST_FOREACH(c, &bs->parents, next_parent) {
Kevin Wolf46181122017-03-06 15:00:13 +01001835 if (g_slist_find(ignore_children, c)) {
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001836 continue;
1837 }
1838
Kevin Wolfd0833192017-01-16 18:26:20 +01001839 if ((new_used_perm & c->shared_perm) != new_used_perm) {
1840 char *user = bdrv_child_user_desc(c);
1841 char *perm_names = bdrv_perm_names(new_used_perm & ~c->shared_perm);
1842 error_setg(errp, "Conflicts with use by %s as '%s', which does not "
1843 "allow '%s' on %s",
1844 user, c->name, perm_names, bdrv_get_node_name(c->bs));
1845 g_free(user);
1846 g_free(perm_names);
1847 return -EPERM;
1848 }
1849
1850 if ((c->perm & new_shared_perm) != c->perm) {
1851 char *user = bdrv_child_user_desc(c);
1852 char *perm_names = bdrv_perm_names(c->perm & ~new_shared_perm);
1853 error_setg(errp, "Conflicts with use by %s as '%s', which uses "
1854 "'%s' on %s",
1855 user, c->name, perm_names, bdrv_get_node_name(c->bs));
1856 g_free(user);
1857 g_free(perm_names);
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001858 return -EPERM;
1859 }
Kevin Wolf33a610c2016-12-15 13:04:20 +01001860
1861 cumulative_perms |= c->perm;
1862 cumulative_shared_perms &= c->shared_perm;
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001863 }
1864
Kevin Wolf3121fb42017-09-14 14:42:12 +02001865 return bdrv_check_perm(bs, q, cumulative_perms, cumulative_shared_perms,
Kevin Wolf46181122017-03-06 15:00:13 +01001866 ignore_children, errp);
Kevin Wolf33a610c2016-12-15 13:04:20 +01001867}
1868
1869/* Needs to be followed by a call to either bdrv_child_set_perm() or
1870 * bdrv_child_abort_perm_update(). */
Kevin Wolf3121fb42017-09-14 14:42:12 +02001871static int bdrv_child_check_perm(BdrvChild *c, BlockReopenQueue *q,
1872 uint64_t perm, uint64_t shared,
Fam Zhengc1cef672017-03-14 10:30:50 +08001873 GSList *ignore_children, Error **errp)
Kevin Wolf33a610c2016-12-15 13:04:20 +01001874{
Kevin Wolf46181122017-03-06 15:00:13 +01001875 int ret;
1876
1877 ignore_children = g_slist_prepend(g_slist_copy(ignore_children), c);
Kevin Wolf3121fb42017-09-14 14:42:12 +02001878 ret = bdrv_check_update_perm(c->bs, q, perm, shared, ignore_children, errp);
Kevin Wolf46181122017-03-06 15:00:13 +01001879 g_slist_free(ignore_children);
1880
1881 return ret;
Kevin Wolf33a610c2016-12-15 13:04:20 +01001882}
1883
Fam Zhengc1cef672017-03-14 10:30:50 +08001884static void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared)
Kevin Wolf33a610c2016-12-15 13:04:20 +01001885{
1886 uint64_t cumulative_perms, cumulative_shared_perms;
1887
1888 c->perm = perm;
1889 c->shared_perm = shared;
1890
1891 bdrv_get_cumulative_perm(c->bs, &cumulative_perms,
1892 &cumulative_shared_perms);
1893 bdrv_set_perm(c->bs, cumulative_perms, cumulative_shared_perms);
1894}
1895
Fam Zhengc1cef672017-03-14 10:30:50 +08001896static void bdrv_child_abort_perm_update(BdrvChild *c)
Kevin Wolf33a610c2016-12-15 13:04:20 +01001897{
1898 bdrv_abort_perm_update(c->bs);
1899}
1900
1901int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared,
1902 Error **errp)
1903{
1904 int ret;
1905
Kevin Wolf3121fb42017-09-14 14:42:12 +02001906 ret = bdrv_child_check_perm(c, NULL, perm, shared, NULL, errp);
Kevin Wolf33a610c2016-12-15 13:04:20 +01001907 if (ret < 0) {
1908 bdrv_child_abort_perm_update(c);
1909 return ret;
1910 }
1911
1912 bdrv_child_set_perm(c, perm, shared);
1913
Kevin Wolfd5e6f432016-12-14 17:24:36 +01001914 return 0;
1915}
1916
Kevin Wolf6a1b9ee2016-12-15 11:27:32 +01001917#define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \
1918 | BLK_PERM_WRITE \
1919 | BLK_PERM_WRITE_UNCHANGED \
1920 | BLK_PERM_RESIZE)
1921#define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH)
1922
1923void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c,
1924 const BdrvChildRole *role,
Kevin Wolfe0995dc2017-09-14 12:47:11 +02001925 BlockReopenQueue *reopen_queue,
Kevin Wolf6a1b9ee2016-12-15 11:27:32 +01001926 uint64_t perm, uint64_t shared,
1927 uint64_t *nperm, uint64_t *nshared)
1928{
1929 if (c == NULL) {
1930 *nperm = perm & DEFAULT_PERM_PASSTHROUGH;
1931 *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED;
1932 return;
1933 }
1934
1935 *nperm = (perm & DEFAULT_PERM_PASSTHROUGH) |
1936 (c->perm & DEFAULT_PERM_UNCHANGED);
1937 *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) |
1938 (c->shared_perm & DEFAULT_PERM_UNCHANGED);
1939}
1940
Kevin Wolf6b1a0442016-12-19 15:21:48 +01001941void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c,
1942 const BdrvChildRole *role,
Kevin Wolfe0995dc2017-09-14 12:47:11 +02001943 BlockReopenQueue *reopen_queue,
Kevin Wolf6b1a0442016-12-19 15:21:48 +01001944 uint64_t perm, uint64_t shared,
1945 uint64_t *nperm, uint64_t *nshared)
1946{
1947 bool backing = (role == &child_backing);
1948 assert(role == &child_backing || role == &child_file);
1949
1950 if (!backing) {
Kevin Wolf5fbfabd2017-11-30 17:38:43 +01001951 int flags = bdrv_reopen_get_flags(reopen_queue, bs);
1952
Kevin Wolf6b1a0442016-12-19 15:21:48 +01001953 /* Apart from the modifications below, the same permissions are
1954 * forwarded and left alone as for filters */
Kevin Wolfe0995dc2017-09-14 12:47:11 +02001955 bdrv_filter_default_perms(bs, c, role, reopen_queue, perm, shared,
1956 &perm, &shared);
Kevin Wolf6b1a0442016-12-19 15:21:48 +01001957
1958 /* Format drivers may touch metadata even if the guest doesn't write */
Kevin Wolf148eb132017-09-14 14:32:04 +02001959 if (bdrv_is_writable(bs, reopen_queue)) {
Kevin Wolf6b1a0442016-12-19 15:21:48 +01001960 perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
1961 }
1962
1963 /* bs->file always needs to be consistent because of the metadata. We
1964 * can never allow other users to resize or write to it. */
Kevin Wolf5fbfabd2017-11-30 17:38:43 +01001965 if (!(flags & BDRV_O_NO_IO)) {
1966 perm |= BLK_PERM_CONSISTENT_READ;
1967 }
Kevin Wolf6b1a0442016-12-19 15:21:48 +01001968 shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE);
1969 } else {
1970 /* We want consistent read from backing files if the parent needs it.
1971 * No other operations are performed on backing files. */
1972 perm &= BLK_PERM_CONSISTENT_READ;
1973
1974 /* If the parent can deal with changing data, we're okay with a
1975 * writable and resizable backing file. */
1976 /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */
1977 if (shared & BLK_PERM_WRITE) {
1978 shared = BLK_PERM_WRITE | BLK_PERM_RESIZE;
1979 } else {
1980 shared = 0;
1981 }
1982
1983 shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD |
1984 BLK_PERM_WRITE_UNCHANGED;
1985 }
1986
Kevin Wolf9c5e6592017-05-04 18:52:40 +02001987 if (bs->open_flags & BDRV_O_INACTIVE) {
1988 shared |= BLK_PERM_WRITE | BLK_PERM_RESIZE;
1989 }
1990
Kevin Wolf6b1a0442016-12-19 15:21:48 +01001991 *nperm = perm;
1992 *nshared = shared;
1993}
1994
Kevin Wolf8ee03992017-03-06 13:45:28 +01001995static void bdrv_replace_child_noperm(BdrvChild *child,
1996 BlockDriverState *new_bs)
Kevin Wolfe9740bc2016-05-23 15:52:26 +02001997{
1998 BlockDriverState *old_bs = child->bs;
Kevin Wolf0152bf42017-12-07 13:03:13 +01001999 int i;
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002000
Fam Zhengbb2614e2017-04-07 14:54:10 +08002001 if (old_bs && new_bs) {
2002 assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs));
2003 }
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002004 if (old_bs) {
Kevin Wolfd736f112017-12-18 16:05:48 +01002005 /* Detach first so that the recursive drain sections coming from @child
2006 * are already gone and we only end the drain sections that came from
2007 * elsewhere. */
2008 if (child->role->detach) {
2009 child->role->detach(child);
2010 }
Kevin Wolf36fe1332016-05-17 14:51:55 +02002011 if (old_bs->quiesce_counter && child->role->drained_end) {
Kevin Wolf0152bf42017-12-07 13:03:13 +01002012 for (i = 0; i < old_bs->quiesce_counter; i++) {
2013 child->role->drained_end(child);
2014 }
Kevin Wolf36fe1332016-05-17 14:51:55 +02002015 }
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002016 QLIST_REMOVE(child, next_parent);
2017 }
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002018
2019 child->bs = new_bs;
Kevin Wolf36fe1332016-05-17 14:51:55 +02002020
2021 if (new_bs) {
2022 QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent);
2023 if (new_bs->quiesce_counter && child->role->drained_begin) {
Kevin Wolf0152bf42017-12-07 13:03:13 +01002024 for (i = 0; i < new_bs->quiesce_counter; i++) {
2025 child->role->drained_begin(child);
2026 }
Kevin Wolf36fe1332016-05-17 14:51:55 +02002027 }
Kevin Wolf33a610c2016-12-15 13:04:20 +01002028
Kevin Wolfd736f112017-12-18 16:05:48 +01002029 /* Attach only after starting new drained sections, so that recursive
2030 * drain sections coming from @child don't get an extra .drained_begin
2031 * callback. */
Kevin Wolfdb95dbb2017-02-08 11:28:52 +01002032 if (child->role->attach) {
2033 child->role->attach(child);
2034 }
Kevin Wolf36fe1332016-05-17 14:51:55 +02002035 }
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002036}
2037
Kevin Wolf466787f2017-03-08 14:44:07 +01002038/*
2039 * Updates @child to change its reference to point to @new_bs, including
2040 * checking and applying the necessary permisson updates both to the old node
2041 * and to @new_bs.
2042 *
2043 * NULL is passed as @new_bs for removing the reference before freeing @child.
2044 *
2045 * If @new_bs is not NULL, bdrv_check_perm() must be called beforehand, as this
2046 * function uses bdrv_set_perm() to update the permissions according to the new
2047 * reference that @new_bs gets.
2048 */
2049static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs)
Kevin Wolf8ee03992017-03-06 13:45:28 +01002050{
2051 BlockDriverState *old_bs = child->bs;
2052 uint64_t perm, shared_perm;
2053
Kevin Wolf8aecf1d2017-08-03 17:02:57 +02002054 bdrv_replace_child_noperm(child, new_bs);
2055
Kevin Wolf8ee03992017-03-06 13:45:28 +01002056 if (old_bs) {
2057 /* Update permissions for old node. This is guaranteed to succeed
2058 * because we're just taking a parent away, so we're loosening
2059 * restrictions. */
2060 bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm);
Kevin Wolf3121fb42017-09-14 14:42:12 +02002061 bdrv_check_perm(old_bs, NULL, perm, shared_perm, NULL, &error_abort);
Kevin Wolf8ee03992017-03-06 13:45:28 +01002062 bdrv_set_perm(old_bs, perm, shared_perm);
2063 }
2064
Kevin Wolf8ee03992017-03-06 13:45:28 +01002065 if (new_bs) {
Kevin Wolff54120f2014-05-26 11:09:59 +02002066 bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm);
Kevin Wolff54120f2014-05-26 11:09:59 +02002067 bdrv_set_perm(new_bs, perm, shared_perm);
Kevin Wolff54120f2014-05-26 11:09:59 +02002068 }
2069}
2070
Kevin Wolff21d96d2016-03-08 13:47:46 +01002071BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs,
2072 const char *child_name,
Kevin Wolf36fe1332016-05-17 14:51:55 +02002073 const BdrvChildRole *child_role,
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002074 uint64_t perm, uint64_t shared_perm,
2075 void *opaque, Error **errp)
Kevin Wolfdf581792015-06-15 11:53:47 +02002076{
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002077 BdrvChild *child;
2078 int ret;
2079
Kevin Wolf3121fb42017-09-14 14:42:12 +02002080 ret = bdrv_check_update_perm(child_bs, NULL, perm, shared_perm, NULL, errp);
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002081 if (ret < 0) {
Kevin Wolf33a610c2016-12-15 13:04:20 +01002082 bdrv_abort_perm_update(child_bs);
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002083 return NULL;
2084 }
2085
2086 child = g_new(BdrvChild, 1);
Kevin Wolfdf581792015-06-15 11:53:47 +02002087 *child = (BdrvChild) {
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002088 .bs = NULL,
2089 .name = g_strdup(child_name),
2090 .role = child_role,
2091 .perm = perm,
2092 .shared_perm = shared_perm,
2093 .opaque = opaque,
Kevin Wolfdf581792015-06-15 11:53:47 +02002094 };
2095
Kevin Wolf33a610c2016-12-15 13:04:20 +01002096 /* This performs the matching bdrv_set_perm() for the above check. */
Kevin Wolf466787f2017-03-08 14:44:07 +01002097 bdrv_replace_child(child, child_bs);
Kevin Wolfb4b059f2015-06-15 13:24:19 +02002098
2099 return child;
Kevin Wolfdf581792015-06-15 11:53:47 +02002100}
2101
Wen Congyang98292c62016-05-10 15:36:38 +08002102BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs,
2103 BlockDriverState *child_bs,
2104 const char *child_name,
Kevin Wolf8b2ff522016-12-20 22:21:17 +01002105 const BdrvChildRole *child_role,
2106 Error **errp)
Kevin Wolff21d96d2016-03-08 13:47:46 +01002107{
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002108 BdrvChild *child;
Kevin Wolff68c5982016-12-20 15:51:12 +01002109 uint64_t perm, shared_perm;
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002110
Kevin Wolff68c5982016-12-20 15:51:12 +01002111 bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm);
2112
2113 assert(parent_bs->drv);
Fam Zhengbb2614e2017-04-07 14:54:10 +08002114 assert(bdrv_get_aio_context(parent_bs) == bdrv_get_aio_context(child_bs));
Kevin Wolfe0995dc2017-09-14 12:47:11 +02002115 bdrv_child_perm(parent_bs, child_bs, NULL, child_role, NULL,
Fam Zhengffd1a5a2017-05-03 00:35:38 +08002116 perm, shared_perm, &perm, &shared_perm);
Kevin Wolff68c5982016-12-20 15:51:12 +01002117
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002118 child = bdrv_root_attach_child(child_bs, child_name, child_role,
Kevin Wolff68c5982016-12-20 15:51:12 +01002119 perm, shared_perm, parent_bs, errp);
Kevin Wolfd5e6f432016-12-14 17:24:36 +01002120 if (child == NULL) {
2121 return NULL;
2122 }
2123
Kevin Wolff21d96d2016-03-08 13:47:46 +01002124 QLIST_INSERT_HEAD(&parent_bs->children, child, next);
2125 return child;
2126}
2127
Kevin Wolf3f09bfb2015-09-15 11:58:23 +02002128static void bdrv_detach_child(BdrvChild *child)
Kevin Wolf33a60402015-06-15 13:51:04 +02002129{
Kevin Wolff21d96d2016-03-08 13:47:46 +01002130 if (child->next.le_prev) {
2131 QLIST_REMOVE(child, next);
2132 child->next.le_prev = NULL;
2133 }
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002134
Kevin Wolf466787f2017-03-08 14:44:07 +01002135 bdrv_replace_child(child, NULL);
Kevin Wolfe9740bc2016-05-23 15:52:26 +02002136
Kevin Wolf260fecf2015-04-27 13:46:22 +02002137 g_free(child->name);
Kevin Wolf33a60402015-06-15 13:51:04 +02002138 g_free(child);
2139}
2140
Kevin Wolff21d96d2016-03-08 13:47:46 +01002141void bdrv_root_unref_child(BdrvChild *child)
Kevin Wolf33a60402015-06-15 13:51:04 +02002142{
Kevin Wolf779020c2015-10-13 14:09:44 +02002143 BlockDriverState *child_bs;
2144
Kevin Wolff21d96d2016-03-08 13:47:46 +01002145 child_bs = child->bs;
2146 bdrv_detach_child(child);
2147 bdrv_unref(child_bs);
2148}
2149
2150void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child)
2151{
Kevin Wolf779020c2015-10-13 14:09:44 +02002152 if (child == NULL) {
2153 return;
2154 }
Kevin Wolf33a60402015-06-15 13:51:04 +02002155
2156 if (child->bs->inherits_from == parent) {
Kevin Wolf4e4bf5c2016-12-16 18:52:37 +01002157 BdrvChild *c;
2158
2159 /* Remove inherits_from only when the last reference between parent and
2160 * child->bs goes away. */
2161 QLIST_FOREACH(c, &parent->children, next) {
2162 if (c != child && c->bs == child->bs) {
2163 break;
2164 }
2165 }
2166 if (c == NULL) {
2167 child->bs->inherits_from = NULL;
2168 }
Kevin Wolf33a60402015-06-15 13:51:04 +02002169 }
2170
Kevin Wolff21d96d2016-03-08 13:47:46 +01002171 bdrv_root_unref_child(child);
Kevin Wolf33a60402015-06-15 13:51:04 +02002172}
2173
Kevin Wolf5c8cab42016-02-24 15:13:35 +01002174
2175static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load)
2176{
2177 BdrvChild *c;
2178 QLIST_FOREACH(c, &bs->parents, next_parent) {
2179 if (c->role->change_media) {
2180 c->role->change_media(c, load);
2181 }
2182 }
2183}
2184
2185static void bdrv_parent_cb_resize(BlockDriverState *bs)
2186{
2187 BdrvChild *c;
2188 QLIST_FOREACH(c, &bs->parents, next_parent) {
2189 if (c->role->resize) {
2190 c->role->resize(c);
2191 }
2192 }
2193}
2194
Kevin Wolf5db15a52015-09-14 15:33:33 +02002195/*
2196 * Sets the backing file link of a BDS. A new reference is created; callers
2197 * which don't need their own reference any more must call bdrv_unref().
2198 */
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002199void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd,
2200 Error **errp)
Fam Zheng8d24cce2014-05-23 21:29:45 +08002201{
Kevin Wolf5db15a52015-09-14 15:33:33 +02002202 if (backing_hd) {
2203 bdrv_ref(backing_hd);
2204 }
Fam Zheng8d24cce2014-05-23 21:29:45 +08002205
Kevin Wolf760e0062015-06-17 14:55:21 +02002206 if (bs->backing) {
Kevin Wolf5db15a52015-09-14 15:33:33 +02002207 bdrv_unref_child(bs, bs->backing);
Fam Zheng826b6ca2014-05-23 21:29:47 +08002208 }
2209
Fam Zheng8d24cce2014-05-23 21:29:45 +08002210 if (!backing_hd) {
Kevin Wolf760e0062015-06-17 14:55:21 +02002211 bs->backing = NULL;
Fam Zheng8d24cce2014-05-23 21:29:45 +08002212 goto out;
2213 }
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002214
Kevin Wolf8b2ff522016-12-20 22:21:17 +01002215 bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_backing,
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002216 errp);
2217 if (!bs->backing) {
2218 bdrv_unref(backing_hd);
2219 }
Fam Zheng826b6ca2014-05-23 21:29:47 +08002220
Kevin Wolf9e7e9402017-03-09 11:45:39 +01002221 bdrv_refresh_filename(bs);
2222
Fam Zheng8d24cce2014-05-23 21:29:45 +08002223out:
Kevin Wolf3baca892014-07-16 17:48:16 +02002224 bdrv_refresh_limits(bs, NULL);
Fam Zheng8d24cce2014-05-23 21:29:45 +08002225}
2226
Kevin Wolf31ca6d02013-03-28 15:29:24 +01002227/*
2228 * Opens the backing file for a BlockDriverState if not yet open
2229 *
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002230 * bdref_key specifies the key for the image's BlockdevRef in the options QDict.
2231 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2232 * itself, all options starting with "${bdref_key}." are considered part of the
2233 * BlockdevRef.
2234 *
2235 * TODO Can this be unified with bdrv_open_image()?
Kevin Wolf31ca6d02013-03-28 15:29:24 +01002236 */
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002237int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options,
2238 const char *bdref_key, Error **errp)
Paolo Bonzini9156df12012-10-18 16:49:17 +02002239{
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002240 char *backing_filename = g_malloc0(PATH_MAX);
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002241 char *bdref_key_dot;
2242 const char *reference = NULL;
Kevin Wolf317fc442014-04-25 13:27:34 +02002243 int ret = 0;
Fam Zheng8d24cce2014-05-23 21:29:45 +08002244 BlockDriverState *backing_hd;
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002245 QDict *options;
2246 QDict *tmp_parent_options = NULL;
Max Reitz34b5d2c2013-09-05 14:45:29 +02002247 Error *local_err = NULL;
Paolo Bonzini9156df12012-10-18 16:49:17 +02002248
Kevin Wolf760e0062015-06-17 14:55:21 +02002249 if (bs->backing != NULL) {
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002250 goto free_exit;
Paolo Bonzini9156df12012-10-18 16:49:17 +02002251 }
2252
Kevin Wolf31ca6d02013-03-28 15:29:24 +01002253 /* NULL means an empty set of options */
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002254 if (parent_options == NULL) {
2255 tmp_parent_options = qdict_new();
2256 parent_options = tmp_parent_options;
Kevin Wolf31ca6d02013-03-28 15:29:24 +01002257 }
2258
Paolo Bonzini9156df12012-10-18 16:49:17 +02002259 bs->open_flags &= ~BDRV_O_NO_BACKING;
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002260
2261 bdref_key_dot = g_strdup_printf("%s.", bdref_key);
2262 qdict_extract_subqdict(parent_options, &options, bdref_key_dot);
2263 g_free(bdref_key_dot);
2264
Markus Armbruster129c7d12017-03-30 19:43:12 +02002265 /*
2266 * Caution: while qdict_get_try_str() is fine, getting non-string
2267 * types would require more care. When @parent_options come from
2268 * -blockdev or blockdev_add, its members are typed according to
2269 * the QAPI schema, but when they come from -drive, they're all
2270 * QString.
