| /* |
| * 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 "config-host.h" |
| #include "qemu-common.h" |
| #include "trace.h" |
| #include "monitor/monitor.h" |
| #include "block/block_int.h" |
| #include "block/blockjob.h" |
| #include "qemu/module.h" |
| #include "qapi/qmp/qjson.h" |
| #include "sysemu/sysemu.h" |
| #include "qemu/notify.h" |
| #include "block/coroutine.h" |
| #include "block/qapi.h" |
| #include "qmp-commands.h" |
| #include "qemu/timer.h" |
| |
| #ifdef CONFIG_BSD |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <sys/ioctl.h> |
| #include <sys/queue.h> |
| #ifndef __DragonFly__ |
| #include <sys/disk.h> |
| #endif |
| #endif |
| |
| #ifdef _WIN32 |
| #include <windows.h> |
| #endif |
| |
| struct BdrvDirtyBitmap { |
| HBitmap *bitmap; |
| QLIST_ENTRY(BdrvDirtyBitmap) list; |
| }; |
| |
| #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ |
| |
| static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load); |
| static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, |
| int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque); |
| static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, |
| int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque); |
| static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| QEMUIOVector *iov); |
| static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| QEMUIOVector *iov); |
| static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, |
| int64_t offset, unsigned int bytes, QEMUIOVector *qiov, |
| BdrvRequestFlags flags); |
| static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, |
| int64_t offset, unsigned int bytes, QEMUIOVector *qiov, |
| BdrvRequestFlags flags); |
| static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, |
| int64_t sector_num, |
| QEMUIOVector *qiov, |
| int nb_sectors, |
| BdrvRequestFlags flags, |
| BlockDriverCompletionFunc *cb, |
| void *opaque, |
| bool is_write); |
| static void coroutine_fn bdrv_co_do_rw(void *opaque); |
| static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, BdrvRequestFlags flags); |
| |
| static QTAILQ_HEAD(, BlockDriverState) bdrv_states = |
| QTAILQ_HEAD_INITIALIZER(bdrv_states); |
| |
| static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states = |
| QTAILQ_HEAD_INITIALIZER(graph_bdrv_states); |
| |
| static QLIST_HEAD(, BlockDriver) bdrv_drivers = |
| QLIST_HEAD_INITIALIZER(bdrv_drivers); |
| |
| /* 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 |
| |
| /* throttling disk I/O limits */ |
| void bdrv_set_io_limits(BlockDriverState *bs, |
| ThrottleConfig *cfg) |
| { |
| int i; |
| |
| throttle_config(&bs->throttle_state, cfg); |
| |
| for (i = 0; i < 2; i++) { |
| qemu_co_enter_next(&bs->throttled_reqs[i]); |
| } |
| } |
| |
| /* this function drain all the throttled IOs */ |
| static bool bdrv_start_throttled_reqs(BlockDriverState *bs) |
| { |
| bool drained = false; |
| bool enabled = bs->io_limits_enabled; |
| int i; |
| |
| bs->io_limits_enabled = false; |
| |
| for (i = 0; i < 2; i++) { |
| while (qemu_co_enter_next(&bs->throttled_reqs[i])) { |
| drained = true; |
| } |
| } |
| |
| bs->io_limits_enabled = enabled; |
| |
| return drained; |
| } |
| |
| void bdrv_io_limits_disable(BlockDriverState *bs) |
| { |
| bs->io_limits_enabled = false; |
| |
| bdrv_start_throttled_reqs(bs); |
| |
| throttle_destroy(&bs->throttle_state); |
| } |
| |
| static void bdrv_throttle_read_timer_cb(void *opaque) |
| { |
| BlockDriverState *bs = opaque; |
| qemu_co_enter_next(&bs->throttled_reqs[0]); |
| } |
| |
| static void bdrv_throttle_write_timer_cb(void *opaque) |
| { |
| BlockDriverState *bs = opaque; |
| qemu_co_enter_next(&bs->throttled_reqs[1]); |
| } |
| |
| /* should be called before bdrv_set_io_limits if a limit is set */ |
| void bdrv_io_limits_enable(BlockDriverState *bs) |
| { |
| assert(!bs->io_limits_enabled); |
| throttle_init(&bs->throttle_state, |
| bdrv_get_aio_context(bs), |
| QEMU_CLOCK_VIRTUAL, |
| bdrv_throttle_read_timer_cb, |
| bdrv_throttle_write_timer_cb, |
| bs); |
| bs->io_limits_enabled = true; |
| } |
| |
| /* This function makes an IO wait if needed |
| * |
| * @nb_sectors: the number of sectors of the IO |
| * @is_write: is the IO a write |
| */ |
| static void bdrv_io_limits_intercept(BlockDriverState *bs, |
| unsigned int bytes, |
| bool is_write) |
| { |
| /* does this io must wait */ |
| bool must_wait = throttle_schedule_timer(&bs->throttle_state, is_write); |
| |
| /* if must wait or any request of this type throttled queue the IO */ |
