| /* |
| * QEMU System Emulator block driver |
| * |
| * Copyright (c) 2003 Fabrice Bellard |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| #include "qemu/osdep.h" |
| #include "block/trace.h" |
| #include "block/block_int.h" |
| #include "block/blockjob.h" |
| #include "block/nbd.h" |
| #include "qemu/error-report.h" |
| #include "module_block.h" |
| #include "qemu/module.h" |
| #include "qapi/qmp/qerror.h" |
| #include "qapi/qmp/qbool.h" |
| #include "qapi/qmp/qjson.h" |
| #include "sysemu/block-backend.h" |
| #include "sysemu/sysemu.h" |
| #include "qemu/notify.h" |
| #include "qemu/coroutine.h" |
| #include "block/qapi.h" |
| #include "qmp-commands.h" |
| #include "qemu/timer.h" |
| #include "qapi-event.h" |
| #include "qemu/cutils.h" |
| #include "qemu/id.h" |
| #include "qapi/util.h" |
| |
| #ifdef CONFIG_BSD |
| #include <sys/ioctl.h> |
| #include <sys/queue.h> |
| #ifndef __DragonFly__ |
| #include <sys/disk.h> |
| #endif |
| #endif |
| |
| #ifdef _WIN32 |
| #include <windows.h> |
| #endif |
| |
| #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ |
| |
| static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states = |
| QTAILQ_HEAD_INITIALIZER(graph_bdrv_states); |
| |
| static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states = |
| QTAILQ_HEAD_INITIALIZER(all_bdrv_states); |
| |
| static QLIST_HEAD(, BlockDriver) bdrv_drivers = |
| QLIST_HEAD_INITIALIZER(bdrv_drivers); |
| |
| static BlockDriverState *bdrv_open_inherit(const char *filename, |
| const char *reference, |
| QDict *options, int flags, |
| BlockDriverState *parent, |
| const BdrvChildRole *child_role, |
| Error **errp); |
| |
| /* If non-zero, use only whitelisted block drivers */ |
| static int use_bdrv_whitelist; |
| |
| #ifdef _WIN32 |
| static int is_windows_drive_prefix(const char *filename) |
| { |
| return (((filename[0] >= 'a' && filename[0] <= 'z') || |
| (filename[0] >= 'A' && filename[0] <= 'Z')) && |
| filename[1] == ':'); |
| } |
| |
| int is_windows_drive(const char *filename) |
| { |
| if (is_windows_drive_prefix(filename) && |
| filename[2] == '\0') |
| return 1; |
| if (strstart(filename, "\\\\.\\", NULL) || |
| strstart(filename, "//./", NULL)) |
| return 1; |
| return 0; |
| } |
| #endif |
| |
| size_t bdrv_opt_mem_align(BlockDriverState *bs) |
| { |
| if (!bs || !bs->drv) { |
| /* page size or 4k (hdd sector size) should be on the safe side */ |
| return MAX(4096, getpagesize()); |
| } |
| |
| return bs->bl.opt_mem_alignment; |
| } |
| |
| size_t bdrv_min_mem_align(BlockDriverState *bs) |
| { |
| if (!bs || !bs->drv) { |
| /* page size or 4k (hdd sector size) should be on the safe side */ |
| return MAX(4096, getpagesize()); |
| } |
| |
| return bs->bl.min_mem_alignment; |
| } |
| |
| /* check if the path starts with "<protocol>:" */ |
| int path_has_protocol(const char *path) |
| { |
| const char *p; |
| |
| #ifdef _WIN32 |
| if (is_windows_drive(path) || |
| is_windows_drive_prefix(path)) { |
| return 0; |
| } |
| p = path + strcspn(path, ":/\\"); |
| #else |
| p = path + strcspn(path, ":/"); |
| #endif |
| |
| return *p == ':'; |
| } |
| |
| int path_is_absolute(const char *path) |
| { |
| #ifdef _WIN32 |
| /* specific case for names like: "\\.\d:" */ |
| if (is_windows_drive(path) || is_windows_drive_prefix(path)) { |
| return 1; |
| } |
| return (*path == '/' || *path == '\\'); |
| #else |
| return (*path == '/'); |
| #endif |
| } |
| |
| /* if filename is absolute, just copy it to dest. Otherwise, build a |
| path to it by considering it is relative to base_path. URL are |
| supported. */ |
| void path_combine(char *dest, int dest_size, |
| const char *base_path, |
| const char *filename) |
| { |
| const char *p, *p1; |
| int len; |
| |
| if (dest_size <= 0) |
| return; |
| if (path_is_absolute(filename)) { |
| pstrcpy(dest, dest_size, filename); |
| } else { |
| p = strchr(base_path, ':'); |
| if (p) |
| p++; |
| else |
| p = base_path; |
| p1 = strrchr(base_path, '/'); |
| #ifdef _WIN32 |
| { |
| const char *p2; |
| p2 = strrchr(base_path, '\\'); |
| if (!p1 || p2 > p1) |
| p1 = p2; |
| } |
| #endif |
| if (p1) |
| p1++; |
| else |
| p1 = base_path; |
| if (p1 > p) |
| p = p1; |
| len = p - base_path; |
| if (len > dest_size - 1) |
| len = dest_size - 1; |
| memcpy(dest, base_path, len); |
| dest[len] = '\0'; |
| pstrcat(dest, dest_size, filename); |
| } |
| } |
| |
| void bdrv_get_full_backing_filename_from_filename(const char *backed, |
| const char *backing, |
| char *dest, size_t sz, |
| Error **errp) |
| { |
| if (backing[0] == '\0' || path_has_protocol(backing) || |
| path_is_absolute(backing)) |
| { |
| pstrcpy(dest, sz, backing); |
| } else if (backed[0] == '\0' || strstart(backed, "json:", NULL)) { |
| error_setg(errp, "Cannot use relative backing file names for '%s'", |
| backed); |
| } else { |
| path_combine(dest, sz, backed, backing); |
| } |
| } |
| |
| void bdrv_get_full_backing_filename(BlockDriverState *bs, char *dest, size_t sz, |
| Error **errp) |
| { |
| char *backed = bs->exact_filename[0] ? bs->exact_filename : bs->filename; |
| |
| bdrv_get_full_backing_filename_from_filename(backed, bs->backing_file, |
| dest, sz, errp); |
| } |
| |
| void bdrv_register(BlockDriver *bdrv) |
| { |
| QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); |
| } |
| |
| BlockDriverState *bdrv_new(void) |
| { |
| BlockDriverState *bs; |
| int i; |
| |
| bs = g_new0(BlockDriverState, 1); |
| QLIST_INIT(&bs->dirty_bitmaps); |
| for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { |
| QLIST_INIT(&bs->op_blockers[i]); |
| } |
| notifier_with_return_list_init(&bs->before_write_notifiers); |
| bs->refcnt = 1; |
| bs->aio_context = qemu_get_aio_context(); |
| |
| qemu_co_queue_init(&bs->flush_queue); |
| |
| QTAILQ_INSERT_TAIL(&all_bdrv_states, bs, bs_list); |
| |
| return bs; |
| } |
| |
| static BlockDriver *bdrv_do_find_format(const char *format_name) |
| { |
| BlockDriver *drv1; |
| |
| QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
| if (!strcmp(drv1->format_name, format_name)) { |
| return drv1; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| BlockDriver *bdrv_find_format(const char *format_name) |
| { |
| BlockDriver *drv1; |
| int i; |
| |
| drv1 = bdrv_do_find_format(format_name); |
| if (drv1) { |
| return drv1; |
| } |
| |
| /* The driver isn't registered, maybe we need to load a module */ |
| for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) { |
| if (!strcmp(block_driver_modules[i].format_name, format_name)) { |
| block_module_load_one(block_driver_modules[i].library_name); |
| break; |
| } |
| } |
| |
| return bdrv_do_find_format(format_name); |
| } |
| |
| static int bdrv_is_whitelisted(BlockDriver *drv, bool read_only) |
| { |
| static const char *whitelist_rw[] = { |
| CONFIG_BDRV_RW_WHITELIST |
| }; |
| static const char *whitelist_ro[] = { |
| CONFIG_BDRV_RO_WHITELIST |
| }; |
| const char **p; |
| |
| if (!whitelist_rw[0] && !whitelist_ro[0]) { |
| return 1; /* no whitelist, anything goes */ |
| } |
| |
| for (p = whitelist_rw; *p; p++) { |
| if (!strcmp(drv->format_name, *p)) { |
| return 1; |
| } |
| } |
| if (read_only) { |
| for (p = whitelist_ro; *p; p++) { |
| if (!strcmp(drv->format_name, *p)) { |
| return 1; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| bool bdrv_uses_whitelist(void) |
| { |
| return use_bdrv_whitelist; |
| } |
| |
| typedef struct CreateCo { |
| BlockDriver *drv; |
| char *filename; |
| QemuOpts *opts; |
| int ret; |
| Error *err; |
| } CreateCo; |
| |
| static void coroutine_fn bdrv_create_co_entry(void *opaque) |
| { |
| Error *local_err = NULL; |
| int ret; |
| |
| CreateCo *cco = opaque; |
| assert(cco->drv); |
| |
| ret = cco->drv->bdrv_create(cco->filename, cco->opts, &local_err); |
| error_propagate(&cco->err, local_err); |
| cco->ret = ret; |
| } |
| |
| int bdrv_create(BlockDriver *drv, const char* filename, |
| QemuOpts *opts, Error **errp) |
| { |
| int ret; |
| |
| Coroutine *co; |
| CreateCo cco = { |
| .drv = drv, |
| .filename = g_strdup(filename), |
| .opts = opts, |
| .ret = NOT_DONE, |
| .err = NULL, |
| }; |
| |
| if (!drv->bdrv_create) { |
| error_setg(errp, "Driver '%s' does not support image creation", drv->format_name); |
| ret = -ENOTSUP; |
| goto out; |
| } |
| |
| if (qemu_in_coroutine()) { |
| /* Fast-path if already in coroutine context */ |
| bdrv_create_co_entry(&cco); |
| } else { |
| co = qemu_coroutine_create(bdrv_create_co_entry, &cco); |
| qemu_coroutine_enter(co); |
| while (cco.ret == NOT_DONE) { |
| aio_poll(qemu_get_aio_context(), true); |
| } |
| } |
| |
| ret = cco.ret; |
| if (ret < 0) { |
| if (cco.err) { |
| error_propagate(errp, cco.err); |
| } else { |
| error_setg_errno(errp, -ret, "Could not create image"); |
| } |
| } |
| |
| out: |
| g_free(cco.filename); |
| return ret; |
| } |
| |
| int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp) |
| { |
| BlockDriver *drv; |
| Error *local_err = NULL; |
| int ret; |
| |
| drv = bdrv_find_protocol(filename, true, errp); |
| if (drv == NULL) { |
| return -ENOENT; |
| } |
| |
| ret = bdrv_create(drv, filename, opts, &local_err); |
| error_propagate(errp, local_err); |
| return ret; |
| } |
| |
| /** |
| * Try to get @bs's logical and physical block size. |
| * On success, store them in @bsz struct and return 0. |
| * On failure return -errno. |
| * @bs must not be empty. |
| */ |
| int bdrv_probe_blocksizes(BlockDriverState *bs, BlockSizes *bsz) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (drv && drv->bdrv_probe_blocksizes) { |
| return drv->bdrv_probe_blocksizes(bs, bsz); |
| } |
| |
| return -ENOTSUP; |
| } |
| |
| /** |
| * Try to get @bs's geometry (cyls, heads, sectors). |
| * On success, store them in @geo struct and return 0. |
| * On failure return -errno. |
| * @bs must not be empty. |
| */ |
| int bdrv_probe_geometry(BlockDriverState *bs, HDGeometry *geo) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (drv && drv->bdrv_probe_geometry) { |
| return drv->bdrv_probe_geometry(bs, geo); |
| } |
| |
| return -ENOTSUP; |
| } |
| |
| /* |
| * Create a uniquely-named empty temporary file. |
| * Return 0 upon success, otherwise a negative errno value. |
| */ |
| int get_tmp_filename(char *filename, int size) |
| { |
| #ifdef _WIN32 |
| char temp_dir[MAX_PATH]; |
| /* GetTempFileName requires that its output buffer (4th param) |
| have length MAX_PATH or greater. */ |
| assert(size >= MAX_PATH); |
| return (GetTempPath(MAX_PATH, temp_dir) |
| && GetTempFileName(temp_dir, "qem", 0, filename) |
| ? 0 : -GetLastError()); |
| #else |
| int fd; |
| const char *tmpdir; |
| tmpdir = getenv("TMPDIR"); |
| if (!tmpdir) { |
| tmpdir = "/var/tmp"; |
| } |
| if (snprintf(filename, size, "%s/vl.XXXXXX", tmpdir) >= size) { |
| return -EOVERFLOW; |
| } |
| fd = mkstemp(filename); |
| if (fd < 0) { |
| return -errno; |
| } |
| if (close(fd) != 0) { |
| unlink(filename); |
| return -errno; |
| } |
| return 0; |
| #endif |
| } |
| |
| /* |
| * Detect host devices. By convention, /dev/cdrom[N] is always |
| * recognized as a host CDROM. |
| */ |
| static BlockDriver *find_hdev_driver(const char *filename) |
| { |
| int score_max = 0, score; |
| BlockDriver *drv = NULL, *d; |
| |
| QLIST_FOREACH(d, &bdrv_drivers, list) { |
| if (d->bdrv_probe_device) { |
| score = d->bdrv_probe_device(filename); |
| if (score > score_max) { |
| score_max = score; |
| drv = d; |
| } |
| } |
| } |
| |
| return drv; |
| } |
| |
| static BlockDriver *bdrv_do_find_protocol(const char *protocol) |
| { |
| BlockDriver *drv1; |
| |
| QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
| if (drv1->protocol_name && !strcmp(drv1->protocol_name, protocol)) { |
| return drv1; |
| } |
| } |
| |
| return NULL; |
| } |
| |
| BlockDriver *bdrv_find_protocol(const char *filename, |
| bool allow_protocol_prefix, |
| Error **errp) |
| { |
| BlockDriver *drv1; |
| char protocol[128]; |
| int len; |
| const char *p; |
| int i; |
| |
| /* TODO Drivers without bdrv_file_open must be specified explicitly */ |
| |
| /* |
| * XXX(hch): we really should not let host device detection |
| * override an explicit protocol specification, but moving this |
| * later breaks access to device names with colons in them. |
| * Thanks to the brain-dead persistent naming schemes on udev- |
| * based Linux systems those actually are quite common. |
| */ |
| drv1 = find_hdev_driver(filename); |
| if (drv1) { |
| return drv1; |
| } |
| |
| if (!path_has_protocol(filename) || !allow_protocol_prefix) { |
| return &bdrv_file; |
| } |
| |
| p = strchr(filename, ':'); |
| assert(p != NULL); |
| len = p - filename; |
| if (len > sizeof(protocol) - 1) |
| len = sizeof(protocol) - 1; |
| memcpy(protocol, filename, len); |
| protocol[len] = '\0'; |
| |
| drv1 = bdrv_do_find_protocol(protocol); |
| if (drv1) { |
| return drv1; |
| } |
| |
| for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); ++i) { |
| if (block_driver_modules[i].protocol_name && |
| !strcmp(block_driver_modules[i].protocol_name, protocol)) { |
| block_module_load_one(block_driver_modules[i].library_name); |
| break; |
| } |
| } |
| |
| drv1 = bdrv_do_find_protocol(protocol); |
| if (!drv1) { |
| error_setg(errp, "Unknown protocol '%s'", protocol); |
| } |
| return drv1; |
| } |
| |
| /* |
| * Guess image format by probing its contents. |
| * This is not a good idea when your image is raw (CVE-2008-2004), but |
| * we do it anyway for backward compatibility. |
| * |
| * @buf contains the image's first @buf_size bytes. |
| * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE, |
| * but can be smaller if the image file is smaller) |
| * @filename is its filename. |
| * |
| * For all block drivers, call the bdrv_probe() method to get its |
| * probing score. |
| * Return the first block driver with the highest probing score. |
| */ |
| BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, |
| const char *filename) |
| { |
| int score_max = 0, score; |
| BlockDriver *drv = NULL, *d; |
| |
| QLIST_FOREACH(d, &bdrv_drivers, list) { |
| if (d->bdrv_probe) { |
| score = d->bdrv_probe(buf, buf_size, filename); |
| if (score > score_max) { |
| score_max = score; |
| drv = d; |
| } |
| } |
| } |
| |
| return drv; |
| } |
| |
| static int find_image_format(BlockBackend *file, const char *filename, |
| BlockDriver **pdrv, Error **errp) |
| { |
| BlockDriver *drv; |
| uint8_t buf[BLOCK_PROBE_BUF_SIZE]; |
| int ret = 0; |
| |
| /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ |
| if (blk_is_sg(file) || !blk_is_inserted(file) || blk_getlength(file) == 0) { |
| *pdrv = &bdrv_raw; |
| return ret; |
| } |
| |
| ret = blk_pread(file, 0, buf, sizeof(buf)); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not read image for determining its " |
| "format"); |
| *pdrv = NULL; |
| return ret; |
| } |
| |
| drv = bdrv_probe_all(buf, ret, filename); |
| if (!drv) { |
| error_setg(errp, "Could not determine image format: No compatible " |
| "driver found"); |
| ret = -ENOENT; |
| } |
| *pdrv = drv; |
| return ret; |
| } |
| |
| /** |
| * Set the current 'total_sectors' value |
| * Return 0 on success, -errno on error. |
| */ |
| static int refresh_total_sectors(BlockDriverState *bs, int64_t hint) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */ |
| if (bdrv_is_sg(bs)) |
| return 0; |
| |
| /* query actual device if possible, otherwise just trust the hint */ |
| if (drv->bdrv_getlength) { |
| int64_t length = drv->bdrv_getlength(bs); |
| if (length < 0) { |
| return length; |
| } |
| hint = DIV_ROUND_UP(length, BDRV_SECTOR_SIZE); |
| } |
| |
| bs->total_sectors = hint; |
| return 0; |
| } |
| |
| /** |
| * Combines a QDict of new block driver @options with any missing options taken |
| * from @old_options, so that leaving out an option defaults to its old value. |
| */ |
| static void bdrv_join_options(BlockDriverState *bs, QDict *options, |
| QDict *old_options) |
| { |
| if (bs->drv && bs->drv->bdrv_join_options) { |
| bs->drv->bdrv_join_options(options, old_options); |