2271 */
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002272 reference = qdict_get_try_str(parent_options, bdref_key);
2273 if (reference || qdict_haskey(options, "file.filename")) {
Kevin Wolf1cb6f502013-04-12 20:27:07 +02002274 backing_filename[0] = '\0';
2275 } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002276 qobject_unref(options);
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002277 goto free_exit;
Fam Zhengdbecebd2013-09-22 20:05:06 +08002278 } else {
Max Reitz9f074292014-11-26 17:20:26 +01002279 bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX,
2280 &local_err);
2281 if (local_err) {
2282 ret = -EINVAL;
2283 error_propagate(errp, local_err);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002284 qobject_unref(options);
Max Reitz9f074292014-11-26 17:20:26 +01002285 goto free_exit;
2286 }
Paolo Bonzini9156df12012-10-18 16:49:17 +02002287 }
2288
Kevin Wolf8ee79e72014-06-04 15:09:35 +02002289 if (!bs->drv || !bs->drv->supports_backing) {
2290 ret = -EINVAL;
2291 error_setg(errp, "Driver doesn't support backing files");
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002292 qobject_unref(options);
Kevin Wolf8ee79e72014-06-04 15:09:35 +02002293 goto free_exit;
2294 }
2295
Peter Krempa6bff5972017-10-12 16:14:10 +02002296 if (!reference &&
2297 bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) {
Eric Blake46f5ac22017-04-27 16:58:17 -05002298 qdict_put_str(options, "driver", bs->backing_format);
Paolo Bonzini9156df12012-10-18 16:49:17 +02002299 }
2300
Max Reitz5b363932016-05-17 16:41:31 +02002301 backing_hd = bdrv_open_inherit(*backing_filename ? backing_filename : NULL,
2302 reference, options, 0, bs, &child_backing,
2303 errp);
2304 if (!backing_hd) {
Paolo Bonzini9156df12012-10-18 16:49:17 +02002305 bs->open_flags |= BDRV_O_NO_BACKING;
Markus Armbrustere43bfd92015-12-18 16:35:15 +01002306 error_prepend(errp, "Could not open backing file: ");
Max Reitz5b363932016-05-17 16:41:31 +02002307 ret = -EINVAL;
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002308 goto free_exit;
Paolo Bonzini9156df12012-10-18 16:49:17 +02002309 }
sochin.jiang5ce6bfe2017-06-26 19:04:24 +08002310 bdrv_set_aio_context(backing_hd, bdrv_get_aio_context(bs));
Kevin Wolfdf581792015-06-15 11:53:47 +02002311
Kevin Wolf5db15a52015-09-14 15:33:33 +02002312 /* Hook up the backing file link; drop our reference, bs owns the
2313 * backing_hd reference now */
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002314 bdrv_set_backing_hd(bs, backing_hd, &local_err);
Kevin Wolf5db15a52015-09-14 15:33:33 +02002315 bdrv_unref(backing_hd);
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002316 if (local_err) {
Fam Zheng8cd1a3e2017-03-17 09:56:30 +08002317 error_propagate(errp, local_err);
Kevin Wolf12fa4af2017-02-17 20:42:32 +01002318 ret = -EINVAL;
2319 goto free_exit;
2320 }
Peter Feinerd80ac652014-01-08 19:43:25 +00002321
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002322 qdict_del(parent_options, bdref_key);
2323
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002324free_exit:
2325 g_free(backing_filename);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002326 qobject_unref(tmp_parent_options);
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002327 return ret;
Paolo Bonzini9156df12012-10-18 16:49:17 +02002328}
2329
Kevin Wolf2d6b86a2017-02-17 17:43:59 +01002330static BlockDriverState *
2331bdrv_open_child_bs(const char *filename, QDict *options, const char *bdref_key,
2332 BlockDriverState *parent, const BdrvChildRole *child_role,
2333 bool allow_none, Error **errp)
Max Reitzda557aa2013-12-20 19:28:11 +01002334{
Kevin Wolf2d6b86a2017-02-17 17:43:59 +01002335 BlockDriverState *bs = NULL;
Max Reitzda557aa2013-12-20 19:28:11 +01002336 QDict *image_options;
Max Reitzda557aa2013-12-20 19:28:11 +01002337 char *bdref_key_dot;
2338 const char *reference;
2339
Kevin Wolfdf581792015-06-15 11:53:47 +02002340 assert(child_role != NULL);
Max Reitzf67503e2014-02-18 18:33:05 +01002341
Max Reitzda557aa2013-12-20 19:28:11 +01002342 bdref_key_dot = g_strdup_printf("%s.", bdref_key);
2343 qdict_extract_subqdict(options, &image_options, bdref_key_dot);
2344 g_free(bdref_key_dot);
2345
Markus Armbruster129c7d12017-03-30 19:43:12 +02002346 /*
2347 * Caution: while qdict_get_try_str() is fine, getting non-string
2348 * types would require more care. When @options come from
2349 * -blockdev or blockdev_add, its members are typed according to
2350 * the QAPI schema, but when they come from -drive, they're all
2351 * QString.
2352 */
Max Reitzda557aa2013-12-20 19:28:11 +01002353 reference = qdict_get_try_str(options, bdref_key);
2354 if (!filename && !reference && !qdict_size(image_options)) {
Kevin Wolfb4b059f2015-06-15 13:24:19 +02002355 if (!allow_none) {
Max Reitzda557aa2013-12-20 19:28:11 +01002356 error_setg(errp, "A block device must be specified for \"%s\"",
2357 bdref_key);
Max Reitzda557aa2013-12-20 19:28:11 +01002358 }
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002359 qobject_unref(image_options);
Max Reitzda557aa2013-12-20 19:28:11 +01002360 goto done;
2361 }
2362
Max Reitz5b363932016-05-17 16:41:31 +02002363 bs = bdrv_open_inherit(filename, reference, image_options, 0,
2364 parent, child_role, errp);
2365 if (!bs) {
Kevin Wolfdf581792015-06-15 11:53:47 +02002366 goto done;
2367 }
2368
Max Reitzda557aa2013-12-20 19:28:11 +01002369done:
2370 qdict_del(options, bdref_key);
Kevin Wolf2d6b86a2017-02-17 17:43:59 +01002371 return bs;
2372}
2373
2374/*
2375 * Opens a disk image whose options are given as BlockdevRef in another block
2376 * device's options.
2377 *
2378 * If allow_none is true, no image will be opened if filename is false and no
2379 * BlockdevRef is given. NULL will be returned, but errp remains unset.
2380 *
2381 * bdrev_key specifies the key for the image's BlockdevRef in the options QDict.
2382 * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict
2383 * itself, all options starting with "${bdref_key}." are considered part of the
2384 * BlockdevRef.
2385 *
2386 * The BlockdevRef will be removed from the options QDict.
2387 */
2388BdrvChild *bdrv_open_child(const char *filename,
2389 QDict *options, const char *bdref_key,
2390 BlockDriverState *parent,
2391 const BdrvChildRole *child_role,
2392 bool allow_none, Error **errp)
2393{
Kevin Wolf8b2ff522016-12-20 22:21:17 +01002394 BdrvChild *c;
Kevin Wolf2d6b86a2017-02-17 17:43:59 +01002395 BlockDriverState *bs;
2396
2397 bs = bdrv_open_child_bs(filename, options, bdref_key, parent, child_role,
2398 allow_none, errp);
2399 if (bs == NULL) {
2400 return NULL;
2401 }
2402
Kevin Wolf8b2ff522016-12-20 22:21:17 +01002403 c = bdrv_attach_child(parent, bs, bdref_key, child_role, errp);
2404 if (!c) {
2405 bdrv_unref(bs);
2406 return NULL;
2407 }
2408
2409 return c;
Kevin Wolfb4b059f2015-06-15 13:24:19 +02002410}
2411
Kevin Wolfe1d74bc2018-01-10 15:52:33 +01002412/* TODO Future callers may need to specify parent/child_role in order for
2413 * option inheritance to work. Existing callers use it for the root node. */
2414BlockDriverState *bdrv_open_blockdev_ref(BlockdevRef *ref, Error **errp)
2415{
2416 BlockDriverState *bs = NULL;
2417 Error *local_err = NULL;
2418 QObject *obj = NULL;
2419 QDict *qdict = NULL;
2420 const char *reference = NULL;
2421 Visitor *v = NULL;
2422
2423 if (ref->type == QTYPE_QSTRING) {
2424 reference = ref->u.reference;
2425 } else {
2426 BlockdevOptions *options = &ref->u.definition;
2427 assert(ref->type == QTYPE_QDICT);
2428
2429 v = qobject_output_visitor_new(&obj);
2430 visit_type_BlockdevOptions(v, NULL, &options, &local_err);
2431 if (local_err) {
2432 error_propagate(errp, local_err);
2433 goto fail;
2434 }
2435 visit_complete(v, &obj);
2436
Max Reitz7dc847e2018-02-24 16:40:29 +01002437 qdict = qobject_to(QDict, obj);
Kevin Wolfe1d74bc2018-01-10 15:52:33 +01002438 qdict_flatten(qdict);
2439
2440 /* bdrv_open_inherit() defaults to the values in bdrv_flags (for
2441 * compatibility with other callers) rather than what we want as the
2442 * real defaults. Apply the defaults here instead. */
2443 qdict_set_default_str(qdict, BDRV_OPT_CACHE_DIRECT, "off");
2444 qdict_set_default_str(qdict, BDRV_OPT_CACHE_NO_FLUSH, "off");
2445 qdict_set_default_str(qdict, BDRV_OPT_READ_ONLY, "off");
2446 }
2447
2448 bs = bdrv_open_inherit(NULL, reference, qdict, 0, NULL, NULL, errp);
2449 obj = NULL;
2450
2451fail:
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002452 qobject_unref(obj);
Kevin Wolfe1d74bc2018-01-10 15:52:33 +01002453 visit_free(v);
2454 return bs;
2455}
2456
Max Reitz66836182016-05-17 16:41:27 +02002457static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs,
2458 int flags,
2459 QDict *snapshot_options,
2460 Error **errp)
Kevin Wolfb9988752014-04-03 12:09:34 +02002461{
2462 /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002463 char *tmp_filename = g_malloc0(PATH_MAX + 1);
Kevin Wolfb9988752014-04-03 12:09:34 +02002464 int64_t total_size;
Chunyan Liu83d05212014-06-05 17:20:51 +08002465 QemuOpts *opts = NULL;
Eric Blakeff6ed712017-04-27 16:58:18 -05002466 BlockDriverState *bs_snapshot = NULL;
Kevin Wolfb2c28322017-02-20 12:46:42 +01002467 Error *local_err = NULL;
Kevin Wolfb9988752014-04-03 12:09:34 +02002468 int ret;
2469
2470 /* if snapshot, we create a temporary backing file and open it
2471 instead of opening 'filename' directly */
2472
2473 /* Get the required size from the image */
Kevin Wolff1877432014-04-04 17:07:19 +02002474 total_size = bdrv_getlength(bs);
2475 if (total_size < 0) {
2476 error_setg_errno(errp, -total_size, "Could not get image size");
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002477 goto out;
Kevin Wolff1877432014-04-04 17:07:19 +02002478 }
Kevin Wolfb9988752014-04-03 12:09:34 +02002479
2480 /* Create the temporary image */
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002481 ret = get_tmp_filename(tmp_filename, PATH_MAX + 1);
Kevin Wolfb9988752014-04-03 12:09:34 +02002482 if (ret < 0) {
2483 error_setg_errno(errp, -ret, "Could not get temporary filename");
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002484 goto out;
Kevin Wolfb9988752014-04-03 12:09:34 +02002485 }
2486
Max Reitzef810432014-12-02 18:32:42 +01002487 opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0,
Chunyan Liuc282e1f2014-06-05 17:21:11 +08002488 &error_abort);
Markus Armbruster39101f22015-02-12 16:46:36 +01002489 qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort);
Markus Armbrustere43bfd92015-12-18 16:35:15 +01002490 ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp);
Chunyan Liu83d05212014-06-05 17:20:51 +08002491 qemu_opts_del(opts);
Kevin Wolfb9988752014-04-03 12:09:34 +02002492 if (ret < 0) {
Markus Armbrustere43bfd92015-12-18 16:35:15 +01002493 error_prepend(errp, "Could not create temporary overlay '%s': ",
2494 tmp_filename);
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002495 goto out;
Kevin Wolfb9988752014-04-03 12:09:34 +02002496 }
2497
Kevin Wolf73176be2016-03-07 13:02:15 +01002498 /* Prepare options QDict for the temporary file */
Eric Blake46f5ac22017-04-27 16:58:17 -05002499 qdict_put_str(snapshot_options, "file.driver", "file");
2500 qdict_put_str(snapshot_options, "file.filename", tmp_filename);
2501 qdict_put_str(snapshot_options, "driver", "qcow2");
Kevin Wolfb9988752014-04-03 12:09:34 +02002502
Max Reitz5b363932016-05-17 16:41:31 +02002503 bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp);
Kevin Wolf73176be2016-03-07 13:02:15 +01002504 snapshot_options = NULL;
Max Reitz5b363932016-05-17 16:41:31 +02002505 if (!bs_snapshot) {
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002506 goto out;
Kevin Wolfb9988752014-04-03 12:09:34 +02002507 }
2508
Eric Blakeff6ed712017-04-27 16:58:18 -05002509 /* bdrv_append() consumes a strong reference to bs_snapshot
2510 * (i.e. it will call bdrv_unref() on it) even on error, so in
2511 * order to be able to return one, we have to increase
2512 * bs_snapshot's refcount here */
Max Reitz66836182016-05-17 16:41:27 +02002513 bdrv_ref(bs_snapshot);
Kevin Wolfb2c28322017-02-20 12:46:42 +01002514 bdrv_append(bs_snapshot, bs, &local_err);
2515 if (local_err) {
2516 error_propagate(errp, local_err);
Eric Blakeff6ed712017-04-27 16:58:18 -05002517 bs_snapshot = NULL;
Kevin Wolfb2c28322017-02-20 12:46:42 +01002518 goto out;
2519 }
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002520
2521out:
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002522 qobject_unref(snapshot_options);
Benoît Canet1ba4b6a2014-04-22 17:05:27 +02002523 g_free(tmp_filename);
Eric Blakeff6ed712017-04-27 16:58:18 -05002524 return bs_snapshot;
Kevin Wolfb9988752014-04-03 12:09:34 +02002525}
2526
Max Reitzda557aa2013-12-20 19:28:11 +01002527/*
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002528 * Opens a disk image (raw, qcow2, vmdk, ...)
Kevin Wolfde9c0ce2013-03-15 10:35:02 +01002529 *
2530 * options is a QDict of options to pass to the block drivers, or NULL for an
2531 * empty set of options. The reference to the QDict belongs to the block layer
2532 * after the call (even on failure), so if the caller intends to reuse the
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002533 * dictionary, it needs to use qobject_ref() before calling bdrv_open.
Max Reitzf67503e2014-02-18 18:33:05 +01002534 *
2535 * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
2536 * If it is not NULL, the referenced BDS will be reused.
Max Reitzddf56362014-02-18 18:33:06 +01002537 *
2538 * The reference parameter may be used to specify an existing block device which
2539 * should be opened. If specified, neither options nor a filename may be given,
2540 * nor can an existing BDS be reused (that is, *pbs has to be NULL).
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002541 */
Max Reitz5b363932016-05-17 16:41:31 +02002542static BlockDriverState *bdrv_open_inherit(const char *filename,
2543 const char *reference,
2544 QDict *options, int flags,
2545 BlockDriverState *parent,
2546 const BdrvChildRole *child_role,
2547 Error **errp)
bellardea2384d2004-08-01 21:59:26 +00002548{
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002549 int ret;
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002550 BlockBackend *file = NULL;
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02002551 BlockDriverState *bs;
Max Reitzce343772015-08-26 19:47:50 +02002552 BlockDriver *drv = NULL;
Kevin Wolf74fe54f2013-07-09 11:09:02 +02002553 const char *drvname;
Alberto Garcia3e8c2e52015-10-26 14:27:15 +02002554 const char *backing;
Max Reitz34b5d2c2013-09-05 14:45:29 +02002555 Error *local_err = NULL;
Kevin Wolf73176be2016-03-07 13:02:15 +01002556 QDict *snapshot_options = NULL;
Kevin Wolfb1e6fc02014-05-06 12:11:42 +02002557 int snapshot_flags = 0;
bellard712e7872005-04-28 21:09:32 +00002558
Kevin Wolff3930ed2015-04-08 13:43:47 +02002559 assert(!child_role || !flags);
2560 assert(!child_role == !parent);
Max Reitzf67503e2014-02-18 18:33:05 +01002561
Max Reitzddf56362014-02-18 18:33:06 +01002562 if (reference) {
2563 bool options_non_empty = options ? qdict_size(options) : false;
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002564 qobject_unref(options);
Max Reitzddf56362014-02-18 18:33:06 +01002565
Max Reitzddf56362014-02-18 18:33:06 +01002566 if (filename || options_non_empty) {
2567 error_setg(errp, "Cannot reference an existing block device with "
2568 "additional options or a new filename");
Max Reitz5b363932016-05-17 16:41:31 +02002569 return NULL;
Max Reitzddf56362014-02-18 18:33:06 +01002570 }
2571
2572 bs = bdrv_lookup_bs(reference, reference, errp);
2573 if (!bs) {
Max Reitz5b363932016-05-17 16:41:31 +02002574 return NULL;
Max Reitzddf56362014-02-18 18:33:06 +01002575 }
Kevin Wolf76b22322016-04-04 17:11:13 +02002576
Max Reitzddf56362014-02-18 18:33:06 +01002577 bdrv_ref(bs);
Max Reitz5b363932016-05-17 16:41:31 +02002578 return bs;
Max Reitzddf56362014-02-18 18:33:06 +01002579 }
2580
Max Reitz5b363932016-05-17 16:41:31 +02002581 bs = bdrv_new();
Max Reitzf67503e2014-02-18 18:33:05 +01002582
Kevin Wolfde9c0ce2013-03-15 10:35:02 +01002583 /* NULL means an empty set of options */
2584 if (options == NULL) {
2585 options = qdict_new();
2586 }
2587
Kevin Wolf145f5982015-05-08 16:15:03 +02002588 /* json: syntax counts as explicit options, as if in the QDict */
Kevin Wolfde3b53f2015-10-29 15:24:41 +01002589 parse_json_protocol(options, &filename, &local_err);
2590 if (local_err) {
Kevin Wolfde3b53f2015-10-29 15:24:41 +01002591 goto fail;
2592 }
2593
Kevin Wolf145f5982015-05-08 16:15:03 +02002594 bs->explicit_options = qdict_clone_shallow(options);
2595
Kevin Wolff3930ed2015-04-08 13:43:47 +02002596 if (child_role) {
Kevin Wolfbddcec32015-04-09 18:47:50 +02002597 bs->inherits_from = parent;
Kevin Wolf8e2160e2015-04-29 17:29:39 +02002598 child_role->inherit_options(&flags, options,
2599 parent->open_flags, parent->options);
Kevin Wolff3930ed2015-04-08 13:43:47 +02002600 }
2601
Kevin Wolfde3b53f2015-10-29 15:24:41 +01002602 ret = bdrv_fill_options(&options, filename, &flags, &local_err);
Kevin Wolf462f5bc2014-05-26 11:39:55 +02002603 if (local_err) {
2604 goto fail;
2605 }
2606
Markus Armbruster129c7d12017-03-30 19:43:12 +02002607 /*
2608 * Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags.
2609 * Caution: getting a boolean member of @options requires care.
2610 * When @options come from -blockdev or blockdev_add, members are
2611 * typed according to the QAPI schema, but when they come from
2612 * -drive, they're all QString.