| if (must_wait || |
| !qemu_co_queue_empty(&bs->throttled_reqs[is_write])) { |
| qemu_co_queue_wait(&bs->throttled_reqs[is_write]); |
| } |
| |
| /* the IO will be executed, do the accounting */ |
| throttle_account(&bs->throttle_state, is_write, bytes); |
| |
| |
| /* if the next request must wait -> do nothing */ |
| if (throttle_schedule_timer(&bs->throttle_state, is_write)) { |
| return; |
| } |
| |
| /* else queue next request for execution */ |
| qemu_co_queue_next(&bs->throttled_reqs[is_write]); |
| } |
| |
| size_t bdrv_opt_mem_align(BlockDriverState *bs) |
| { |
| if (!bs || !bs->drv) { |
| /* 4k should be on the safe side */ |
| return 4096; |
| } |
| |
| return bs->bl.opt_mem_alignment; |
| } |
| |
| /* check if the path starts with "<protocol>:" */ |
| static 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(BlockDriverState *bs, char *dest, size_t sz) |
| { |
| if (bs->backing_file[0] == '\0' || path_has_protocol(bs->backing_file)) { |
| pstrcpy(dest, sz, bs->backing_file); |
| } else { |
| path_combine(dest, sz, bs->filename, bs->backing_file); |
| } |
| } |
| |
| void bdrv_register(BlockDriver *bdrv) |
| { |
| /* Block drivers without coroutine functions need emulation */ |
| if (!bdrv->bdrv_co_readv) { |
| bdrv->bdrv_co_readv = bdrv_co_readv_em; |
| bdrv->bdrv_co_writev = bdrv_co_writev_em; |
| |
| /* bdrv_co_readv_em()/brdv_co_writev_em() work in terms of aio, so if |
| * the block driver lacks aio we need to emulate that too. |
| */ |
| if (!bdrv->bdrv_aio_readv) { |
| /* add AIO emulation layer */ |
| bdrv->bdrv_aio_readv = bdrv_aio_readv_em; |
| bdrv->bdrv_aio_writev = bdrv_aio_writev_em; |
| } |
| } |
| |
| QLIST_INSERT_HEAD(&bdrv_drivers, bdrv, list); |
| } |
| |
| /* create a new block device (by default it is empty) */ |
| BlockDriverState *bdrv_new(const char *device_name, Error **errp) |
| { |
| BlockDriverState *bs; |
| int i; |
| |
| if (bdrv_find(device_name)) { |
| error_setg(errp, "Device with id '%s' already exists", |
| device_name); |
| return NULL; |
| } |
| if (bdrv_find_node(device_name)) { |
| error_setg(errp, "Device with node-name '%s' already exists", |
| device_name); |
| return NULL; |
| } |
| |
| bs = g_malloc0(sizeof(BlockDriverState)); |
| QLIST_INIT(&bs->dirty_bitmaps); |
| pstrcpy(bs->device_name, sizeof(bs->device_name), device_name); |
| if (device_name[0] != '\0') { |
| QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list); |
| } |
| for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { |
| QLIST_INIT(&bs->op_blockers[i]); |
| } |
| bdrv_iostatus_disable(bs); |
| notifier_list_init(&bs->close_notifiers); |
| notifier_with_return_list_init(&bs->before_write_notifiers); |
| qemu_co_queue_init(&bs->throttled_reqs[0]); |
| qemu_co_queue_init(&bs->throttled_reqs[1]); |
| bs->refcnt = 1; |
| bs->aio_context = qemu_get_aio_context(); |
| |
| return bs; |
| } |
| |
| void bdrv_add_close_notifier(BlockDriverState *bs, Notifier *notify) |
| { |
| notifier_list_add(&bs->close_notifiers, notify); |
| } |
| |
| BlockDriver *bdrv_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; |
| } |
| |
| 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; |
| } |
| |
| BlockDriver *bdrv_find_whitelisted_format(const char *format_name, |
| bool read_only) |
| { |
| BlockDriver *drv = bdrv_find_format(format_name); |
| return drv && bdrv_is_whitelisted(drv, read_only) ? drv : NULL; |
| } |
| |
| typedef struct CreateCo { |
| BlockDriver *drv; |
| char *filename; |
| QEMUOptionParameter *options; |
| 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->options, &local_err); |
| if (local_err) { |
| error_propagate(&cco->err, local_err); |
| } |
| cco->ret = ret; |
| } |
| |
| int bdrv_create(BlockDriver *drv, const char* filename, |
| QEMUOptionParameter *options, Error **errp) |
| { |
| int ret; |
| |
| Coroutine *co; |
| CreateCo cco = { |
| .drv = drv, |
| .filename = g_strdup(filename), |
| .options = options, |
| .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); |
| qemu_coroutine_enter(co, &cco); |
| while (cco.ret == NOT_DONE) { |
| qemu_aio_wait(); |
| } |
| } |
| |
| 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, QEMUOptionParameter *options, |
| Error **errp) |
| { |
| BlockDriver *drv; |
| Error *local_err = NULL; |
| int ret; |
| |
| drv = bdrv_find_protocol(filename, true); |
| if (drv == NULL) { |
| error_setg(errp, "Could not find protocol for file '%s'", filename); |
| return -ENOENT; |
| } |
| |