| } else { |
| qdict_join(options, old_options, false); |
| } |
| } |
| |
| /** |
| * Set open flags for a given discard mode |
| * |
| * Return 0 on success, -1 if the discard mode was invalid. |
| */ |
| int bdrv_parse_discard_flags(const char *mode, int *flags) |
| { |
| *flags &= ~BDRV_O_UNMAP; |
| |
| if (!strcmp(mode, "off") || !strcmp(mode, "ignore")) { |
| /* do nothing */ |
| } else if (!strcmp(mode, "on") || !strcmp(mode, "unmap")) { |
| *flags |= BDRV_O_UNMAP; |
| } else { |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * Set open flags for a given cache mode |
| * |
| * Return 0 on success, -1 if the cache mode was invalid. |
| */ |
| int bdrv_parse_cache_mode(const char *mode, int *flags, bool *writethrough) |
| { |
| *flags &= ~BDRV_O_CACHE_MASK; |
| |
| if (!strcmp(mode, "off") || !strcmp(mode, "none")) { |
| *writethrough = false; |
| *flags |= BDRV_O_NOCACHE; |
| } else if (!strcmp(mode, "directsync")) { |
| *writethrough = true; |
| *flags |= BDRV_O_NOCACHE; |
| } else if (!strcmp(mode, "writeback")) { |
| *writethrough = false; |
| } else if (!strcmp(mode, "unsafe")) { |
| *writethrough = false; |
| *flags |= BDRV_O_NO_FLUSH; |
| } else if (!strcmp(mode, "writethrough")) { |
| *writethrough = true; |
| } else { |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| static char *bdrv_child_get_parent_desc(BdrvChild *c) |
| { |
| BlockDriverState *parent = c->opaque; |
| return g_strdup(bdrv_get_device_or_node_name(parent)); |
| } |
| |
| static void bdrv_child_cb_drained_begin(BdrvChild *child) |
| { |
| BlockDriverState *bs = child->opaque; |
| bdrv_drained_begin(bs); |
| } |
| |
| static void bdrv_child_cb_drained_end(BdrvChild *child) |
| { |
| BlockDriverState *bs = child->opaque; |
| bdrv_drained_end(bs); |
| } |
| |
| /* |
| * Returns the options and flags that a temporary snapshot should get, based on |
| * the originally requested flags (the originally requested image will have |
| * flags like a backing file) |
| */ |
| static void bdrv_temp_snapshot_options(int *child_flags, QDict *child_options, |
| int parent_flags, QDict *parent_options) |
| { |
| *child_flags = (parent_flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY; |
| |
| /* For temporary files, unconditional cache=unsafe is fine */ |
| qdict_set_default_str(child_options, BDRV_OPT_CACHE_DIRECT, "off"); |
| qdict_set_default_str(child_options, BDRV_OPT_CACHE_NO_FLUSH, "on"); |
| |
| /* Copy the read-only option from the parent */ |
| qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY); |
| |
| /* aio=native doesn't work for cache.direct=off, so disable it for the |
| * temporary snapshot */ |
| *child_flags &= ~BDRV_O_NATIVE_AIO; |
| } |
| |
| /* |
| * Returns the options and flags that bs->file should get if a protocol driver |
| * is expected, based on the given options and flags for the parent BDS |
| */ |
| static void bdrv_inherited_options(int *child_flags, QDict *child_options, |
| int parent_flags, QDict *parent_options) |
| { |
| int flags = parent_flags; |
| |
| /* Enable protocol handling, disable format probing for bs->file */ |
| flags |= BDRV_O_PROTOCOL; |
| |
| /* If the cache mode isn't explicitly set, inherit direct and no-flush from |
| * the parent. */ |
| qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); |
| qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); |
| |
| /* Inherit the read-only option from the parent if it's not set */ |
| qdict_copy_default(child_options, parent_options, BDRV_OPT_READ_ONLY); |
| |
| /* Our block drivers take care to send flushes and respect unmap policy, |
| * so we can default to enable both on lower layers regardless of the |
| * corresponding parent options. */ |
| qdict_set_default_str(child_options, BDRV_OPT_DISCARD, "unmap"); |
| |
| /* Clear flags that only apply to the top layer */ |
| flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ | |
| BDRV_O_NO_IO); |
| |
| *child_flags = flags; |
| } |
| |
| const BdrvChildRole child_file = { |
| .get_parent_desc = bdrv_child_get_parent_desc, |
| .inherit_options = bdrv_inherited_options, |
| .drained_begin = bdrv_child_cb_drained_begin, |
| .drained_end = bdrv_child_cb_drained_end, |
| }; |
| |
| /* |
| * Returns the options and flags that bs->file should get if the use of formats |
| * (and not only protocols) is permitted for it, based on the given options and |
| * flags for the parent BDS |
| */ |
| static void bdrv_inherited_fmt_options(int *child_flags, QDict *child_options, |
| int parent_flags, QDict *parent_options) |
| { |
| child_file.inherit_options(child_flags, child_options, |
| parent_flags, parent_options); |
| |
| *child_flags &= ~(BDRV_O_PROTOCOL | BDRV_O_NO_IO); |
| } |
| |
| const BdrvChildRole child_format = { |
| .get_parent_desc = bdrv_child_get_parent_desc, |
| .inherit_options = bdrv_inherited_fmt_options, |
| .drained_begin = bdrv_child_cb_drained_begin, |
| .drained_end = bdrv_child_cb_drained_end, |
| }; |
| |
| static void bdrv_backing_attach(BdrvChild *c) |
| { |
| BlockDriverState *parent = c->opaque; |
| BlockDriverState *backing_hd = c->bs; |
| |
| assert(!parent->backing_blocker); |
| error_setg(&parent->backing_blocker, |
| "node is used as backing hd of '%s'", |
| bdrv_get_device_or_node_name(parent)); |
| |
| parent->open_flags &= ~BDRV_O_NO_BACKING; |
| pstrcpy(parent->backing_file, sizeof(parent->backing_file), |
| backing_hd->filename); |
| pstrcpy(parent->backing_format, sizeof(parent->backing_format), |
| backing_hd->drv ? backing_hd->drv->format_name : ""); |
| |
| bdrv_op_block_all(backing_hd, parent->backing_blocker); |
| /* Otherwise we won't be able to commit or stream */ |
| bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_COMMIT_TARGET, |
| parent->backing_blocker); |
| bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_STREAM, |
| parent->backing_blocker); |
| /* |
| * We do backup in 3 ways: |
| * 1. drive backup |
| * The target bs is new opened, and the source is top BDS |
| * 2. blockdev backup |
| * Both the source and the target are top BDSes. |
| * 3. internal backup(used for block replication) |
| * Both the source and the target are backing file |
| * |
| * In case 1 and 2, neither the source nor the target is the backing file. |
| * In case 3, we will block the top BDS, so there is only one block job |
| * for the top BDS and its backing chain. |
| */ |
| bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_SOURCE, |
| parent->backing_blocker); |
| bdrv_op_unblock(backing_hd, BLOCK_OP_TYPE_BACKUP_TARGET, |
| parent->backing_blocker); |
| } |
| |
| static void bdrv_backing_detach(BdrvChild *c) |
| { |
| BlockDriverState *parent = c->opaque; |
| |
| assert(parent->backing_blocker); |
| bdrv_op_unblock_all(c->bs, parent->backing_blocker); |
| error_free(parent->backing_blocker); |
| parent->backing_blocker = NULL; |
| } |
| |
| /* |
| * Returns the options and flags that bs->backing should get, based on the |
| * given options and flags for the parent BDS |
| */ |
| static void bdrv_backing_options(int *child_flags, QDict *child_options, |
| int parent_flags, QDict *parent_options) |
| { |
| int flags = parent_flags; |
| |
| /* The cache mode is inherited unmodified for backing files; except WCE, |
| * which is only applied on the top level (BlockBackend) */ |
| qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_DIRECT); |
| qdict_copy_default(child_options, parent_options, BDRV_OPT_CACHE_NO_FLUSH); |
| |
| /* backing files always opened read-only */ |
| qdict_set_default_str(child_options, BDRV_OPT_READ_ONLY, "on"); |
| flags &= ~BDRV_O_COPY_ON_READ; |
| |
| /* snapshot=on is handled on the top layer */ |
| flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY); |
| |
| *child_flags = flags; |
| } |
| |
| const BdrvChildRole child_backing = { |
| .get_parent_desc = bdrv_child_get_parent_desc, |
| .attach = bdrv_backing_attach, |
| .detach = bdrv_backing_detach, |
| .inherit_options = bdrv_backing_options, |
| .drained_begin = bdrv_child_cb_drained_begin, |
| .drained_end = bdrv_child_cb_drained_end, |
| }; |
| |
| static int bdrv_open_flags(BlockDriverState *bs, int flags) |
| { |
| int open_flags = flags; |
| |
| /* |
| * Clear flags that are internal to the block layer before opening the |
| * image. |
| */ |
| open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_PROTOCOL); |
| |
| /* |
| * Snapshots should be writable. |
| */ |
| if (flags & BDRV_O_TEMPORARY) { |
| open_flags |= BDRV_O_RDWR; |
| } |
| |
| return open_flags; |
| } |
| |
| static void update_flags_from_options(int *flags, QemuOpts *opts) |
| { |
| *flags &= ~BDRV_O_CACHE_MASK; |
| |
| assert(qemu_opt_find(opts, BDRV_OPT_CACHE_NO_FLUSH)); |
| if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_NO_FLUSH, false)) { |
| *flags |= BDRV_O_NO_FLUSH; |
| } |
| |
| assert(qemu_opt_find(opts, BDRV_OPT_CACHE_DIRECT)); |
| if (qemu_opt_get_bool(opts, BDRV_OPT_CACHE_DIRECT, false)) { |
| *flags |= BDRV_O_NOCACHE; |
| } |
| |
| *flags &= ~BDRV_O_RDWR; |
| |
| assert(qemu_opt_find(opts, BDRV_OPT_READ_ONLY)); |
| if (!qemu_opt_get_bool(opts, BDRV_OPT_READ_ONLY, false)) { |
| *flags |= BDRV_O_RDWR; |
| } |
| |
| } |
| |
| static void update_options_from_flags(QDict *options, int flags) |
| { |
| if (!qdict_haskey(options, BDRV_OPT_CACHE_DIRECT)) { |
| qdict_put(options, BDRV_OPT_CACHE_DIRECT, |
| qbool_from_bool(flags & BDRV_O_NOCACHE)); |
| } |
| if (!qdict_haskey(options, BDRV_OPT_CACHE_NO_FLUSH)) { |
| qdict_put(options, BDRV_OPT_CACHE_NO_FLUSH, |
| qbool_from_bool(flags & BDRV_O_NO_FLUSH)); |
| } |
| if (!qdict_haskey(options, BDRV_OPT_READ_ONLY)) { |
| qdict_put(options, BDRV_OPT_READ_ONLY, |
| qbool_from_bool(!(flags & BDRV_O_RDWR))); |
| } |
| } |
| |
| static void bdrv_assign_node_name(BlockDriverState *bs, |
| const char *node_name, |
| Error **errp) |
| { |
| char *gen_node_name = NULL; |
| |
| if (!node_name) { |
| node_name = gen_node_name = id_generate(ID_BLOCK); |
| } else if (!id_wellformed(node_name)) { |
| /* |
| * Check for empty string or invalid characters, but not if it is |
| * generated (generated names use characters not available to the user) |
| */ |
| error_setg(errp, "Invalid node name"); |
| return; |
| } |
| |
| /* takes care of avoiding namespaces collisions */ |
| if (blk_by_name(node_name)) { |
| error_setg(errp, "node-name=%s is conflicting with a device id", |
| node_name); |
| goto out; |
| } |
| |
| /* takes care of avoiding duplicates node names */ |
| if (bdrv_find_node(node_name)) { |
| error_setg(errp, "Duplicate node name"); |
| goto out; |
| } |
| |
| /* copy node name into the bs and insert it into the graph list */ |
| pstrcpy(bs->node_name, sizeof(bs->node_name), node_name); |
| QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs, node_list); |
| out: |
| g_free(gen_node_name); |
| } |
| |
| static int bdrv_open_driver(BlockDriverState *bs, BlockDriver *drv, |
| const char *node_name, QDict *options, |
| int open_flags, Error **errp) |
| { |
| Error *local_err = NULL; |
| int ret; |
| |
| bdrv_assign_node_name(bs, node_name, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| return -EINVAL; |
| } |
| |
| bs->drv = drv; |
| bs->read_only = !(bs->open_flags & BDRV_O_RDWR); |
| bs->opaque = g_malloc0(drv->instance_size); |
| |
| if (drv->bdrv_file_open) { |
| assert(!drv->bdrv_needs_filename || bs->filename[0]); |
| ret = drv->bdrv_file_open(bs, options, open_flags, &local_err); |
| } else if (drv->bdrv_open) { |
| ret = drv->bdrv_open(bs, options, open_flags, &local_err); |
| } else { |
| ret = 0; |
| } |
| |
| if (ret < 0) { |
| if (local_err) { |
| error_propagate(errp, local_err); |
| } else if (bs->filename[0]) { |
| error_setg_errno(errp, -ret, "Could not open '%s'", bs->filename); |
| } else { |
| error_setg_errno(errp, -ret, "Could not open image"); |
| } |
| goto free_and_fail; |
| } |
| |
| ret = refresh_total_sectors(bs, bs->total_sectors); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not refresh total sector count"); |
| goto free_and_fail; |
| } |
| |
| bdrv_refresh_limits(bs, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto free_and_fail; |
| } |
| |
| assert(bdrv_opt_mem_align(bs) != 0); |
| assert(bdrv_min_mem_align(bs) != 0); |
| assert(is_power_of_2(bs->bl.request_alignment)); |
| |
| return 0; |
| |
| free_and_fail: |
| /* FIXME Close bs first if already opened*/ |
| g_free(bs->opaque); |
| bs->opaque = NULL; |
| bs->drv = NULL; |
| return ret; |
| } |
| |
| BlockDriverState *bdrv_new_open_driver(BlockDriver *drv, const char *node_name, |
| int flags, Error **errp) |
| { |
| BlockDriverState *bs; |
| int ret; |
| |
| bs = bdrv_new(); |
| bs->open_flags = flags; |
| bs->explicit_options = qdict_new(); |
| bs->options = qdict_new(); |
| bs->opaque = NULL; |
| |
| update_options_from_flags(bs->options, flags); |
| |
| ret = bdrv_open_driver(bs, drv, node_name, bs->options, flags, errp); |
| if (ret < 0) { |
| QDECREF(bs->explicit_options); |
| QDECREF(bs->options); |
| bdrv_unref(bs); |
| return NULL; |
| } |
| |
| return bs; |
| } |
| |
| QemuOptsList bdrv_runtime_opts = { |
| .name = "bdrv_common", |
| .head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head), |
| .desc = { |
| { |
| .name = "node-name", |
| .type = QEMU_OPT_STRING, |
| .help = "Node name of the block device node", |
| }, |
| { |
| .name = "driver", |
| .type = QEMU_OPT_STRING, |
| .help = "Block driver to use for the node", |
| }, |
| { |
| .name = BDRV_OPT_CACHE_DIRECT, |
| .type = QEMU_OPT_BOOL, |
| .help = "Bypass software writeback cache on the host", |
| }, |
| { |
| .name = BDRV_OPT_CACHE_NO_FLUSH, |
| .type = QEMU_OPT_BOOL, |
| .help = "Ignore flush requests", |
| }, |
| { |
| .name = BDRV_OPT_READ_ONLY, |
| .type = QEMU_OPT_BOOL, |
| .help = "Node is opened in read-only mode", |
| }, |
| { |
| .name = "detect-zeroes", |
| .type = QEMU_OPT_STRING, |
| .help = "try to optimize zero writes (off, on, unmap)", |
| }, |
| { |
| .name = "discard", |
| .type = QEMU_OPT_STRING, |
| .help = "discard operation (ignore/off, unmap/on)", |
| }, |
| { /* end of list */ } |
| }, |
| }; |
| |
| /* |
| * Common part for opening disk images and files |
| * |
| * Removes all processed options from *options. |
| */ |
| static int bdrv_open_common(BlockDriverState *bs, BlockBackend *file, |
| QDict *options, Error **errp) |
| { |
| int ret, open_flags; |
| const char *filename; |
| const char *driver_name = NULL; |
| const char *node_name = NULL; |
| const char *discard; |
| const char *detect_zeroes; |
| QemuOpts *opts; |
| BlockDriver *drv; |
| Error *local_err = NULL; |
| |
| assert(bs->file == NULL); |
| assert(options != NULL && bs->options != options); |
| |
| opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); |
| qemu_opts_absorb_qdict(opts, options, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto fail_opts; |
| } |
| |
| update_flags_from_options(&bs->open_flags, opts); |
| |
| driver_name = qemu_opt_get(opts, "driver"); |
| drv = bdrv_find_format(driver_name); |
| assert(drv != NULL); |
| |
| if (file != NULL) { |
| filename = blk_bs(file)->filename; |
| } else { |
| filename = qdict_get_try_str(options, "filename"); |
| } |
| |
| if (drv->bdrv_needs_filename && !filename) { |
| error_setg(errp, "The '%s' block driver requires a file name", |
| drv->format_name); |
| ret = -EINVAL; |
| goto fail_opts; |
| } |
| |
| trace_bdrv_open_common(bs, filename ?: "", bs->open_flags, |
| drv->format_name); |
| |
| bs->read_only = !(bs->open_flags & BDRV_O_RDWR); |
| |
| if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) { |
| error_setg(errp, |
| !bs->read_only && bdrv_is_whitelisted(drv, true) |
| ? "Driver '%s' can only be used for read-only devices" |
| : "Driver '%s' is not whitelisted", |
| drv->format_name); |
| ret = -ENOTSUP; |
| goto fail_opts; |
| } |
| |
| assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */ |
| if (bs->open_flags & BDRV_O_COPY_ON_READ) { |
| if (!bs->read_only) { |
| bdrv_enable_copy_on_read(bs); |