2613 */
Alberto Garciaf87a0e22016-09-15 17:53:02 +03002614 if (g_strcmp0(qdict_get_try_str(options, BDRV_OPT_READ_ONLY), "on") &&
2615 !qdict_get_try_bool(options, BDRV_OPT_READ_ONLY, false)) {
2616 flags |= (BDRV_O_RDWR | BDRV_O_ALLOW_RDWR);
2617 } else {
2618 flags &= ~BDRV_O_RDWR;
Alberto Garcia14499ea2016-09-15 17:53:00 +03002619 }
2620
2621 if (flags & BDRV_O_SNAPSHOT) {
2622 snapshot_options = qdict_new();
2623 bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options,
2624 flags, options);
Alberto Garciaf87a0e22016-09-15 17:53:02 +03002625 /* Let bdrv_backing_options() override "read-only" */
2626 qdict_del(options, BDRV_OPT_READ_ONLY);
Alberto Garcia14499ea2016-09-15 17:53:00 +03002627 bdrv_backing_options(&flags, options, flags, options);
2628 }
2629
Kevin Wolf62392eb2015-04-24 16:38:02 +02002630 bs->open_flags = flags;
2631 bs->options = options;
2632 options = qdict_clone_shallow(options);
2633
Kevin Wolf76c591b2014-06-04 14:19:44 +02002634 /* Find the right image format driver */
Markus Armbruster129c7d12017-03-30 19:43:12 +02002635 /* See cautionary note on accessing @options above */
Kevin Wolf76c591b2014-06-04 14:19:44 +02002636 drvname = qdict_get_try_str(options, "driver");
2637 if (drvname) {
2638 drv = bdrv_find_format(drvname);
Kevin Wolf76c591b2014-06-04 14:19:44 +02002639 if (!drv) {
2640 error_setg(errp, "Unknown driver: '%s'", drvname);
Kevin Wolf76c591b2014-06-04 14:19:44 +02002641 goto fail;
2642 }
2643 }
2644
2645 assert(drvname || !(flags & BDRV_O_PROTOCOL));
Kevin Wolf76c591b2014-06-04 14:19:44 +02002646
Markus Armbruster129c7d12017-03-30 19:43:12 +02002647 /* See cautionary note on accessing @options above */
Alberto Garcia3e8c2e52015-10-26 14:27:15 +02002648 backing = qdict_get_try_str(options, "backing");
Max Reitze59a0cf2018-02-24 16:40:32 +01002649 if (qobject_to(QNull, qdict_get(options, "backing")) != NULL ||
2650 (backing && *backing == '\0'))
2651 {
Max Reitz4f7be282018-02-24 16:40:33 +01002652 if (backing) {
2653 warn_report("Use of \"backing\": \"\" is deprecated; "
2654 "use \"backing\": null instead");
2655 }
Alberto Garcia3e8c2e52015-10-26 14:27:15 +02002656 flags |= BDRV_O_NO_BACKING;
2657 qdict_del(options, "backing");
2658 }
2659
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002660 /* Open image file without format layer. This BlockBackend is only used for
Kevin Wolf4e4bf5c2016-12-16 18:52:37 +01002661 * probing, the block drivers will do their own bdrv_open_child() for the
2662 * same BDS, which is why we put the node name back into options. */
Kevin Wolff4788ad2014-06-03 16:44:19 +02002663 if ((flags & BDRV_O_PROTOCOL) == 0) {
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002664 BlockDriverState *file_bs;
2665
2666 file_bs = bdrv_open_child_bs(filename, options, "file", bs,
2667 &child_file, true, &local_err);
Kevin Wolf1fdd6932015-06-15 14:11:51 +02002668 if (local_err) {
Max Reitz5469a2a2014-02-18 18:33:10 +01002669 goto fail;
2670 }
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002671 if (file_bs != NULL) {
Kevin Wolfdacaa162017-11-20 14:59:13 +01002672 /* Not requesting BLK_PERM_CONSISTENT_READ because we're only
2673 * looking at the header to guess the image format. This works even
2674 * in cases where a guest would not see a consistent state. */
2675 file = blk_new(0, BLK_PERM_ALL);
Kevin Wolfd7086422017-01-13 19:02:32 +01002676 blk_insert_bs(file, file_bs, &local_err);
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002677 bdrv_unref(file_bs);
Kevin Wolfd7086422017-01-13 19:02:32 +01002678 if (local_err) {
2679 goto fail;
2680 }
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002681
Eric Blake46f5ac22017-04-27 16:58:17 -05002682 qdict_put_str(options, "file", bdrv_get_node_name(file_bs));
Kevin Wolf4e4bf5c2016-12-16 18:52:37 +01002683 }
Max Reitz5469a2a2014-02-18 18:33:10 +01002684 }
2685
Kevin Wolf76c591b2014-06-04 14:19:44 +02002686 /* Image format probing */
Kevin Wolf38f3ef52014-11-20 16:27:12 +01002687 bs->probed = !drv;
Kevin Wolf76c591b2014-06-04 14:19:44 +02002688 if (!drv && file) {
Kevin Wolfcf2ab8f2016-06-20 18:24:02 +02002689 ret = find_image_format(file, filename, &drv, &local_err);
Kevin Wolf17b005f2014-05-27 10:50:29 +02002690 if (ret < 0) {
Kevin Wolf8bfea152014-04-11 19:16:36 +02002691 goto fail;
Max Reitz2a05cbe2013-12-20 19:28:10 +01002692 }
Kevin Wolf62392eb2015-04-24 16:38:02 +02002693 /*
2694 * This option update would logically belong in bdrv_fill_options(),
2695 * but we first need to open bs->file for the probing to work, while
2696 * opening bs->file already requires the (mostly) final set of options
2697 * so that cache mode etc. can be inherited.
2698 *
2699 * Adding the driver later is somewhat ugly, but it's not an option
2700 * that would ever be inherited, so it's correct. We just need to make
2701 * sure to update both bs->options (which has the full effective
2702 * options for bs) and options (which has file.* already removed).
2703 */
Eric Blake46f5ac22017-04-27 16:58:17 -05002704 qdict_put_str(bs->options, "driver", drv->format_name);
2705 qdict_put_str(options, "driver", drv->format_name);
Kevin Wolf76c591b2014-06-04 14:19:44 +02002706 } else if (!drv) {
Kevin Wolf17b005f2014-05-27 10:50:29 +02002707 error_setg(errp, "Must specify either driver or file");
Kevin Wolf8bfea152014-04-11 19:16:36 +02002708 goto fail;
Kevin Wolff500a6d2012-11-12 17:35:27 +01002709 }
2710
Max Reitz53a29512015-03-19 14:53:16 -04002711 /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */
2712 assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open);
2713 /* file must be NULL if a protocol BDS is about to be created
2714 * (the inverse results in an error message from bdrv_open_common()) */
2715 assert(!(flags & BDRV_O_PROTOCOL) || !file);
2716
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002717 /* Open the image */
Kevin Wolf82dc8b42016-01-11 19:07:50 +01002718 ret = bdrv_open_common(bs, file, options, &local_err);
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002719 if (ret < 0) {
Kevin Wolf8bfea152014-04-11 19:16:36 +02002720 goto fail;
Christoph Hellwig69873072010-01-20 18:13:25 +01002721 }
2722
Kevin Wolf4e4bf5c2016-12-16 18:52:37 +01002723 if (file) {
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002724 blk_unref(file);
Kevin Wolff500a6d2012-11-12 17:35:27 +01002725 file = NULL;
2726 }
2727
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002728 /* If there is a backing file, use it */
Paolo Bonzini9156df12012-10-18 16:49:17 +02002729 if ((flags & BDRV_O_NO_BACKING) == 0) {
Kevin Wolfd9b7b052015-01-16 18:23:41 +01002730 ret = bdrv_open_backing_file(bs, options, "backing", &local_err);
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002731 if (ret < 0) {
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002732 goto close_and_fail;
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002733 }
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002734 }
2735
Max Reitz91af7012014-07-18 20:24:56 +02002736 bdrv_refresh_filename(bs);
2737
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002738 /* Check if any unknown options were used */
Paolo Bonzini7ad27572017-01-04 15:59:14 +01002739 if (qdict_size(options) != 0) {
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002740 const QDictEntry *entry = qdict_first(options);
Max Reitz5acd9d82014-02-18 18:33:11 +01002741 if (flags & BDRV_O_PROTOCOL) {
2742 error_setg(errp, "Block protocol '%s' doesn't support the option "
2743 "'%s'", drv->format_name, entry->key);
2744 } else {
Max Reitzd0e46a52016-03-16 19:54:34 +01002745 error_setg(errp,
2746 "Block format '%s' does not support the option '%s'",
2747 drv->format_name, entry->key);
Max Reitz5acd9d82014-02-18 18:33:11 +01002748 }
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002749
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002750 goto close_and_fail;
2751 }
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002752
Daniel P. Berrangec01c2142017-06-23 17:24:16 +01002753 bdrv_parent_cb_change_media(bs, true);
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002754
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002755 qobject_unref(options);
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02002756
2757 /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
2758 * temporary snapshot afterwards. */
2759 if (snapshot_flags) {
Max Reitz66836182016-05-17 16:41:27 +02002760 BlockDriverState *snapshot_bs;
2761 snapshot_bs = bdrv_append_temp_snapshot(bs, snapshot_flags,
2762 snapshot_options, &local_err);
Kevin Wolf73176be2016-03-07 13:02:15 +01002763 snapshot_options = NULL;
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02002764 if (local_err) {
2765 goto close_and_fail;
2766 }
Max Reitz5b363932016-05-17 16:41:31 +02002767 /* We are not going to return bs but the overlay on top of it
2768 * (snapshot_bs); thus, we have to drop the strong reference to bs
2769 * (which we obtained by calling bdrv_new()). bs will not be deleted,
2770 * though, because the overlay still has a reference to it. */
2771 bdrv_unref(bs);
2772 bs = snapshot_bs;
Max Reitz66836182016-05-17 16:41:27 +02002773 }
2774
Max Reitz5b363932016-05-17 16:41:31 +02002775 return bs;
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002776
Kevin Wolf8bfea152014-04-11 19:16:36 +02002777fail:
Kevin Wolf5696c6e2017-02-17 18:39:24 +01002778 blk_unref(file);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002779 qobject_unref(snapshot_options);
2780 qobject_unref(bs->explicit_options);
2781 qobject_unref(bs->options);
2782 qobject_unref(options);
Kevin Wolfde9c0ce2013-03-15 10:35:02 +01002783 bs->options = NULL;
Manos Pitsidianakis998cbd62017-07-14 17:35:47 +03002784 bs->explicit_options = NULL;
Max Reitz5b363932016-05-17 16:41:31 +02002785 bdrv_unref(bs);
Eduardo Habkost621ff942016-06-13 18:57:56 -03002786 error_propagate(errp, local_err);
Max Reitz5b363932016-05-17 16:41:31 +02002787 return NULL;
Kevin Wolfde9c0ce2013-03-15 10:35:02 +01002788
Kevin Wolfb6ad4912013-03-15 10:35:04 +01002789close_and_fail:
Max Reitz5b363932016-05-17 16:41:31 +02002790 bdrv_unref(bs);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002791 qobject_unref(snapshot_options);
2792 qobject_unref(options);
Eduardo Habkost621ff942016-06-13 18:57:56 -03002793 error_propagate(errp, local_err);
Max Reitz5b363932016-05-17 16:41:31 +02002794 return NULL;
Kevin Wolfb6ce07a2010-04-12 16:37:13 +02002795}
2796
Max Reitz5b363932016-05-17 16:41:31 +02002797BlockDriverState *bdrv_open(const char *filename, const char *reference,
2798 QDict *options, int flags, Error **errp)
Kevin Wolff3930ed2015-04-08 13:43:47 +02002799{
Max Reitz5b363932016-05-17 16:41:31 +02002800 return bdrv_open_inherit(filename, reference, options, flags, NULL,
Max Reitzce343772015-08-26 19:47:50 +02002801 NULL, errp);
Kevin Wolff3930ed2015-04-08 13:43:47 +02002802}
2803
Jeff Codye971aa12012-09-20 15:13:19 -04002804/*
2805 * Adds a BlockDriverState to a simple queue for an atomic, transactional
2806 * reopen of multiple devices.
2807 *
2808 * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT
2809 * already performed, or alternatively may be NULL a new BlockReopenQueue will
2810 * be created and initialized. This newly created BlockReopenQueue should be
2811 * passed back in for subsequent calls that are intended to be of the same
2812 * atomic 'set'.
2813 *
2814 * bs is the BlockDriverState to add to the reopen queue.
2815 *
Kevin Wolf4d2cb092015-04-10 17:50:50 +02002816 * options contains the changed options for the associated bs
2817 * (the BlockReopenQueue takes ownership)
2818 *
Jeff Codye971aa12012-09-20 15:13:19 -04002819 * flags contains the open flags for the associated bs
2820 *
2821 * returns a pointer to bs_queue, which is either the newly allocated
2822 * bs_queue, or the existing bs_queue being used.
2823 *
Kevin Wolf1a63a902017-12-06 20:24:44 +01002824 * bs must be drained between bdrv_reopen_queue() and bdrv_reopen_multiple().
Jeff Codye971aa12012-09-20 15:13:19 -04002825 */
Kevin Wolf28518102015-05-08 17:07:31 +02002826static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue,
2827 BlockDriverState *bs,
2828 QDict *options,
2829 int flags,
2830 const BdrvChildRole *role,
2831 QDict *parent_options,
2832 int parent_flags)
Jeff Codye971aa12012-09-20 15:13:19 -04002833{
2834 assert(bs != NULL);
2835
2836 BlockReopenQueueEntry *bs_entry;
Kevin Wolf67251a32015-04-09 18:54:04 +02002837 BdrvChild *child;
Kevin Wolf145f5982015-05-08 16:15:03 +02002838 QDict *old_options, *explicit_options;
Kevin Wolf67251a32015-04-09 18:54:04 +02002839
Kevin Wolf1a63a902017-12-06 20:24:44 +01002840 /* Make sure that the caller remembered to use a drained section. This is
2841 * important to avoid graph changes between the recursive queuing here and
2842 * bdrv_reopen_multiple(). */
2843 assert(bs->quiesce_counter > 0);
2844
Jeff Codye971aa12012-09-20 15:13:19 -04002845 if (bs_queue == NULL) {
2846 bs_queue = g_new0(BlockReopenQueue, 1);
2847 QSIMPLEQ_INIT(bs_queue);
2848 }
2849
Kevin Wolf4d2cb092015-04-10 17:50:50 +02002850 if (!options) {
2851 options = qdict_new();
2852 }
2853
Alberto Garcia5b7ba052016-09-15 17:53:03 +03002854 /* Check if this BlockDriverState is already in the queue */
2855 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
2856 if (bs == bs_entry->state.bs) {
2857 break;
2858 }
2859 }
2860
Kevin Wolf28518102015-05-08 17:07:31 +02002861 /*
2862 * Precedence of options:
2863 * 1. Explicitly passed in options (highest)
Kevin Wolf91a097e2015-05-08 17:49:53 +02002864 * 2. Set in flags (only for top level)
Kevin Wolf145f5982015-05-08 16:15:03 +02002865 * 3. Retained from explicitly set options of bs
Kevin Wolf8e2160e2015-04-29 17:29:39 +02002866 * 4. Inherited from parent node
Kevin Wolf28518102015-05-08 17:07:31 +02002867 * 5. Retained from effective options of bs
2868 */
2869
Kevin Wolf91a097e2015-05-08 17:49:53 +02002870 if (!parent_options) {
2871 /*
2872 * Any setting represented by flags is always updated. If the
2873 * corresponding QDict option is set, it takes precedence. Otherwise
2874 * the flag is translated into a QDict option. The old setting of bs is
2875 * not considered.
2876 */
2877 update_options_from_flags(options, flags);
2878 }
2879
Kevin Wolf145f5982015-05-08 16:15:03 +02002880 /* Old explicitly set values (don't overwrite by inherited value) */
Alberto Garcia5b7ba052016-09-15 17:53:03 +03002881 if (bs_entry) {
2882 old_options = qdict_clone_shallow(bs_entry->state.explicit_options);
2883 } else {
2884 old_options = qdict_clone_shallow(bs->explicit_options);
2885 }
Kevin Wolf145f5982015-05-08 16:15:03 +02002886 bdrv_join_options(bs, options, old_options);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002887 qobject_unref(old_options);
Kevin Wolf145f5982015-05-08 16:15:03 +02002888
2889 explicit_options = qdict_clone_shallow(options);
2890
Kevin Wolf28518102015-05-08 17:07:31 +02002891 /* Inherit from parent node */
2892 if (parent_options) {
Fam Zheng1a529732018-03-13 22:20:02 +08002893 QemuOpts *opts;
2894 QDict *options_copy;
Kevin Wolf28518102015-05-08 17:07:31 +02002895 assert(!flags);
Kevin Wolf8e2160e2015-04-29 17:29:39 +02002896 role->inherit_options(&flags, options, parent_flags, parent_options);
Fam Zheng1a529732018-03-13 22:20:02 +08002897 options_copy = qdict_clone_shallow(options);
2898 opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
2899 qemu_opts_absorb_qdict(opts, options_copy, NULL);
2900 update_flags_from_options(&flags, opts);
2901 qemu_opts_del(opts);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002902 qobject_unref(options_copy);
Kevin Wolf28518102015-05-08 17:07:31 +02002903 }
2904
2905 /* Old values are used for options that aren't set yet */
Kevin Wolf4d2cb092015-04-10 17:50:50 +02002906 old_options = qdict_clone_shallow(bs->options);
Kevin Wolfcddff5b2015-11-16 16:43:27 +01002907 bdrv_join_options(bs, options, old_options);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002908 qobject_unref(old_options);
Kevin Wolf4d2cb092015-04-10 17:50:50 +02002909
Kevin Wolffd452022017-08-03 17:02:59 +02002910 /* bdrv_open_inherit() sets and clears some additional flags internally */
Kevin Wolff1f25a22014-04-25 19:04:55 +02002911 flags &= ~BDRV_O_PROTOCOL;
Kevin Wolffd452022017-08-03 17:02:59 +02002912 if (flags & BDRV_O_RDWR) {
2913 flags |= BDRV_O_ALLOW_RDWR;
2914 }
Kevin Wolff1f25a22014-04-25 19:04:55 +02002915
Kevin Wolf1857c972017-09-14 14:53:46 +02002916 if (!bs_entry) {
2917 bs_entry = g_new0(BlockReopenQueueEntry, 1);
2918 QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry);
2919 } else {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02002920 qobject_unref(bs_entry->state.options);
2921 qobject_unref(bs_entry->state.explicit_options);
Kevin Wolf1857c972017-09-14 14:53:46 +02002922 }
2923
2924 bs_entry->state.bs = bs;
2925 bs_entry->state.options = options;
2926 bs_entry->state.explicit_options = explicit_options;
2927 bs_entry->state.flags = flags;
2928
Kevin Wolf30450252017-07-03 17:07:35 +02002929 /* This needs to be overwritten in bdrv_reopen_prepare() */
2930 bs_entry->state.perm = UINT64_MAX;
2931 bs_entry->state.shared_perm = 0;
2932
Kevin Wolf67251a32015-04-09 18:54:04 +02002933 QLIST_FOREACH(child, &bs->children, next) {
Kevin Wolf4c9dfe52015-05-08 15:14:15 +02002934 QDict *new_child_options;
2935 char *child_key_dot;
Kevin Wolf67251a32015-04-09 18:54:04 +02002936
Kevin Wolf4c9dfe52015-05-08 15:14:15 +02002937 /* reopen can only change the options of block devices that were
2938 * implicitly created and inherited options. For other (referenced)
2939 * block devices, a syntax like "backing.foo" results in an error. */
Kevin Wolf67251a32015-04-09 18:54:04 +02002940 if (child->bs->inherits_from != bs) {
2941 continue;
2942 }
2943
Kevin Wolf4c9dfe52015-05-08 15:14:15 +02002944 child_key_dot = g_strdup_printf("%s.", child->name);
2945 qdict_extract_subqdict(options, &new_child_options, child_key_dot);
2946 g_free(child_key_dot);
2947
Kevin Wolf28518102015-05-08 17:07:31 +02002948 bdrv_reopen_queue_child(bs_queue, child->bs, new_child_options, 0,
2949 child->role, options, flags);
Jeff Codye971aa12012-09-20 15:13:19 -04002950 }
2951
Jeff Codye971aa12012-09-20 15:13:19 -04002952 return bs_queue;
2953}
2954
Kevin Wolf28518102015-05-08 17:07:31 +02002955BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue,
2956 BlockDriverState *bs,
2957 QDict *options, int flags)
2958{
2959 return bdrv_reopen_queue_child(bs_queue, bs, options, flags,
2960 NULL, NULL, 0);
2961}
2962
Jeff Codye971aa12012-09-20 15:13:19 -04002963/*
2964 * Reopen multiple BlockDriverStates atomically & transactionally.
2965 *
2966 * The queue passed in (bs_queue) must have been built up previous
2967 * via bdrv_reopen_queue().
2968 *
2969 * Reopens all BDS specified in the queue, with the appropriate
2970 * flags. All devices are prepared for reopen, and failure of any
2971 * device will cause all device changes to be abandonded, and intermediate
2972 * data cleaned up.
2973 *
2974 * If all devices prepare successfully, then the changes are committed
2975 * to all devices.
2976 *
Kevin Wolf1a63a902017-12-06 20:24:44 +01002977 * All affected nodes must be drained between bdrv_reopen_queue() and
2978 * bdrv_reopen_multiple().
Jeff Codye971aa12012-09-20 15:13:19 -04002979 */
Paolo Bonzini720150f2016-10-27 12:49:02 +02002980int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp)
Jeff Codye971aa12012-09-20 15:13:19 -04002981{
2982 int ret = -1;
2983 BlockReopenQueueEntry *bs_entry, *next;
2984 Error *local_err = NULL;
2985
2986 assert(bs_queue != NULL);
2987
Jeff Codye971aa12012-09-20 15:13:19 -04002988 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
Kevin Wolf1a63a902017-12-06 20:24:44 +01002989 assert(bs_entry->state.bs->quiesce_counter > 0);
Jeff Codye971aa12012-09-20 15:13:19 -04002990 if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) {
2991 error_propagate(errp, local_err);
2992 goto cleanup;
2993 }
2994 bs_entry->prepared = true;
2995 }
2996
2997 /* If we reach this point, we have success and just need to apply the
2998 * changes
2999 */
3000 QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) {
3001 bdrv_reopen_commit(&bs_entry->state);
3002 }
3003
3004 ret = 0;
3005
3006cleanup:
3007 QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
3008 if (ret && bs_entry->prepared) {
3009 bdrv_reopen_abort(&bs_entry->state);
Kevin Wolf145f5982015-05-08 16:15:03 +02003010 } else if (ret) {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02003011 qobject_unref(bs_entry->state.explicit_options);
Jeff Codye971aa12012-09-20 15:13:19 -04003012 }
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02003013 qobject_unref(bs_entry->state.options);
Jeff Codye971aa12012-09-20 15:13:19 -04003014 g_free(bs_entry);
3015 }
3016 g_free(bs_queue);
Alberto Garcia40840e42016-10-28 10:08:03 +03003017
Jeff Codye971aa12012-09-20 15:13:19 -04003018 return ret;
3019}
3020
3021
3022/* Reopen a single BlockDriverState with the specified flags. */
3023int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp)
3024{
3025 int ret = -1;
3026 Error *local_err = NULL;
Kevin Wolf1a63a902017-12-06 20:24:44 +01003027 BlockReopenQueue *queue;
Jeff Codye971aa12012-09-20 15:13:19 -04003028
Kevin Wolf1a63a902017-12-06 20:24:44 +01003029 bdrv_subtree_drained_begin(bs);
3030
3031 queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags);
Paolo Bonzini720150f2016-10-27 12:49:02 +02003032 ret = bdrv_reopen_multiple(bdrv_get_aio_context(bs), queue, &local_err);
Jeff Codye971aa12012-09-20 15:13:19 -04003033 if (local_err != NULL) {
3034 error_propagate(errp, local_err);
3035 }
Kevin Wolf1a63a902017-12-06 20:24:44 +01003036
3037 bdrv_subtree_drained_end(bs);
3038
Jeff Codye971aa12012-09-20 15:13:19 -04003039 return ret;
3040}
3041
Kevin Wolf30450252017-07-03 17:07:35 +02003042static BlockReopenQueueEntry *find_parent_in_reopen_queue(BlockReopenQueue *q,
3043 BdrvChild *c)
3044{
3045 BlockReopenQueueEntry *entry;
3046
3047 QSIMPLEQ_FOREACH(entry, q, entry) {
3048 BlockDriverState *bs = entry->state.bs;
3049 BdrvChild *child;
3050
3051 QLIST_FOREACH(child, &bs->children, next) {
3052 if (child == c) {
3053 return entry;
3054 }
3055 }
3056 }
3057
3058 return NULL;
3059}
3060
3061static void bdrv_reopen_perm(BlockReopenQueue *q, BlockDriverState *bs,
3062 uint64_t *perm, uint64_t *shared)
3063{
3064 BdrvChild *c;
3065 BlockReopenQueueEntry *parent;
3066 uint64_t cumulative_perms = 0;
3067 uint64_t cumulative_shared_perms = BLK_PERM_ALL;
3068
3069 QLIST_FOREACH(c, &bs->parents, next_parent) {
3070 parent = find_parent_in_reopen_queue(q, c);
3071 if (!parent) {
3072 cumulative_perms |= c->perm;
3073 cumulative_shared_perms &= c->shared_perm;
3074 } else {
3075 uint64_t nperm, nshared;
3076
3077 bdrv_child_perm(parent->state.bs, bs, c, c->role, q,
3078 parent->state.perm, parent->state.shared_perm,
3079 &nperm, &nshared);
3080
3081 cumulative_perms |= nperm;
3082 cumulative_shared_perms &= nshared;
3083 }
3084 }
3085 *perm = cumulative_perms;
3086 *shared = cumulative_shared_perms;
3087}
Jeff Codye971aa12012-09-20 15:13:19 -04003088
3089/*
3090 * Prepares a BlockDriverState for reopen. All changes are staged in the
3091 * 'opaque' field of the BDRVReopenState, which is used and allocated by
3092 * the block driver layer .bdrv_reopen_prepare()
3093 *
3094 * bs is the BlockDriverState to reopen
3095 * flags are the new open flags
3096 * queue is the reopen queue
3097 *
3098 * Returns 0 on success, non-zero on error. On error errp will be set
3099 * as well.