| ret = bdrv_create(drv, filename, options, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| } |
| return ret; |
| } |
| |
| int bdrv_refresh_limits(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| memset(&bs->bl, 0, sizeof(bs->bl)); |
| |
| if (!drv) { |
| return 0; |
| } |
| |
| /* Take some limits from the children as a default */ |
| if (bs->file) { |
| bdrv_refresh_limits(bs->file); |
| bs->bl.opt_transfer_length = bs->file->bl.opt_transfer_length; |
| bs->bl.opt_mem_alignment = bs->file->bl.opt_mem_alignment; |
| } else { |
| bs->bl.opt_mem_alignment = 512; |
| } |
| |
| if (bs->backing_hd) { |
| bdrv_refresh_limits(bs->backing_hd); |
| bs->bl.opt_transfer_length = |
| MAX(bs->bl.opt_transfer_length, |
| bs->backing_hd->bl.opt_transfer_length); |
| bs->bl.opt_mem_alignment = |
| MAX(bs->bl.opt_mem_alignment, |
| bs->backing_hd->bl.opt_mem_alignment); |
| } |
| |
| /* Then let the driver override it */ |
| if (drv->bdrv_refresh_limits) { |
| return drv->bdrv_refresh_limits(bs); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * 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; |
| } |
| |
| BlockDriver *bdrv_find_protocol(const char *filename, |
| bool allow_protocol_prefix) |
| { |
| BlockDriver *drv1; |
| char protocol[128]; |
| int len; |
| const char *p; |
| |
| /* 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_find_format("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'; |
| QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
| if (drv1->protocol_name && |
| !strcmp(drv1->protocol_name, protocol)) { |
| return drv1; |
| } |
| } |
| return NULL; |
| } |
| |
| static int find_image_format(BlockDriverState *bs, const char *filename, |
| BlockDriver **pdrv, Error **errp) |
| { |
| int score, score_max; |
| BlockDriver *drv1, *drv; |
| uint8_t buf[2048]; |
| int ret = 0; |
| |
| /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ |
| if (bs->sg || !bdrv_is_inserted(bs) || bdrv_getlength(bs) == 0) { |
| drv = bdrv_find_format("raw"); |
| if (!drv) { |
| error_setg(errp, "Could not find raw image format"); |
| ret = -ENOENT; |
| } |
| *pdrv = drv; |
| return ret; |
| } |
| |
| ret = bdrv_pread(bs, 0, buf, sizeof(buf)); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not read image for determining its " |
| "format"); |
| *pdrv = NULL; |
| return ret; |
| } |
| |
| score_max = 0; |
| drv = NULL; |
| QLIST_FOREACH(drv1, &bdrv_drivers, list) { |
| if (drv1->bdrv_probe) { |
| score = drv1->bdrv_probe(buf, ret, filename); |
| if (score > score_max) { |
| score_max = score; |
| drv = drv1; |
| } |
| } |
| } |
| 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 |
| */ |
| 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 (bs->sg) |
| 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; |
| } |
| |
| /** |
| * 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_flags(const char *mode, int *flags) |
| { |
| *flags &= ~BDRV_O_CACHE_MASK; |
| |
| if (!strcmp(mode, "off") || !strcmp(mode, "none")) { |
| *flags |= BDRV_O_NOCACHE | BDRV_O_CACHE_WB; |
| } else if (!strcmp(mode, "directsync")) { |
| *flags |= BDRV_O_NOCACHE; |
| } else if (!strcmp(mode, "writeback")) { |
| *flags |= BDRV_O_CACHE_WB; |
| } else if (!strcmp(mode, "unsafe")) { |
| *flags |= BDRV_O_CACHE_WB; |
| *flags |= BDRV_O_NO_FLUSH; |
| } else if (!strcmp(mode, "writethrough")) { |
| /* this is the default */ |
| } else { |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * The copy-on-read flag is actually a reference count so multiple users may |
| * use the feature without worrying about clobbering its previous state. |
| * Copy-on-read stays enabled until all users have called to disable it. |
| */ |
| void bdrv_enable_copy_on_read(BlockDriverState *bs) |
| { |
| bs->copy_on_read++; |
| } |
| |
| void bdrv_disable_copy_on_read(BlockDriverState *bs) |
| { |
| assert(bs->copy_on_read > 0); |
| bs->copy_on_read--; |
| } |
| |
| /* |
| * Returns the 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 int bdrv_temp_snapshot_flags(int flags) |
| { |
| return (flags & ~BDRV_O_SNAPSHOT) | BDRV_O_TEMPORARY; |
| } |
| |
| /* |
| * Returns the flags that bs->file should get, based on the given flags for |
| * the parent BDS |
| */ |
| static int bdrv_inherited_flags(int flags) |
| { |
| /* Enable protocol handling, disable format probing for bs->file */ |
| flags |= BDRV_O_PROTOCOL; |
| |
| /* Our block drivers take care to send flushes and respect unmap policy, |
| * so we can enable both unconditionally on lower layers. */ |