| } else { |
| error_setg(errp, "Can't use copy-on-read on read-only device"); |
| ret = -EINVAL; |
| goto fail_opts; |
| } |
| } |
| |
| discard = qemu_opt_get(opts, "discard"); |
| if (discard != NULL) { |
| if (bdrv_parse_discard_flags(discard, &bs->open_flags) != 0) { |
| error_setg(errp, "Invalid discard option"); |
| ret = -EINVAL; |
| goto fail_opts; |
| } |
| } |
| |
| detect_zeroes = qemu_opt_get(opts, "detect-zeroes"); |
| if (detect_zeroes) { |
| BlockdevDetectZeroesOptions value = |
| qapi_enum_parse(BlockdevDetectZeroesOptions_lookup, |
| detect_zeroes, |
| BLOCKDEV_DETECT_ZEROES_OPTIONS__MAX, |
| BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF, |
| &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto fail_opts; |
| } |
| |
| if (value == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP && |
| !(bs->open_flags & BDRV_O_UNMAP)) |
| { |
| error_setg(errp, "setting detect-zeroes to unmap is not allowed " |
| "without setting discard operation to unmap"); |
| ret = -EINVAL; |
| goto fail_opts; |
| } |
| |
| bs->detect_zeroes = value; |
| } |
| |
| if (filename != NULL) { |
| pstrcpy(bs->filename, sizeof(bs->filename), filename); |
| } else { |
| bs->filename[0] = '\0'; |
| } |
| pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), bs->filename); |
| |
| /* Open the image, either directly or using a protocol */ |
| open_flags = bdrv_open_flags(bs, bs->open_flags); |
| node_name = qemu_opt_get(opts, "node-name"); |
| |
| assert(!drv->bdrv_file_open || file == NULL); |
| ret = bdrv_open_driver(bs, drv, node_name, options, open_flags, errp); |
| if (ret < 0) { |
| goto fail_opts; |
| } |
| |
| qemu_opts_del(opts); |
| return 0; |
| |
| fail_opts: |
| qemu_opts_del(opts); |
| return ret; |
| } |
| |
| static QDict *parse_json_filename(const char *filename, Error **errp) |
| { |
| QObject *options_obj; |
| QDict *options; |
| int ret; |
| |
| ret = strstart(filename, "json:", &filename); |
| assert(ret); |
| |
| options_obj = qobject_from_json(filename); |
| if (!options_obj) { |
| error_setg(errp, "Could not parse the JSON options"); |
| return NULL; |
| } |
| |
| options = qobject_to_qdict(options_obj); |
| if (!options) { |
| qobject_decref(options_obj); |
| error_setg(errp, "Invalid JSON object given"); |
| return NULL; |
| } |
| |
| qdict_flatten(options); |
| |
| return options; |
| } |
| |
| static void parse_json_protocol(QDict *options, const char **pfilename, |
| Error **errp) |
| { |
| QDict *json_options; |
| Error *local_err = NULL; |
| |
| /* Parse json: pseudo-protocol */ |
| if (!*pfilename || !g_str_has_prefix(*pfilename, "json:")) { |
| return; |
| } |
| |
| json_options = parse_json_filename(*pfilename, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| return; |
| } |
| |
| /* Options given in the filename have lower priority than options |
| * specified directly */ |
| qdict_join(options, json_options, false); |
| QDECREF(json_options); |
| *pfilename = NULL; |
| } |
| |
| /* |
| * Fills in default options for opening images and converts the legacy |
| * filename/flags pair to option QDict entries. |
| * The BDRV_O_PROTOCOL flag in *flags will be set or cleared accordingly if a |
| * block driver has been specified explicitly. |
| */ |
| static int bdrv_fill_options(QDict **options, const char *filename, |
| int *flags, Error **errp) |
| { |
| const char *drvname; |
| bool protocol = *flags & BDRV_O_PROTOCOL; |
| bool parse_filename = false; |
| BlockDriver *drv = NULL; |
| Error *local_err = NULL; |
| |
| drvname = qdict_get_try_str(*options, "driver"); |
| if (drvname) { |
| drv = bdrv_find_format(drvname); |
| if (!drv) { |
| error_setg(errp, "Unknown driver '%s'", drvname); |
| return -ENOENT; |
| } |
| /* If the user has explicitly specified the driver, this choice should |
| * override the BDRV_O_PROTOCOL flag */ |
| protocol = drv->bdrv_file_open; |
| } |
| |
| if (protocol) { |
| *flags |= BDRV_O_PROTOCOL; |
| } else { |
| *flags &= ~BDRV_O_PROTOCOL; |
| } |
| |
| /* Translate cache options from flags into options */ |
| update_options_from_flags(*options, *flags); |
| |
| /* Fetch the file name from the options QDict if necessary */ |
| if (protocol && filename) { |
| if (!qdict_haskey(*options, "filename")) { |
| qdict_put(*options, "filename", qstring_from_str(filename)); |
| parse_filename = true; |
| } else { |
| error_setg(errp, "Can't specify 'file' and 'filename' options at " |
| "the same time"); |
| return -EINVAL; |
| } |
| } |
| |
| /* Find the right block driver */ |
| filename = qdict_get_try_str(*options, "filename"); |
| |
| if (!drvname && protocol) { |
| if (filename) { |
| drv = bdrv_find_protocol(filename, parse_filename, errp); |
| if (!drv) { |
| return -EINVAL; |
| } |
| |
| drvname = drv->format_name; |
| qdict_put(*options, "driver", qstring_from_str(drvname)); |
| } else { |
| error_setg(errp, "Must specify either driver or file"); |
| return -EINVAL; |
| } |
| } |
| |
| assert(drv || !protocol); |
| |
| /* Driver-specific filename parsing */ |
| if (drv && drv->bdrv_parse_filename && parse_filename) { |
| drv->bdrv_parse_filename(filename, *options, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| return -EINVAL; |
| } |
| |
| if (!drv->bdrv_needs_filename) { |
| qdict_del(*options, "filename"); |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Check whether permissions on this node can be changed in a way that |
| * @cumulative_perms and @cumulative_shared_perms are the new cumulative |
| * permissions of all its parents. This involves checking whether all necessary |
| * permission changes to child nodes can be performed. |
| * |
| * A call to this function must always be followed by a call to bdrv_set_perm() |
| * or bdrv_abort_perm_update(). |
| */ |
| static int bdrv_check_perm(BlockDriverState *bs, uint64_t cumulative_perms, |
| uint64_t cumulative_shared_perms, Error **errp) |
| { |
| BlockDriver *drv = bs->drv; |
| BdrvChild *c; |
| int ret; |
| |
| /* Write permissions never work with read-only images */ |
| if ((cumulative_perms & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) && |
| bdrv_is_read_only(bs)) |
| { |
| error_setg(errp, "Block node is read-only"); |
| return -EPERM; |
| } |
| |
| /* Check this node */ |
| if (!drv) { |
| return 0; |
| } |
| |
| if (drv->bdrv_check_perm) { |
| return drv->bdrv_check_perm(bs, cumulative_perms, |
| cumulative_shared_perms, errp); |
| } |
| |
| /* Drivers that never have children can omit .bdrv_child_perm() */ |
| if (!drv->bdrv_child_perm) { |
| assert(QLIST_EMPTY(&bs->children)); |
| return 0; |
| } |
| |
| /* Check all children */ |
| QLIST_FOREACH(c, &bs->children, next) { |
| uint64_t cur_perm, cur_shared; |
| drv->bdrv_child_perm(bs, c, c->role, |
| cumulative_perms, cumulative_shared_perms, |
| &cur_perm, &cur_shared); |
| ret = bdrv_child_check_perm(c, cur_perm, cur_shared, errp); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Notifies drivers that after a previous bdrv_check_perm() call, the |
| * permission update is not performed and any preparations made for it (e.g. |
| * taken file locks) need to be undone. |
| * |
| * This function recursively notifies all child nodes. |
| */ |
| static void bdrv_abort_perm_update(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| BdrvChild *c; |
| |
| if (!drv) { |
| return; |
| } |
| |
| if (drv->bdrv_abort_perm_update) { |
| drv->bdrv_abort_perm_update(bs); |
| } |
| |
| QLIST_FOREACH(c, &bs->children, next) { |
| bdrv_child_abort_perm_update(c); |
| } |
| } |
| |
| static void bdrv_set_perm(BlockDriverState *bs, uint64_t cumulative_perms, |
| uint64_t cumulative_shared_perms) |
| { |
| BlockDriver *drv = bs->drv; |
| BdrvChild *c; |
| |
| if (!drv) { |
| return; |
| } |
| |
| /* Update this node */ |
| if (drv->bdrv_set_perm) { |
| drv->bdrv_set_perm(bs, cumulative_perms, cumulative_shared_perms); |
| } |
| |
| /* Drivers that never have children can omit .bdrv_child_perm() */ |
| if (!drv->bdrv_child_perm) { |
| assert(QLIST_EMPTY(&bs->children)); |
| return; |
| } |
| |
| /* Update all children */ |
| QLIST_FOREACH(c, &bs->children, next) { |
| uint64_t cur_perm, cur_shared; |
| drv->bdrv_child_perm(bs, c, c->role, |
| cumulative_perms, cumulative_shared_perms, |
| &cur_perm, &cur_shared); |
| bdrv_child_set_perm(c, cur_perm, cur_shared); |
| } |
| } |
| |
| static void bdrv_get_cumulative_perm(BlockDriverState *bs, uint64_t *perm, |
| uint64_t *shared_perm) |
| { |
| BdrvChild *c; |
| uint64_t cumulative_perms = 0; |
| uint64_t cumulative_shared_perms = BLK_PERM_ALL; |
| |
| QLIST_FOREACH(c, &bs->parents, next_parent) { |
| cumulative_perms |= c->perm; |
| cumulative_shared_perms &= c->shared_perm; |
| } |
| |
| *perm = cumulative_perms; |
| *shared_perm = cumulative_shared_perms; |
| } |
| |
| static char *bdrv_child_user_desc(BdrvChild *c) |
| { |
| if (c->role->get_parent_desc) { |
| return c->role->get_parent_desc(c); |
| } |
| |
| return g_strdup("another user"); |
| } |
| |
| static char *bdrv_perm_names(uint64_t perm) |
| { |
| struct perm_name { |
| uint64_t perm; |
| const char *name; |
| } permissions[] = { |
| { BLK_PERM_CONSISTENT_READ, "consistent read" }, |
| { BLK_PERM_WRITE, "write" }, |
| { BLK_PERM_WRITE_UNCHANGED, "write unchanged" }, |
| { BLK_PERM_RESIZE, "resize" }, |
| { BLK_PERM_GRAPH_MOD, "change children" }, |
| { 0, NULL } |
| }; |
| |
| char *result = g_strdup(""); |
| struct perm_name *p; |
| |
| for (p = permissions; p->name; p++) { |
| if (perm & p->perm) { |
| char *old = result; |
| result = g_strdup_printf("%s%s%s", old, *old ? ", " : "", p->name); |
| g_free(old); |
| } |
| } |
| |
| return result; |
| } |
| |
| /* |
| * Checks whether a new reference to @bs can be added if the new user requires |
| * @new_used_perm/@new_shared_perm as its permissions. If @ignore_child is set, |
| * this old reference is ignored in the calculations; this allows checking |
| * permission updates for an existing reference. |
| * |
| * Needs to be followed by a call to either bdrv_set_perm() or |
| * bdrv_abort_perm_update(). */ |
| static int bdrv_check_update_perm(BlockDriverState *bs, uint64_t new_used_perm, |
| uint64_t new_shared_perm, |
| BdrvChild *ignore_child, Error **errp) |
| { |
| BdrvChild *c; |
| uint64_t cumulative_perms = new_used_perm; |
| uint64_t cumulative_shared_perms = new_shared_perm; |
| |
| /* There is no reason why anyone couldn't tolerate write_unchanged */ |
| assert(new_shared_perm & BLK_PERM_WRITE_UNCHANGED); |
| |
| QLIST_FOREACH(c, &bs->parents, next_parent) { |
| if (c == ignore_child) { |
| continue; |
| } |
| |
| if ((new_used_perm & c->shared_perm) != new_used_perm) { |
| char *user = bdrv_child_user_desc(c); |
| char *perm_names = bdrv_perm_names(new_used_perm & ~c->shared_perm); |
| error_setg(errp, "Conflicts with use by %s as '%s', which does not " |
| "allow '%s' on %s", |
| user, c->name, perm_names, bdrv_get_node_name(c->bs)); |
| g_free(user); |
| g_free(perm_names); |
| return -EPERM; |
| } |
| |
| if ((c->perm & new_shared_perm) != c->perm) { |
| char *user = bdrv_child_user_desc(c); |
| char *perm_names = bdrv_perm_names(c->perm & ~new_shared_perm); |
| error_setg(errp, "Conflicts with use by %s as '%s', which uses " |
| "'%s' on %s", |
| user, c->name, perm_names, bdrv_get_node_name(c->bs)); |
| g_free(user); |
| g_free(perm_names); |
| return -EPERM; |
| } |
| |
| cumulative_perms |= c->perm; |
| cumulative_shared_perms &= c->shared_perm; |
| } |
| |
| return bdrv_check_perm(bs, cumulative_perms, cumulative_shared_perms, errp); |
| } |
| |
| /* Needs to be followed by a call to either bdrv_child_set_perm() or |
| * bdrv_child_abort_perm_update(). */ |
| int bdrv_child_check_perm(BdrvChild *c, uint64_t perm, uint64_t shared, |
| Error **errp) |
| { |
| return bdrv_check_update_perm(c->bs, perm, shared, c, errp); |
| } |
| |
| void bdrv_child_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared) |
| { |
| uint64_t cumulative_perms, cumulative_shared_perms; |
| |
| c->perm = perm; |
| c->shared_perm = shared; |
| |
| bdrv_get_cumulative_perm(c->bs, &cumulative_perms, |
| &cumulative_shared_perms); |
| bdrv_set_perm(c->bs, cumulative_perms, cumulative_shared_perms); |
| } |
| |
| void bdrv_child_abort_perm_update(BdrvChild *c) |
| { |
| bdrv_abort_perm_update(c->bs); |
| } |
| |
| int bdrv_child_try_set_perm(BdrvChild *c, uint64_t perm, uint64_t shared, |
| Error **errp) |
| { |
| int ret; |
| |
| ret = bdrv_child_check_perm(c, perm, shared, errp); |
| if (ret < 0) { |
| bdrv_child_abort_perm_update(c); |
| return ret; |
| } |
| |
| bdrv_child_set_perm(c, perm, shared); |
| |
| return 0; |
| } |
| |
| #define DEFAULT_PERM_PASSTHROUGH (BLK_PERM_CONSISTENT_READ \ |
| | BLK_PERM_WRITE \ |
| | BLK_PERM_WRITE_UNCHANGED \ |
| | BLK_PERM_RESIZE) |
| #define DEFAULT_PERM_UNCHANGED (BLK_PERM_ALL & ~DEFAULT_PERM_PASSTHROUGH) |
| |
| void bdrv_filter_default_perms(BlockDriverState *bs, BdrvChild *c, |
| const BdrvChildRole *role, |
| uint64_t perm, uint64_t shared, |
| uint64_t *nperm, uint64_t *nshared) |
| { |
| if (c == NULL) { |
| *nperm = perm & DEFAULT_PERM_PASSTHROUGH; |
| *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | DEFAULT_PERM_UNCHANGED; |
| return; |
| } |
| |
| *nperm = (perm & DEFAULT_PERM_PASSTHROUGH) | |
| (c->perm & DEFAULT_PERM_UNCHANGED); |
| *nshared = (shared & DEFAULT_PERM_PASSTHROUGH) | |
| (c->shared_perm & DEFAULT_PERM_UNCHANGED); |
| } |
| |
| void bdrv_format_default_perms(BlockDriverState *bs, BdrvChild *c, |
| const BdrvChildRole *role, |
| uint64_t perm, uint64_t shared, |
| uint64_t *nperm, uint64_t *nshared) |
| { |
| bool backing = (role == &child_backing); |
| assert(role == &child_backing || role == &child_file); |
| |
| if (!backing) { |
| /* Apart from the modifications below, the same permissions are |
| * forwarded and left alone as for filters */ |
| bdrv_filter_default_perms(bs, c, role, perm, shared, &perm, &shared); |
| |
| /* Format drivers may touch metadata even if the guest doesn't write */ |
| if (!bdrv_is_read_only(bs)) { |
| perm |= BLK_PERM_WRITE | BLK_PERM_RESIZE; |
| } |
| |
| /* bs->file always needs to be consistent because of the metadata. We |
| * can never allow other users to resize or write to it. */ |
| perm |= BLK_PERM_CONSISTENT_READ; |
| shared &= ~(BLK_PERM_WRITE | BLK_PERM_RESIZE); |
| } else { |
| /* We want consistent read from backing files if the parent needs it. |
| * No other operations are performed on backing files. */ |
| perm &= BLK_PERM_CONSISTENT_READ; |
| |
| /* If the parent can deal with changing data, we're okay with a |
| * writable and resizable backing file. */ |
| /* TODO Require !(perm & BLK_PERM_CONSISTENT_READ), too? */ |
| if (shared & BLK_PERM_WRITE) { |
| shared = BLK_PERM_WRITE | BLK_PERM_RESIZE; |
| } else { |
| shared = 0; |
| } |
| |
| shared |= BLK_PERM_CONSISTENT_READ | BLK_PERM_GRAPH_MOD | |
| BLK_PERM_WRITE_UNCHANGED; |
| } |
| |
| *nperm = perm; |
| *nshared = shared; |
| } |
| |
| static void bdrv_replace_child_noperm(BdrvChild *child, |
| BlockDriverState *new_bs) |
| { |
| BlockDriverState *old_bs = child->bs; |
| |
| if (old_bs) { |
| if (old_bs->quiesce_counter && child->role->drained_end) { |
| child->role->drained_end(child); |
| } |
| if (child->role->detach) { |
| child->role->detach(child); |
| } |
| QLIST_REMOVE(child, next_parent); |
| } |
| |
| child->bs = new_bs; |
| |
| if (new_bs) { |
| QLIST_INSERT_HEAD(&new_bs->parents, child, next_parent); |
| if (new_bs->quiesce_counter && child->role->drained_begin) { |
| child->role->drained_begin(child); |
| } |
| |
| if (child->role->attach) { |
| child->role->attach(child); |
| } |
| } |
| } |
| |
| static void bdrv_replace_child(BdrvChild *child, BlockDriverState *new_bs, |
| bool check_new_perm) |
| { |
| BlockDriverState *old_bs = child->bs; |
| uint64_t perm, shared_perm; |
| |
| if (old_bs) { |
| /* Update permissions for old node. This is guaranteed to succeed |
| * because we're just taking a parent away, so we're loosening |