3100 *
3101 * On failure, bdrv_reopen_abort() will be called to clean up any data.
3102 * It is the responsibility of the caller to then call the abort() or
3103 * commit() for any other BDS that have been left in a prepare() state
3104 *
3105 */
3106int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
3107 Error **errp)
3108{
3109 int ret = -1;
3110 Error *local_err = NULL;
3111 BlockDriver *drv;
Kevin Wolfccf9dc02015-05-08 17:24:56 +02003112 QemuOpts *opts;
3113 const char *value;
Jeff Cody3d8ce172017-04-07 16:55:30 -04003114 bool read_only;
Jeff Codye971aa12012-09-20 15:13:19 -04003115
3116 assert(reopen_state != NULL);
3117 assert(reopen_state->bs->drv != NULL);
3118 drv = reopen_state->bs->drv;
3119
Kevin Wolfccf9dc02015-05-08 17:24:56 +02003120 /* Process generic block layer options */
3121 opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort);
3122 qemu_opts_absorb_qdict(opts, reopen_state->options, &local_err);
3123 if (local_err) {
3124 error_propagate(errp, local_err);
3125 ret = -EINVAL;
3126 goto error;
3127 }
3128
Kevin Wolf91a097e2015-05-08 17:49:53 +02003129 update_flags_from_options(&reopen_state->flags, opts);
3130
Kevin Wolfccf9dc02015-05-08 17:24:56 +02003131 /* node-name and driver must be unchanged. Put them back into the QDict, so
3132 * that they are checked at the end of this function. */
3133 value = qemu_opt_get(opts, "node-name");
3134 if (value) {
Eric Blake46f5ac22017-04-27 16:58:17 -05003135 qdict_put_str(reopen_state->options, "node-name", value);
Kevin Wolfccf9dc02015-05-08 17:24:56 +02003136 }
3137
3138 value = qemu_opt_get(opts, "driver");
3139 if (value) {
Eric Blake46f5ac22017-04-27 16:58:17 -05003140 qdict_put_str(reopen_state->options, "driver", value);
Kevin Wolfccf9dc02015-05-08 17:24:56 +02003141 }
3142
Jeff Cody3d8ce172017-04-07 16:55:30 -04003143 /* If we are to stay read-only, do not allow permission change
3144 * to r/w. Attempting to set to r/w may fail if either BDRV_O_ALLOW_RDWR is
3145 * not set, or if the BDS still has copy_on_read enabled */
3146 read_only = !(reopen_state->flags & BDRV_O_RDWR);
Kevin Wolf54a32bf2017-08-03 17:02:58 +02003147 ret = bdrv_can_set_read_only(reopen_state->bs, read_only, true, &local_err);
Jeff Cody3d8ce172017-04-07 16:55:30 -04003148 if (local_err) {
3149 error_propagate(errp, local_err);
Jeff Codye971aa12012-09-20 15:13:19 -04003150 goto error;
3151 }
3152
Kevin Wolf30450252017-07-03 17:07:35 +02003153 /* Calculate required permissions after reopening */
3154 bdrv_reopen_perm(queue, reopen_state->bs,
3155 &reopen_state->perm, &reopen_state->shared_perm);
Jeff Codye971aa12012-09-20 15:13:19 -04003156
3157 ret = bdrv_flush(reopen_state->bs);
3158 if (ret) {
Eric Blake455b0fd2015-11-10 23:51:20 -07003159 error_setg_errno(errp, -ret, "Error flushing drive");
Jeff Codye971aa12012-09-20 15:13:19 -04003160 goto error;
3161 }
3162
3163 if (drv->bdrv_reopen_prepare) {
3164 ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err);
3165 if (ret) {
3166 if (local_err != NULL) {
3167 error_propagate(errp, local_err);
3168 } else {
Luiz Capitulinod8b68952013-06-10 11:29:27 -04003169 error_setg(errp, "failed while preparing to reopen image '%s'",
3170 reopen_state->bs->filename);
Jeff Codye971aa12012-09-20 15:13:19 -04003171 }
3172 goto error;
3173 }
3174 } else {
3175 /* It is currently mandatory to have a bdrv_reopen_prepare()
3176 * handler for each supported drv. */
Alberto Garcia81e5f782015-04-08 12:29:19 +03003177 error_setg(errp, "Block format '%s' used by node '%s' "
3178 "does not support reopening files", drv->format_name,
3179 bdrv_get_device_or_node_name(reopen_state->bs));
Jeff Codye971aa12012-09-20 15:13:19 -04003180 ret = -1;
3181 goto error;
3182 }
3183
Kevin Wolf4d2cb092015-04-10 17:50:50 +02003184 /* Options that are not handled are only okay if they are unchanged
3185 * compared to the old state. It is expected that some options are only
3186 * used for the initial open, but not reopen (e.g. filename) */
3187 if (qdict_size(reopen_state->options)) {
3188 const QDictEntry *entry = qdict_first(reopen_state->options);
3189
3190 do {
Max Reitz54fd1b02017-11-14 19:01:26 +01003191 QObject *new = entry->value;
3192 QObject *old = qdict_get(reopen_state->bs->options, entry->key);
Kevin Wolf4d2cb092015-04-10 17:50:50 +02003193
Max Reitz54fd1b02017-11-14 19:01:26 +01003194 /*
3195 * TODO: When using -drive to specify blockdev options, all values
3196 * will be strings; however, when using -blockdev, blockdev-add or
3197 * filenames using the json:{} pseudo-protocol, they will be
3198 * correctly typed.
3199 * In contrast, reopening options are (currently) always strings
3200 * (because you can only specify them through qemu-io; all other
3201 * callers do not specify any options).
3202 * Therefore, when using anything other than -drive to create a BDS,
3203 * this cannot detect non-string options as unchanged, because
3204 * qobject_is_equal() always returns false for objects of different
3205 * type. In the future, this should be remedied by correctly typing
3206 * all options. For now, this is not too big of an issue because
3207 * the user can simply omit options which cannot be changed anyway,
3208 * so they will stay unchanged.
3209 */
3210 if (!qobject_is_equal(new, old)) {
Kevin Wolf4d2cb092015-04-10 17:50:50 +02003211 error_setg(errp, "Cannot change the option '%s'", entry->key);
3212 ret = -EINVAL;
3213 goto error;
3214 }
3215 } while ((entry = qdict_next(reopen_state->options, entry)));
3216 }
3217
Kevin Wolf30450252017-07-03 17:07:35 +02003218 ret = bdrv_check_perm(reopen_state->bs, queue, reopen_state->perm,
3219 reopen_state->shared_perm, NULL, errp);
3220 if (ret < 0) {
3221 goto error;
3222 }
3223
Jeff Codye971aa12012-09-20 15:13:19 -04003224 ret = 0;
3225
3226error:
Kevin Wolfccf9dc02015-05-08 17:24:56 +02003227 qemu_opts_del(opts);
Jeff Codye971aa12012-09-20 15:13:19 -04003228 return ret;
3229}
3230
3231/*
3232 * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and
3233 * makes them final by swapping the staging BlockDriverState contents into
3234 * the active BlockDriverState contents.
3235 */
3236void bdrv_reopen_commit(BDRVReopenState *reopen_state)
3237{
3238 BlockDriver *drv;
Vladimir Sementsov-Ogievskiy50bf65b2017-06-28 15:05:12 +03003239 BlockDriverState *bs;
Vladimir Sementsov-Ogievskiycb9ff6c2017-06-28 15:05:13 +03003240 bool old_can_write, new_can_write;
Jeff Codye971aa12012-09-20 15:13:19 -04003241
3242 assert(reopen_state != NULL);
Vladimir Sementsov-Ogievskiy50bf65b2017-06-28 15:05:12 +03003243 bs = reopen_state->bs;
3244 drv = bs->drv;
Jeff Codye971aa12012-09-20 15:13:19 -04003245 assert(drv != NULL);
3246
Vladimir Sementsov-Ogievskiycb9ff6c2017-06-28 15:05:13 +03003247 old_can_write =
3248 !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE);
3249
Jeff Codye971aa12012-09-20 15:13:19 -04003250 /* If there are any driver level actions to take */
3251 if (drv->bdrv_reopen_commit) {
3252 drv->bdrv_reopen_commit(reopen_state);
3253 }
3254
3255 /* set BDS specific flags now */
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02003256 qobject_unref(bs->explicit_options);
Kevin Wolf145f5982015-05-08 16:15:03 +02003257
Vladimir Sementsov-Ogievskiy50bf65b2017-06-28 15:05:12 +03003258 bs->explicit_options = reopen_state->explicit_options;
3259 bs->open_flags = reopen_state->flags;
3260 bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
Kevin Wolf355ef4a2013-12-11 20:14:09 +01003261
Vladimir Sementsov-Ogievskiy50bf65b2017-06-28 15:05:12 +03003262 bdrv_refresh_limits(bs, NULL);
Vladimir Sementsov-Ogievskiycb9ff6c2017-06-28 15:05:13 +03003263
Kevin Wolf30450252017-07-03 17:07:35 +02003264 bdrv_set_perm(reopen_state->bs, reopen_state->perm,
3265 reopen_state->shared_perm);
3266
Vladimir Sementsov-Ogievskiycb9ff6c2017-06-28 15:05:13 +03003267 new_can_write =
3268 !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) & BDRV_O_INACTIVE);
3269 if (!old_can_write && new_can_write && drv->bdrv_reopen_bitmaps_rw) {
3270 Error *local_err = NULL;
3271 if (drv->bdrv_reopen_bitmaps_rw(bs, &local_err) < 0) {
3272 /* This is not fatal, bitmaps just left read-only, so all following
3273 * writes will fail. User can remove read-only bitmaps to unblock
3274 * writes.
3275 */
3276 error_reportf_err(local_err,
3277 "%s: Failed to make dirty bitmaps writable: ",
3278 bdrv_get_node_name(bs));
3279 }
3280 }
Jeff Codye971aa12012-09-20 15:13:19 -04003281}
3282
3283/*
3284 * Abort the reopen, and delete and free the staged changes in
3285 * reopen_state
3286 */
3287void bdrv_reopen_abort(BDRVReopenState *reopen_state)
3288{
3289 BlockDriver *drv;
3290
3291 assert(reopen_state != NULL);
3292 drv = reopen_state->bs->drv;
3293 assert(drv != NULL);
3294
3295 if (drv->bdrv_reopen_abort) {
3296 drv->bdrv_reopen_abort(reopen_state);
3297 }
Kevin Wolf145f5982015-05-08 16:15:03 +02003298
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02003299 qobject_unref(reopen_state->explicit_options);
Kevin Wolf30450252017-07-03 17:07:35 +02003300
3301 bdrv_abort_perm_update(reopen_state->bs);
Jeff Codye971aa12012-09-20 15:13:19 -04003302}
3303
3304
Max Reitz64dff522016-01-29 16:36:10 +01003305static void bdrv_close(BlockDriverState *bs)
bellardfc01f7e2003-06-30 10:03:06 +00003306{
Max Reitz33384422014-06-20 21:57:33 +02003307 BdrvAioNotifier *ban, *ban_next;
Alberto Garcia50a3efb2017-11-06 16:53:45 +02003308 BdrvChild *child, *next;
Max Reitz33384422014-06-20 21:57:33 +02003309
Max Reitzca9bd242016-01-29 16:36:14 +01003310 assert(!bs->job);
Max Reitz30f55fb2016-05-17 16:41:32 +02003311 assert(!bs->refcnt);
Alberto Garcia99b7e772015-09-25 16:41:44 +03003312
Paolo Bonzinifc272912015-12-23 11:48:24 +01003313 bdrv_drained_begin(bs); /* complete I/O */
Stefan Hajnoczi58fda172013-07-02 15:36:25 +02003314 bdrv_flush(bs);
Fam Zheng53ec73e2015-05-29 18:53:14 +08003315 bdrv_drain(bs); /* in case flush left pending I/O */
Paolo Bonzinifc272912015-12-23 11:48:24 +01003316
Paolo Bonzini3cbc0022012-10-19 11:36:48 +02003317 if (bs->drv) {
Kevin Wolf9a7dedb2015-06-16 10:58:20 +02003318 bs->drv->bdrv_close(bs);
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02003319 bs->drv = NULL;
bellardb3380822004-03-14 21:38:54 +00003320 }
Zhi Yong Wu98f90db2011-11-08 13:00:14 +08003321
Alberto Garcia50a3efb2017-11-06 16:53:45 +02003322 bdrv_set_backing_hd(bs, NULL, &error_abort);
3323
3324 if (bs->file != NULL) {
3325 bdrv_unref_child(bs, bs->file);
3326 bs->file = NULL;
3327 }
3328
3329 QLIST_FOREACH_SAFE(child, &bs->children, next, next) {
3330 /* TODO Remove bdrv_unref() from drivers' close function and use
3331 * bdrv_unref_child() here */
3332 if (child->bs->inherits_from == bs) {
3333 child->bs->inherits_from = NULL;
3334 }
3335 bdrv_detach_child(child);
3336 }
3337
3338 g_free(bs->opaque);
3339 bs->opaque = NULL;
3340 atomic_set(&bs->copy_on_read, 0);
3341 bs->backing_file[0] = '\0';
3342 bs->backing_format[0] = '\0';
3343 bs->total_sectors = 0;
3344 bs->encrypted = false;
3345 bs->sg = false;
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02003346 qobject_unref(bs->options);
3347 qobject_unref(bs->explicit_options);
Alberto Garcia50a3efb2017-11-06 16:53:45 +02003348 bs->options = NULL;
3349 bs->explicit_options = NULL;
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02003350 qobject_unref(bs->full_open_options);
Alberto Garcia50a3efb2017-11-06 16:53:45 +02003351 bs->full_open_options = NULL;
3352
Vladimir Sementsov-Ogievskiycca43ae2017-06-28 15:05:16 +03003353 bdrv_release_named_dirty_bitmaps(bs);
3354 assert(QLIST_EMPTY(&bs->dirty_bitmaps));
3355
Max Reitz33384422014-06-20 21:57:33 +02003356 QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
3357 g_free(ban);
3358 }
3359 QLIST_INIT(&bs->aio_notifiers);
Paolo Bonzinifc272912015-12-23 11:48:24 +01003360 bdrv_drained_end(bs);
bellardb3380822004-03-14 21:38:54 +00003361}
3362
MORITA Kazutaka2bc93fe2010-05-28 11:44:57 +09003363void bdrv_close_all(void)
3364{
Kevin Wolfb3b52992018-05-16 13:46:37 +02003365 assert(job_next(NULL) == NULL);
Kevin Wolfcd7fca92016-07-06 11:22:39 +02003366 nbd_export_close_all();
MORITA Kazutaka2bc93fe2010-05-28 11:44:57 +09003367
Max Reitzca9bd242016-01-29 16:36:14 +01003368 /* Drop references from requests still in flight, such as canceled block
3369 * jobs whose AIO context has not been polled yet */
3370 bdrv_drain_all();
Stefan Hajnoczied78cda2014-05-08 16:34:35 +02003371
Max Reitzca9bd242016-01-29 16:36:14 +01003372 blk_remove_all_bs();
3373 blockdev_close_all_bdrv_states();
3374
Kevin Wolfa1a2af02016-04-08 18:26:37 +02003375 assert(QTAILQ_EMPTY(&all_bdrv_states));
MORITA Kazutaka2bc93fe2010-05-28 11:44:57 +09003376}
3377
Kevin Wolfd0ac0382017-03-01 17:30:41 +01003378static bool should_update_child(BdrvChild *c, BlockDriverState *to)
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003379{
Kevin Wolfd0ac0382017-03-01 17:30:41 +01003380 BdrvChild *to_c;
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003381
Kevin Wolfd0ac0382017-03-01 17:30:41 +01003382 if (c->role->stay_at_node) {
3383 return false;
3384 }
3385
3386 if (c->role == &child_backing) {
3387 /* If @from is a backing file of @to, ignore the child to avoid
3388 * creating a loop. We only want to change the pointer of other
3389 * parents. */
3390 QLIST_FOREACH(to_c, &to->children, next) {
3391 if (to_c == c) {
3392 break;
3393 }
3394 }
3395 if (to_c) {
3396 return false;
3397 }
3398 }
3399
3400 return true;
3401}
3402
Kevin Wolf5fe31c22017-03-06 16:20:51 +01003403void bdrv_replace_node(BlockDriverState *from, BlockDriverState *to,
3404 Error **errp)
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003405{
Kevin Wolfd0ac0382017-03-01 17:30:41 +01003406 BdrvChild *c, *next;
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003407 GSList *list = NULL, *p;
3408 uint64_t old_perm, old_shared;
3409 uint64_t perm = 0, shared = BLK_PERM_ALL;
3410 int ret;
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003411
Kevin Wolf5fe31c22017-03-06 16:20:51 +01003412 assert(!atomic_read(&from->in_flight));
3413 assert(!atomic_read(&to->in_flight));
3414
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003415 /* Make sure that @from doesn't go away until we have successfully attached
3416 * all of its parents to @to. */
3417 bdrv_ref(from);
3418
3419 /* Put all parents into @list and calculate their cumulative permissions */
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003420 QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) {
Kevin Wolfd0ac0382017-03-01 17:30:41 +01003421 if (!should_update_child(c, to)) {
Kevin Wolf26de9432017-01-17 13:39:34 +01003422 continue;
3423 }
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003424 list = g_slist_prepend(list, c);
3425 perm |= c->perm;
3426 shared &= c->shared_perm;
3427 }
3428
3429 /* Check whether the required permissions can be granted on @to, ignoring
3430 * all BdrvChild in @list so that they can't block themselves. */
Kevin Wolf3121fb42017-09-14 14:42:12 +02003431 ret = bdrv_check_update_perm(to, NULL, perm, shared, list, errp);
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003432 if (ret < 0) {
3433 bdrv_abort_perm_update(to);
3434 goto out;
3435 }
3436
3437 /* Now actually perform the change. We performed the permission check for
3438 * all elements of @list at once, so set the permissions all at once at the
3439 * very end. */
3440 for (p = list; p != NULL; p = p->next) {
3441 c = p->data;
Max Reitz9bd910e2016-06-10 20:57:46 +02003442
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003443 bdrv_ref(to);
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003444 bdrv_replace_child_noperm(c, to);
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003445 bdrv_unref(from);
3446 }
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003447
3448 bdrv_get_cumulative_perm(to, &old_perm, &old_shared);
3449 bdrv_set_perm(to, old_perm | perm, old_shared | shared);
3450
3451out:
3452 g_slist_free(list);
3453 bdrv_unref(from);
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003454}
3455
Jeff Cody8802d1f2012-02-28 15:54:06 -05003456/*
3457 * Add new bs contents at the top of an image chain while the chain is
3458 * live, while keeping required fields on the top layer.
3459 *
3460 * This will modify the BlockDriverState fields, and swap contents
3461 * between bs_new and bs_top. Both bs_new and bs_top are modified.
3462 *
Markus Armbrusterbfb197e2014-10-07 13:59:11 +02003463 * bs_new must not be attached to a BlockBackend.
Jeff Codyf6801b82012-03-27 16:30:19 -04003464 *
Jeff Cody8802d1f2012-02-28 15:54:06 -05003465 * This function does not create any image files.
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003466 *
3467 * bdrv_append() takes ownership of a bs_new reference and unrefs it because
3468 * that's what the callers commonly need. bs_new will be referenced by the old
3469 * parents of bs_top after bdrv_append() returns. If the caller needs to keep a
3470 * reference of its own, it must call bdrv_ref().