| flags |= BDRV_O_CACHE_WB | BDRV_O_UNMAP; |
| |
| /* Clear flags that only apply to the top layer */ |
| flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_COPY_ON_READ); |
| |
| return flags; |
| } |
| |
| /* |
| * Returns the flags that bs->backing_hd should get, based on the given flags |
| * for the parent BDS |
| */ |
| static int bdrv_backing_flags(int flags) |
| { |
| /* backing files always opened read-only */ |
| flags &= ~(BDRV_O_RDWR | BDRV_O_COPY_ON_READ); |
| |
| /* snapshot=on is handled on the top layer */ |
| flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_TEMPORARY); |
| |
| return flags; |
| } |
| |
| static int bdrv_open_flags(BlockDriverState *bs, int flags) |
| { |
| int open_flags = flags | BDRV_O_CACHE_WB; |
| |
| /* |
| * Clear flags that are internal to the block layer before opening the |
| * image. |
| */ |
| open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); |
| |
| /* |
| * Snapshots should be writable. |
| */ |
| if (flags & BDRV_O_TEMPORARY) { |
| open_flags |= BDRV_O_RDWR; |
| } |
| |
| return open_flags; |
| } |
| |
| static void bdrv_assign_node_name(BlockDriverState *bs, |
| const char *node_name, |
| Error **errp) |
| { |
| if (!node_name) { |
| return; |
| } |
| |
| /* empty string node name is invalid */ |
| if (node_name[0] == '\0') { |
| error_setg(errp, "Empty node name"); |
| return; |
| } |
| |
| /* takes care of avoiding namespaces collisions */ |
| if (bdrv_find(node_name)) { |
| error_setg(errp, "node-name=%s is conflicting with a device id", |
| node_name); |
| return; |
| } |
| |
| /* takes care of avoiding duplicates node names */ |
| if (bdrv_find_node(node_name)) { |
| error_setg(errp, "Duplicate node name"); |
| return; |
| } |
| |
| /* 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); |
| } |
| |
| /* |
| * Common part for opening disk images and files |
| * |
| * Removes all processed options from *options. |
| */ |
| static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file, |
| QDict *options, int flags, BlockDriver *drv, Error **errp) |
| { |
| int ret, open_flags; |
| const char *filename; |
| const char *node_name = NULL; |
| Error *local_err = NULL; |
| |
| assert(drv != NULL); |
| assert(bs->file == NULL); |
| assert(options != NULL && bs->options != options); |
| |
| if (file != NULL) { |
| filename = 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); |
| return -EINVAL; |
| } |
| |
| trace_bdrv_open_common(bs, filename ?: "", flags, drv->format_name); |
| |
| node_name = qdict_get_try_str(options, "node-name"); |
| bdrv_assign_node_name(bs, node_name, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| return -EINVAL; |
| } |
| qdict_del(options, "node-name"); |
| |
| /* bdrv_open() with directly using a protocol as drv. This layer is already |
| * opened, so assign it to bs (while file becomes a closed BlockDriverState) |
| * and return immediately. */ |
| if (file != NULL && drv->bdrv_file_open) { |
| bdrv_swap(file, bs); |
| return 0; |
| } |
| |
| bs->open_flags = flags; |
| bs->guest_block_size = 512; |
| bs->request_alignment = 512; |
| bs->zero_beyond_eof = true; |
| open_flags = bdrv_open_flags(bs, flags); |
| bs->read_only = !(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); |
| return -ENOTSUP; |
| } |
| |
| assert(bs->copy_on_read == 0); /* bdrv_new() and bdrv_close() make it so */ |
| if (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"); |
| return -EINVAL; |
| } |
| } |
| |
| if (filename != NULL) { |
| pstrcpy(bs->filename, sizeof(bs->filename), filename); |
| } else { |
| bs->filename[0] = '\0'; |
| } |
| |
| bs->drv = drv; |
| bs->opaque = g_malloc0(drv->instance_size); |
| |
| bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB); |
| |
| /* Open the image, either directly or using a protocol */ |
| if (drv->bdrv_file_open) { |
| assert(file == NULL); |
| assert(!drv->bdrv_needs_filename || filename != NULL); |
| ret = drv->bdrv_file_open(bs, options, open_flags, &local_err); |
| } else { |
| if (file == NULL) { |
| error_setg(errp, "Can't use '%s' as a block driver for the " |
| "protocol level", drv->format_name); |
| ret = -EINVAL; |
| goto free_and_fail; |
| } |
| bs->file = file; |
| ret = drv->bdrv_open(bs, options, open_flags, &local_err); |
| } |
| |
| 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); |
| assert(bdrv_opt_mem_align(bs) != 0); |
| assert((bs->request_alignment != 0) || bs->sg); |
| return 0; |
| |
| free_and_fail: |