| * restrictions. */ |
| bdrv_get_cumulative_perm(old_bs, &perm, &shared_perm); |
| bdrv_check_perm(old_bs, perm, shared_perm, &error_abort); |
| bdrv_set_perm(old_bs, perm, shared_perm); |
| } |
| |
| bdrv_replace_child_noperm(child, new_bs); |
| |
| if (new_bs) { |
| bdrv_get_cumulative_perm(new_bs, &perm, &shared_perm); |
| if (check_new_perm) { |
| bdrv_check_perm(new_bs, perm, shared_perm, &error_abort); |
| } |
| bdrv_set_perm(new_bs, perm, shared_perm); |
| } |
| } |
| |
| BdrvChild *bdrv_root_attach_child(BlockDriverState *child_bs, |
| const char *child_name, |
| const BdrvChildRole *child_role, |
| uint64_t perm, uint64_t shared_perm, |
| void *opaque, Error **errp) |
| { |
| BdrvChild *child; |
| int ret; |
| |
| ret = bdrv_check_update_perm(child_bs, perm, shared_perm, NULL, errp); |
| if (ret < 0) { |
| bdrv_abort_perm_update(child_bs); |
| return NULL; |
| } |
| |
| child = g_new(BdrvChild, 1); |
| *child = (BdrvChild) { |
| .bs = NULL, |
| .name = g_strdup(child_name), |
| .role = child_role, |
| .perm = perm, |
| .shared_perm = shared_perm, |
| .opaque = opaque, |
| }; |
| |
| /* This performs the matching bdrv_set_perm() for the above check. */ |
| bdrv_replace_child(child, child_bs, false); |
| |
| return child; |
| } |
| |
| BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, |
| BlockDriverState *child_bs, |
| const char *child_name, |
| const BdrvChildRole *child_role, |
| Error **errp) |
| { |
| BdrvChild *child; |
| uint64_t perm, shared_perm; |
| |
| bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm); |
| |
| assert(parent_bs->drv); |
| parent_bs->drv->bdrv_child_perm(parent_bs, NULL, child_role, |
| perm, shared_perm, &perm, &shared_perm); |
| |
| child = bdrv_root_attach_child(child_bs, child_name, child_role, |
| perm, shared_perm, parent_bs, errp); |
| if (child == NULL) { |
| return NULL; |
| } |
| |
| QLIST_INSERT_HEAD(&parent_bs->children, child, next); |
| return child; |
| } |
| |
| static void bdrv_detach_child(BdrvChild *child) |
| { |
| if (child->next.le_prev) { |
| QLIST_REMOVE(child, next); |
| child->next.le_prev = NULL; |
| } |
| |
| bdrv_replace_child(child, NULL, false); |
| |
| g_free(child->name); |
| g_free(child); |
| } |
| |
| void bdrv_root_unref_child(BdrvChild *child) |
| { |
| BlockDriverState *child_bs; |
| |
| child_bs = child->bs; |
| bdrv_detach_child(child); |
| bdrv_unref(child_bs); |
| } |
| |
| void bdrv_unref_child(BlockDriverState *parent, BdrvChild *child) |
| { |
| if (child == NULL) { |
| return; |
| } |
| |
| if (child->bs->inherits_from == parent) { |
| BdrvChild *c; |
| |
| /* Remove inherits_from only when the last reference between parent and |
| * child->bs goes away. */ |
| QLIST_FOREACH(c, &parent->children, next) { |
| if (c != child && c->bs == child->bs) { |
| break; |
| } |
| } |
| if (c == NULL) { |
| child->bs->inherits_from = NULL; |
| } |
| } |
| |
| bdrv_root_unref_child(child); |
| } |
| |
| |
| static void bdrv_parent_cb_change_media(BlockDriverState *bs, bool load) |
| { |
| BdrvChild *c; |
| QLIST_FOREACH(c, &bs->parents, next_parent) { |
| if (c->role->change_media) { |
| c->role->change_media(c, load); |
| } |
| } |
| } |
| |
| static void bdrv_parent_cb_resize(BlockDriverState *bs) |
| { |
| BdrvChild *c; |
| QLIST_FOREACH(c, &bs->parents, next_parent) { |
| if (c->role->resize) { |
| c->role->resize(c); |
| } |
| } |
| } |
| |
| /* |
| * Sets the backing file link of a BDS. A new reference is created; callers |
| * which don't need their own reference any more must call bdrv_unref(). |
| */ |
| void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd, |
| Error **errp) |
| { |
| if (backing_hd) { |
| bdrv_ref(backing_hd); |
| } |
| |
| if (bs->backing) { |
| bdrv_unref_child(bs, bs->backing); |
| } |
| |
| if (!backing_hd) { |
| bs->backing = NULL; |
| goto out; |
| } |
| |
| bs->backing = bdrv_attach_child(bs, backing_hd, "backing", &child_backing, |
| errp); |
| if (!bs->backing) { |
| bdrv_unref(backing_hd); |
| } |
| |
| out: |
| bdrv_refresh_limits(bs, NULL); |
| } |
| |
| /* |
| * Opens the backing file for a BlockDriverState if not yet open |
| * |
| * bdref_key specifies the key for the image's BlockdevRef in the options QDict. |
| * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict |
| * itself, all options starting with "${bdref_key}." are considered part of the |
| * BlockdevRef. |
| * |
| * TODO Can this be unified with bdrv_open_image()? |
| */ |
| int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, |
| const char *bdref_key, Error **errp) |
| { |
| char *backing_filename = g_malloc0(PATH_MAX); |
| char *bdref_key_dot; |
| const char *reference = NULL; |
| int ret = 0; |
| BlockDriverState *backing_hd; |
| QDict *options; |
| QDict *tmp_parent_options = NULL; |
| Error *local_err = NULL; |
| |
| if (bs->backing != NULL) { |
| goto free_exit; |
| } |
| |
| /* NULL means an empty set of options */ |
| if (parent_options == NULL) { |
| tmp_parent_options = qdict_new(); |
| parent_options = tmp_parent_options; |
| } |
| |
| bs->open_flags &= ~BDRV_O_NO_BACKING; |
| |
| bdref_key_dot = g_strdup_printf("%s.", bdref_key); |
| qdict_extract_subqdict(parent_options, &options, bdref_key_dot); |
| g_free(bdref_key_dot); |
| |
| reference = qdict_get_try_str(parent_options, bdref_key); |
| if (reference || qdict_haskey(options, "file.filename")) { |
| backing_filename[0] = '\0'; |
| } else if (bs->backing_file[0] == '\0' && qdict_size(options) == 0) { |
| QDECREF(options); |
| goto free_exit; |
| } else { |
| bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX, |
| &local_err); |
| if (local_err) { |
| ret = -EINVAL; |
| error_propagate(errp, local_err); |
| QDECREF(options); |
| goto free_exit; |
| } |
| } |
| |
| if (!bs->drv || !bs->drv->supports_backing) { |
| ret = -EINVAL; |
| error_setg(errp, "Driver doesn't support backing files"); |
| QDECREF(options); |
| goto free_exit; |
| } |
| |
| if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { |
| qdict_put(options, "driver", qstring_from_str(bs->backing_format)); |
| } |
| |
| backing_hd = bdrv_open_inherit(*backing_filename ? backing_filename : NULL, |
| reference, options, 0, bs, &child_backing, |
| errp); |
| if (!backing_hd) { |
| bs->open_flags |= BDRV_O_NO_BACKING; |
| error_prepend(errp, "Could not open backing file: "); |
| ret = -EINVAL; |
| goto free_exit; |
| } |
| |
| /* Hook up the backing file link; drop our reference, bs owns the |
| * backing_hd reference now */ |
| bdrv_set_backing_hd(bs, backing_hd, &local_err); |
| bdrv_unref(backing_hd); |
| if (local_err) { |
| ret = -EINVAL; |
| goto free_exit; |
| } |
| |
| qdict_del(parent_options, bdref_key); |
| |
| free_exit: |
| g_free(backing_filename); |
| QDECREF(tmp_parent_options); |
| return ret; |
| } |
| |
| static BlockDriverState * |
| bdrv_open_child_bs(const char *filename, QDict *options, const char *bdref_key, |
| BlockDriverState *parent, const BdrvChildRole *child_role, |
| bool allow_none, Error **errp) |
| { |
| BlockDriverState *bs = NULL; |
| QDict *image_options; |
| char *bdref_key_dot; |
| const char *reference; |
| |
| assert(child_role != NULL); |
| |
| bdref_key_dot = g_strdup_printf("%s.", bdref_key); |
| qdict_extract_subqdict(options, &image_options, bdref_key_dot); |
| g_free(bdref_key_dot); |
| |
| reference = qdict_get_try_str(options, bdref_key); |
| if (!filename && !reference && !qdict_size(image_options)) { |
| if (!allow_none) { |
| error_setg(errp, "A block device must be specified for \"%s\"", |
| bdref_key); |
| } |
| QDECREF(image_options); |
| goto done; |
| } |
| |
| bs = bdrv_open_inherit(filename, reference, image_options, 0, |
| parent, child_role, errp); |
| if (!bs) { |
| goto done; |
| } |
| |
| done: |
| qdict_del(options, bdref_key); |
| return bs; |
| } |
| |
| /* |
| * Opens a disk image whose options are given as BlockdevRef in another block |
| * device's options. |
| * |
| * If allow_none is true, no image will be opened if filename is false and no |
| * BlockdevRef is given. NULL will be returned, but errp remains unset. |
| * |
| * bdrev_key specifies the key for the image's BlockdevRef in the options QDict. |
| * That QDict has to be flattened; therefore, if the BlockdevRef is a QDict |
| * itself, all options starting with "${bdref_key}." are considered part of the |
| * BlockdevRef. |
| * |
| * The BlockdevRef will be removed from the options QDict. |
| */ |
| BdrvChild *bdrv_open_child(const char *filename, |
| QDict *options, const char *bdref_key, |
| BlockDriverState *parent, |
| const BdrvChildRole *child_role, |
| bool allow_none, Error **errp) |
| { |
| BdrvChild *c; |
| BlockDriverState *bs; |
| |
| bs = bdrv_open_child_bs(filename, options, bdref_key, parent, child_role, |
| allow_none, errp); |
| if (bs == NULL) { |
| return NULL; |
| } |
| |
| c = bdrv_attach_child(parent, bs, bdref_key, child_role, errp); |
| if (!c) { |
| bdrv_unref(bs); |
| return NULL; |
| } |
| |
| return c; |
| } |
| |
| static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs, |
| int flags, |
| QDict *snapshot_options, |
| Error **errp) |
| { |
| /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */ |
| char *tmp_filename = g_malloc0(PATH_MAX + 1); |
| int64_t total_size; |
| QemuOpts *opts = NULL; |
| BlockDriverState *bs_snapshot; |
| Error *local_err = NULL; |
| int ret; |
| |
| /* if snapshot, we create a temporary backing file and open it |
| instead of opening 'filename' directly */ |
| |
| /* Get the required size from the image */ |
| total_size = bdrv_getlength(bs); |
| if (total_size < 0) { |
| error_setg_errno(errp, -total_size, "Could not get image size"); |
| goto out; |
| } |
| |
| /* Create the temporary image */ |
| ret = get_tmp_filename(tmp_filename, PATH_MAX + 1); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not get temporary filename"); |
| goto out; |
| } |
| |
| opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0, |
| &error_abort); |
| qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort); |
| ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp); |
| qemu_opts_del(opts); |
| if (ret < 0) { |
| error_prepend(errp, "Could not create temporary overlay '%s': ", |
| tmp_filename); |
| goto out; |
| } |
| |
| /* Prepare options QDict for the temporary file */ |
| qdict_put(snapshot_options, "file.driver", |
| qstring_from_str("file")); |
| qdict_put(snapshot_options, "file.filename", |
| qstring_from_str(tmp_filename)); |
| qdict_put(snapshot_options, "driver", |
| qstring_from_str("qcow2")); |
| |
| bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp); |
| snapshot_options = NULL; |
| if (!bs_snapshot) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will |
| * call bdrv_unref() on it), so in order to be able to return one, we have |
| * to increase bs_snapshot's refcount here */ |
| bdrv_ref(bs_snapshot); |
| bdrv_append(bs_snapshot, bs, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| g_free(tmp_filename); |
| return bs_snapshot; |
| |
| out: |
| QDECREF(snapshot_options); |
| g_free(tmp_filename); |
| return NULL; |
| } |
| |
| /* |
| * Opens a disk image (raw, qcow2, vmdk, ...) |
| * |
| * options is a QDict of options to pass to the block drivers, or NULL for an |
| * empty set of options. The reference to the QDict belongs to the block layer |
| * after the call (even on failure), so if the caller intends to reuse the |
| * dictionary, it needs to use QINCREF() before calling bdrv_open. |
| * |
| * If *pbs is NULL, a new BDS will be created with a pointer to it stored there. |
| * If it is not NULL, the referenced BDS will be reused. |
| * |
| * The reference parameter may be used to specify an existing block device which |
| * should be opened. If specified, neither options nor a filename may be given, |
| * nor can an existing BDS be reused (that is, *pbs has to be NULL). |
| */ |
| static BlockDriverState *bdrv_open_inherit(const char *filename, |
| const char *reference, |
| QDict *options, int flags, |
| BlockDriverState *parent, |
| const BdrvChildRole *child_role, |
| Error **errp) |
| { |
| int ret; |
| BlockBackend *file = NULL; |
| BlockDriverState *bs; |
| BlockDriver *drv = NULL; |
| const char *drvname; |
| const char *backing; |
| Error *local_err = NULL; |
| QDict *snapshot_options = NULL; |
| int snapshot_flags = 0; |
| |
| assert(!child_role || !flags); |
| assert(!child_role == !parent); |
| |
| if (reference) { |
| bool options_non_empty = options ? qdict_size(options) : false; |
| QDECREF(options); |
| |
| if (filename || options_non_empty) { |
| error_setg(errp, "Cannot reference an existing block device with " |
| "additional options or a new filename"); |
| return NULL; |
| } |
| |
| bs = bdrv_lookup_bs(reference, reference, errp); |
| if (!bs) { |
| return NULL; |
| } |
| |
| bdrv_ref(bs); |
| return bs; |
| } |
| |
| bs = bdrv_new(); |
| |
| /* NULL means an empty set of options */ |
| if (options == NULL) { |
| options = qdict_new(); |
| } |
| |
| /* json: syntax counts as explicit options, as if in the QDict */ |
| parse_json_protocol(options, &filename, &local_err); |
| if (local_err) { |
| goto fail; |
| } |
| |
| bs->explicit_options = qdict_clone_shallow(options); |
| |
| if (child_role) { |
| bs->inherits_from = parent; |
| child_role->inherit_options(&flags, options, |
| parent->open_flags, parent->options); |
| } |
| |
| ret = bdrv_fill_options(&options, filename, &flags, &local_err); |
| if (local_err) { |
| goto fail; |
| } |
| |
| /* Set the BDRV_O_RDWR and BDRV_O_ALLOW_RDWR flags. |
| * FIXME: we're parsing the QDict to avoid having to create a |
| * QemuOpts just for this, but neither option is optimal. */ |
| if (g_strcmp0(qdict_get_try_str(options, BDRV_OPT_READ_ONLY), "on") && |
| !qdict_get_try_bool(options, BDRV_OPT_READ_ONLY, false)) { |
| flags |= (BDRV_O_RDWR | BDRV_O_ALLOW_RDWR); |
| } else { |
| flags &= ~BDRV_O_RDWR; |
| } |
| |
| if (flags & BDRV_O_SNAPSHOT) { |
| snapshot_options = qdict_new(); |
| bdrv_temp_snapshot_options(&snapshot_flags, snapshot_options, |
| flags, options); |
| /* Let bdrv_backing_options() override "read-only" */ |
| qdict_del(options, BDRV_OPT_READ_ONLY); |
| bdrv_backing_options(&flags, options, flags, options); |
| } |
| |
| bs->open_flags = flags; |
| bs->options = options; |
| options = qdict_clone_shallow(options); |
| |
| /* Find the right image format driver */ |
| drvname = qdict_get_try_str(options, "driver"); |
| if (drvname) { |
| drv = bdrv_find_format(drvname); |
| if (!drv) { |
| error_setg(errp, "Unknown driver: '%s'", drvname); |
| goto fail; |
| } |
| } |
| |
| assert(drvname || !(flags & BDRV_O_PROTOCOL)); |
| |
| backing = qdict_get_try_str(options, "backing"); |
| if (backing && *backing == '\0') { |
| flags |= BDRV_O_NO_BACKING; |
| qdict_del(options, "backing"); |
| } |
| |
| /* Open image file without format layer. This BlockBackend is only used for |
| * probing, the block drivers will do their own bdrv_open_child() for the |
| * same BDS, which is why we put the node name back into options. */ |
| if ((flags & BDRV_O_PROTOCOL) == 0) { |
| BlockDriverState *file_bs; |
| |
| file_bs = bdrv_open_child_bs(filename, options, "file", bs, |
| &child_file, true, &local_err); |
| if (local_err) { |
| goto fail; |
| } |
| if (file_bs != NULL) { |
| file = blk_new(BLK_PERM_CONSISTENT_READ, BLK_PERM_ALL); |
| blk_insert_bs(file, file_bs, &local_err); |
| bdrv_unref(file_bs); |
| if (local_err) { |
| goto fail; |
| } |
| |
| qdict_put(options, "file", |
| qstring_from_str(bdrv_get_node_name(file_bs))); |
| } |
| } |
| |
| /* Image format probing */ |
| bs->probed = !drv; |
| if (!drv && file) { |
| ret = find_image_format(file, filename, &drv, &local_err); |
| if (ret < 0) { |
| goto fail; |
| } |
| /* |
| * This option update would logically belong in bdrv_fill_options(), |
| * but we first need to open bs->file for the probing to work, while |
| * opening bs->file already requires the (mostly) final set of options |