Jeff Cody8802d1f2012-02-28 15:54:06 -05003471 */
Kevin Wolfb2c28322017-02-20 12:46:42 +01003472void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top,
3473 Error **errp)
Jeff Cody8802d1f2012-02-28 15:54:06 -05003474{
Kevin Wolfb2c28322017-02-20 12:46:42 +01003475 Error *local_err = NULL;
3476
Kevin Wolfb2c28322017-02-20 12:46:42 +01003477 bdrv_set_backing_hd(bs_new, bs_top, &local_err);
3478 if (local_err) {
3479 error_propagate(errp, local_err);
3480 goto out;
3481 }
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003482
Kevin Wolf5fe31c22017-03-06 16:20:51 +01003483 bdrv_replace_node(bs_top, bs_new, &local_err);
Kevin Wolf234ac1a2017-03-02 18:43:00 +01003484 if (local_err) {
3485 error_propagate(errp, local_err);
3486 bdrv_set_backing_hd(bs_new, NULL, &error_abort);
3487 goto out;
3488 }
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003489
3490 /* bs_new is now referenced by its new parents, we don't need the
3491 * additional reference any more. */
Kevin Wolfb2c28322017-02-20 12:46:42 +01003492out:
Kevin Wolfdd62f1c2015-06-18 14:09:57 +02003493 bdrv_unref(bs_new);
Jeff Cody8802d1f2012-02-28 15:54:06 -05003494}
3495
Fam Zheng4f6fd342013-08-23 09:14:47 +08003496static void bdrv_delete(BlockDriverState *bs)
bellardb3380822004-03-14 21:38:54 +00003497{
Paolo Bonzini3e914652012-03-30 13:17:11 +02003498 assert(!bs->job);
Fam Zheng3718d8a2014-05-23 21:29:43 +08003499 assert(bdrv_op_blocker_is_empty(bs));
Fam Zheng4f6fd342013-08-23 09:14:47 +08003500 assert(!bs->refcnt);
Markus Armbruster18846de2010-06-29 16:58:30 +02003501
Stefan Hajnoczie1b5c522013-06-27 15:32:26 +02003502 bdrv_close(bs);
3503
Stefan Hajnoczi1b7bdbc2010-04-10 07:02:42 +01003504 /* remove from list, if necessary */
Kevin Wolf63eaaae2016-03-18 10:46:57 +01003505 if (bs->node_name[0] != '\0') {
3506 QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list);
3507 }
Max Reitz2c1d04e2016-01-29 16:36:11 +01003508 QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list);
3509
Anthony Liguori7267c092011-08-20 22:09:37 -05003510 g_free(bs);
bellardfc01f7e2003-06-30 10:03:06 +00003511}
3512
aliguorie97fc192009-04-21 23:11:50 +00003513/*
3514 * Run consistency checks on an image
3515 *
Kevin Wolfe076f332010-06-29 11:43:13 +02003516 * Returns 0 if the check could be completed (it doesn't mean that the image is
Stefan Weila1c72732011-04-28 17:20:38 +02003517 * free of errors) or -errno when an internal error occurred. The results of the
Kevin Wolfe076f332010-06-29 11:43:13 +02003518 * check are stored in res.
aliguorie97fc192009-04-21 23:11:50 +00003519 */
Paolo Bonzini2fd61632018-03-01 17:36:19 +01003520static int coroutine_fn bdrv_co_check(BlockDriverState *bs,
3521 BdrvCheckResult *res, BdrvCheckMode fix)
aliguorie97fc192009-04-21 23:11:50 +00003522{
Max Reitz908bcd52014-08-07 22:47:55 +02003523 if (bs->drv == NULL) {
3524 return -ENOMEDIUM;
3525 }
Paolo Bonzini2fd61632018-03-01 17:36:19 +01003526 if (bs->drv->bdrv_co_check == NULL) {
aliguorie97fc192009-04-21 23:11:50 +00003527 return -ENOTSUP;
3528 }
3529
Kevin Wolfe076f332010-06-29 11:43:13 +02003530 memset(res, 0, sizeof(*res));
Paolo Bonzini2fd61632018-03-01 17:36:19 +01003531 return bs->drv->bdrv_co_check(bs, res, fix);
3532}
3533
3534typedef struct CheckCo {
3535 BlockDriverState *bs;
3536 BdrvCheckResult *res;
3537 BdrvCheckMode fix;
3538 int ret;
3539} CheckCo;
3540
3541static void bdrv_check_co_entry(void *opaque)
3542{
3543 CheckCo *cco = opaque;
3544 cco->ret = bdrv_co_check(cco->bs, cco->res, cco->fix);
3545}
3546
3547int bdrv_check(BlockDriverState *bs,
3548 BdrvCheckResult *res, BdrvCheckMode fix)
3549{
3550 Coroutine *co;
3551 CheckCo cco = {
3552 .bs = bs,
3553 .res = res,
3554 .ret = -EINPROGRESS,
3555 .fix = fix,
3556 };
3557
3558 if (qemu_in_coroutine()) {
3559 /* Fast-path if already in coroutine context */
3560 bdrv_check_co_entry(&cco);
3561 } else {
3562 co = qemu_coroutine_create(bdrv_check_co_entry, &cco);
3563 qemu_coroutine_enter(co);
3564 BDRV_POLL_WHILE(bs, cco.ret == -EINPROGRESS);
3565 }
3566
3567 return cco.ret;
aliguorie97fc192009-04-21 23:11:50 +00003568}
3569
Kevin Wolf756e6732010-01-12 12:55:17 +01003570/*
3571 * Return values:
3572 * 0 - success
3573 * -EINVAL - backing format specified, but no file
3574 * -ENOSPC - can't update the backing file because no space is left in the
3575 * image file header
3576 * -ENOTSUP - format driver doesn't support changing the backing file
3577 */
3578int bdrv_change_backing_file(BlockDriverState *bs,
3579 const char *backing_file, const char *backing_fmt)
3580{
3581 BlockDriver *drv = bs->drv;
Paolo Bonzini469ef352012-04-12 14:01:02 +02003582 int ret;
Kevin Wolf756e6732010-01-12 12:55:17 +01003583
Max Reitzd470ad42017-11-10 21:31:09 +01003584 if (!drv) {
3585 return -ENOMEDIUM;
3586 }
3587
Paolo Bonzini5f377792012-04-12 14:01:01 +02003588 /* Backing file format doesn't make sense without a backing file */
3589 if (backing_fmt && !backing_file) {
3590 return -EINVAL;
3591 }
3592
Kevin Wolf756e6732010-01-12 12:55:17 +01003593 if (drv->bdrv_change_backing_file != NULL) {
Paolo Bonzini469ef352012-04-12 14:01:02 +02003594 ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
Kevin Wolf756e6732010-01-12 12:55:17 +01003595 } else {
Paolo Bonzini469ef352012-04-12 14:01:02 +02003596 ret = -ENOTSUP;
Kevin Wolf756e6732010-01-12 12:55:17 +01003597 }
Paolo Bonzini469ef352012-04-12 14:01:02 +02003598
3599 if (ret == 0) {
3600 pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: "");
3601 pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: "");
3602 }
3603 return ret;
Kevin Wolf756e6732010-01-12 12:55:17 +01003604}
3605
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003606/*
3607 * Finds the image layer in the chain that has 'bs' as its backing file.
3608 *
3609 * active is the current topmost image.
3610 *
3611 * Returns NULL if bs is not found in active's image chain,
3612 * or if active == bs.
Jeff Cody4caf0fc2014-06-25 15:35:26 -04003613 *
3614 * Returns the bottommost base image if bs == NULL.
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003615 */
3616BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
3617 BlockDriverState *bs)
3618{
Kevin Wolf760e0062015-06-17 14:55:21 +02003619 while (active && bs != backing_bs(active)) {
3620 active = backing_bs(active);
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003621 }
3622
Jeff Cody4caf0fc2014-06-25 15:35:26 -04003623 return active;
3624}
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003625
Jeff Cody4caf0fc2014-06-25 15:35:26 -04003626/* Given a BDS, searches for the base layer. */
3627BlockDriverState *bdrv_find_base(BlockDriverState *bs)
3628{
3629 return bdrv_find_overlay(bs, NULL);
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003630}
3631
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003632/*
3633 * Drops images above 'base' up to and including 'top', and sets the image
3634 * above 'top' to have base as its backing file.
3635 *
3636 * Requires that the overlay to 'top' is opened r/w, so that the backing file
3637 * information in 'bs' can be properly updated.
3638 *
3639 * E.g., this will convert the following chain:
3640 * bottom <- base <- intermediate <- top <- active
3641 *
3642 * to
3643 *
3644 * bottom <- base <- active
3645 *
3646 * It is allowed for bottom==base, in which case it converts:
3647 *
3648 * base <- intermediate <- top <- active
3649 *
3650 * to
3651 *
3652 * base <- active
3653 *
Jeff Cody54e26902014-06-25 15:40:10 -04003654 * If backing_file_str is non-NULL, it will be used when modifying top's
3655 * overlay image metadata.
3656 *
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003657 * Error conditions:
3658 * if active == top, that is considered an error
3659 *
3660 */
Kevin Wolfbde70712017-06-27 20:36:18 +02003661int bdrv_drop_intermediate(BlockDriverState *top, BlockDriverState *base,
3662 const char *backing_file_str)
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003663{
Kevin Wolf61f09ce2017-09-19 16:22:54 +02003664 BdrvChild *c, *next;
Kevin Wolf12fa4af2017-02-17 20:42:32 +01003665 Error *local_err = NULL;
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003666 int ret = -EIO;
3667
Kevin Wolf6858eba2017-06-29 19:32:21 +02003668 bdrv_ref(top);
3669
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003670 if (!top->drv || !base->drv) {
3671 goto exit;
3672 }
3673
Kevin Wolf5db15a52015-09-14 15:33:33 +02003674 /* Make sure that base is in the backing chain of top */
3675 if (!bdrv_chain_contains(top, base)) {
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003676 goto exit;
3677 }
3678
3679 /* success - we can delete the intermediate states, and link top->base */
Kevin Wolfbde70712017-06-27 20:36:18 +02003680 /* TODO Check graph modification op blockers (BLK_PERM_GRAPH_MOD) once
3681 * we've figured out how they should work. */
Kevin Wolf61f09ce2017-09-19 16:22:54 +02003682 backing_file_str = backing_file_str ? backing_file_str : base->filename;
3683
3684 QLIST_FOREACH_SAFE(c, &top->parents, next_parent, next) {
3685 /* Check whether we are allowed to switch c from top to base */
3686 GSList *ignore_children = g_slist_prepend(NULL, c);
3687 bdrv_check_update_perm(base, NULL, c->perm, c->shared_perm,
3688 ignore_children, &local_err);
Fam Zheng2c860e72018-03-15 11:51:57 +08003689 g_slist_free(ignore_children);
Kevin Wolf61f09ce2017-09-19 16:22:54 +02003690 if (local_err) {
3691 ret = -EPERM;
3692 error_report_err(local_err);
Kevin Wolf6858eba2017-06-29 19:32:21 +02003693 goto exit;
3694 }
Kevin Wolf12fa4af2017-02-17 20:42:32 +01003695
Kevin Wolf61f09ce2017-09-19 16:22:54 +02003696 /* If so, update the backing file path in the image file */
3697 if (c->role->update_filename) {
3698 ret = c->role->update_filename(c, base, backing_file_str,
3699 &local_err);
3700 if (ret < 0) {
3701 bdrv_abort_perm_update(base);
3702 error_report_err(local_err);
3703 goto exit;
3704 }
3705 }
3706
3707 /* Do the actual switch in the in-memory graph.
3708 * Completes bdrv_check_update_perm() transaction internally. */
3709 bdrv_ref(base);
3710 bdrv_replace_child(c, base);
3711 bdrv_unref(top);
Kevin Wolf12fa4af2017-02-17 20:42:32 +01003712 }
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003713
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003714 ret = 0;
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003715exit:
Kevin Wolf6858eba2017-06-29 19:32:21 +02003716 bdrv_unref(top);
Jeff Cody6ebdcee2012-09-27 13:29:12 -04003717 return ret;
3718}
3719
bellard83f64092006-08-01 16:21:11 +00003720/**
bellard83f64092006-08-01 16:21:11 +00003721 * Truncate file to 'offset' bytes (needed only for file protocols)
3722 */
Max Reitz7ea37c32017-06-13 22:20:53 +02003723int bdrv_truncate(BdrvChild *child, int64_t offset, PreallocMode prealloc,
3724 Error **errp)
bellard83f64092006-08-01 16:21:11 +00003725{
Kevin Wolf52cdbc52017-02-16 18:39:03 +01003726 BlockDriverState *bs = child->bs;
bellard83f64092006-08-01 16:21:11 +00003727 BlockDriver *drv = bs->drv;
Stefan Hajnoczi51762282010-04-19 16:56:41 +01003728 int ret;
Kevin Wolfc8f6d582017-02-17 14:52:00 +01003729
Max Reitz362b3782017-04-11 17:52:26 +02003730 assert(child->perm & BLK_PERM_RESIZE);
Kevin Wolfc8f6d582017-02-17 14:52:00 +01003731
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +03003732 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
Max Reitzed3d2ec2017-03-28 22:51:27 +02003733 if (!drv) {
3734 error_setg(errp, "No medium inserted");
bellard19cb3732006-08-19 11:45:59 +00003735 return -ENOMEDIUM;
Max Reitzed3d2ec2017-03-28 22:51:27 +02003736 }
Kevin Wolfcd8b7aa2018-02-07 17:58:47 +01003737 if (offset < 0) {
3738 error_setg(errp, "Image size cannot be negative");
3739 return -EINVAL;
3740 }
3741
Max Reitzed3d2ec2017-03-28 22:51:27 +02003742 if (!drv->bdrv_truncate) {
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +03003743 if (bs->file && drv->is_filter) {
3744 return bdrv_truncate(bs->file, offset, prealloc, errp);
3745 }
Max Reitzed3d2ec2017-03-28 22:51:27 +02003746 error_setg(errp, "Image format driver does not support resize");
bellard83f64092006-08-01 16:21:11 +00003747 return -ENOTSUP;
Max Reitzed3d2ec2017-03-28 22:51:27 +02003748 }
3749 if (bs->read_only) {
3750 error_setg(errp, "Image is read-only");
Naphtali Sprei59f26892009-10-26 16:25:16 +02003751 return -EACCES;
Max Reitzed3d2ec2017-03-28 22:51:27 +02003752 }
Jeff Cody9c75e162014-06-25 16:55:30 -04003753
Denis V. Lunev504c2052017-04-05 18:18:25 +03003754 assert(!(bs->open_flags & BDRV_O_INACTIVE));
3755
Max Reitz7ea37c32017-06-13 22:20:53 +02003756 ret = drv->bdrv_truncate(bs, offset, prealloc, errp);
Eric Blake1b6cc572017-09-25 09:55:11 -05003757 if (ret < 0) {
3758 return ret;
Stefan Hajnoczi51762282010-04-19 16:56:41 +01003759 }
Eric Blake1b6cc572017-09-25 09:55:11 -05003760 ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS);
3761 if (ret < 0) {
3762 error_setg_errno(errp, -ret, "Could not refresh total sector count");
3763 } else {
3764 offset = bs->total_sectors * BDRV_SECTOR_SIZE;
3765 }
3766 bdrv_dirty_bitmap_truncate(bs, offset);
3767 bdrv_parent_cb_resize(bs);
3768 atomic_inc(&bs->write_gen);
Stefan Hajnoczi51762282010-04-19 16:56:41 +01003769 return ret;
bellard83f64092006-08-01 16:21:11 +00003770}
3771
3772/**
Fam Zheng4a1d5e12011-07-12 19:56:39 +08003773 * Length of a allocated file in bytes. Sparse files are counted by actual
3774 * allocated space. Return < 0 if error or unknown.
3775 */
3776int64_t bdrv_get_allocated_file_size(BlockDriverState *bs)
3777{
3778 BlockDriver *drv = bs->drv;
3779 if (!drv) {
3780 return -ENOMEDIUM;
3781 }
3782 if (drv->bdrv_get_allocated_file_size) {
3783 return drv->bdrv_get_allocated_file_size(bs);
3784 }
3785 if (bs->file) {
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02003786 return bdrv_get_allocated_file_size(bs->file->bs);
Fam Zheng4a1d5e12011-07-12 19:56:39 +08003787 }
3788 return -ENOTSUP;
3789}
3790
Stefan Hajnoczi90880ff2017-07-05 13:57:30 +01003791/*
3792 * bdrv_measure:
3793 * @drv: Format driver
3794 * @opts: Creation options for new image
3795 * @in_bs: Existing image containing data for new image (may be NULL)
3796 * @errp: Error object
3797 * Returns: A #BlockMeasureInfo (free using qapi_free_BlockMeasureInfo())
3798 * or NULL on error
3799 *
3800 * Calculate file size required to create a new image.
3801 *
3802 * If @in_bs is given then space for allocated clusters and zero clusters
3803 * from that image are included in the calculation. If @opts contains a
3804 * backing file that is shared by @in_bs then backing clusters may be omitted
3805 * from the calculation.
3806 *
3807 * If @in_bs is NULL then the calculation includes no allocated clusters
3808 * unless a preallocation option is given in @opts.
3809 *
3810 * Note that @in_bs may use a different BlockDriver from @drv.
3811 *
3812 * If an error occurs the @errp pointer is set.
3813 */
3814BlockMeasureInfo *bdrv_measure(BlockDriver *drv, QemuOpts *opts,
3815 BlockDriverState *in_bs, Error **errp)
3816{
3817 if (!drv->bdrv_measure) {
3818 error_setg(errp, "Block driver '%s' does not support size measurement",
3819 drv->format_name);
3820 return NULL;
3821 }
3822
3823 return drv->bdrv_measure(opts, in_bs, errp);
3824}
3825
Fam Zheng4a1d5e12011-07-12 19:56:39 +08003826/**
Markus Armbruster65a9bb22014-06-26 13:23:17 +02003827 * Return number of sectors on success, -errno on error.
bellard83f64092006-08-01 16:21:11 +00003828 */
Markus Armbruster65a9bb22014-06-26 13:23:17 +02003829int64_t bdrv_nb_sectors(BlockDriverState *bs)
bellard83f64092006-08-01 16:21:11 +00003830{
3831 BlockDriver *drv = bs->drv;
Markus Armbruster65a9bb22014-06-26 13:23:17 +02003832
bellard83f64092006-08-01 16:21:11 +00003833 if (!drv)
bellard19cb3732006-08-19 11:45:59 +00003834 return -ENOMEDIUM;
Stefan Hajnoczi51762282010-04-19 16:56:41 +01003835
Kevin Wolfb94a2612013-10-29 12:18:58 +01003836 if (drv->has_variable_length) {
3837 int ret = refresh_total_sectors(bs, bs->total_sectors);
3838 if (ret < 0) {
3839 return ret;
Stefan Hajnoczi46a4e4e2011-03-29 20:04:41 +01003840 }
bellard83f64092006-08-01 16:21:11 +00003841 }
Markus Armbruster65a9bb22014-06-26 13:23:17 +02003842 return bs->total_sectors;
3843}
3844
3845/**
3846 * Return length in bytes on success, -errno on error.
3847 * The length is always a multiple of BDRV_SECTOR_SIZE.