| bs->file = NULL; |
| g_free(bs->opaque); |
| bs->opaque = NULL; |
| bs->drv = NULL; |
| return ret; |
| } |
| |
| /* |
| * Opens a file using a protocol (file, host_device, nbd, ...) |
| * |
| * options is an indirect pointer to a QDict of options to pass to the block |
| * drivers, or pointer to NULL for an empty set of options. If this function |
| * takes ownership of the QDict reference, it will set *options to NULL; |
| * otherwise, it will contain unused/unrecognized options after this function |
| * returns. Then, the caller is responsible for freeing it. If it intends to |
| * reuse the QDict, QINCREF() should be called beforehand. |
| */ |
| static int bdrv_file_open(BlockDriverState *bs, const char *filename, |
| QDict **options, int flags, Error **errp) |
| { |
| BlockDriver *drv; |
| const char *drvname; |
| bool parse_filename = false; |
| Error *local_err = NULL; |
| int ret; |
| |
| /* Fetch the file name from the options QDict if necessary */ |
| if (!filename) { |
| filename = qdict_get_try_str(*options, "filename"); |
| } else if (filename && !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"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| /* Find the right block driver */ |
| drvname = qdict_get_try_str(*options, "driver"); |
| if (drvname) { |
| drv = bdrv_find_format(drvname); |
| if (!drv) { |
| error_setg(errp, "Unknown driver '%s'", drvname); |
| } |
| qdict_del(*options, "driver"); |
| } else if (filename) { |
| drv = bdrv_find_protocol(filename, parse_filename); |
| if (!drv) { |
| error_setg(errp, "Unknown protocol"); |
| } |
| } else { |
| error_setg(errp, "Must specify either driver or file"); |
| drv = NULL; |
| } |
| |
| if (!drv) { |
| /* errp has been set already */ |
| ret = -ENOENT; |
| goto fail; |
| } |
| |
| /* Parse the filename and open it */ |
| if (drv->bdrv_parse_filename && parse_filename) { |
| drv->bdrv_parse_filename(filename, *options, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| if (!drv->bdrv_needs_filename) { |
| qdict_del(*options, "filename"); |
| } else { |
| filename = qdict_get_str(*options, "filename"); |
| } |
| } |
| |
| if (!drv->bdrv_file_open) { |
| ret = bdrv_open(&bs, filename, NULL, *options, flags, drv, &local_err); |
| *options = NULL; |
| } else { |
| ret = bdrv_open_common(bs, NULL, *options, flags, drv, &local_err); |
| } |
| if (ret < 0) { |
| error_propagate(errp, local_err); |
| goto fail; |
| } |
| |
| bs->growable = 1; |
| return 0; |
| |
| fail: |
| return ret; |
| } |
| |
| void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) |
| { |
| |
| if (bs->backing_hd) { |
| assert(bs->backing_blocker); |
| bdrv_op_unblock_all(bs->backing_hd, bs->backing_blocker); |
| } else if (backing_hd) { |
| error_setg(&bs->backing_blocker, |
| "device is used as backing hd of '%s'", |
| bs->device_name); |
| } |
| |
| bs->backing_hd = backing_hd; |
| if (!backing_hd) { |
| error_free(bs->backing_blocker); |
| bs->backing_blocker = NULL; |
| goto out; |
| } |
| bs->open_flags &= ~BDRV_O_NO_BACKING; |
| pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename); |
| pstrcpy(bs->backing_format, sizeof(bs->backing_format), |
| backing_hd->drv ? backing_hd->drv->format_name : ""); |
| |
| bdrv_op_block_all(bs->backing_hd, bs->backing_blocker); |
| /* Otherwise we won't be able to commit due to check in bdrv_commit */ |
| bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_COMMIT, |
| bs->backing_blocker); |
| out: |
| bdrv_refresh_limits(bs); |
| } |
| |
| /* |
| * Opens the backing file for a BlockDriverState if not yet open |
| * |
| * 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 is transferred to this |
| * function (even on failure), so if the caller intends to reuse the dictionary, |
| * it needs to use QINCREF() before calling bdrv_file_open. |
| */ |
| int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) |
| { |
| char *backing_filename = g_malloc0(PATH_MAX); |
| int ret = 0; |
| BlockDriver *back_drv = NULL; |
| BlockDriverState *backing_hd; |
| Error *local_err = NULL; |
| |
| if (bs->backing_hd != NULL) { |
| QDECREF(options); |
| goto free_exit; |
| } |
| |
| /* NULL means an empty set of options */ |
| if (options == NULL) { |
| options = qdict_new(); |
| } |
| |
| bs->open_flags &= ~BDRV_O_NO_BACKING; |
| if (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); |
| } |
| |
| backing_hd = bdrv_new("", errp); |
| |
| if (bs->backing_format[0] != '\0') { |
| back_drv = bdrv_find_format(bs->backing_format); |