| * so that cache mode etc. can be inherited. |
| * |
| * Adding the driver later is somewhat ugly, but it's not an option |
| * that would ever be inherited, so it's correct. We just need to make |
| * sure to update both bs->options (which has the full effective |
| * options for bs) and options (which has file.* already removed). |
| */ |
| qdict_put(bs->options, "driver", qstring_from_str(drv->format_name)); |
| qdict_put(options, "driver", qstring_from_str(drv->format_name)); |
| } else if (!drv) { |
| error_setg(errp, "Must specify either driver or file"); |
| goto fail; |
| } |
| |
| /* BDRV_O_PROTOCOL must be set iff a protocol BDS is about to be created */ |
| assert(!!(flags & BDRV_O_PROTOCOL) == !!drv->bdrv_file_open); |
| /* file must be NULL if a protocol BDS is about to be created |
| * (the inverse results in an error message from bdrv_open_common()) */ |
| assert(!(flags & BDRV_O_PROTOCOL) || !file); |
| |
| /* Open the image */ |
| ret = bdrv_open_common(bs, file, options, &local_err); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| if (file) { |
| blk_unref(file); |
| file = NULL; |
| } |
| |
| /* If there is a backing file, use it */ |
| if ((flags & BDRV_O_NO_BACKING) == 0) { |
| ret = bdrv_open_backing_file(bs, options, "backing", &local_err); |
| if (ret < 0) { |
| goto close_and_fail; |
| } |
| } |
| |
| bdrv_refresh_filename(bs); |
| |
| /* Check if any unknown options were used */ |
| if (qdict_size(options) != 0) { |
| const QDictEntry *entry = qdict_first(options); |
| if (flags & BDRV_O_PROTOCOL) { |
| error_setg(errp, "Block protocol '%s' doesn't support the option " |
| "'%s'", drv->format_name, entry->key); |
| } else { |
| error_setg(errp, |
| "Block format '%s' does not support the option '%s'", |
| drv->format_name, entry->key); |
| } |
| |
| goto close_and_fail; |
| } |
| |
| if (!bdrv_key_required(bs)) { |
| bdrv_parent_cb_change_media(bs, true); |
| } else if (!runstate_check(RUN_STATE_PRELAUNCH) |
| && !runstate_check(RUN_STATE_INMIGRATE) |
| && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */ |
| error_setg(errp, |
| "Guest must be stopped for opening of encrypted image"); |
| goto close_and_fail; |
| } |
| |
| QDECREF(options); |
| |
| /* For snapshot=on, create a temporary qcow2 overlay. bs points to the |
| * temporary snapshot afterwards. */ |
| if (snapshot_flags) { |
| BlockDriverState *snapshot_bs; |
| snapshot_bs = bdrv_append_temp_snapshot(bs, snapshot_flags, |
| snapshot_options, &local_err); |
| snapshot_options = NULL; |
| if (local_err) { |
| goto close_and_fail; |
| } |
| /* We are not going to return bs but the overlay on top of it |
| * (snapshot_bs); thus, we have to drop the strong reference to bs |
| * (which we obtained by calling bdrv_new()). bs will not be deleted, |
| * though, because the overlay still has a reference to it. */ |
| bdrv_unref(bs); |
| bs = snapshot_bs; |
| } |
| |
| return bs; |
| |
| fail: |
| blk_unref(file); |
| if (bs->file != NULL) { |
| bdrv_unref_child(bs, bs->file); |
| } |
| QDECREF(snapshot_options); |
| QDECREF(bs->explicit_options); |
| QDECREF(bs->options); |
| QDECREF(options); |
| bs->options = NULL; |
| bdrv_unref(bs); |
| error_propagate(errp, local_err); |
| return NULL; |
| |
| close_and_fail: |
| bdrv_unref(bs); |
| QDECREF(snapshot_options); |
| QDECREF(options); |
| error_propagate(errp, local_err); |
| return NULL; |
| } |
| |
| BlockDriverState *bdrv_open(const char *filename, const char *reference, |
| QDict *options, int flags, Error **errp) |
| { |
| return bdrv_open_inherit(filename, reference, options, flags, NULL, |
| NULL, errp); |
| } |
| |
| typedef struct BlockReopenQueueEntry { |
| bool prepared; |
| BDRVReopenState state; |
| QSIMPLEQ_ENTRY(BlockReopenQueueEntry) entry; |
| } BlockReopenQueueEntry; |
| |
| /* |
| * Adds a BlockDriverState to a simple queue for an atomic, transactional |
| * reopen of multiple devices. |
| * |
| * bs_queue can either be an existing BlockReopenQueue that has had QSIMPLE_INIT |
| * already performed, or alternatively may be NULL a new BlockReopenQueue will |
| * be created and initialized. This newly created BlockReopenQueue should be |
| * passed back in for subsequent calls that are intended to be of the same |
| * atomic 'set'. |
| * |
| * bs is the BlockDriverState to add to the reopen queue. |
| * |
| * options contains the changed options for the associated bs |
| * (the BlockReopenQueue takes ownership) |
| * |
| * flags contains the open flags for the associated bs |
| * |
| * returns a pointer to bs_queue, which is either the newly allocated |
| * bs_queue, or the existing bs_queue being used. |
| * |
| */ |
| static BlockReopenQueue *bdrv_reopen_queue_child(BlockReopenQueue *bs_queue, |
| BlockDriverState *bs, |
| QDict *options, |
| int flags, |
| const BdrvChildRole *role, |
| QDict *parent_options, |
| int parent_flags) |
| { |
| assert(bs != NULL); |
| |
| BlockReopenQueueEntry *bs_entry; |
| BdrvChild *child; |
| QDict *old_options, *explicit_options; |
| |
| if (bs_queue == NULL) { |
| bs_queue = g_new0(BlockReopenQueue, 1); |
| QSIMPLEQ_INIT(bs_queue); |
| } |
| |
| if (!options) { |
| options = qdict_new(); |
| } |
| |
| /* Check if this BlockDriverState is already in the queue */ |
| QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { |
| if (bs == bs_entry->state.bs) { |
| break; |
| } |
| } |
| |
| /* |
| * Precedence of options: |
| * 1. Explicitly passed in options (highest) |
| * 2. Set in flags (only for top level) |
| * 3. Retained from explicitly set options of bs |
| * 4. Inherited from parent node |
| * 5. Retained from effective options of bs |
| */ |
| |
| if (!parent_options) { |
| /* |
| * Any setting represented by flags is always updated. If the |
| * corresponding QDict option is set, it takes precedence. Otherwise |
| * the flag is translated into a QDict option. The old setting of bs is |
| * not considered. |
| */ |
| update_options_from_flags(options, flags); |
| } |
| |
| /* Old explicitly set values (don't overwrite by inherited value) */ |
| if (bs_entry) { |
| old_options = qdict_clone_shallow(bs_entry->state.explicit_options); |
| } else { |
| old_options = qdict_clone_shallow(bs->explicit_options); |
| } |
| bdrv_join_options(bs, options, old_options); |
| QDECREF(old_options); |
| |
| explicit_options = qdict_clone_shallow(options); |
| |
| /* Inherit from parent node */ |
| if (parent_options) { |
| assert(!flags); |
| role->inherit_options(&flags, options, parent_flags, parent_options); |
| } |
| |
| /* Old values are used for options that aren't set yet */ |
| old_options = qdict_clone_shallow(bs->options); |
| bdrv_join_options(bs, options, old_options); |
| QDECREF(old_options); |
| |
| /* bdrv_open() masks this flag out */ |
| flags &= ~BDRV_O_PROTOCOL; |
| |
| QLIST_FOREACH(child, &bs->children, next) { |
| QDict *new_child_options; |
| char *child_key_dot; |
| |
| /* reopen can only change the options of block devices that were |
| * implicitly created and inherited options. For other (referenced) |
| * block devices, a syntax like "backing.foo" results in an error. */ |
| if (child->bs->inherits_from != bs) { |
| continue; |
| } |
| |
| child_key_dot = g_strdup_printf("%s.", child->name); |
| qdict_extract_subqdict(options, &new_child_options, child_key_dot); |
| g_free(child_key_dot); |
| |
| bdrv_reopen_queue_child(bs_queue, child->bs, new_child_options, 0, |
| child->role, options, flags); |
| } |
| |
| if (!bs_entry) { |
| bs_entry = g_new0(BlockReopenQueueEntry, 1); |
| QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); |
| } else { |
| QDECREF(bs_entry->state.options); |
| QDECREF(bs_entry->state.explicit_options); |
| } |
| |
| bs_entry->state.bs = bs; |
| bs_entry->state.options = options; |
| bs_entry->state.explicit_options = explicit_options; |
| bs_entry->state.flags = flags; |
| |
| return bs_queue; |
| } |
| |
| BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, |
| BlockDriverState *bs, |
| QDict *options, int flags) |
| { |
| return bdrv_reopen_queue_child(bs_queue, bs, options, flags, |
| NULL, NULL, 0); |
| } |
| |
| /* |
| * Reopen multiple BlockDriverStates atomically & transactionally. |
| * |
| * The queue passed in (bs_queue) must have been built up previous |
| * via bdrv_reopen_queue(). |
| * |
| * Reopens all BDS specified in the queue, with the appropriate |
| * flags. All devices are prepared for reopen, and failure of any |
| * device will cause all device changes to be abandonded, and intermediate |
| * data cleaned up. |
| * |
| * If all devices prepare successfully, then the changes are committed |
| * to all devices. |
| * |
| */ |
| int bdrv_reopen_multiple(AioContext *ctx, BlockReopenQueue *bs_queue, Error **errp) |
| { |
| int ret = -1; |
| BlockReopenQueueEntry *bs_entry, *next; |
| Error *local_err = NULL; |
| |
| assert(bs_queue != NULL); |
| |
| aio_context_release(ctx); |
| bdrv_drain_all_begin(); |
| aio_context_acquire(ctx); |
| |
| QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { |
| if (bdrv_reopen_prepare(&bs_entry->state, bs_queue, &local_err)) { |
| error_propagate(errp, local_err); |
| goto cleanup; |
| } |
| bs_entry->prepared = true; |
| } |
| |
| /* If we reach this point, we have success and just need to apply the |
| * changes |
| */ |
| QSIMPLEQ_FOREACH(bs_entry, bs_queue, entry) { |
| bdrv_reopen_commit(&bs_entry->state); |
| } |
| |
| ret = 0; |
| |
| cleanup: |
| QSIMPLEQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) { |
| if (ret && bs_entry->prepared) { |
| bdrv_reopen_abort(&bs_entry->state); |
| } else if (ret) { |
| QDECREF(bs_entry->state.explicit_options); |
| } |
| QDECREF(bs_entry->state.options); |
| g_free(bs_entry); |
| } |
| g_free(bs_queue); |
| |
| bdrv_drain_all_end(); |
| |
| return ret; |
| } |
| |
| |
| /* Reopen a single BlockDriverState with the specified flags. */ |
| int bdrv_reopen(BlockDriverState *bs, int bdrv_flags, Error **errp) |
| { |
| int ret = -1; |
| Error *local_err = NULL; |
| BlockReopenQueue *queue = bdrv_reopen_queue(NULL, bs, NULL, bdrv_flags); |
| |
| ret = bdrv_reopen_multiple(bdrv_get_aio_context(bs), queue, &local_err); |
| if (local_err != NULL) { |
| error_propagate(errp, local_err); |
| } |
| return ret; |
| } |
| |
| |
| /* |
| * Prepares a BlockDriverState for reopen. All changes are staged in the |
| * 'opaque' field of the BDRVReopenState, which is used and allocated by |
| * the block driver layer .bdrv_reopen_prepare() |
| * |
| * bs is the BlockDriverState to reopen |
| * flags are the new open flags |
| * queue is the reopen queue |
| * |
| * Returns 0 on success, non-zero on error. On error errp will be set |
| * as well. |
| * |
| * On failure, bdrv_reopen_abort() will be called to clean up any data. |
| * It is the responsibility of the caller to then call the abort() or |
| * commit() for any other BDS that have been left in a prepare() state |
| * |
| */ |
| int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, |
| Error **errp) |
| { |
| int ret = -1; |
| Error *local_err = NULL; |
| BlockDriver *drv; |
| QemuOpts *opts; |
| const char *value; |
| |
| assert(reopen_state != NULL); |
| assert(reopen_state->bs->drv != NULL); |
| drv = reopen_state->bs->drv; |
| |
| /* Process generic block layer options */ |
| opts = qemu_opts_create(&bdrv_runtime_opts, NULL, 0, &error_abort); |
| qemu_opts_absorb_qdict(opts, reopen_state->options, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto error; |
| } |
| |
| update_flags_from_options(&reopen_state->flags, opts); |
| |
| /* node-name and driver must be unchanged. Put them back into the QDict, so |
| * that they are checked at the end of this function. */ |
| value = qemu_opt_get(opts, "node-name"); |
| if (value) { |
| qdict_put(reopen_state->options, "node-name", qstring_from_str(value)); |
| } |
| |
| value = qemu_opt_get(opts, "driver"); |
| if (value) { |
| qdict_put(reopen_state->options, "driver", qstring_from_str(value)); |
| } |
| |
| /* if we are to stay read-only, do not allow permission change |
| * to r/w */ |
| if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) && |
| reopen_state->flags & BDRV_O_RDWR) { |
| error_setg(errp, "Node '%s' is read only", |
| bdrv_get_device_or_node_name(reopen_state->bs)); |
| goto error; |
| } |
| |
| |
| ret = bdrv_flush(reopen_state->bs); |
| if (ret) { |
| error_setg_errno(errp, -ret, "Error flushing drive"); |
| goto error; |
| } |
| |
| if (drv->bdrv_reopen_prepare) { |
| ret = drv->bdrv_reopen_prepare(reopen_state, queue, &local_err); |
| if (ret) { |
| if (local_err != NULL) { |
| error_propagate(errp, local_err); |
| } else { |
| error_setg(errp, "failed while preparing to reopen image '%s'", |
| reopen_state->bs->filename); |
| } |
| goto error; |
| } |
| } else { |
| /* It is currently mandatory to have a bdrv_reopen_prepare() |
| * handler for each supported drv. */ |
| error_setg(errp, "Block format '%s' used by node '%s' " |
| "does not support reopening files", drv->format_name, |
| bdrv_get_device_or_node_name(reopen_state->bs)); |
| ret = -1; |
| goto error; |
| } |
| |
| /* Options that are not handled are only okay if they are unchanged |
| * compared to the old state. It is expected that some options are only |
| * used for the initial open, but not reopen (e.g. filename) */ |
| if (qdict_size(reopen_state->options)) { |
| const QDictEntry *entry = qdict_first(reopen_state->options); |
| |
| do { |
| QString *new_obj = qobject_to_qstring(entry->value); |
| const char *new = qstring_get_str(new_obj); |
| const char *old = qdict_get_try_str(reopen_state->bs->options, |
| entry->key); |
| |
| if (!old || strcmp(new, old)) { |
| error_setg(errp, "Cannot change the option '%s'", entry->key); |
| ret = -EINVAL; |
| goto error; |
| } |
| } while ((entry = qdict_next(reopen_state->options, entry))); |
| } |
| |
| ret = 0; |
| |
| error: |
| qemu_opts_del(opts); |
| return ret; |
| } |
| |
| /* |
| * Takes the staged changes for the reopen from bdrv_reopen_prepare(), and |
| * makes them final by swapping the staging BlockDriverState contents into |
| * the active BlockDriverState contents. |
| */ |
| void bdrv_reopen_commit(BDRVReopenState *reopen_state) |
| { |
| BlockDriver *drv; |
| |
| assert(reopen_state != NULL); |
| drv = reopen_state->bs->drv; |
| assert(drv != NULL); |
| |
| /* If there are any driver level actions to take */ |
| if (drv->bdrv_reopen_commit) { |
| drv->bdrv_reopen_commit(reopen_state); |
| } |
| |
| /* set BDS specific flags now */ |
| QDECREF(reopen_state->bs->explicit_options); |
| |
| reopen_state->bs->explicit_options = reopen_state->explicit_options; |
| reopen_state->bs->open_flags = reopen_state->flags; |
| reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR); |
| |
| bdrv_refresh_limits(reopen_state->bs, NULL); |
| } |
| |
| /* |
| * Abort the reopen, and delete and free the staged changes in |
| * reopen_state |
| */ |
| void bdrv_reopen_abort(BDRVReopenState *reopen_state) |
| { |
| BlockDriver *drv; |
| |
| assert(reopen_state != NULL); |
| drv = reopen_state->bs->drv; |
| assert(drv != NULL); |
| |
| if (drv->bdrv_reopen_abort) { |
| drv->bdrv_reopen_abort(reopen_state); |
| } |
| |
| QDECREF(reopen_state->explicit_options); |
| } |
| |
| |
| static void bdrv_close(BlockDriverState *bs) |
| { |
| BdrvAioNotifier *ban, *ban_next; |
| |
| assert(!bs->job); |
| assert(!bs->refcnt); |
| |
| bdrv_drained_begin(bs); /* complete I/O */ |
| bdrv_flush(bs); |
| bdrv_drain(bs); /* in case flush left pending I/O */ |
| |
| bdrv_release_named_dirty_bitmaps(bs); |
| assert(QLIST_EMPTY(&bs->dirty_bitmaps)); |
| |
| if (bs->drv) { |
| BdrvChild *child, *next; |
| |
| bs->drv->bdrv_close(bs); |
| bs->drv = NULL; |
| |
| bdrv_set_backing_hd(bs, NULL, &error_abort); |
| |
| if (bs->file != NULL) { |
| bdrv_unref_child(bs, bs->file); |
| bs->file = NULL; |
| } |
| |
| QLIST_FOREACH_SAFE(child, &bs->children, next, next) { |
| /* TODO Remove bdrv_unref() from drivers' close function and use |