3848 */
3849int64_t bdrv_getlength(BlockDriverState *bs)
3850{
3851 int64_t ret = bdrv_nb_sectors(bs);
3852
Fam Zheng4a9c9ea2015-05-15 16:36:05 +08003853 ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret;
Markus Armbruster65a9bb22014-06-26 13:23:17 +02003854 return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE;
bellardfc01f7e2003-06-30 10:03:06 +00003855}
3856
bellard19cb3732006-08-19 11:45:59 +00003857/* return 0 as number of sectors if no device present or error */
ths96b8f132007-12-17 01:35:20 +00003858void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
bellardfc01f7e2003-06-30 10:03:06 +00003859{
Markus Armbruster65a9bb22014-06-26 13:23:17 +02003860 int64_t nb_sectors = bdrv_nb_sectors(bs);
3861
3862 *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors;
bellardfc01f7e2003-06-30 10:03:06 +00003863}
bellardcf989512004-02-16 21:56:36 +00003864
Eric Blake54115412016-06-23 16:37:26 -06003865bool bdrv_is_sg(BlockDriverState *bs)
ths985a03b2007-12-24 16:10:43 +00003866{
3867 return bs->sg;
3868}
3869
Eric Blake54115412016-06-23 16:37:26 -06003870bool bdrv_is_encrypted(BlockDriverState *bs)
bellardea2384d2004-08-01 21:59:26 +00003871{
Kevin Wolf760e0062015-06-17 14:55:21 +02003872 if (bs->backing && bs->backing->bs->encrypted) {
Eric Blake54115412016-06-23 16:37:26 -06003873 return true;
Kevin Wolf760e0062015-06-17 14:55:21 +02003874 }
bellardea2384d2004-08-01 21:59:26 +00003875 return bs->encrypted;
3876}
3877
Markus Armbrusterf8d6bba2012-06-13 10:11:48 +02003878const char *bdrv_get_format_name(BlockDriverState *bs)
bellardea2384d2004-08-01 21:59:26 +00003879{
Markus Armbrusterf8d6bba2012-06-13 10:11:48 +02003880 return bs->drv ? bs->drv->format_name : NULL;
bellardea2384d2004-08-01 21:59:26 +00003881}
3882
Stefan Hajnocziada42402014-08-27 12:08:55 +01003883static int qsort_strcmp(const void *a, const void *b)
3884{
Max Reitzceff5bd2016-10-12 22:49:05 +02003885 return strcmp(*(char *const *)a, *(char *const *)b);
Stefan Hajnocziada42402014-08-27 12:08:55 +01003886}
3887
ths5fafdf22007-09-16 21:08:06 +00003888void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
bellardea2384d2004-08-01 21:59:26 +00003889 void *opaque)
3890{
3891 BlockDriver *drv;
Jeff Codye855e4f2014-04-28 18:29:54 -04003892 int count = 0;
Stefan Hajnocziada42402014-08-27 12:08:55 +01003893 int i;
Jeff Codye855e4f2014-04-28 18:29:54 -04003894 const char **formats = NULL;
bellardea2384d2004-08-01 21:59:26 +00003895
Stefan Hajnoczi8a22f022010-04-13 10:29:33 +01003896 QLIST_FOREACH(drv, &bdrv_drivers, list) {
Jeff Codye855e4f2014-04-28 18:29:54 -04003897 if (drv->format_name) {
3898 bool found = false;
3899 int i = count;
3900 while (formats && i && !found) {
3901 found = !strcmp(formats[--i], drv->format_name);
3902 }
3903
3904 if (!found) {
Markus Armbruster5839e532014-08-19 10:31:08 +02003905 formats = g_renew(const char *, formats, count + 1);
Jeff Codye855e4f2014-04-28 18:29:54 -04003906 formats[count++] = drv->format_name;
Jeff Codye855e4f2014-04-28 18:29:54 -04003907 }
3908 }
bellardea2384d2004-08-01 21:59:26 +00003909 }
Stefan Hajnocziada42402014-08-27 12:08:55 +01003910
Max Reitzeb0df692016-10-12 22:49:06 +02003911 for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); i++) {
3912 const char *format_name = block_driver_modules[i].format_name;
3913
3914 if (format_name) {
3915 bool found = false;
3916 int j = count;
3917
3918 while (formats && j && !found) {
3919 found = !strcmp(formats[--j], format_name);
3920 }
3921
3922 if (!found) {
3923 formats = g_renew(const char *, formats, count + 1);
3924 formats[count++] = format_name;
3925 }
3926 }
3927 }
3928
Stefan Hajnocziada42402014-08-27 12:08:55 +01003929 qsort(formats, count, sizeof(formats[0]), qsort_strcmp);
3930
3931 for (i = 0; i < count; i++) {
3932 it(opaque, formats[i]);
3933 }
3934
Jeff Codye855e4f2014-04-28 18:29:54 -04003935 g_free(formats);
bellardea2384d2004-08-01 21:59:26 +00003936}
3937
Benoît Canetdc364f42014-01-23 21:31:32 +01003938/* This function is to find a node in the bs graph */
3939BlockDriverState *bdrv_find_node(const char *node_name)
3940{
3941 BlockDriverState *bs;
3942
3943 assert(node_name);
3944
3945 QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
3946 if (!strcmp(node_name, bs->node_name)) {
3947 return bs;
3948 }
3949 }
3950 return NULL;
3951}
3952
Benoît Canetc13163f2014-01-23 21:31:34 +01003953/* Put this QMP function here so it can access the static graph_bdrv_states. */
Alberto Garciad5a8ee62015-04-17 14:52:43 +03003954BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp)
Benoît Canetc13163f2014-01-23 21:31:34 +01003955{
3956 BlockDeviceInfoList *list, *entry;
3957 BlockDriverState *bs;
3958
3959 list = NULL;
3960 QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
Kevin Wolfc83f9fb2016-03-03 11:37:48 +01003961 BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, errp);
Alberto Garciad5a8ee62015-04-17 14:52:43 +03003962 if (!info) {
3963 qapi_free_BlockDeviceInfoList(list);
3964 return NULL;
3965 }
Benoît Canetc13163f2014-01-23 21:31:34 +01003966 entry = g_malloc0(sizeof(*entry));
Alberto Garciad5a8ee62015-04-17 14:52:43 +03003967 entry->value = info;
Benoît Canetc13163f2014-01-23 21:31:34 +01003968 entry->next = list;
3969 list = entry;
3970 }
3971
3972 return list;
3973}
3974
Benoît Canet12d3ba82014-01-23 21:31:35 +01003975BlockDriverState *bdrv_lookup_bs(const char *device,
3976 const char *node_name,
3977 Error **errp)
3978{
Markus Armbruster7f06d472014-10-07 13:59:12 +02003979 BlockBackend *blk;
3980 BlockDriverState *bs;
Benoît Canet12d3ba82014-01-23 21:31:35 +01003981
Benoît Canet12d3ba82014-01-23 21:31:35 +01003982 if (device) {
Markus Armbruster7f06d472014-10-07 13:59:12 +02003983 blk = blk_by_name(device);
Benoît Canet12d3ba82014-01-23 21:31:35 +01003984
Markus Armbruster7f06d472014-10-07 13:59:12 +02003985 if (blk) {
Alberto Garcia9f4ed6f2015-10-26 16:46:49 +02003986 bs = blk_bs(blk);
3987 if (!bs) {
Max Reitz5433c242015-10-19 17:53:29 +02003988 error_setg(errp, "Device '%s' has no medium", device);
Max Reitz5433c242015-10-19 17:53:29 +02003989 }
3990
Alberto Garcia9f4ed6f2015-10-26 16:46:49 +02003991 return bs;
Benoît Canet12d3ba82014-01-23 21:31:35 +01003992 }
Benoît Canet12d3ba82014-01-23 21:31:35 +01003993 }
3994
Benoît Canetdd67fa52014-02-12 17:15:06 +01003995 if (node_name) {
3996 bs = bdrv_find_node(node_name);
Benoît Canet12d3ba82014-01-23 21:31:35 +01003997
Benoît Canetdd67fa52014-02-12 17:15:06 +01003998 if (bs) {
3999 return bs;
4000 }
Benoît Canet12d3ba82014-01-23 21:31:35 +01004001 }
4002
Benoît Canetdd67fa52014-02-12 17:15:06 +01004003 error_setg(errp, "Cannot find device=%s nor node_name=%s",
4004 device ? device : "",
4005 node_name ? node_name : "");
4006 return NULL;
Benoît Canet12d3ba82014-01-23 21:31:35 +01004007}
4008
Jeff Cody5a6684d2014-06-25 15:40:09 -04004009/* If 'base' is in the same chain as 'top', return true. Otherwise,
4010 * return false. If either argument is NULL, return false. */
4011bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base)
4012{
4013 while (top && top != base) {
Kevin Wolf760e0062015-06-17 14:55:21 +02004014 top = backing_bs(top);
Jeff Cody5a6684d2014-06-25 15:40:09 -04004015 }
4016
4017 return top != NULL;
4018}
4019
Fam Zheng04df7652014-10-31 11:32:54 +08004020BlockDriverState *bdrv_next_node(BlockDriverState *bs)
4021{
4022 if (!bs) {
4023 return QTAILQ_FIRST(&graph_bdrv_states);
4024 }
4025 return QTAILQ_NEXT(bs, node_list);
4026}
4027
Fam Zheng20a9e772014-10-31 11:32:55 +08004028const char *bdrv_get_node_name(const BlockDriverState *bs)
4029{
4030 return bs->node_name;
4031}
4032
Kevin Wolf1f0c4612016-03-22 18:38:44 +01004033const char *bdrv_get_parent_name(const BlockDriverState *bs)
Kevin Wolf4c265bf2016-02-26 10:22:16 +01004034{
4035 BdrvChild *c;
4036 const char *name;
4037
4038 /* If multiple parents have a name, just pick the first one. */
4039 QLIST_FOREACH(c, &bs->parents, next_parent) {
4040 if (c->role->get_name) {
4041 name = c->role->get_name(c);
4042 if (name && *name) {
4043 return name;
4044 }
4045 }
4046 }
4047
4048 return NULL;
4049}
4050
Markus Armbruster7f06d472014-10-07 13:59:12 +02004051/* TODO check what callers really want: bs->node_name or blk_name() */
Markus Armbrusterbfb197e2014-10-07 13:59:11 +02004052const char *bdrv_get_device_name(const BlockDriverState *bs)
bellardea2384d2004-08-01 21:59:26 +00004053{
Kevin Wolf4c265bf2016-02-26 10:22:16 +01004054 return bdrv_get_parent_name(bs) ?: "";
bellardea2384d2004-08-01 21:59:26 +00004055}
4056
Alberto Garcia9b2aa842015-04-08 12:29:18 +03004057/* This can be used to identify nodes that might not have a device
4058 * name associated. Since node and device names live in the same
4059 * namespace, the result is unambiguous. The exception is if both are
4060 * absent, then this returns an empty (non-null) string. */
4061const char *bdrv_get_device_or_node_name(const BlockDriverState *bs)
4062{
Kevin Wolf4c265bf2016-02-26 10:22:16 +01004063 return bdrv_get_parent_name(bs) ?: bs->node_name;
Alberto Garcia9b2aa842015-04-08 12:29:18 +03004064}
4065
Markus Armbrusterc8433282012-06-05 16:49:24 +02004066int bdrv_get_flags(BlockDriverState *bs)
4067{
4068 return bs->open_flags;
4069}
4070
Peter Lieven3ac21622013-06-28 12:47:42 +02004071int bdrv_has_zero_init_1(BlockDriverState *bs)
4072{
4073 return 1;
4074}
4075
Kevin Wolff2feebb2010-04-14 17:30:35 +02004076int bdrv_has_zero_init(BlockDriverState *bs)
4077{
Max Reitzd470ad42017-11-10 21:31:09 +01004078 if (!bs->drv) {
4079 return 0;
4080 }
Kevin Wolff2feebb2010-04-14 17:30:35 +02004081
Paolo Bonzini11212d82013-09-04 19:00:27 +02004082 /* If BS is a copy on write image, it is initialized to
4083 the contents of the base image, which may not be zeroes. */
Kevin Wolf760e0062015-06-17 14:55:21 +02004084 if (bs->backing) {
Paolo Bonzini11212d82013-09-04 19:00:27 +02004085 return 0;
4086 }
Kevin Wolf336c1c12010-07-28 11:26:29 +02004087 if (bs->drv->bdrv_has_zero_init) {
4088 return bs->drv->bdrv_has_zero_init(bs);
Kevin Wolff2feebb2010-04-14 17:30:35 +02004089 }
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +03004090 if (bs->file && bs->drv->is_filter) {
4091 return bdrv_has_zero_init(bs->file->bs);
4092 }
Kevin Wolff2feebb2010-04-14 17:30:35 +02004093
Peter Lieven3ac21622013-06-28 12:47:42 +02004094 /* safe default */
4095 return 0;
Kevin Wolff2feebb2010-04-14 17:30:35 +02004096}
4097
Peter Lieven4ce78692013-10-24 12:06:54 +02004098bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs)
4099{
4100 BlockDriverInfo bdi;
4101
Kevin Wolf760e0062015-06-17 14:55:21 +02004102 if (bs->backing) {
Peter Lieven4ce78692013-10-24 12:06:54 +02004103 return false;
4104 }
4105
4106 if (bdrv_get_info(bs, &bdi) == 0) {
4107 return bdi.unallocated_blocks_are_zero;
4108 }
4109
4110 return false;
4111}
4112
4113bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs)
4114{
Denis V. Lunev2f0342e2016-07-14 16:33:26 +03004115 if (!(bs->open_flags & BDRV_O_UNMAP)) {
Peter Lieven4ce78692013-10-24 12:06:54 +02004116 return false;
4117 }
4118
Eric Blakee24d8132018-01-26 13:34:39 -06004119 return bs->supported_zero_flags & BDRV_REQ_MAY_UNMAP;
Peter Lieven4ce78692013-10-24 12:06:54 +02004120}
4121
aliguori045df332009-03-05 23:00:48 +00004122const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
4123{
Kevin Wolf760e0062015-06-17 14:55:21 +02004124 if (bs->backing && bs->backing->bs->encrypted)
aliguori045df332009-03-05 23:00:48 +00004125 return bs->backing_file;
4126 else if (bs->encrypted)
4127 return bs->filename;
4128 else
4129 return NULL;
4130}
4131
ths5fafdf22007-09-16 21:08:06 +00004132void bdrv_get_backing_filename(BlockDriverState *bs,
bellard83f64092006-08-01 16:21:11 +00004133 char *filename, int filename_size)
bellardea2384d2004-08-01 21:59:26 +00004134{
Kevin Wolf3574c602011-10-26 11:02:11 +02004135 pstrcpy(filename, filename_size, bs->backing_file);
bellardea2384d2004-08-01 21:59:26 +00004136}
4137
bellardfaea38e2006-08-05 21:31:00 +00004138int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
4139{
4140 BlockDriver *drv = bs->drv;
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +03004141 /* if bs->drv == NULL, bs is closed, so there's nothing to do here */
4142 if (!drv) {
bellard19cb3732006-08-19 11:45:59 +00004143 return -ENOMEDIUM;
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +03004144 }
4145 if (!drv->bdrv_get_info) {
4146 if (bs->file && drv->is_filter) {
4147 return bdrv_get_info(bs->file->bs, bdi);
4148 }
bellardfaea38e2006-08-05 21:31:00 +00004149 return -ENOTSUP;
Manos Pitsidianakis5a612c02017-07-13 18:30:25 +03004150 }
bellardfaea38e2006-08-05 21:31:00 +00004151 memset(bdi, 0, sizeof(*bdi));
4152 return drv->bdrv_get_info(bs, bdi);
4153}
4154
Max Reitzeae041f2013-10-09 10:46:16 +02004155ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs)
4156{
4157 BlockDriver *drv = bs->drv;
4158 if (drv && drv->bdrv_get_specific_info) {
4159 return drv->bdrv_get_specific_info(bs);
4160 }
4161 return NULL;
4162}
4163
Eric Blakea31939e2015-11-18 01:52:54 -07004164void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event)
Kevin Wolf8b9b0cc2010-03-15 17:27:00 +01004165{
Kevin Wolfbf736fe2013-06-05 15:17:55 +02004166 if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
Kevin Wolf8b9b0cc2010-03-15 17:27:00 +01004167 return;
4168 }
4169
Kevin Wolfbf736fe2013-06-05 15:17:55 +02004170 bs->drv->bdrv_debug_event(bs, event);
Kevin Wolf41c695c2012-12-06 14:32:58 +01004171}
Kevin Wolf8b9b0cc2010-03-15 17:27:00 +01004172
Kevin Wolf41c695c2012-12-06 14:32:58 +01004173int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event,
4174 const char *tag)
4175{
4176 while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) {
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02004177 bs = bs->file ? bs->file->bs : NULL;
Kevin Wolf41c695c2012-12-06 14:32:58 +01004178 }
4179
4180 if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) {
4181 return bs->drv->bdrv_debug_breakpoint(bs, event, tag);
4182 }
4183
4184 return -ENOTSUP;
4185}
4186
Fam Zheng4cc70e92013-11-20 10:01:54 +08004187int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag)
4188{
4189 while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) {
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02004190 bs = bs->file ? bs->file->bs : NULL;
Fam Zheng4cc70e92013-11-20 10:01:54 +08004191 }
4192
4193 if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) {
4194 return bs->drv->bdrv_debug_remove_breakpoint(bs, tag);
4195 }
4196
4197 return -ENOTSUP;
4198}
4199
Kevin Wolf41c695c2012-12-06 14:32:58 +01004200int bdrv_debug_resume(BlockDriverState *bs, const char *tag)
4201{
Max Reitz938789e2014-03-10 23:44:08 +01004202 while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) {
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02004203 bs = bs->file ? bs->file->bs : NULL;
Kevin Wolf41c695c2012-12-06 14:32:58 +01004204 }
4205
4206 if (bs && bs->drv && bs->drv->bdrv_debug_resume) {
4207 return bs->drv->bdrv_debug_resume(bs, tag);
4208 }
4209
4210 return -ENOTSUP;
4211}
4212
4213bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag)
4214{
4215 while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) {
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02004216 bs = bs->file ? bs->file->bs : NULL;
Kevin Wolf41c695c2012-12-06 14:32:58 +01004217 }
4218
4219 if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) {
4220 return bs->drv->bdrv_debug_is_suspended(bs, tag);
4221 }
4222
4223 return false;
Kevin Wolf8b9b0cc2010-03-15 17:27:00 +01004224}
4225
Jeff Codyb1b1d782012-10-16 15:49:09 -04004226/* backing_file can either be relative, or absolute, or a protocol. If it is
4227 * relative, it must be relative to the chain. So, passing in bs->filename
4228 * from a BDS as backing_file should not be done, as that may be relative to
4229 * the CWD rather than the chain. */
Marcelo Tosattie8a6bb92012-01-18 14:40:51 +00004230BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs,
4231 const char *backing_file)
4232{
Jeff Codyb1b1d782012-10-16 15:49:09 -04004233 char *filename_full = NULL;
4234 char *backing_file_full = NULL;
4235 char *filename_tmp = NULL;
4236 int is_protocol = 0;
4237 BlockDriverState *curr_bs = NULL;
4238 BlockDriverState *retval = NULL;
Jeff Cody418661e2017-01-25 20:08:20 -05004239 Error *local_error = NULL;
Jeff Codyb1b1d782012-10-16 15:49:09 -04004240
4241 if (!bs || !bs->drv || !backing_file) {
Marcelo Tosattie8a6bb92012-01-18 14:40:51 +00004242 return NULL;
4243 }
4244
Jeff Codyb1b1d782012-10-16 15:49:09 -04004245 filename_full = g_malloc(PATH_MAX);
4246 backing_file_full = g_malloc(PATH_MAX);
4247 filename_tmp = g_malloc(PATH_MAX);
4248
4249 is_protocol = path_has_protocol(backing_file);
4250
Kevin Wolf760e0062015-06-17 14:55:21 +02004251 for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) {
Jeff Codyb1b1d782012-10-16 15:49:09 -04004252
4253 /* If either of the filename paths is actually a protocol, then
4254 * compare unmodified paths; otherwise make paths relative */
4255 if (is_protocol || path_has_protocol(curr_bs->backing_file)) {
4256 if (strcmp(backing_file, curr_bs->backing_file) == 0) {
Kevin Wolf760e0062015-06-17 14:55:21 +02004257 retval = curr_bs->backing->bs;
Jeff Codyb1b1d782012-10-16 15:49:09 -04004258 break;
4259 }
Jeff Cody418661e2017-01-25 20:08:20 -05004260 /* Also check against the full backing filename for the image */
4261 bdrv_get_full_backing_filename(curr_bs, backing_file_full, PATH_MAX,
4262 &local_error);
4263 if (local_error == NULL) {
4264 if (strcmp(backing_file, backing_file_full) == 0) {
4265 retval = curr_bs->backing->bs;
4266 break;
4267 }
4268 } else {
4269 error_free(local_error);
4270 local_error = NULL;
4271 }
Marcelo Tosattie8a6bb92012-01-18 14:40:51 +00004272 } else {
Jeff Codyb1b1d782012-10-16 15:49:09 -04004273 /* If not an absolute filename path, make it relative to the current
4274 * image's filename path */
4275 path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
4276 backing_file);
4277
4278 /* We are going to compare absolute pathnames */
4279 if (!realpath(filename_tmp, filename_full)) {
4280 continue;
4281 }
4282
4283 /* We need to make sure the backing filename we are comparing against
4284 * is relative to the current image filename (or absolute) */
4285 path_combine(filename_tmp, PATH_MAX, curr_bs->filename,
4286 curr_bs->backing_file);
4287
4288 if (!realpath(filename_tmp, backing_file_full)) {
4289 continue;
4290 }
4291
4292 if (strcmp(backing_file_full, filename_full) == 0) {
Kevin Wolf760e0062015-06-17 14:55:21 +02004293 retval = curr_bs->backing->bs;
Jeff Codyb1b1d782012-10-16 15:49:09 -04004294 break;
4295 }
Marcelo Tosattie8a6bb92012-01-18 14:40:51 +00004296 }
4297 }
4298
Jeff Codyb1b1d782012-10-16 15:49:09 -04004299 g_free(filename_full);
4300 g_free(backing_file_full);
4301 g_free(filename_tmp);
4302 return retval;
Marcelo Tosattie8a6bb92012-01-18 14:40:51 +00004303}
4304
bellardea2384d2004-08-01 21:59:26 +00004305void bdrv_init(void)
4306{
Anthony Liguori5efa9d52009-05-09 17:03:42 -05004307 module_call_init(MODULE_INIT_BLOCK);
bellardea2384d2004-08-01 21:59:26 +00004308}
pbrookce1a14d2006-08-07 02:38:06 +00004309
Markus Armbrustereb852012009-10-27 18:41:44 +01004310void bdrv_init_with_whitelist(void)
4311{
4312 use_bdrv_whitelist = 1;
4313 bdrv_init();
4314}
4315
Paolo Bonzini2b148f32018-03-01 17:36:18 +01004316static void coroutine_fn bdrv_co_invalidate_cache(BlockDriverState *bs,
4317 Error **errp)
Anthony Liguori0f154232011-11-14 15:09:45 -06004318{
Kevin Wolf4417ab72017-05-04 18:52:37 +02004319 BdrvChild *child, *parent;
Kevin Wolf9c5e6592017-05-04 18:52:40 +02004320 uint64_t perm, shared_perm;
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01004321 Error *local_err = NULL;
4322 int ret;
4323
Kevin Wolf3456a8d2014-03-11 10:58:39 +01004324 if (!bs->drv) {
4325 return;
Anthony Liguori0f154232011-11-14 15:09:45 -06004326 }
Kevin Wolf3456a8d2014-03-11 10:58:39 +01004327
Kevin Wolf04c01a52016-01-13 15:56:06 +01004328 if (!(bs->open_flags & BDRV_O_INACTIVE)) {
Alexey Kardashevskiy7ea2d262014-10-09 13:50:46 +11004329 return;
4330 }
Alexey Kardashevskiy7ea2d262014-10-09 13:50:46 +11004331
Vladimir Sementsov-Ogievskiy16e977d2017-01-31 14:23:08 +03004332 QLIST_FOREACH(child, &bs->children, next) {
Paolo Bonzini2b148f32018-03-01 17:36:18 +01004333 bdrv_co_invalidate_cache(child->bs, &local_err);
Fam Zheng0d1c5c92016-05-11 10:45:33 +08004334 if (local_err) {
Fam Zheng0d1c5c92016-05-11 10:45:33 +08004335 error_propagate(errp, local_err);
4336 return;
4337 }
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01004338 }
Fam Zheng0d1c5c92016-05-11 10:45:33 +08004339
Kevin Wolfdafe0962017-11-16 13:00:01 +01004340 /*
4341 * Update permissions, they may differ for inactive nodes.
4342 *
4343 * Note that the required permissions of inactive images are always a
4344 * subset of the permissions required after activating the image. This
4345 * allows us to just get the permissions upfront without restricting
4346 * drv->bdrv_invalidate_cache().
4347 *
4348 * It also means that in error cases, we don't have to try and revert to
4349 * the old permissions (which is an operation that could fail, too). We can
4350 * just keep the extended permissions for the next time that an activation
4351 * of the image is tried.