| } |
| |
| assert(bs->backing_hd == NULL); |
| ret = bdrv_open(&backing_hd, |
| *backing_filename ? backing_filename : NULL, NULL, options, |
| bdrv_backing_flags(bs->open_flags), back_drv, &local_err); |
| if (ret < 0) { |
| bdrv_unref(backing_hd); |
| backing_hd = NULL; |
| bs->open_flags |= BDRV_O_NO_BACKING; |
| error_setg(errp, "Could not open backing file: %s", |
| error_get_pretty(local_err)); |
| error_free(local_err); |
| goto free_exit; |
| } |
| bdrv_set_backing_hd(bs, backing_hd); |
| |
| free_exit: |
| g_free(backing_filename); |
| return ret; |
| } |
| |
| /* |
| * 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. *pbs will remain unchanged and 0 will be returned. |
| * |
| * 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. |
| * |
| * To conform with the behavior of bdrv_open(), *pbs has to be NULL. |
| */ |
| int bdrv_open_image(BlockDriverState **pbs, const char *filename, |
| QDict *options, const char *bdref_key, int flags, |
| bool allow_none, Error **errp) |
| { |
| QDict *image_options; |
| int ret; |
| char *bdref_key_dot; |
| const char *reference; |
| |
| assert(pbs); |
| assert(*pbs == 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) { |
| ret = 0; |
| } else { |
| error_setg(errp, "A block device must be specified for \"%s\"", |
| bdref_key); |
| ret = -EINVAL; |
| } |
| QDECREF(image_options); |
| goto done; |
| } |
| |
| ret = bdrv_open(pbs, filename, reference, image_options, flags, NULL, errp); |
| |
| done: |
| qdict_del(options, bdref_key); |
| return ret; |
| } |
| |
| void bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, 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; |
| BlockDriver *bdrv_qcow2; |
| QEMUOptionParameter *create_options; |
| QDict *snapshot_options; |
| BlockDriverState *bs_snapshot; |
| Error *local_err; |
| 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; |
| } |
| total_size &= BDRV_SECTOR_MASK; |
| |
| /* 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; |
| } |
| |
| bdrv_qcow2 = bdrv_find_format("qcow2"); |
| create_options = parse_option_parameters("", bdrv_qcow2->create_options, |
| NULL); |
| |
| set_option_parameter_int(create_options, BLOCK_OPT_SIZE, total_size); |
| |
| ret = bdrv_create(bdrv_qcow2, tmp_filename, create_options, &local_err); |
| free_option_parameters(create_options); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not create temporary overlay " |
| "'%s': %s", tmp_filename, |
| error_get_pretty(local_err)); |
| error_free(local_err); |
| goto out; |
| } |
| |
| /* Prepare a new options QDict for the temporary file */ |
| snapshot_options = qdict_new(); |
| qdict_put(snapshot_options, "file.driver", |
| qstring_from_str("file")); |
| qdict_put(snapshot_options, "file.filename", |
| qstring_from_str(tmp_filename)); |
| |
| bs_snapshot = bdrv_new("", &error_abort); |
| |
| ret = bdrv_open(&bs_snapshot, NULL, NULL, snapshot_options, |
| flags, bdrv_qcow2, &local_err); |
| if (ret < 0) { |
| error_propagate(errp, local_err); |
| goto out; |
| } |
| |
| bdrv_append(bs_snapshot, bs); |
| |
| out: |
| g_free(tmp_filename); |
| } |
| |
| 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; |
| } |
| |
| if (qobject_type(options_obj) != QTYPE_QDICT) { |
| qobject_decref(options_obj); |
| error_setg(errp, "Invalid JSON object given"); |
| return NULL; |
| } |
| |
| options = qobject_to_qdict(options_obj); |
| qdict_flatten(options); |
| |
| return options; |
| } |
| |
| /* |
| * 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). |
| */ |
| int bdrv_open(BlockDriverState **pbs, const char *filename, |
| const char *reference, QDict *options, int flags, |
| BlockDriver *drv, Error **errp) |
| { |
| int ret; |
| BlockDriverState *file = NULL, *bs; |
| const char *drvname; |
| Error *local_err = NULL; |
| int snapshot_flags = 0; |
| |
| assert(pbs); |
| |
| if (reference) { |
| bool options_non_empty = options ? qdict_size(options) : false; |
| QDECREF(options); |
| |
| if (*pbs) { |
| error_setg(errp, "Cannot reuse an existing BDS when referencing " |
| "another block device"); |
| return -EINVAL; |
| } |
| |
| if (filename || options_non_empty) { |
| error_setg(errp, "Cannot reference an existing block device with " |
| "additional options or a new filename"); |
| return -EINVAL; |
| } |
| |
| bs = bdrv_lookup_bs(reference, reference, errp); |
| if (!bs) { |
| return -ENODEV; |
| } |
| bdrv_ref(bs); |
| *pbs = bs; |
| return 0; |
| } |
| |
| if (*pbs) { |
| bs = *pbs; |
| } else { |