| * bdrv_unref_child() here */ |
| if (child->bs->inherits_from == bs) { |
| child->bs->inherits_from = NULL; |
| } |
| bdrv_detach_child(child); |
| } |
| |
| g_free(bs->opaque); |
| bs->opaque = NULL; |
| bs->copy_on_read = 0; |
| bs->backing_file[0] = '\0'; |
| bs->backing_format[0] = '\0'; |
| bs->total_sectors = 0; |
| bs->encrypted = false; |
| bs->valid_key = false; |
| bs->sg = false; |
| QDECREF(bs->options); |
| QDECREF(bs->explicit_options); |
| bs->options = NULL; |
| QDECREF(bs->full_open_options); |
| bs->full_open_options = NULL; |
| } |
| |
| QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { |
| g_free(ban); |
| } |
| QLIST_INIT(&bs->aio_notifiers); |
| bdrv_drained_end(bs); |
| } |
| |
| void bdrv_close_all(void) |
| { |
| block_job_cancel_sync_all(); |
| nbd_export_close_all(); |
| |
| /* Drop references from requests still in flight, such as canceled block |
| * jobs whose AIO context has not been polled yet */ |
| bdrv_drain_all(); |
| |
| blk_remove_all_bs(); |
| blockdev_close_all_bdrv_states(); |
| |
| assert(QTAILQ_EMPTY(&all_bdrv_states)); |
| } |
| |
| static bool should_update_child(BdrvChild *c, BlockDriverState *to) |
| { |
| BdrvChild *to_c; |
| |
| if (c->role->stay_at_node) { |
| return false; |
| } |
| |
| if (c->role == &child_backing) { |
| /* If @from is a backing file of @to, ignore the child to avoid |
| * creating a loop. We only want to change the pointer of other |
| * parents. */ |
| QLIST_FOREACH(to_c, &to->children, next) { |
| if (to_c == c) { |
| break; |
| } |
| } |
| if (to_c) { |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| static void change_parent_backing_link(BlockDriverState *from, |
| BlockDriverState *to) |
| { |
| BdrvChild *c, *next; |
| |
| QLIST_FOREACH_SAFE(c, &from->parents, next_parent, next) { |
| if (!should_update_child(c, to)) { |
| continue; |
| } |
| |
| bdrv_ref(to); |
| /* FIXME Are we sure that bdrv_replace_child() can't run into |
| * &error_abort because of permissions? */ |
| bdrv_replace_child(c, to, true); |
| bdrv_unref(from); |
| } |
| } |
| |
| /* |
| * Add new bs contents at the top of an image chain while the chain is |
| * live, while keeping required fields on the top layer. |
| * |
| * This will modify the BlockDriverState fields, and swap contents |
| * between bs_new and bs_top. Both bs_new and bs_top are modified. |
| * |
| * bs_new must not be attached to a BlockBackend. |
| * |
| * This function does not create any image files. |
| * |
| * bdrv_append() takes ownership of a bs_new reference and unrefs it because |
| * that's what the callers commonly need. bs_new will be referenced by the old |
| * parents of bs_top after bdrv_append() returns. If the caller needs to keep a |
| * reference of its own, it must call bdrv_ref(). |
| */ |
| void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top, |
| Error **errp) |
| { |
| Error *local_err = NULL; |
| |
| assert(!atomic_read(&bs_top->in_flight)); |
| assert(!atomic_read(&bs_new->in_flight)); |
| |
| bdrv_set_backing_hd(bs_new, bs_top, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| goto out; |
| } |
| |
| change_parent_backing_link(bs_top, bs_new); |
| |
| /* bs_new is now referenced by its new parents, we don't need the |
| * additional reference any more. */ |
| out: |
| bdrv_unref(bs_new); |
| } |
| |
| void bdrv_replace_in_backing_chain(BlockDriverState *old, BlockDriverState *new) |
| { |
| assert(!bdrv_requests_pending(old)); |
| assert(!bdrv_requests_pending(new)); |
| |
| bdrv_ref(old); |
| |
| change_parent_backing_link(old, new); |
| |
| bdrv_unref(old); |
| } |
| |
| static void bdrv_delete(BlockDriverState *bs) |
| { |
| assert(!bs->job); |
| assert(bdrv_op_blocker_is_empty(bs)); |
| assert(!bs->refcnt); |
| |
| bdrv_close(bs); |
| |
| /* remove from list, if necessary */ |
| if (bs->node_name[0] != '\0') { |
| QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list); |
| } |
| QTAILQ_REMOVE(&all_bdrv_states, bs, bs_list); |
| |
| g_free(bs); |
| } |
| |
| /* |
| * Run consistency checks on an image |
| * |
| * Returns 0 if the check could be completed (it doesn't mean that the image is |
| * free of errors) or -errno when an internal error occurred. The results of the |
| * check are stored in res. |
| */ |
| int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix) |
| { |
| if (bs->drv == NULL) { |
| return -ENOMEDIUM; |
| } |
| if (bs->drv->bdrv_check == NULL) { |
| return -ENOTSUP; |
| } |
| |
| memset(res, 0, sizeof(*res)); |
| return bs->drv->bdrv_check(bs, res, fix); |
| } |
| |
| /* |
| * Return values: |
| * 0 - success |
| * -EINVAL - backing format specified, but no file |
| * -ENOSPC - can't update the backing file because no space is left in the |
| * image file header |
| * -ENOTSUP - format driver doesn't support changing the backing file |
| */ |
| int bdrv_change_backing_file(BlockDriverState *bs, |
| const char *backing_file, const char *backing_fmt) |
| { |
| BlockDriver *drv = bs->drv; |
| int ret; |
| |
| /* Backing file format doesn't make sense without a backing file */ |
| if (backing_fmt && !backing_file) { |
| return -EINVAL; |
| } |
| |
| if (drv->bdrv_change_backing_file != NULL) { |
| ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt); |
| } else { |
| ret = -ENOTSUP; |
| } |
| |
| if (ret == 0) { |
| pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_file ?: ""); |
| pstrcpy(bs->backing_format, sizeof(bs->backing_format), backing_fmt ?: ""); |
| } |
| return ret; |
| } |
| |
| /* |
| * Finds the image layer in the chain that has 'bs' as its backing file. |
| * |
| * active is the current topmost image. |
| * |
| * Returns NULL if bs is not found in active's image chain, |
| * or if active == bs. |
| * |
| * Returns the bottommost base image if bs == NULL. |
| */ |
| BlockDriverState *bdrv_find_overlay(BlockDriverState *active, |
| BlockDriverState *bs) |
| { |
| while (active && bs != backing_bs(active)) { |
| active = backing_bs(active); |
| } |
| |
| return active; |
| } |
| |
| /* Given a BDS, searches for the base layer. */ |
| BlockDriverState *bdrv_find_base(BlockDriverState *bs) |
| { |
| return bdrv_find_overlay(bs, NULL); |
| } |
| |
| /* |
| * Drops images above 'base' up to and including 'top', and sets the image |
| * above 'top' to have base as its backing file. |
| * |
| * Requires that the overlay to 'top' is opened r/w, so that the backing file |
| * information in 'bs' can be properly updated. |
| * |
| * E.g., this will convert the following chain: |
| * bottom <- base <- intermediate <- top <- active |
| * |
| * to |
| * |
| * bottom <- base <- active |
| * |
| * It is allowed for bottom==base, in which case it converts: |
| * |
| * base <- intermediate <- top <- active |
| * |
| * to |
| * |
| * base <- active |
| * |
| * If backing_file_str is non-NULL, it will be used when modifying top's |
| * overlay image metadata. |
| * |
| * Error conditions: |
| * if active == top, that is considered an error |
| * |
| */ |
| int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, |
| BlockDriverState *base, const char *backing_file_str) |
| { |
| BlockDriverState *new_top_bs = NULL; |
| Error *local_err = NULL; |
| int ret = -EIO; |
| |
| if (!top->drv || !base->drv) { |
| goto exit; |
| } |
| |
| new_top_bs = bdrv_find_overlay(active, top); |
| |
| if (new_top_bs == NULL) { |
| /* we could not find the image above 'top', this is an error */ |
| goto exit; |
| } |
| |
| /* special case of new_top_bs->backing->bs already pointing to base - nothing |
| * to do, no intermediate images */ |
| if (backing_bs(new_top_bs) == base) { |
| ret = 0; |
| goto exit; |
| } |
| |
| /* Make sure that base is in the backing chain of top */ |
| if (!bdrv_chain_contains(top, base)) { |
| goto exit; |
| } |
| |
| /* success - we can delete the intermediate states, and link top->base */ |
| backing_file_str = backing_file_str ? backing_file_str : base->filename; |
| ret = bdrv_change_backing_file(new_top_bs, backing_file_str, |
| base->drv ? base->drv->format_name : ""); |
| if (ret) { |
| goto exit; |
| } |
| |
| bdrv_set_backing_hd(new_top_bs, base, &local_err); |
| if (local_err) { |
| ret = -EPERM; |
| error_report_err(local_err); |
| goto exit; |
| } |
| |
| ret = 0; |
| exit: |
| return ret; |
| } |
| |
| /** |
| * Truncate file to 'offset' bytes (needed only for file protocols) |
| */ |
| int bdrv_truncate(BdrvChild *child, int64_t offset) |
| { |
| BlockDriverState *bs = child->bs; |
| BlockDriver *drv = bs->drv; |
| int ret; |
| |
| assert(child->perm & BLK_PERM_RESIZE); |
| |
| if (!drv) |
| return -ENOMEDIUM; |
| if (!drv->bdrv_truncate) |
| return -ENOTSUP; |
| if (bs->read_only) |
| return -EACCES; |
| |
| ret = drv->bdrv_truncate(bs, offset); |
| if (ret == 0) { |
| ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); |
| bdrv_dirty_bitmap_truncate(bs); |
| bdrv_parent_cb_resize(bs); |
| ++bs->write_gen; |
| } |
| return ret; |
| } |
| |
| /** |
| * Length of a allocated file in bytes. Sparse files are counted by actual |
| * allocated space. Return < 0 if error or unknown. |
| */ |
| int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) { |
| return -ENOMEDIUM; |
| } |
| if (drv->bdrv_get_allocated_file_size) { |
| return drv->bdrv_get_allocated_file_size(bs); |
| } |
| if (bs->file) { |
| return bdrv_get_allocated_file_size(bs->file->bs); |
| } |
| return -ENOTSUP; |
| } |
| |
| /** |
| * Return number of sectors on success, -errno on error. |
| */ |
| int64_t bdrv_nb_sectors(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (!drv) |
| return -ENOMEDIUM; |
| |
| if (drv->has_variable_length) { |
| int ret = refresh_total_sectors(bs, bs->total_sectors); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| return bs->total_sectors; |
| } |
| |
| /** |
| * Return length in bytes on success, -errno on error. |
| * The length is always a multiple of BDRV_SECTOR_SIZE. |
| */ |
| int64_t bdrv_getlength(BlockDriverState *bs) |
| { |
| int64_t ret = bdrv_nb_sectors(bs); |
| |
| ret = ret > INT64_MAX / BDRV_SECTOR_SIZE ? -EFBIG : ret; |
| return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE; |
| } |
| |
| /* return 0 as number of sectors if no device present or error */ |
| void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr) |
| { |
| int64_t nb_sectors = bdrv_nb_sectors(bs); |
| |
| *nb_sectors_ptr = nb_sectors < 0 ? 0 : nb_sectors; |
| } |
| |
| bool bdrv_is_read_only(BlockDriverState *bs) |
| { |
| return bs->read_only; |
| } |
| |
| bool bdrv_is_sg(BlockDriverState *bs) |
| { |
| return bs->sg; |
| } |
| |
| bool bdrv_is_encrypted(BlockDriverState *bs) |
| { |
| if (bs->backing && bs->backing->bs->encrypted) { |
| return true; |
| } |
| return bs->encrypted; |
| } |
| |
| bool bdrv_key_required(BlockDriverState *bs) |
| { |
| BdrvChild *backing = bs->backing; |
| |
| if (backing && backing->bs->encrypted && !backing->bs->valid_key) { |
| return true; |
| } |
| return (bs->encrypted && !bs->valid_key); |
| } |
| |
| int bdrv_set_key(BlockDriverState *bs, const char *key) |
| { |
| int ret; |
| if (bs->backing && bs->backing->bs->encrypted) { |
| ret = bdrv_set_key(bs->backing->bs, key); |
| if (ret < 0) |
| return ret; |
| if (!bs->encrypted) |
| return 0; |
| } |
| if (!bs->encrypted) { |
| return -EINVAL; |
| } else if (!bs->drv || !bs->drv->bdrv_set_key) { |
| return -ENOMEDIUM; |
| } |
| ret = bs->drv->bdrv_set_key(bs, key); |
| if (ret < 0) { |
| bs->valid_key = false; |
| } else if (!bs->valid_key) { |
| /* call the change callback now, we skipped it on open */ |
| bs->valid_key = true; |
| bdrv_parent_cb_change_media(bs, true); |
| } |
| return ret; |
| } |
| |
| /* |
| * Provide an encryption key for @bs. |
| * If @key is non-null: |
| * If @bs is not encrypted, fail. |
| * Else if the key is invalid, fail. |
| * Else set @bs's key to @key, replacing the existing key, if any. |
| * If @key is null: |
| * If @bs is encrypted and still lacks a key, fail. |
| * Else do nothing. |
| * On failure, store an error object through @errp if non-null. |
| */ |
| void bdrv_add_key(BlockDriverState *bs, const char *key, Error **errp) |
| { |
| if (key) { |
| if (!bdrv_is_encrypted(bs)) { |
| error_setg(errp, "Node '%s' is not encrypted", |
| bdrv_get_device_or_node_name(bs)); |
| } else if (bdrv_set_key(bs, key) < 0) { |
| error_setg(errp, QERR_INVALID_PASSWORD); |
| } |
| } else { |
| if (bdrv_key_required(bs)) { |
| error_set(errp, ERROR_CLASS_DEVICE_ENCRYPTED, |
| "'%s' (%s) is encrypted", |
| bdrv_get_device_or_node_name(bs), |
| bdrv_get_encrypted_filename(bs)); |
| } |
| } |
| } |
| |
| const char *bdrv_get_format_name(BlockDriverState *bs) |
| { |
| return bs->drv ? bs->drv->format_name : NULL; |
| } |
| |
| static int qsort_strcmp(const void *a, const void *b) |
| { |
| return strcmp(*(char *const *)a, *(char *const *)b); |
| } |
| |
| void bdrv_iterate_format(void (*it)(void *opaque, const char *name), |
| void *opaque) |
| { |
| BlockDriver *drv; |
| int count = 0; |
| int i; |
| const char **formats = NULL; |
| |
| QLIST_FOREACH(drv, &bdrv_drivers, list) { |
| if (drv->format_name) { |
| bool found = false; |
| int i = count; |
| while (formats && i && !found) { |
| found = !strcmp(formats[--i], drv->format_name); |
| } |
| |
| if (!found) { |
| formats = g_renew(const char *, formats, count + 1); |
| formats[count++] = drv->format_name; |
| } |
| } |
| } |
| |
| for (i = 0; i < (int)ARRAY_SIZE(block_driver_modules); i++) { |
| const char *format_name = block_driver_modules[i].format_name; |
| |
| if (format_name) { |
| bool found = false; |
| int j = count; |
| |
| while (formats && j && !found) { |
| found = !strcmp(formats[--j], format_name); |
| } |
| |
| if (!found) { |
| formats = g_renew(const char *, formats, count + 1); |
| formats[count++] = format_name; |
| } |
| } |
| } |
| |
| qsort(formats, count, sizeof(formats[0]), qsort_strcmp); |
| |
| for (i = 0; i < count; i++) { |
| it(opaque, formats[i]); |
| } |
| |
| g_free(formats); |
| } |
| |
| /* This function is to find a node in the bs graph */ |
| BlockDriverState *bdrv_find_node(const char *node_name) |
| { |
| BlockDriverState *bs; |
| |
| assert(node_name); |
| |
| QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { |
| if (!strcmp(node_name, bs->node_name)) { |
| return bs; |
| } |
| } |
| return NULL; |
| } |
| |
| /* Put this QMP function here so it can access the static graph_bdrv_states. */ |
| BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp) |
| { |
| BlockDeviceInfoList *list, *entry; |
| BlockDriverState *bs; |
| |
| list = NULL; |
| QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { |
| BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, errp); |
| if (!info) { |
| qapi_free_BlockDeviceInfoList(list); |
| return NULL; |
| } |
| entry = g_malloc0(sizeof(*entry)); |
| entry->value = info; |
| entry->next = list; |
| list = entry; |
| } |
| |
| return list; |
| } |
| |
| BlockDriverState *bdrv_lookup_bs(const char *device, |
| const char *node_name, |
| Error **errp) |
| { |
| BlockBackend *blk; |
| BlockDriverState *bs; |
| |
| if (device) { |
| blk = blk_by_name(device); |
| |
| if (blk) { |
| bs = blk_bs(blk); |
| if (!bs) { |
| error_setg(errp, "Device '%s' has no medium", device); |
| } |
| |
| return bs; |
| } |
| } |
| |
| if (node_name) { |
| bs = bdrv_find_node(node_name); |
| |
| if (bs) { |
| return bs; |
| } |
| } |
| |
| error_setg(errp, "Cannot find device=%s nor node_name=%s", |
| device ? device : "", |
| node_name ? node_name : ""); |
| return NULL; |
| } |
| |
| /* If 'base' is in the same chain as 'top', return true. Otherwise, |
| * return false. If either argument is NULL, return false. */ |
| bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) |
| { |
| while (top && top != base) { |
| top = backing_bs(top); |
| } |
| |
| return top != NULL; |
| } |
| |
| BlockDriverState *bdrv_next_node(BlockDriverState *bs) |
| { |
| if (!bs) { |
| return QTAILQ_FIRST(&graph_bdrv_states); |