4352 */
Vladimir Sementsov-Ogievskiy16e977d2017-01-31 14:23:08 +03004353 bs->open_flags &= ~BDRV_O_INACTIVE;
Kevin Wolfdafe0962017-11-16 13:00:01 +01004354 bdrv_get_cumulative_perm(bs, &perm, &shared_perm);
4355 ret = bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, &local_err);
4356 if (ret < 0) {
4357 bs->open_flags |= BDRV_O_INACTIVE;
4358 error_propagate(errp, local_err);
4359 return;
4360 }
4361 bdrv_set_perm(bs, perm, shared_perm);
4362
Paolo Bonzini2b148f32018-03-01 17:36:18 +01004363 if (bs->drv->bdrv_co_invalidate_cache) {
4364 bs->drv->bdrv_co_invalidate_cache(bs, &local_err);
Fam Zheng0d1c5c92016-05-11 10:45:33 +08004365 if (local_err) {
4366 bs->open_flags |= BDRV_O_INACTIVE;
4367 error_propagate(errp, local_err);
4368 return;
4369 }
Kevin Wolf3456a8d2014-03-11 10:58:39 +01004370 }
4371
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01004372 ret = refresh_total_sectors(bs, bs->total_sectors);
4373 if (ret < 0) {
Kevin Wolf04c01a52016-01-13 15:56:06 +01004374 bs->open_flags |= BDRV_O_INACTIVE;
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01004375 error_setg_errno(errp, -ret, "Could not refresh total sector count");
4376 return;
4377 }
Kevin Wolf4417ab72017-05-04 18:52:37 +02004378
4379 QLIST_FOREACH(parent, &bs->parents, next_parent) {
4380 if (parent->role->activate) {
4381 parent->role->activate(parent, &local_err);
4382 if (local_err) {
4383 error_propagate(errp, local_err);
4384 return;
4385 }
4386 }
4387 }
Anthony Liguori0f154232011-11-14 15:09:45 -06004388}
4389
Paolo Bonzini2b148f32018-03-01 17:36:18 +01004390typedef struct InvalidateCacheCo {
4391 BlockDriverState *bs;
4392 Error **errp;
4393 bool done;
4394} InvalidateCacheCo;
4395
4396static void coroutine_fn bdrv_invalidate_cache_co_entry(void *opaque)
4397{
4398 InvalidateCacheCo *ico = opaque;
4399 bdrv_co_invalidate_cache(ico->bs, ico->errp);
4400 ico->done = true;
4401}
4402
4403void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp)
4404{
4405 Coroutine *co;
4406 InvalidateCacheCo ico = {
4407 .bs = bs,
4408 .done = false,
4409 .errp = errp
4410 };
4411
4412 if (qemu_in_coroutine()) {
4413 /* Fast-path if already in coroutine context */
4414 bdrv_invalidate_cache_co_entry(&ico);
4415 } else {
4416 co = qemu_coroutine_create(bdrv_invalidate_cache_co_entry, &ico);
4417 qemu_coroutine_enter(co);
4418 BDRV_POLL_WHILE(bs, !ico.done);
4419 }
4420}
4421
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01004422void bdrv_invalidate_cache_all(Error **errp)
Anthony Liguori0f154232011-11-14 15:09:45 -06004423{
Kevin Wolf7c8eece2016-03-22 18:58:50 +01004424 BlockDriverState *bs;
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01004425 Error *local_err = NULL;
Kevin Wolf88be7b42016-05-20 18:49:07 +02004426 BdrvNextIterator it;
Anthony Liguori0f154232011-11-14 15:09:45 -06004427
Kevin Wolf88be7b42016-05-20 18:49:07 +02004428 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
Stefan Hajnoczied78cda2014-05-08 16:34:35 +02004429 AioContext *aio_context = bdrv_get_aio_context(bs);
4430
4431 aio_context_acquire(aio_context);
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01004432 bdrv_invalidate_cache(bs, &local_err);
Stefan Hajnoczied78cda2014-05-08 16:34:35 +02004433 aio_context_release(aio_context);
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01004434 if (local_err) {
4435 error_propagate(errp, local_err);
Max Reitz5e003f12017-11-10 18:25:45 +01004436 bdrv_next_cleanup(&it);
Kevin Wolf5a8a30d2014-03-12 15:59:16 +01004437 return;
4438 }
Anthony Liguori0f154232011-11-14 15:09:45 -06004439 }
4440}
4441
Fam Zhengaad0b7a2016-05-11 10:45:35 +08004442static int bdrv_inactivate_recurse(BlockDriverState *bs,
4443 bool setting_flag)
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01004444{
Kevin Wolfcfa1a572017-05-04 18:52:38 +02004445 BdrvChild *child, *parent;
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01004446 int ret;
4447
Max Reitzd470ad42017-11-10 21:31:09 +01004448 if (!bs->drv) {
4449 return -ENOMEDIUM;
4450 }
4451
Fam Zhengaad0b7a2016-05-11 10:45:35 +08004452 if (!setting_flag && bs->drv->bdrv_inactivate) {
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01004453 ret = bs->drv->bdrv_inactivate(bs);
4454 if (ret < 0) {
4455 return ret;
4456 }
4457 }
4458
Stefan Hajnoczi7d5b5262017-08-23 21:42:42 +08004459 if (setting_flag && !(bs->open_flags & BDRV_O_INACTIVE)) {
Kevin Wolf9c5e6592017-05-04 18:52:40 +02004460 uint64_t perm, shared_perm;
4461
Kevin Wolfcfa1a572017-05-04 18:52:38 +02004462 QLIST_FOREACH(parent, &bs->parents, next_parent) {
4463 if (parent->role->inactivate) {
4464 ret = parent->role->inactivate(parent);
4465 if (ret < 0) {
Kevin Wolfcfa1a572017-05-04 18:52:38 +02004466 return ret;
4467 }
4468 }
4469 }
Kevin Wolf9c5e6592017-05-04 18:52:40 +02004470
Stefan Hajnoczi7d5b5262017-08-23 21:42:42 +08004471 bs->open_flags |= BDRV_O_INACTIVE;
4472
Kevin Wolf9c5e6592017-05-04 18:52:40 +02004473 /* Update permissions, they may differ for inactive nodes */
4474 bdrv_get_cumulative_perm(bs, &perm, &shared_perm);
Kevin Wolf3121fb42017-09-14 14:42:12 +02004475 bdrv_check_perm(bs, NULL, perm, shared_perm, NULL, &error_abort);
Kevin Wolf9c5e6592017-05-04 18:52:40 +02004476 bdrv_set_perm(bs, perm, shared_perm);
Fam Zhengaad0b7a2016-05-11 10:45:35 +08004477 }
Kevin Wolf38701b62017-05-04 18:52:39 +02004478
4479 QLIST_FOREACH(child, &bs->children, next) {
4480 ret = bdrv_inactivate_recurse(child->bs, setting_flag);
4481 if (ret < 0) {
4482 return ret;
4483 }
4484 }
4485
Vladimir Sementsov-Ogievskiy615b5dc2017-06-28 15:05:30 +03004486 /* At this point persistent bitmaps should be already stored by the format
4487 * driver */
4488 bdrv_release_persistent_dirty_bitmaps(bs);
4489
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01004490 return 0;
4491}
4492
4493int bdrv_inactivate_all(void)
4494{
Max Reitz79720af2016-03-16 19:54:44 +01004495 BlockDriverState *bs = NULL;
Kevin Wolf88be7b42016-05-20 18:49:07 +02004496 BdrvNextIterator it;
Fam Zhengaad0b7a2016-05-11 10:45:35 +08004497 int ret = 0;
4498 int pass;
Paolo Bonzinibd6458e2017-12-07 20:13:15 +00004499 GSList *aio_ctxs = NULL, *ctx;
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01004500
Kevin Wolf88be7b42016-05-20 18:49:07 +02004501 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
Paolo Bonzinibd6458e2017-12-07 20:13:15 +00004502 AioContext *aio_context = bdrv_get_aio_context(bs);
4503
4504 if (!g_slist_find(aio_ctxs, aio_context)) {
4505 aio_ctxs = g_slist_prepend(aio_ctxs, aio_context);
4506 aio_context_acquire(aio_context);
4507 }
Fam Zhengaad0b7a2016-05-11 10:45:35 +08004508 }
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01004509
Fam Zhengaad0b7a2016-05-11 10:45:35 +08004510 /* We do two passes of inactivation. The first pass calls to drivers'
4511 * .bdrv_inactivate callbacks recursively so all cache is flushed to disk;
4512 * the second pass sets the BDRV_O_INACTIVE flag so that no further write
4513 * is allowed. */
4514 for (pass = 0; pass < 2; pass++) {
Kevin Wolf88be7b42016-05-20 18:49:07 +02004515 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
Fam Zhengaad0b7a2016-05-11 10:45:35 +08004516 ret = bdrv_inactivate_recurse(bs, pass);
4517 if (ret < 0) {
Max Reitz5e003f12017-11-10 18:25:45 +01004518 bdrv_next_cleanup(&it);
Fam Zhengaad0b7a2016-05-11 10:45:35 +08004519 goto out;
4520 }
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01004521 }
4522 }
4523
Fam Zhengaad0b7a2016-05-11 10:45:35 +08004524out:
Paolo Bonzinibd6458e2017-12-07 20:13:15 +00004525 for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) {
4526 AioContext *aio_context = ctx->data;
4527 aio_context_release(aio_context);
Fam Zhengaad0b7a2016-05-11 10:45:35 +08004528 }
Paolo Bonzinibd6458e2017-12-07 20:13:15 +00004529 g_slist_free(aio_ctxs);
Fam Zhengaad0b7a2016-05-11 10:45:35 +08004530
4531 return ret;
Kevin Wolf76b1c7f2015-12-22 14:07:08 +01004532}
4533
Kevin Wolff9f05dc2011-07-15 13:50:26 +02004534/**************************************************************/
bellard19cb3732006-08-19 11:45:59 +00004535/* removable device support */
4536
4537/**
4538 * Return TRUE if the media is present
4539 */
Max Reitze031f752015-10-19 17:53:11 +02004540bool bdrv_is_inserted(BlockDriverState *bs)
bellard19cb3732006-08-19 11:45:59 +00004541{
4542 BlockDriver *drv = bs->drv;
Max Reitz28d7a782015-10-19 17:53:13 +02004543 BdrvChild *child;
Markus Armbrustera1aff5b2011-09-06 18:58:41 +02004544
Max Reitze031f752015-10-19 17:53:11 +02004545 if (!drv) {
4546 return false;
4547 }
Max Reitz28d7a782015-10-19 17:53:13 +02004548 if (drv->bdrv_is_inserted) {
4549 return drv->bdrv_is_inserted(bs);
Max Reitze031f752015-10-19 17:53:11 +02004550 }
Max Reitz28d7a782015-10-19 17:53:13 +02004551 QLIST_FOREACH(child, &bs->children, next) {
4552 if (!bdrv_is_inserted(child->bs)) {
4553 return false;
4554 }
4555 }
4556 return true;
bellard19cb3732006-08-19 11:45:59 +00004557}
4558
4559/**
bellard19cb3732006-08-19 11:45:59 +00004560 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
4561 */
Luiz Capitulinof36f3942012-02-03 16:24:53 -02004562void bdrv_eject(BlockDriverState *bs, bool eject_flag)
bellard19cb3732006-08-19 11:45:59 +00004563{
4564 BlockDriver *drv = bs->drv;
bellard19cb3732006-08-19 11:45:59 +00004565
Markus Armbruster822e1cd2011-07-20 18:23:42 +02004566 if (drv && drv->bdrv_eject) {
4567 drv->bdrv_eject(bs, eject_flag);
bellard19cb3732006-08-19 11:45:59 +00004568 }
bellard19cb3732006-08-19 11:45:59 +00004569}
4570
bellard19cb3732006-08-19 11:45:59 +00004571/**
4572 * Lock or unlock the media (if it is locked, the user won't be able
4573 * to eject it manually).
4574 */
Markus Armbruster025e8492011-09-06 18:58:47 +02004575void bdrv_lock_medium(BlockDriverState *bs, bool locked)
bellard19cb3732006-08-19 11:45:59 +00004576{
4577 BlockDriver *drv = bs->drv;
4578
Markus Armbruster025e8492011-09-06 18:58:47 +02004579 trace_bdrv_lock_medium(bs, locked);
Stefan Hajnoczib8c6d092011-03-29 20:04:40 +01004580
Markus Armbruster025e8492011-09-06 18:58:47 +02004581 if (drv && drv->bdrv_lock_medium) {
4582 drv->bdrv_lock_medium(bs, locked);
bellard19cb3732006-08-19 11:45:59 +00004583 }
4584}
ths985a03b2007-12-24 16:10:43 +00004585
Fam Zheng9fcb0252013-08-23 09:14:46 +08004586/* Get a reference to bs */
4587void bdrv_ref(BlockDriverState *bs)
4588{
4589 bs->refcnt++;
4590}
4591
4592/* Release a previously grabbed reference to bs.
4593 * If after releasing, reference count is zero, the BlockDriverState is
4594 * deleted. */
4595void bdrv_unref(BlockDriverState *bs)
4596{
Jeff Cody9a4d5ca2014-07-23 17:22:57 -04004597 if (!bs) {
4598 return;
4599 }
Fam Zheng9fcb0252013-08-23 09:14:46 +08004600 assert(bs->refcnt > 0);
4601 if (--bs->refcnt == 0) {
4602 bdrv_delete(bs);
4603 }
4604}
4605
Fam Zhengfbe40ff2014-05-23 21:29:42 +08004606struct BdrvOpBlocker {
4607 Error *reason;
4608 QLIST_ENTRY(BdrvOpBlocker) list;
4609};
4610
4611bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp)
4612{
4613 BdrvOpBlocker *blocker;
4614 assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
4615 if (!QLIST_EMPTY(&bs->op_blockers[op])) {
4616 blocker = QLIST_FIRST(&bs->op_blockers[op]);
Eduardo Habkost57ef3f12017-06-08 10:39:03 -03004617 error_propagate(errp, error_copy(blocker->reason));
4618 error_prepend(errp, "Node '%s' is busy: ",
4619 bdrv_get_device_or_node_name(bs));
Fam Zhengfbe40ff2014-05-23 21:29:42 +08004620 return true;
4621 }
4622 return false;
4623}
4624
4625void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason)
4626{
4627 BdrvOpBlocker *blocker;
4628 assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
4629
Markus Armbruster5839e532014-08-19 10:31:08 +02004630 blocker = g_new0(BdrvOpBlocker, 1);
Fam Zhengfbe40ff2014-05-23 21:29:42 +08004631 blocker->reason = reason;
4632 QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list);
4633}
4634
4635void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason)
4636{
4637 BdrvOpBlocker *blocker, *next;
4638 assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX);
4639 QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) {
4640 if (blocker->reason == reason) {
4641 QLIST_REMOVE(blocker, list);
4642 g_free(blocker);
4643 }
4644 }
4645}
4646
4647void bdrv_op_block_all(BlockDriverState *bs, Error *reason)
4648{
4649 int i;
4650 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
4651 bdrv_op_block(bs, i, reason);
4652 }
4653}
4654
4655void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason)
4656{
4657 int i;
4658 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
4659 bdrv_op_unblock(bs, i, reason);
4660 }
4661}
4662
4663bool bdrv_op_blocker_is_empty(BlockDriverState *bs)
4664{
4665 int i;
4666
4667 for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) {
4668 if (!QLIST_EMPTY(&bs->op_blockers[i])) {
4669 return false;
4670 }
4671 }
4672 return true;
4673}
4674
Luiz Capitulinod92ada22012-11-30 10:52:09 -02004675void bdrv_img_create(const char *filename, const char *fmt,
4676 const char *base_filename, const char *base_fmt,
Fam Zheng92172832017-04-21 20:27:01 +08004677 char *options, uint64_t img_size, int flags, bool quiet,
4678 Error **errp)
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004679{
Chunyan Liu83d05212014-06-05 17:20:51 +08004680 QemuOptsList *create_opts = NULL;
4681 QemuOpts *opts = NULL;
4682 const char *backing_fmt, *backing_file;
4683 int64_t size;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004684 BlockDriver *drv, *proto_drv;
Max Reitzcc84d902013-09-06 17:14:26 +02004685 Error *local_err = NULL;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004686 int ret = 0;
4687
4688 /* Find driver and parse its options */
4689 drv = bdrv_find_format(fmt);
4690 if (!drv) {
Luiz Capitulino71c79812012-11-30 10:52:04 -02004691 error_setg(errp, "Unknown file format '%s'", fmt);
Luiz Capitulinod92ada22012-11-30 10:52:09 -02004692 return;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004693 }
4694
Max Reitzb65a5e12015-02-05 13:58:12 -05004695 proto_drv = bdrv_find_protocol(filename, true, errp);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004696 if (!proto_drv) {
Luiz Capitulinod92ada22012-11-30 10:52:09 -02004697 return;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004698 }
4699
Max Reitzc6149722014-12-02 18:32:45 +01004700 if (!drv->create_opts) {
4701 error_setg(errp, "Format driver '%s' does not support image creation",
4702 drv->format_name);
4703 return;
4704 }
4705
4706 if (!proto_drv->create_opts) {
4707 error_setg(errp, "Protocol driver '%s' does not support image creation",
4708 proto_drv->format_name);
4709 return;
4710 }
4711
Chunyan Liuc282e1f2014-06-05 17:21:11 +08004712 create_opts = qemu_opts_append(create_opts, drv->create_opts);
4713 create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004714
4715 /* Create parameter list with default values */
Chunyan Liu83d05212014-06-05 17:20:51 +08004716 opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
Markus Armbruster39101f22015-02-12 16:46:36 +01004717 qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004718
4719 /* Parse -o options */
4720 if (options) {
Markus Armbrusterdc523cd342015-02-12 18:37:11 +01004721 qemu_opts_do_parse(opts, options, NULL, &local_err);
4722 if (local_err) {
4723 error_report_err(local_err);
4724 local_err = NULL;
Chunyan Liu83d05212014-06-05 17:20:51 +08004725 error_setg(errp, "Invalid options for file format '%s'", fmt);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004726 goto out;
4727 }
4728 }
4729
4730 if (base_filename) {
Markus Armbrusterf43e47d2015-02-12 17:52:20 +01004731 qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, &local_err);
Markus Armbruster6be41942015-02-12 17:49:02 +01004732 if (local_err) {
Luiz Capitulino71c79812012-11-30 10:52:04 -02004733 error_setg(errp, "Backing file not supported for file format '%s'",
4734 fmt);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004735 goto out;
4736 }
4737 }
4738
4739 if (base_fmt) {
Markus Armbrusterf43e47d2015-02-12 17:52:20 +01004740 qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, &local_err);
Markus Armbruster6be41942015-02-12 17:49:02 +01004741 if (local_err) {
Luiz Capitulino71c79812012-11-30 10:52:04 -02004742 error_setg(errp, "Backing file format not supported for file "
4743 "format '%s'", fmt);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004744 goto out;
4745 }
4746 }
4747
Chunyan Liu83d05212014-06-05 17:20:51 +08004748 backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE);
4749 if (backing_file) {
4750 if (!strcmp(filename, backing_file)) {
Luiz Capitulino71c79812012-11-30 10:52:04 -02004751 error_setg(errp, "Error: Trying to create an image with the "
4752 "same filename as the backing file");
Jes Sorensen792da932010-12-16 13:52:17 +01004753 goto out;
4754 }
4755 }
4756
Chunyan Liu83d05212014-06-05 17:20:51 +08004757 backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004758
John Snow6e6e55f2017-07-17 20:34:22 -04004759 /* The size for the image must always be specified, unless we have a backing
4760 * file and we have not been forbidden from opening it. */
Eric Blakea8b42a12017-09-25 09:55:07 -05004761 size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, img_size);
John Snow6e6e55f2017-07-17 20:34:22 -04004762 if (backing_file && !(flags & BDRV_O_NO_BACKING)) {
4763 BlockDriverState *bs;
4764 char *full_backing = g_new0(char, PATH_MAX);
4765 int back_flags;
4766 QDict *backing_options = NULL;
Paolo Bonzini63090da2012-04-12 14:01:03 +02004767
John Snow6e6e55f2017-07-17 20:34:22 -04004768 bdrv_get_full_backing_filename_from_filename(filename, backing_file,
4769 full_backing, PATH_MAX,
4770 &local_err);
4771 if (local_err) {
Max Reitz29168012014-11-26 17:20:27 +01004772 g_free(full_backing);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004773 goto out;
4774 }
John Snow6e6e55f2017-07-17 20:34:22 -04004775
4776 /* backing files always opened read-only */
4777 back_flags = flags;
4778 back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
4779
Fam Zhengcc954f02017-12-15 16:04:45 +08004780 backing_options = qdict_new();
John Snow6e6e55f2017-07-17 20:34:22 -04004781 if (backing_fmt) {
John Snow6e6e55f2017-07-17 20:34:22 -04004782 qdict_put_str(backing_options, "driver", backing_fmt);
4783 }
Fam Zhengcc954f02017-12-15 16:04:45 +08004784 qdict_put_bool(backing_options, BDRV_OPT_FORCE_SHARE, true);
John Snow6e6e55f2017-07-17 20:34:22 -04004785
4786 bs = bdrv_open(full_backing, NULL, backing_options, back_flags,
4787 &local_err);
4788 g_free(full_backing);
4789 if (!bs && size != -1) {
4790 /* Couldn't open BS, but we have a size, so it's nonfatal */
4791 warn_reportf_err(local_err,
4792 "Could not verify backing image. "
4793 "This may become an error in future versions.\n");
4794 local_err = NULL;
4795 } else if (!bs) {
4796 /* Couldn't open bs, do not have size */
4797 error_append_hint(&local_err,
4798 "Could not open backing image to determine size.\n");
4799 goto out;
4800 } else {
4801 if (size == -1) {
4802 /* Opened BS, have no size */
4803 size = bdrv_getlength(bs);
4804 if (size < 0) {
4805 error_setg_errno(errp, -size, "Could not get size of '%s'",
4806 backing_file);
4807 bdrv_unref(bs);
4808 goto out;
4809 }
4810 qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort);
4811 }
4812 bdrv_unref(bs);
4813 }
4814 } /* (backing_file && !(flags & BDRV_O_NO_BACKING)) */
4815
4816 if (size == -1) {
4817 error_setg(errp, "Image creation needs a size parameter");
4818 goto out;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004819 }
4820
Miroslav Rezaninaf382d432013-02-13 09:09:40 +01004821 if (!quiet) {
Kővágó, Zoltánfe646692015-07-07 16:42:10 +02004822 printf("Formatting '%s', fmt=%s ", filename, fmt);
Fam Zheng43c5d8f2014-12-09 15:38:04 +08004823 qemu_opts_print(opts, " ");
Miroslav Rezaninaf382d432013-02-13 09:09:40 +01004824 puts("");
4825 }
Chunyan Liu83d05212014-06-05 17:20:51 +08004826
Chunyan Liuc282e1f2014-06-05 17:21:11 +08004827 ret = bdrv_create(drv, filename, opts, &local_err);
Chunyan Liu83d05212014-06-05 17:20:51 +08004828
Max Reitzcc84d902013-09-06 17:14:26 +02004829 if (ret == -EFBIG) {
4830 /* This is generally a better message than whatever the driver would
4831 * deliver (especially because of the cluster_size_hint), since that
4832 * is most probably not much different from "image too large". */
4833 const char *cluster_size_hint = "";
Chunyan Liu83d05212014-06-05 17:20:51 +08004834 if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) {
Max Reitzcc84d902013-09-06 17:14:26 +02004835 cluster_size_hint = " (try using a larger cluster size)";
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004836 }
Max Reitzcc84d902013-09-06 17:14:26 +02004837 error_setg(errp, "The image size is too large for file format '%s'"
4838 "%s", fmt, cluster_size_hint);
4839 error_free(local_err);
4840 local_err = NULL;
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004841 }
4842
4843out:
Chunyan Liu83d05212014-06-05 17:20:51 +08004844 qemu_opts_del(opts);
4845 qemu_opts_free(create_opts);
Eduardo Habkost621ff942016-06-13 18:57:56 -03004846 error_propagate(errp, local_err);
Jes Sorensenf88e1a42010-12-16 13:52:15 +01004847}
Stefan Hajnoczi85d126f2013-03-07 13:41:48 +01004848
4849AioContext *bdrv_get_aio_context(BlockDriverState *bs)
4850{
Stefan Hajnoczi33f2a752018-02-16 16:50:13 +00004851 return bs ? bs->aio_context : qemu_get_aio_context();
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004852}
4853
Stefan Hajnoczi7719f3c2018-02-16 16:50:12 +00004854AioWait *bdrv_get_aio_wait(BlockDriverState *bs)
4855{
4856 return bs ? &bs->wait : NULL;
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004857}
4858
Fam Zheng052a7572017-04-10 20:09:25 +08004859void bdrv_coroutine_enter(BlockDriverState *bs, Coroutine *co)
4860{
4861 aio_co_enter(bdrv_get_aio_context(bs), co);
4862}
4863
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01004864static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban)
4865{
4866 QLIST_REMOVE(ban, list);
4867 g_free(ban);
4868}
4869
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004870void bdrv_detach_aio_context(BlockDriverState *bs)
4871{
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01004872 BdrvAioNotifier *baf, *baf_tmp;
Max Reitzb97511c2016-05-17 13:38:04 +02004873 BdrvChild *child;
Max Reitz33384422014-06-20 21:57:33 +02004874
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004875 if (!bs->drv) {
4876 return;
4877 }
4878
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01004879 assert(!bs->walking_aio_notifiers);
4880 bs->walking_aio_notifiers = true;
4881 QLIST_FOREACH_SAFE(baf, &bs->aio_notifiers, list, baf_tmp) {
4882 if (baf->deleted) {
4883 bdrv_do_remove_aio_context_notifier(baf);
4884 } else {
4885 baf->detach_aio_context(baf->opaque);
4886 }
Max Reitz33384422014-06-20 21:57:33 +02004887 }
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01004888 /* Never mind iterating again to check for ->deleted. bdrv_close() will
4889 * remove remaining aio notifiers if we aren't called again.