| bs = bdrv_new("", &error_abort); |
| } |
| |
| /* NULL means an empty set of options */ |
| if (options == NULL) { |
| options = qdict_new(); |
| } |
| |
| if (filename && g_str_has_prefix(filename, "json:")) { |
| QDict *json_options = parse_json_filename(filename, &local_err); |
| if (local_err) { |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| /* Options given in the filename have lower priority than options |
| * specified directly */ |
| qdict_join(options, json_options, false); |
| QDECREF(json_options); |
| filename = NULL; |
| } |
| |
| bs->options = options; |
| options = qdict_clone_shallow(options); |
| |
| if (flags & BDRV_O_PROTOCOL) { |
| assert(!drv); |
| ret = bdrv_file_open(bs, filename, &options, flags & ~BDRV_O_PROTOCOL, |
| &local_err); |
| if (!ret) { |
| drv = bs->drv; |
| goto done; |
| } else if (bs->drv) { |
| goto close_and_fail; |
| } else { |
| goto fail; |
| } |
| } |
| |
| /* Open image file without format layer */ |
| if (flags & BDRV_O_RDWR) { |
| flags |= BDRV_O_ALLOW_RDWR; |
| } |
| if (flags & BDRV_O_SNAPSHOT) { |
| snapshot_flags = bdrv_temp_snapshot_flags(flags); |
| flags = bdrv_backing_flags(flags); |
| } |
| |
| assert(file == NULL); |
| ret = bdrv_open_image(&file, filename, options, "file", |
| bdrv_inherited_flags(flags), |
| true, &local_err); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| /* Find the right image format driver */ |
| drvname = qdict_get_try_str(options, "driver"); |
| if (drvname) { |
| drv = bdrv_find_format(drvname); |
| qdict_del(options, "driver"); |
| if (!drv) { |
| error_setg(errp, "Invalid driver: '%s'", drvname); |
| ret = -EINVAL; |
| goto fail; |
| } |
| } |
| |
| if (!drv) { |
| if (file) { |
| ret = find_image_format(file, filename, &drv, &local_err); |
| } else { |
| error_setg(errp, "Must specify either driver or file"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| } |
| |
| if (!drv) { |
| goto fail; |
| } |
| |
| /* Open the image */ |
| ret = bdrv_open_common(bs, file, options, flags, drv, &local_err); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| if (file && (bs->file != file)) { |
| bdrv_unref(file); |
| file = NULL; |
| } |
| |
| /* If there is a backing file, use it */ |
| if ((flags & BDRV_O_NO_BACKING) == 0) { |
| QDict *backing_options; |
| |
| qdict_extract_subqdict(options, &backing_options, "backing."); |
| ret = bdrv_open_backing_file(bs, backing_options, &local_err); |
| if (ret < 0) { |
| goto close_and_fail; |
| } |
| } |
| |
| /* For snapshot=on, create a temporary qcow2 overlay. bs points to the |
| * temporary snapshot afterwards. */ |
| if (snapshot_flags) { |
| bdrv_append_temp_snapshot(bs, snapshot_flags, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| goto close_and_fail; |
| } |
| } |
| |
| |
| done: |
| /* Check if any unknown options were used */ |
| if (options && (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' used by device '%s' doesn't " |
| "support the option '%s'", drv->format_name, |
| bs->device_name, entry->key); |
| } |
| |
| ret = -EINVAL; |
| goto close_and_fail; |
| } |
| |
| if (!bdrv_key_required(bs)) { |
| bdrv_dev_change_media_cb(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"); |
| ret = -EBUSY; |
| goto close_and_fail; |
| } |
| |
| QDECREF(options); |
| *pbs = bs; |
| return 0; |
| |
| fail: |
| if (file != NULL) { |
| bdrv_unref(file); |
| } |
| QDECREF(bs->options); |
| QDECREF(options); |
| bs->options = NULL; |
| if (!*pbs) { |
| /* If *pbs is NULL, a new BDS has been created in this function and |
| needs to be freed now. Otherwise, it does not need to be closed, |
| since it has not really been opened yet. */ |
| bdrv_unref(bs); |
| } |
| if (local_err) { |
| error_propagate(errp, local_err); |
| } |
| return ret; |
| |
| close_and_fail: |
| /* See fail path, but now the BDS has to be always closed */ |
| if (*pbs) { |
| bdrv_close(bs); |
| } else { |
| bdrv_unref(bs); |
| } |
| QDECREF(options); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| } |
| return ret; |
| } |
| |
| 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. |
| * |
| * 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. |
| * |
| */ |
| BlockReopenQueue *bdrv_reopen_queue(BlockReopenQueue *bs_queue, |
| BlockDriverState *bs, int flags) |
| { |
| assert(bs != NULL); |
| |
| BlockReopenQueueEntry *bs_entry; |
| if (bs_queue == NULL) { |
| bs_queue = g_new0(BlockReopenQueue, 1); |
| QSIMPLEQ_INIT(bs_queue); |
| } |
| |
| /* bdrv_open() masks this flag out */ |