| } |
| return QTAILQ_NEXT(bs, node_list); |
| } |
| |
| const char *bdrv_get_node_name(const BlockDriverState *bs) |
| { |
| return bs->node_name; |
| } |
| |
| const char *bdrv_get_parent_name(const BlockDriverState *bs) |
| { |
| BdrvChild *c; |
| const char *name; |
| |
| /* If multiple parents have a name, just pick the first one. */ |
| QLIST_FOREACH(c, &bs->parents, next_parent) { |
| if (c->role->get_name) { |
| name = c->role->get_name(c); |
| if (name && *name) { |
| return name; |
| } |
| } |
| } |
| |
| return NULL; |
| } |
| |
| /* TODO check what callers really want: bs->node_name or blk_name() */ |
| const char *bdrv_get_device_name(const BlockDriverState *bs) |
| { |
| return bdrv_get_parent_name(bs) ?: ""; |
| } |
| |
| /* This can be used to identify nodes that might not have a device |
| * name associated. Since node and device names live in the same |
| * namespace, the result is unambiguous. The exception is if both are |
| * absent, then this returns an empty (non-null) string. */ |
| const char *bdrv_get_device_or_node_name(const BlockDriverState *bs) |
| { |
| return bdrv_get_parent_name(bs) ?: bs->node_name; |
| } |
| |
| int bdrv_get_flags(BlockDriverState *bs) |
| { |
| return bs->open_flags; |
| } |
| |
| int bdrv_has_zero_init_1(BlockDriverState *bs) |
| { |
| return 1; |
| } |
| |
| int bdrv_has_zero_init(BlockDriverState *bs) |
| { |
| assert(bs->drv); |
| |
| /* If BS is a copy on write image, it is initialized to |
| the contents of the base image, which may not be zeroes. */ |
| if (bs->backing) { |
| return 0; |
| } |
| if (bs->drv->bdrv_has_zero_init) { |
| return bs->drv->bdrv_has_zero_init(bs); |
| } |
| |
| /* safe default */ |
| return 0; |
| } |
| |
| bool bdrv_unallocated_blocks_are_zero(BlockDriverState *bs) |
| { |
| BlockDriverInfo bdi; |
| |
| if (bs->backing) { |
| return false; |
| } |
| |
| if (bdrv_get_info(bs, &bdi) == 0) { |
| return bdi.unallocated_blocks_are_zero; |
| } |
| |
| return false; |
| } |
| |
| bool bdrv_can_write_zeroes_with_unmap(BlockDriverState *bs) |
| { |
| BlockDriverInfo bdi; |
| |
| if (!(bs->open_flags & BDRV_O_UNMAP)) { |
| return false; |
| } |
| |
| if (bdrv_get_info(bs, &bdi) == 0) { |
| return bdi.can_write_zeroes_with_unmap; |
| } |
| |
| return false; |
| } |
| |
| const char *bdrv_get_encrypted_filename(BlockDriverState *bs) |
| { |
| if (bs->backing && bs->backing->bs->encrypted) |
| return bs->backing_file; |
| else if (bs->encrypted) |
| return bs->filename; |
| else |
| return NULL; |
| } |
| |
| void bdrv_get_backing_filename(BlockDriverState *bs, |
| char *filename, int filename_size) |
| { |
| pstrcpy(filename, filename_size, bs->backing_file); |
| } |
| |
| int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (!drv->bdrv_get_info) |
| return -ENOTSUP; |
| memset(bdi, 0, sizeof(*bdi)); |
| return drv->bdrv_get_info(bs, bdi); |
| } |
| |
| ImageInfoSpecific *bdrv_get_specific_info(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| if (drv && drv->bdrv_get_specific_info) { |
| return drv->bdrv_get_specific_info(bs); |
| } |
| return NULL; |
| } |
| |
| void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event) |
| { |
| if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) { |
| return; |
| } |
| |
| bs->drv->bdrv_debug_event(bs, event); |
| } |
| |
| int bdrv_debug_breakpoint(BlockDriverState *bs, const char *event, |
| const char *tag) |
| { |
| while (bs && bs->drv && !bs->drv->bdrv_debug_breakpoint) { |
| bs = bs->file ? bs->file->bs : NULL; |
| } |
| |
| if (bs && bs->drv && bs->drv->bdrv_debug_breakpoint) { |
| return bs->drv->bdrv_debug_breakpoint(bs, event, tag); |
| } |
| |
| return -ENOTSUP; |
| } |
| |
| int bdrv_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) |
| { |
| while (bs && bs->drv && !bs->drv->bdrv_debug_remove_breakpoint) { |
| bs = bs->file ? bs->file->bs : NULL; |
| } |
| |
| if (bs && bs->drv && bs->drv->bdrv_debug_remove_breakpoint) { |
| return bs->drv->bdrv_debug_remove_breakpoint(bs, tag); |
| } |
| |
| return -ENOTSUP; |
| } |
| |
| int bdrv_debug_resume(BlockDriverState *bs, const char *tag) |
| { |
| while (bs && (!bs->drv || !bs->drv->bdrv_debug_resume)) { |
| bs = bs->file ? bs->file->bs : NULL; |
| } |
| |
| if (bs && bs->drv && bs->drv->bdrv_debug_resume) { |
| return bs->drv->bdrv_debug_resume(bs, tag); |
| } |
| |
| return -ENOTSUP; |
| } |
| |
| bool bdrv_debug_is_suspended(BlockDriverState *bs, const char *tag) |
| { |
| while (bs && bs->drv && !bs->drv->bdrv_debug_is_suspended) { |
| bs = bs->file ? bs->file->bs : NULL; |
| } |
| |
| if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) { |
| return bs->drv->bdrv_debug_is_suspended(bs, tag); |
| } |
| |
| return false; |
| } |
| |
| /* backing_file can either be relative, or absolute, or a protocol. If it is |
| * relative, it must be relative to the chain. So, passing in bs->filename |
| * from a BDS as backing_file should not be done, as that may be relative to |
| * the CWD rather than the chain. */ |
| BlockDriverState *bdrv_find_backing_image(BlockDriverState *bs, |
| const char *backing_file) |
| { |
| char *filename_full = NULL; |
| char *backing_file_full = NULL; |
| char *filename_tmp = NULL; |
| int is_protocol = 0; |
| BlockDriverState *curr_bs = NULL; |
| BlockDriverState *retval = NULL; |
| Error *local_error = NULL; |
| |
| if (!bs || !bs->drv || !backing_file) { |
| return NULL; |
| } |
| |
| filename_full = g_malloc(PATH_MAX); |
| backing_file_full = g_malloc(PATH_MAX); |
| filename_tmp = g_malloc(PATH_MAX); |
| |
| is_protocol = path_has_protocol(backing_file); |
| |
| for (curr_bs = bs; curr_bs->backing; curr_bs = curr_bs->backing->bs) { |
| |
| /* If either of the filename paths is actually a protocol, then |
| * compare unmodified paths; otherwise make paths relative */ |
| if (is_protocol || path_has_protocol(curr_bs->backing_file)) { |
| if (strcmp(backing_file, curr_bs->backing_file) == 0) { |
| retval = curr_bs->backing->bs; |
| break; |
| } |
| /* Also check against the full backing filename for the image */ |
| bdrv_get_full_backing_filename(curr_bs, backing_file_full, PATH_MAX, |
| &local_error); |
| if (local_error == NULL) { |
| if (strcmp(backing_file, backing_file_full) == 0) { |
| retval = curr_bs->backing->bs; |
| break; |
| } |
| } else { |
| error_free(local_error); |
| local_error = NULL; |
| } |
| } else { |
| /* If not an absolute filename path, make it relative to the current |
| * image's filename path */ |
| path_combine(filename_tmp, PATH_MAX, curr_bs->filename, |
| backing_file); |
| |
| /* We are going to compare absolute pathnames */ |
| if (!realpath(filename_tmp, filename_full)) { |
| continue; |
| } |
| |
| /* We need to make sure the backing filename we are comparing against |
| * is relative to the current image filename (or absolute) */ |
| path_combine(filename_tmp, PATH_MAX, curr_bs->filename, |
| curr_bs->backing_file); |
| |
| if (!realpath(filename_tmp, backing_file_full)) { |
| continue; |
| } |
| |
| if (strcmp(backing_file_full, filename_full) == 0) { |
| retval = curr_bs->backing->bs; |
| break; |
| } |
| } |
| } |
| |
| g_free(filename_full); |
| g_free(backing_file_full); |
| g_free(filename_tmp); |
| return retval; |
| } |
| |
| int bdrv_get_backing_file_depth(BlockDriverState *bs) |
| { |
| if (!bs->drv) { |
| return 0; |
| } |
| |
| if (!bs->backing) { |
| return 0; |
| } |
| |
| return 1 + bdrv_get_backing_file_depth(bs->backing->bs); |
| } |
| |
| void bdrv_init(void) |
| { |
| module_call_init(MODULE_INIT_BLOCK); |
| } |
| |
| void bdrv_init_with_whitelist(void) |
| { |
| use_bdrv_whitelist = 1; |
| bdrv_init(); |
| } |
| |
| void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) |
| { |
| BdrvChild *child; |
| Error *local_err = NULL; |
| int ret; |
| |
| if (!bs->drv) { |
| return; |
| } |
| |
| if (!(bs->open_flags & BDRV_O_INACTIVE)) { |
| return; |
| } |
| |
| QLIST_FOREACH(child, &bs->children, next) { |
| bdrv_invalidate_cache(child->bs, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| return; |
| } |
| } |
| |
| bs->open_flags &= ~BDRV_O_INACTIVE; |
| if (bs->drv->bdrv_invalidate_cache) { |
| bs->drv->bdrv_invalidate_cache(bs, &local_err); |
| if (local_err) { |
| bs->open_flags |= BDRV_O_INACTIVE; |
| error_propagate(errp, local_err); |
| return; |
| } |
| } |
| |
| ret = refresh_total_sectors(bs, bs->total_sectors); |
| if (ret < 0) { |
| bs->open_flags |= BDRV_O_INACTIVE; |
| error_setg_errno(errp, -ret, "Could not refresh total sector count"); |
| return; |
| } |
| } |
| |
| void bdrv_invalidate_cache_all(Error **errp) |
| { |
| BlockDriverState *bs; |
| Error *local_err = NULL; |
| BdrvNextIterator it; |
| |
| for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
| AioContext *aio_context = bdrv_get_aio_context(bs); |
| |
| aio_context_acquire(aio_context); |
| bdrv_invalidate_cache(bs, &local_err); |
| aio_context_release(aio_context); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| return; |
| } |
| } |
| } |
| |
| static int bdrv_inactivate_recurse(BlockDriverState *bs, |
| bool setting_flag) |
| { |
| BdrvChild *child; |
| int ret; |
| |
| if (!setting_flag && bs->drv->bdrv_inactivate) { |
| ret = bs->drv->bdrv_inactivate(bs); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| |
| QLIST_FOREACH(child, &bs->children, next) { |
| ret = bdrv_inactivate_recurse(child->bs, setting_flag); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| |
| if (setting_flag) { |
| bs->open_flags |= BDRV_O_INACTIVE; |
| } |
| return 0; |
| } |
| |
| int bdrv_inactivate_all(void) |
| { |
| BlockDriverState *bs = NULL; |
| BdrvNextIterator it; |
| int ret = 0; |
| int pass; |
| |
| for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
| aio_context_acquire(bdrv_get_aio_context(bs)); |
| } |
| |
| /* We do two passes of inactivation. The first pass calls to drivers' |
| * .bdrv_inactivate callbacks recursively so all cache is flushed to disk; |
| * the second pass sets the BDRV_O_INACTIVE flag so that no further write |
| * is allowed. */ |
| for (pass = 0; pass < 2; pass++) { |
| for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
| ret = bdrv_inactivate_recurse(bs, pass); |
| if (ret < 0) { |
| goto out; |
| } |
| } |
| } |
| |
| out: |
| for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
| aio_context_release(bdrv_get_aio_context(bs)); |
| } |
| |
| return ret; |
| } |
| |
| /**************************************************************/ |
| /* removable device support */ |
| |
| /** |
| * Return TRUE if the media is present |
| */ |
| bool bdrv_is_inserted(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| BdrvChild *child; |
| |
| if (!drv) { |
| return false; |
| } |
| if (drv->bdrv_is_inserted) { |
| return drv->bdrv_is_inserted(bs); |
| } |
| QLIST_FOREACH(child, &bs->children, next) { |
| if (!bdrv_is_inserted(child->bs)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Return whether the media changed since the last call to this |
| * function, or -ENOTSUP if we don't know. Most drivers don't know. |
| */ |
| int bdrv_media_changed(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (drv && drv->bdrv_media_changed) { |
| return drv->bdrv_media_changed(bs); |
| } |
| return -ENOTSUP; |
| } |
| |
| /** |
| * If eject_flag is TRUE, eject the media. Otherwise, close the tray |
| */ |
| void bdrv_eject(BlockDriverState *bs, bool eject_flag) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (drv && drv->bdrv_eject) { |
| drv->bdrv_eject(bs, eject_flag); |
| } |
| } |
| |
| /** |
| * Lock or unlock the media (if it is locked, the user won't be able |
| * to eject it manually). |
| */ |
| void bdrv_lock_medium(BlockDriverState *bs, bool locked) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| trace_bdrv_lock_medium(bs, locked); |
| |
| if (drv && drv->bdrv_lock_medium) { |
| drv->bdrv_lock_medium(bs, locked); |
| } |
| } |
| |
| /* Get a reference to bs */ |
| void bdrv_ref(BlockDriverState *bs) |
| { |
| bs->refcnt++; |
| } |
| |
| /* Release a previously grabbed reference to bs. |
| * If after releasing, reference count is zero, the BlockDriverState is |
| * deleted. */ |
| void bdrv_unref(BlockDriverState *bs) |
| { |
| if (!bs) { |
| return; |
| } |
| assert(bs->refcnt > 0); |
| if (--bs->refcnt == 0) { |
| bdrv_delete(bs); |
| } |
| } |
| |
| struct BdrvOpBlocker { |
| Error *reason; |
| QLIST_ENTRY(BdrvOpBlocker) list; |
| }; |
| |
| bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp) |
| { |
| BdrvOpBlocker *blocker; |
| assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); |
| if (!QLIST_EMPTY(&bs->op_blockers[op])) { |
| blocker = QLIST_FIRST(&bs->op_blockers[op]); |
| if (errp) { |
| *errp = error_copy(blocker->reason); |
| error_prepend(errp, "Node '%s' is busy: ", |
| bdrv_get_device_or_node_name(bs)); |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason) |
| { |
| BdrvOpBlocker *blocker; |
| assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); |
| |
| blocker = g_new0(BdrvOpBlocker, 1); |
| blocker->reason = reason; |
| QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list); |
| } |
| |
| void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason) |
| { |
| BdrvOpBlocker *blocker, *next; |
| assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); |
| QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) { |
| if (blocker->reason == reason) { |
| QLIST_REMOVE(blocker, list); |
| g_free(blocker); |
| } |
| } |
| } |
| |
| void bdrv_op_block_all(BlockDriverState *bs, Error *reason) |
| { |
| int i; |
| for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { |
| bdrv_op_block(bs, i, reason); |
| } |
| } |
| |
| void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason) |
| { |
| int i; |
| for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { |
| bdrv_op_unblock(bs, i, reason); |
| } |
| } |
| |
| bool bdrv_op_blocker_is_empty(BlockDriverState *bs) |
| { |
| int i; |
| |
| for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { |
| if (!QLIST_EMPTY(&bs->op_blockers[i])) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| void bdrv_img_create(const char *filename, const char *fmt, |
| const char *base_filename, const char *base_fmt, |
| char *options, uint64_t img_size, int flags, |
| Error **errp, bool quiet) |
| { |
| QemuOptsList *create_opts = NULL; |
| QemuOpts *opts = NULL; |
| const char *backing_fmt, *backing_file; |
| int64_t size; |
| BlockDriver *drv, *proto_drv; |
| Error *local_err = NULL; |
| int ret = 0; |
| |
| /* Find driver and parse its options */ |
| drv = bdrv_find_format(fmt); |
| if (!drv) { |
| error_setg(errp, "Unknown file format '%s'", fmt); |
| return; |
| } |
| |
| proto_drv = bdrv_find_protocol(filename, true, errp); |
| if (!proto_drv) { |
| return; |
| } |
| |
| if (!drv->create_opts) { |
| error_setg(errp, "Format driver '%s' does not support image creation", |
| drv->format_name); |
| return; |
| } |
| |
| if (!proto_drv->create_opts) { |
| error_setg(errp, "Protocol driver '%s' does not support image creation", |
| proto_drv->format_name); |
| return; |
| } |
| |
| create_opts = qemu_opts_append(create_opts, drv->create_opts); |
| create_opts = qemu_opts_append(create_opts, proto_drv->create_opts); |
| |
| /* Create parameter list with default values */ |
| opts = qemu_opts_create(create_opts, NULL, 0, &error_abort); |
| qemu_opt_set_number(opts, BLOCK_OPT_SIZE, img_size, &error_abort); |
| |
| /* Parse -o options */ |
| if (options) { |
| qemu_opts_do_parse(opts, options, NULL, &local_err); |
| if (local_err) { |
| error_report_err(local_err); |
| local_err = NULL; |
| error_setg(errp, "Invalid options for file format '%s'", fmt); |
| goto out; |
| } |
| } |
| |
| if (base_filename) { |
| qemu_opt_set(opts, BLOCK_OPT_BACKING_FILE, base_filename, &local_err); |
| if (local_err) { |
| error_setg(errp, "Backing file not supported for file format '%s'", |
| fmt); |
| goto out; |
| } |
| } |
| |
| if (base_fmt) { |