4890 */
4891 bs->walking_aio_notifiers = false;
Max Reitz33384422014-06-20 21:57:33 +02004892
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004893 if (bs->drv->bdrv_detach_aio_context) {
4894 bs->drv->bdrv_detach_aio_context(bs);
4895 }
Max Reitzb97511c2016-05-17 13:38:04 +02004896 QLIST_FOREACH(child, &bs->children, next) {
4897 bdrv_detach_aio_context(child->bs);
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004898 }
4899
4900 bs->aio_context = NULL;
4901}
4902
4903void bdrv_attach_aio_context(BlockDriverState *bs,
4904 AioContext *new_context)
4905{
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01004906 BdrvAioNotifier *ban, *ban_tmp;
Max Reitzb97511c2016-05-17 13:38:04 +02004907 BdrvChild *child;
Max Reitz33384422014-06-20 21:57:33 +02004908
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004909 if (!bs->drv) {
4910 return;
4911 }
4912
4913 bs->aio_context = new_context;
4914
Max Reitzb97511c2016-05-17 13:38:04 +02004915 QLIST_FOREACH(child, &bs->children, next) {
4916 bdrv_attach_aio_context(child->bs, new_context);
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004917 }
4918 if (bs->drv->bdrv_attach_aio_context) {
4919 bs->drv->bdrv_attach_aio_context(bs, new_context);
4920 }
Max Reitz33384422014-06-20 21:57:33 +02004921
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01004922 assert(!bs->walking_aio_notifiers);
4923 bs->walking_aio_notifiers = true;
4924 QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_tmp) {
4925 if (ban->deleted) {
4926 bdrv_do_remove_aio_context_notifier(ban);
4927 } else {
4928 ban->attached_aio_context(new_context, ban->opaque);
4929 }
Max Reitz33384422014-06-20 21:57:33 +02004930 }
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01004931 bs->walking_aio_notifiers = false;
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004932}
4933
4934void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context)
4935{
Fam Zhengaabf5912017-04-05 14:44:24 +08004936 AioContext *ctx = bdrv_get_aio_context(bs);
Paolo Bonzinic2b64282017-03-14 12:11:57 +01004937
Fam Zhengaabf5912017-04-05 14:44:24 +08004938 aio_disable_external(ctx);
Kevin Wolf0152bf42017-12-07 13:03:13 +01004939 bdrv_parent_drained_begin(bs, NULL);
Fam Zheng53ec73e2015-05-29 18:53:14 +08004940 bdrv_drain(bs); /* ensure there are no in-flight requests */
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004941
Paolo Bonzinic2b64282017-03-14 12:11:57 +01004942 while (aio_poll(ctx, false)) {
4943 /* wait for all bottom halves to execute */
4944 }
4945
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004946 bdrv_detach_aio_context(bs);
4947
4948 /* This function executes in the old AioContext so acquire the new one in
4949 * case it runs in a different thread.
4950 */
4951 aio_context_acquire(new_context);
4952 bdrv_attach_aio_context(bs, new_context);
Kevin Wolf0152bf42017-12-07 13:03:13 +01004953 bdrv_parent_drained_end(bs, NULL);
Fam Zhengaabf5912017-04-05 14:44:24 +08004954 aio_enable_external(ctx);
Stefan Hajnoczidcd04222014-05-08 16:34:37 +02004955 aio_context_release(new_context);
Stefan Hajnoczi85d126f2013-03-07 13:41:48 +01004956}
Stefan Hajnoczid616b222013-06-24 17:13:10 +02004957
Max Reitz33384422014-06-20 21:57:33 +02004958void bdrv_add_aio_context_notifier(BlockDriverState *bs,
4959 void (*attached_aio_context)(AioContext *new_context, void *opaque),
4960 void (*detach_aio_context)(void *opaque), void *opaque)
4961{
4962 BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1);
4963 *ban = (BdrvAioNotifier){
4964 .attached_aio_context = attached_aio_context,
4965 .detach_aio_context = detach_aio_context,
4966 .opaque = opaque
4967 };
4968
4969 QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list);
4970}
4971
4972void bdrv_remove_aio_context_notifier(BlockDriverState *bs,
4973 void (*attached_aio_context)(AioContext *,
4974 void *),
4975 void (*detach_aio_context)(void *),
4976 void *opaque)
4977{
4978 BdrvAioNotifier *ban, *ban_next;
4979
4980 QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) {
4981 if (ban->attached_aio_context == attached_aio_context &&
4982 ban->detach_aio_context == detach_aio_context &&
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01004983 ban->opaque == opaque &&
4984 ban->deleted == false)
Max Reitz33384422014-06-20 21:57:33 +02004985 {
Stefan Hajnoczie8a095d2016-06-16 17:56:26 +01004986 if (bs->walking_aio_notifiers) {
4987 ban->deleted = true;
4988 } else {
4989 bdrv_do_remove_aio_context_notifier(ban);
4990 }
Max Reitz33384422014-06-20 21:57:33 +02004991 return;
4992 }
4993 }
4994
4995 abort();
4996}
4997
Max Reitz77485432014-10-27 11:12:50 +01004998int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts,
Max Reitzd1402b52018-05-09 23:00:18 +02004999 BlockDriverAmendStatusCB *status_cb, void *cb_opaque,
5000 Error **errp)
Max Reitz6f176b42013-09-03 10:09:50 +02005001{
Max Reitzd470ad42017-11-10 21:31:09 +01005002 if (!bs->drv) {
Max Reitzd1402b52018-05-09 23:00:18 +02005003 error_setg(errp, "Node is ejected");
Max Reitzd470ad42017-11-10 21:31:09 +01005004 return -ENOMEDIUM;
5005 }
Chunyan Liuc282e1f2014-06-05 17:21:11 +08005006 if (!bs->drv->bdrv_amend_options) {
Max Reitzd1402b52018-05-09 23:00:18 +02005007 error_setg(errp, "Block driver '%s' does not support option amendment",
5008 bs->drv->format_name);
Max Reitz6f176b42013-09-03 10:09:50 +02005009 return -ENOTSUP;
5010 }
Max Reitzd1402b52018-05-09 23:00:18 +02005011 return bs->drv->bdrv_amend_options(bs, opts, status_cb, cb_opaque, errp);
Max Reitz6f176b42013-09-03 10:09:50 +02005012}
Benoît Canetf6186f42013-10-02 14:33:48 +02005013
Benoît Canetb5042a32014-03-03 19:11:34 +01005014/* This function will be called by the bdrv_recurse_is_first_non_filter method
5015 * of block filter and by bdrv_is_first_non_filter.
5016 * It is used to test if the given bs is the candidate or recurse more in the
5017 * node graph.
Benoît Canet212a5a82014-01-23 21:31:36 +01005018 */
Benoît Canet212a5a82014-01-23 21:31:36 +01005019bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
5020 BlockDriverState *candidate)
Benoît Canetf6186f42013-10-02 14:33:48 +02005021{
Benoît Canetb5042a32014-03-03 19:11:34 +01005022 /* return false if basic checks fails */
5023 if (!bs || !bs->drv) {
5024 return false;
5025 }
5026
5027 /* the code reached a non block filter driver -> check if the bs is
5028 * the same as the candidate. It's the recursion termination condition.
5029 */
5030 if (!bs->drv->is_filter) {
5031 return bs == candidate;
5032 }
5033 /* Down this path the driver is a block filter driver */
5034
5035 /* If the block filter recursion method is defined use it to recurse down
5036 * the node graph.
5037 */
5038 if (bs->drv->bdrv_recurse_is_first_non_filter) {
Benoît Canet212a5a82014-01-23 21:31:36 +01005039 return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate);
5040 }
5041
Benoît Canetb5042a32014-03-03 19:11:34 +01005042 /* the driver is a block filter but don't allow to recurse -> return false
5043 */
5044 return false;
Benoît Canet212a5a82014-01-23 21:31:36 +01005045}
5046
5047/* This function checks if the candidate is the first non filter bs down it's
5048 * bs chain. Since we don't have pointers to parents it explore all bs chains
5049 * from the top. Some filters can choose not to pass down the recursion.
5050 */
5051bool bdrv_is_first_non_filter(BlockDriverState *candidate)
5052{
Kevin Wolf7c8eece2016-03-22 18:58:50 +01005053 BlockDriverState *bs;
Kevin Wolf88be7b42016-05-20 18:49:07 +02005054 BdrvNextIterator it;
Benoît Canet212a5a82014-01-23 21:31:36 +01005055
5056 /* walk down the bs forest recursively */
Kevin Wolf88be7b42016-05-20 18:49:07 +02005057 for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
Benoît Canet212a5a82014-01-23 21:31:36 +01005058 bool perm;
5059
Benoît Canetb5042a32014-03-03 19:11:34 +01005060 /* try to recurse in this top level bs */
Kevin Wolfe6dc8a12014-02-04 11:45:31 +01005061 perm = bdrv_recurse_is_first_non_filter(bs, candidate);
Benoît Canet212a5a82014-01-23 21:31:36 +01005062
5063 /* candidate is the first non filter */
5064 if (perm) {
Max Reitz5e003f12017-11-10 18:25:45 +01005065 bdrv_next_cleanup(&it);
Benoît Canet212a5a82014-01-23 21:31:36 +01005066 return true;
5067 }
5068 }
5069
5070 return false;
Benoît Canetf6186f42013-10-02 14:33:48 +02005071}
Benoît Canet09158f02014-06-27 18:25:25 +02005072
Wen Congyange12f3782015-07-17 10:12:22 +08005073BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
5074 const char *node_name, Error **errp)
Benoît Canet09158f02014-06-27 18:25:25 +02005075{
5076 BlockDriverState *to_replace_bs = bdrv_find_node(node_name);
Stefan Hajnoczi5a7e7a02014-10-21 12:03:58 +01005077 AioContext *aio_context;
5078
Benoît Canet09158f02014-06-27 18:25:25 +02005079 if (!to_replace_bs) {
5080 error_setg(errp, "Node name '%s' not found", node_name);
5081 return NULL;
5082 }
5083
Stefan Hajnoczi5a7e7a02014-10-21 12:03:58 +01005084 aio_context = bdrv_get_aio_context(to_replace_bs);
5085 aio_context_acquire(aio_context);
5086
Benoît Canet09158f02014-06-27 18:25:25 +02005087 if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) {
Stefan Hajnoczi5a7e7a02014-10-21 12:03:58 +01005088 to_replace_bs = NULL;
5089 goto out;
Benoît Canet09158f02014-06-27 18:25:25 +02005090 }
5091
5092 /* We don't want arbitrary node of the BDS chain to be replaced only the top
5093 * most non filter in order to prevent data corruption.
5094 * Another benefit is that this tests exclude backing files which are
5095 * blocked by the backing blockers.
5096 */
Wen Congyange12f3782015-07-17 10:12:22 +08005097 if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) {
Benoît Canet09158f02014-06-27 18:25:25 +02005098 error_setg(errp, "Only top most non filter can be replaced");
Stefan Hajnoczi5a7e7a02014-10-21 12:03:58 +01005099 to_replace_bs = NULL;
5100 goto out;
Benoît Canet09158f02014-06-27 18:25:25 +02005101 }
5102
Stefan Hajnoczi5a7e7a02014-10-21 12:03:58 +01005103out:
5104 aio_context_release(aio_context);
Benoît Canet09158f02014-06-27 18:25:25 +02005105 return to_replace_bs;
5106}
Ming Lei448ad912014-07-04 18:04:33 +08005107
Max Reitz91af7012014-07-18 20:24:56 +02005108static bool append_open_options(QDict *d, BlockDriverState *bs)
5109{
5110 const QDictEntry *entry;
Kevin Wolf9e700c12015-04-24 15:20:28 +02005111 QemuOptDesc *desc;
Kevin Wolf260fecf2015-04-27 13:46:22 +02005112 BdrvChild *child;
Max Reitz91af7012014-07-18 20:24:56 +02005113 bool found_any = false;
Kevin Wolf260fecf2015-04-27 13:46:22 +02005114 const char *p;
Max Reitz91af7012014-07-18 20:24:56 +02005115
5116 for (entry = qdict_first(bs->options); entry;
5117 entry = qdict_next(bs->options, entry))
5118 {
Kevin Wolf260fecf2015-04-27 13:46:22 +02005119 /* Exclude options for children */
5120 QLIST_FOREACH(child, &bs->children, next) {
5121 if (strstart(qdict_entry_key(entry), child->name, &p)
5122 && (!*p || *p == '.'))
5123 {
5124 break;
5125 }
5126 }
5127 if (child) {
Kevin Wolf9e700c12015-04-24 15:20:28 +02005128 continue;
Max Reitz91af7012014-07-18 20:24:56 +02005129 }
Kevin Wolf9e700c12015-04-24 15:20:28 +02005130
5131 /* And exclude all non-driver-specific options */
5132 for (desc = bdrv_runtime_opts.desc; desc->name; desc++) {
5133 if (!strcmp(qdict_entry_key(entry), desc->name)) {
5134 break;
5135 }
5136 }
5137 if (desc->name) {
5138 continue;
5139 }
5140
Marc-André Lureauf5a74a52018-04-19 17:01:44 +02005141 qdict_put_obj(d, qdict_entry_key(entry),
5142 qobject_ref(qdict_entry_value(entry)));
Kevin Wolf9e700c12015-04-24 15:20:28 +02005143 found_any = true;
Max Reitz91af7012014-07-18 20:24:56 +02005144 }
5145
5146 return found_any;
5147}
5148
5149/* Updates the following BDS fields:
5150 * - exact_filename: A filename which may be used for opening a block device
5151 * which (mostly) equals the given BDS (even without any
5152 * other options; so reading and writing must return the same
5153 * results, but caching etc. may be different)
5154 * - full_open_options: Options which, when given when opening a block device
5155 * (without a filename), result in a BDS (mostly)
5156 * equalling the given one
5157 * - filename: If exact_filename is set, it is copied here. Otherwise,
5158 * full_open_options is converted to a JSON object, prefixed with
5159 * "json:" (for use through the JSON pseudo protocol) and put here.
5160 */
5161void bdrv_refresh_filename(BlockDriverState *bs)
5162{
5163 BlockDriver *drv = bs->drv;
5164 QDict *opts;
5165
5166 if (!drv) {
5167 return;
5168 }
5169
5170 /* This BDS's file name will most probably depend on its file's name, so
5171 * refresh that first */
5172 if (bs->file) {
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02005173 bdrv_refresh_filename(bs->file->bs);
Max Reitz91af7012014-07-18 20:24:56 +02005174 }
5175
5176 if (drv->bdrv_refresh_filename) {
5177 /* Obsolete information is of no use here, so drop the old file name
5178 * information before refreshing it */
5179 bs->exact_filename[0] = '\0';
5180 if (bs->full_open_options) {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02005181 qobject_unref(bs->full_open_options);
Max Reitz91af7012014-07-18 20:24:56 +02005182 bs->full_open_options = NULL;
5183 }
5184
Kevin Wolf4cdd01d2015-04-27 13:50:54 +02005185 opts = qdict_new();
5186 append_open_options(opts, bs);
5187 drv->bdrv_refresh_filename(bs, opts);
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02005188 qobject_unref(opts);
Max Reitz91af7012014-07-18 20:24:56 +02005189 } else if (bs->file) {
5190 /* Try to reconstruct valid information from the underlying file */
5191 bool has_open_options;
5192
5193 bs->exact_filename[0] = '\0';
5194 if (bs->full_open_options) {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02005195 qobject_unref(bs->full_open_options);
Max Reitz91af7012014-07-18 20:24:56 +02005196 bs->full_open_options = NULL;
5197 }
5198
5199 opts = qdict_new();
5200 has_open_options = append_open_options(opts, bs);
5201
5202 /* If no specific options have been given for this BDS, the filename of
5203 * the underlying file should suffice for this one as well */
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02005204 if (bs->file->bs->exact_filename[0] && !has_open_options) {
5205 strcpy(bs->exact_filename, bs->file->bs->exact_filename);
Max Reitz91af7012014-07-18 20:24:56 +02005206 }
5207 /* Reconstructing the full options QDict is simple for most format block
5208 * drivers, as long as the full options are known for the underlying
5209 * file BDS. The full options QDict of that file BDS should somehow
5210 * contain a representation of the filename, therefore the following
5211 * suffices without querying the (exact_)filename of this BDS. */
Kevin Wolf9a4f4c32015-06-16 14:19:22 +02005212 if (bs->file->bs->full_open_options) {
Eric Blake46f5ac22017-04-27 16:58:17 -05005213 qdict_put_str(opts, "driver", drv->format_name);
Marc-André Lureauf5a74a52018-04-19 17:01:44 +02005214 qdict_put(opts, "file",
5215 qobject_ref(bs->file->bs->full_open_options));
Max Reitz91af7012014-07-18 20:24:56 +02005216
5217 bs->full_open_options = opts;
5218 } else {
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02005219 qobject_unref(opts);
Max Reitz91af7012014-07-18 20:24:56 +02005220 }
5221 } else if (!bs->full_open_options && qdict_size(bs->options)) {
5222 /* There is no underlying file BDS (at least referenced by BDS.file),
5223 * so the full options QDict should be equal to the options given
5224 * specifically for this block device when it was opened (plus the
5225 * driver specification).
5226 * Because those options don't change, there is no need to update
5227 * full_open_options when it's already set. */
5228
5229 opts = qdict_new();
5230 append_open_options(opts, bs);
Eric Blake46f5ac22017-04-27 16:58:17 -05005231 qdict_put_str(opts, "driver", drv->format_name);
Max Reitz91af7012014-07-18 20:24:56 +02005232
5233 if (bs->exact_filename[0]) {
5234 /* This may not work for all block protocol drivers (some may
5235 * require this filename to be parsed), but we have to find some
5236 * default solution here, so just include it. If some block driver
5237 * does not support pure options without any filename at all or
5238 * needs some special format of the options QDict, it needs to
5239 * implement the driver-specific bdrv_refresh_filename() function.
5240 */
Eric Blake46f5ac22017-04-27 16:58:17 -05005241 qdict_put_str(opts, "filename", bs->exact_filename);
Max Reitz91af7012014-07-18 20:24:56 +02005242 }
5243
5244 bs->full_open_options = opts;
5245 }
5246
5247 if (bs->exact_filename[0]) {
5248 pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename);
5249 } else if (bs->full_open_options) {
5250 QString *json = qobject_to_json(QOBJECT(bs->full_open_options));
5251 snprintf(bs->filename, sizeof(bs->filename), "json:%s",
5252 qstring_get_str(json));
Marc-André Lureaucb3e7f02018-04-19 17:01:43 +02005253 qobject_unref(json);
Max Reitz91af7012014-07-18 20:24:56 +02005254 }
5255}
Wen Congyange06018a2016-05-10 15:36:37 +08005256
5257/*
5258 * Hot add/remove a BDS's child. So the user can take a child offline when
5259 * it is broken and take a new child online
5260 */
5261void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs,
5262 Error **errp)
5263{
5264
5265 if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) {
5266 error_setg(errp, "The node %s does not support adding a child",
5267 bdrv_get_device_or_node_name(parent_bs));
5268 return;
5269 }
5270
5271 if (!QLIST_EMPTY(&child_bs->parents)) {
5272 error_setg(errp, "The node %s already has a parent",
5273 child_bs->node_name);
5274 return;
5275 }
5276
5277 parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp);
5278}
5279
5280void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp)
5281{
5282 BdrvChild *tmp;
5283
5284 if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) {
5285 error_setg(errp, "The node %s does not support removing a child",
5286 bdrv_get_device_or_node_name(parent_bs));
5287 return;
5288 }
5289
5290 QLIST_FOREACH(tmp, &parent_bs->children, next) {
5291 if (tmp == child) {
5292 break;
5293 }
5294 }
5295
5296 if (!tmp) {
5297 error_setg(errp, "The node %s does not have a child named %s",
5298 bdrv_get_device_or_node_name(parent_bs),
5299 bdrv_get_device_or_node_name(child->bs));
5300 return;
5301 }
5302
5303 parent_bs->drv->bdrv_del_child(parent_bs, child, errp);
5304}
Vladimir Sementsov-Ogievskiy67b792f2017-06-28 15:05:21 +03005305
5306bool bdrv_can_store_new_dirty_bitmap(BlockDriverState *bs, const char *name,
5307 uint32_t granularity, Error **errp)
5308{
5309 BlockDriver *drv = bs->drv;
5310
5311 if (!drv) {
5312 error_setg_errno(errp, ENOMEDIUM,
5313 "Can't store persistent bitmaps to %s",
5314 bdrv_get_device_or_node_name(bs));
5315 return false;
5316 }
5317
5318 if (!drv->bdrv_can_store_new_dirty_bitmap) {
5319 error_setg_errno(errp, ENOTSUP,
5320 "Can't store persistent bitmaps to %s",
5321 bdrv_get_device_or_node_name(bs));
5322 return false;
5323 }
5324
5325 return drv->bdrv_can_store_new_dirty_bitmap(bs, name, granularity, errp);
5326}