| qemu_opt_set(opts, BLOCK_OPT_BACKING_FMT, base_fmt, &local_err); |
| if (local_err) { |
| error_setg(errp, "Backing file format not supported for file " |
| "format '%s'", fmt); |
| goto out; |
| } |
| } |
| |
| backing_file = qemu_opt_get(opts, BLOCK_OPT_BACKING_FILE); |
| if (backing_file) { |
| if (!strcmp(filename, backing_file)) { |
| error_setg(errp, "Error: Trying to create an image with the " |
| "same filename as the backing file"); |
| goto out; |
| } |
| } |
| |
| backing_fmt = qemu_opt_get(opts, BLOCK_OPT_BACKING_FMT); |
| |
| // The size for the image must always be specified, with one exception: |
| // If we are using a backing file, we can obtain the size from there |
| size = qemu_opt_get_size(opts, BLOCK_OPT_SIZE, 0); |
| if (size == -1) { |
| if (backing_file) { |
| BlockDriverState *bs; |
| char *full_backing = g_new0(char, PATH_MAX); |
| int64_t size; |
| int back_flags; |
| QDict *backing_options = NULL; |
| |
| bdrv_get_full_backing_filename_from_filename(filename, backing_file, |
| full_backing, PATH_MAX, |
| &local_err); |
| if (local_err) { |
| g_free(full_backing); |
| goto out; |
| } |
| |
| /* backing files always opened read-only */ |
| back_flags = flags; |
| back_flags &= ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); |
| |
| if (backing_fmt) { |
| backing_options = qdict_new(); |
| qdict_put(backing_options, "driver", |
| qstring_from_str(backing_fmt)); |
| } |
| |
| bs = bdrv_open(full_backing, NULL, backing_options, back_flags, |
| &local_err); |
| g_free(full_backing); |
| if (!bs) { |
| goto out; |
| } |
| size = bdrv_getlength(bs); |
| if (size < 0) { |
| error_setg_errno(errp, -size, "Could not get size of '%s'", |
| backing_file); |
| bdrv_unref(bs); |
| goto out; |
| } |
| |
| qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort); |
| |
| bdrv_unref(bs); |
| } else { |
| error_setg(errp, "Image creation needs a size parameter"); |
| goto out; |
| } |
| } |
| |
| if (!quiet) { |
| printf("Formatting '%s', fmt=%s ", filename, fmt); |
| qemu_opts_print(opts, " "); |
| puts(""); |
| } |
| |
| ret = bdrv_create(drv, filename, opts, &local_err); |
| |
| if (ret == -EFBIG) { |
| /* This is generally a better message than whatever the driver would |
| * deliver (especially because of the cluster_size_hint), since that |
| * is most probably not much different from "image too large". */ |
| const char *cluster_size_hint = ""; |
| if (qemu_opt_get_size(opts, BLOCK_OPT_CLUSTER_SIZE, 0)) { |
| cluster_size_hint = " (try using a larger cluster size)"; |
| } |
| error_setg(errp, "The image size is too large for file format '%s'" |
| "%s", fmt, cluster_size_hint); |
| error_free(local_err); |
| local_err = NULL; |
| } |
| |
| out: |
| qemu_opts_del(opts); |
| qemu_opts_free(create_opts); |
| error_propagate(errp, local_err); |
| } |
| |
| AioContext *bdrv_get_aio_context(BlockDriverState *bs) |
| { |
| return bs->aio_context; |
| } |
| |
| static void bdrv_do_remove_aio_context_notifier(BdrvAioNotifier *ban) |
| { |
| QLIST_REMOVE(ban, list); |
| g_free(ban); |
| } |
| |
| void bdrv_detach_aio_context(BlockDriverState *bs) |
| { |
| BdrvAioNotifier *baf, *baf_tmp; |
| BdrvChild *child; |
| |
| if (!bs->drv) { |
| return; |
| } |
| |
| assert(!bs->walking_aio_notifiers); |
| bs->walking_aio_notifiers = true; |
| QLIST_FOREACH_SAFE(baf, &bs->aio_notifiers, list, baf_tmp) { |
| if (baf->deleted) { |
| bdrv_do_remove_aio_context_notifier(baf); |
| } else { |
| baf->detach_aio_context(baf->opaque); |
| } |
| } |
| /* Never mind iterating again to check for ->deleted. bdrv_close() will |
| * remove remaining aio notifiers if we aren't called again. |
| */ |
| bs->walking_aio_notifiers = false; |
| |
| if (bs->drv->bdrv_detach_aio_context) { |
| bs->drv->bdrv_detach_aio_context(bs); |
| } |
| QLIST_FOREACH(child, &bs->children, next) { |
| bdrv_detach_aio_context(child->bs); |
| } |
| |
| bs->aio_context = NULL; |
| } |
| |
| void bdrv_attach_aio_context(BlockDriverState *bs, |
| AioContext *new_context) |
| { |
| BdrvAioNotifier *ban, *ban_tmp; |
| BdrvChild *child; |
| |
| if (!bs->drv) { |
| return; |
| } |
| |
| bs->aio_context = new_context; |
| |
| QLIST_FOREACH(child, &bs->children, next) { |
| bdrv_attach_aio_context(child->bs, new_context); |
| } |
| if (bs->drv->bdrv_attach_aio_context) { |
| bs->drv->bdrv_attach_aio_context(bs, new_context); |
| } |
| |
| assert(!bs->walking_aio_notifiers); |
| bs->walking_aio_notifiers = true; |
| QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_tmp) { |
| if (ban->deleted) { |
| bdrv_do_remove_aio_context_notifier(ban); |
| } else { |
| ban->attached_aio_context(new_context, ban->opaque); |
| } |
| } |
| bs->walking_aio_notifiers = false; |
| } |
| |
| void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) |
| { |
| bdrv_drain(bs); /* ensure there are no in-flight requests */ |
| |
| bdrv_detach_aio_context(bs); |
| |
| /* This function executes in the old AioContext so acquire the new one in |
| * case it runs in a different thread. |
| */ |
| aio_context_acquire(new_context); |
| bdrv_attach_aio_context(bs, new_context); |
| aio_context_release(new_context); |
| } |
| |
| void bdrv_add_aio_context_notifier(BlockDriverState *bs, |
| void (*attached_aio_context)(AioContext *new_context, void *opaque), |
| void (*detach_aio_context)(void *opaque), void *opaque) |
| { |
| BdrvAioNotifier *ban = g_new(BdrvAioNotifier, 1); |
| *ban = (BdrvAioNotifier){ |
| .attached_aio_context = attached_aio_context, |
| .detach_aio_context = detach_aio_context, |
| .opaque = opaque |
| }; |
| |
| QLIST_INSERT_HEAD(&bs->aio_notifiers, ban, list); |
| } |
| |
| void bdrv_remove_aio_context_notifier(BlockDriverState *bs, |
| void (*attached_aio_context)(AioContext *, |
| void *), |
| void (*detach_aio_context)(void *), |
| void *opaque) |
| { |
| BdrvAioNotifier *ban, *ban_next; |
| |
| QLIST_FOREACH_SAFE(ban, &bs->aio_notifiers, list, ban_next) { |
| if (ban->attached_aio_context == attached_aio_context && |
| ban->detach_aio_context == detach_aio_context && |
| ban->opaque == opaque && |
| ban->deleted == false) |
| { |
| if (bs->walking_aio_notifiers) { |
| ban->deleted = true; |
| } else { |
| bdrv_do_remove_aio_context_notifier(ban); |
| } |
| return; |
| } |
| } |
| |
| abort(); |
| } |
| |
| int bdrv_amend_options(BlockDriverState *bs, QemuOpts *opts, |
| BlockDriverAmendStatusCB *status_cb, void *cb_opaque) |
| { |
| if (!bs->drv->bdrv_amend_options) { |
| return -ENOTSUP; |
| } |
| return bs->drv->bdrv_amend_options(bs, opts, status_cb, cb_opaque); |
| } |
| |
| /* This function will be called by the bdrv_recurse_is_first_non_filter method |
| * of block filter and by bdrv_is_first_non_filter. |
| * It is used to test if the given bs is the candidate or recurse more in the |
| * node graph. |
| */ |
| bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs, |
| BlockDriverState *candidate) |
| { |
| /* return false if basic checks fails */ |
| if (!bs || !bs->drv) { |
| return false; |
| } |
| |
| /* the code reached a non block filter driver -> check if the bs is |
| * the same as the candidate. It's the recursion termination condition. |
| */ |
| if (!bs->drv->is_filter) { |
| return bs == candidate; |
| } |
| /* Down this path the driver is a block filter driver */ |
| |
| /* If the block filter recursion method is defined use it to recurse down |
| * the node graph. |
| */ |
| if (bs->drv->bdrv_recurse_is_first_non_filter) { |
| return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate); |
| } |
| |
| /* the driver is a block filter but don't allow to recurse -> return false |
| */ |
| return false; |
| } |
| |
| /* This function checks if the candidate is the first non filter bs down it's |
| * bs chain. Since we don't have pointers to parents it explore all bs chains |
| * from the top. Some filters can choose not to pass down the recursion. |
| */ |
| bool bdrv_is_first_non_filter(BlockDriverState *candidate) |
| { |
| BlockDriverState *bs; |
| BdrvNextIterator it; |
| |
| /* walk down the bs forest recursively */ |
| for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) { |
| bool perm; |
| |
| /* try to recurse in this top level bs */ |
| perm = bdrv_recurse_is_first_non_filter(bs, candidate); |
| |
| /* candidate is the first non filter */ |
| if (perm) { |
| return true; |
| } |
| } |
| |
| return false; |
| } |
| |
| BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs, |
| const char *node_name, Error **errp) |
| { |
| BlockDriverState *to_replace_bs = bdrv_find_node(node_name); |
| AioContext *aio_context; |
| |
| if (!to_replace_bs) { |
| error_setg(errp, "Node name '%s' not found", node_name); |
| return NULL; |
| } |
| |
| aio_context = bdrv_get_aio_context(to_replace_bs); |
| aio_context_acquire(aio_context); |
| |
| if (bdrv_op_is_blocked(to_replace_bs, BLOCK_OP_TYPE_REPLACE, errp)) { |
| to_replace_bs = NULL; |
| goto out; |
| } |
| |
| /* We don't want arbitrary node of the BDS chain to be replaced only the top |
| * most non filter in order to prevent data corruption. |
| * Another benefit is that this tests exclude backing files which are |
| * blocked by the backing blockers. |
| */ |
| if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) { |
| error_setg(errp, "Only top most non filter can be replaced"); |
| to_replace_bs = NULL; |
| goto out; |
| } |
| |
| out: |
| aio_context_release(aio_context); |
| return to_replace_bs; |
| } |
| |
| static bool append_open_options(QDict *d, BlockDriverState *bs) |
| { |
| const QDictEntry *entry; |
| QemuOptDesc *desc; |
| BdrvChild *child; |
| bool found_any = false; |
| const char *p; |
| |
| for (entry = qdict_first(bs->options); entry; |
| entry = qdict_next(bs->options, entry)) |
| { |
| /* Exclude options for children */ |
| QLIST_FOREACH(child, &bs->children, next) { |
| if (strstart(qdict_entry_key(entry), child->name, &p) |
| && (!*p || *p == '.')) |
| { |
| break; |
| } |
| } |
| if (child) { |
| continue; |
| } |
| |
| /* And exclude all non-driver-specific options */ |
| for (desc = bdrv_runtime_opts.desc; desc->name; desc++) { |
| if (!strcmp(qdict_entry_key(entry), desc->name)) { |
| break; |
| } |
| } |
| if (desc->name) { |
| continue; |
| } |
| |
| qobject_incref(qdict_entry_value(entry)); |
| qdict_put_obj(d, qdict_entry_key(entry), qdict_entry_value(entry)); |
| found_any = true; |
| } |
| |
| return found_any; |
| } |
| |
| /* Updates the following BDS fields: |
| * - exact_filename: A filename which may be used for opening a block device |
| * which (mostly) equals the given BDS (even without any |
| * other options; so reading and writing must return the same |
| * results, but caching etc. may be different) |
| * - full_open_options: Options which, when given when opening a block device |
| * (without a filename), result in a BDS (mostly) |
| * equalling the given one |
| * - filename: If exact_filename is set, it is copied here. Otherwise, |
| * full_open_options is converted to a JSON object, prefixed with |
| * "json:" (for use through the JSON pseudo protocol) and put here. |
| */ |
| void bdrv_refresh_filename(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| QDict *opts; |
| |
| if (!drv) { |
| return; |
| } |
| |
| /* This BDS's file name will most probably depend on its file's name, so |
| * refresh that first */ |
| if (bs->file) { |
| bdrv_refresh_filename(bs->file->bs); |
| } |
| |
| if (drv->bdrv_refresh_filename) { |
| /* Obsolete information is of no use here, so drop the old file name |
| * information before refreshing it */ |
| bs->exact_filename[0] = '\0'; |
| if (bs->full_open_options) { |
| QDECREF(bs->full_open_options); |
| bs->full_open_options = NULL; |
| } |
| |
| opts = qdict_new(); |
| append_open_options(opts, bs); |
| drv->bdrv_refresh_filename(bs, opts); |
| QDECREF(opts); |
| } else if (bs->file) { |
| /* Try to reconstruct valid information from the underlying file */ |
| bool has_open_options; |
| |
| bs->exact_filename[0] = '\0'; |
| if (bs->full_open_options) { |
| QDECREF(bs->full_open_options); |
| bs->full_open_options = NULL; |
| } |
| |
| opts = qdict_new(); |
| has_open_options = append_open_options(opts, bs); |
| |
| /* If no specific options have been given for this BDS, the filename of |
| * the underlying file should suffice for this one as well */ |
| if (bs->file->bs->exact_filename[0] && !has_open_options) { |
| strcpy(bs->exact_filename, bs->file->bs->exact_filename); |
| } |
| /* Reconstructing the full options QDict is simple for most format block |
| * drivers, as long as the full options are known for the underlying |
| * file BDS. The full options QDict of that file BDS should somehow |
| * contain a representation of the filename, therefore the following |
| * suffices without querying the (exact_)filename of this BDS. */ |
| if (bs->file->bs->full_open_options) { |
| qdict_put_obj(opts, "driver", |
| QOBJECT(qstring_from_str(drv->format_name))); |
| QINCREF(bs->file->bs->full_open_options); |
| qdict_put_obj(opts, "file", |
| QOBJECT(bs->file->bs->full_open_options)); |
| |
| bs->full_open_options = opts; |
| } else { |
| QDECREF(opts); |
| } |
| } else if (!bs->full_open_options && qdict_size(bs->options)) { |
| /* There is no underlying file BDS (at least referenced by BDS.file), |
| * so the full options QDict should be equal to the options given |
| * specifically for this block device when it was opened (plus the |
| * driver specification). |
| * Because those options don't change, there is no need to update |
| * full_open_options when it's already set. */ |
| |
| opts = qdict_new(); |
| append_open_options(opts, bs); |
| qdict_put_obj(opts, "driver", |
| QOBJECT(qstring_from_str(drv->format_name))); |
| |
| if (bs->exact_filename[0]) { |
| /* This may not work for all block protocol drivers (some may |
| * require this filename to be parsed), but we have to find some |
| * default solution here, so just include it. If some block driver |
| * does not support pure options without any filename at all or |
| * needs some special format of the options QDict, it needs to |
| * implement the driver-specific bdrv_refresh_filename() function. |
| */ |
| qdict_put_obj(opts, "filename", |
| QOBJECT(qstring_from_str(bs->exact_filename))); |
| } |
| |
| bs->full_open_options = opts; |
| } |
| |
| if (bs->exact_filename[0]) { |
| pstrcpy(bs->filename, sizeof(bs->filename), bs->exact_filename); |
| } else if (bs->full_open_options) { |
| QString *json = qobject_to_json(QOBJECT(bs->full_open_options)); |
| snprintf(bs->filename, sizeof(bs->filename), "json:%s", |
| qstring_get_str(json)); |
| QDECREF(json); |
| } |
| } |
| |
| /* |
| * Hot add/remove a BDS's child. So the user can take a child offline when |
| * it is broken and take a new child online |
| */ |
| void bdrv_add_child(BlockDriverState *parent_bs, BlockDriverState *child_bs, |
| Error **errp) |
| { |
| |
| if (!parent_bs->drv || !parent_bs->drv->bdrv_add_child) { |
| error_setg(errp, "The node %s does not support adding a child", |
| bdrv_get_device_or_node_name(parent_bs)); |
| return; |
| } |
| |
| if (!QLIST_EMPTY(&child_bs->parents)) { |
| error_setg(errp, "The node %s already has a parent", |
| child_bs->node_name); |
| return; |
| } |
| |
| parent_bs->drv->bdrv_add_child(parent_bs, child_bs, errp); |
| } |
| |
| void bdrv_del_child(BlockDriverState *parent_bs, BdrvChild *child, Error **errp) |
| { |
| BdrvChild *tmp; |
| |
| if (!parent_bs->drv || !parent_bs->drv->bdrv_del_child) { |
| error_setg(errp, "The node %s does not support removing a child", |
| bdrv_get_device_or_node_name(parent_bs)); |
| return; |
| } |
| |
| QLIST_FOREACH(tmp, &parent_bs->children, next) { |
| if (tmp == child) { |
| break; |
| } |
| } |
| |
| if (!tmp) { |
| error_setg(errp, "The node %s does not have a child named %s", |
| bdrv_get_device_or_node_name(parent_bs), |
| bdrv_get_device_or_node_name(child->bs)); |
| return; |
| } |
| |
| parent_bs->drv->bdrv_del_child(parent_bs, child, errp); |
| } |