| flags &= ~BDRV_O_PROTOCOL; |
| |
| if (bs->file) { |
| bdrv_reopen_queue(bs_queue, bs->file, bdrv_inherited_flags(flags)); |
| } |
| |
| bs_entry = g_new0(BlockReopenQueueEntry, 1); |
| QSIMPLEQ_INSERT_TAIL(bs_queue, bs_entry, entry); |
| |
| bs_entry->state.bs = bs; |
| bs_entry->state.flags = flags; |
| |
| return bs_queue; |
| } |
| |
| /* |
| * 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(BlockReopenQueue *bs_queue, Error **errp) |
| { |
| int ret = -1; |
| BlockReopenQueueEntry *bs_entry, *next; |
| Error *local_err = NULL; |
| |
| assert(bs_queue != NULL); |
| |
| bdrv_drain_all(); |
| |
| 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); |
| } |
| g_free(bs_entry); |
| } |
| g_free(bs_queue); |
| 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, bdrv_flags); |
| |
| ret = bdrv_reopen_multiple(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; |
| |
| assert(reopen_state != NULL); |
| assert(reopen_state->bs->drv != NULL); |
| drv = reopen_state->bs->drv; |
| |
| /* 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_set(errp, QERR_DEVICE_IS_READ_ONLY, |
| reopen_state->bs->device_name); |
| goto error; |
| } |
| |
| |
| ret = bdrv_flush(reopen_state->bs); |
| if (ret) { |
| error_set(errp, ERROR_CLASS_GENERIC_ERROR, "Error (%s) flushing drive", |
| strerror(-ret)); |
| 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_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, |
| drv->format_name, reopen_state->bs->device_name, |
| "reopening of file"); |
| ret = -1; |
| goto error; |
| } |
| |
| ret = 0; |
| |
| error: |
| 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 */ |
| reopen_state->bs->open_flags = reopen_state->flags; |
| reopen_state->bs->enable_write_cache = !!(reopen_state->flags & |
| BDRV_O_CACHE_WB); |
| reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR); |
| |
| bdrv_refresh_limits(reopen_state->bs); |
| } |
| |
| /* |
| * 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); |
| } |
| } |
| |
| |
| void bdrv_close(BlockDriverState *bs) |
| { |
| if (bs->job) { |
| block_job_cancel_sync(bs->job); |
| } |
| bdrv_drain_all(); /* complete I/O */ |
| bdrv_flush(bs); |
| bdrv_drain_all(); /* in case flush left pending I/O */ |
| notifier_list_notify(&bs->close_notifiers, bs); |
| |
| if (bs->drv) { |
| if (bs->backing_hd) { |
| BlockDriverState *backing_hd = bs->backing_hd; |
| bdrv_set_backing_hd(bs, NULL); |
| bdrv_unref(backing_hd); |
| } |
| bs->drv->bdrv_close(bs); |
| g_free(bs->opaque); |
| bs->opaque = NULL; |
| bs->drv = NULL; |
| bs->copy_on_read = 0; |
| bs->backing_file[0] = '\0'; |
| bs->backing_format[0] = '\0'; |
| bs->total_sectors = 0; |
| bs->encrypted = 0; |
| bs->valid_key = 0; |
| bs->sg = 0; |
| bs->growable = 0; |
| bs->zero_beyond_eof = false; |
| QDECREF(bs->options); |
| bs->options = NULL; |
| |
| if (bs->file != NULL) { |
| bdrv_unref(bs->file); |
| bs->file = NULL; |
| } |
| } |
| |
| bdrv_dev_change_media_cb(bs, false); |
| |
| /*throttling disk I/O limits*/ |
| if (bs->io_limits_enabled) { |
| bdrv_io_limits_disable(bs); |
| } |
| } |
| |
| void bdrv_close_all(void) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
| AioContext *aio_context = bdrv_get_aio_context(bs); |
| |
| aio_context_acquire(aio_context); |
| bdrv_close(bs); |
| aio_context_release(aio_context); |
| } |
| } |
| |
| /* Check if any requests are in-flight (including throttled requests) */ |
| static bool bdrv_requests_pending(BlockDriverState *bs) |
| { |
| if (!QLIST_EMPTY(&bs->tracked_requests)) { |
| return true; |
| } |
| if (!qemu_co_queue_empty(&bs->throttled_reqs[0])) { |
| return true; |
| } |
| if (!qemu_co_queue_empty(&bs->throttled_reqs[1])) { |
| return true; |
| } |
| if (bs->file && bdrv_requests_pending(bs->file)) { |
| return true; |
| } |
| if (bs->backing_hd && bdrv_requests_pending(bs->backing_hd)) { |
| return true; |
| } |
| return false; |
| } |
| |
| /* |
| * Wait for pending requests to complete across all BlockDriverStates |
| * |
| * This function does not flush data to disk, use bdrv_flush_all() for that |
| * after calling this function. |
| * |
| * Note that completion of an asynchronous I/O operation can trigger any |
| * number of other I/O operations on other devices---for example a coroutine |
| * can be arbitrarily complex and a constant flow of I/O can come until the |
| * coroutine is complete. Because of this, it is not possible to have a |
| * function to drain a single device's I/O queue. |
| */ |
| void bdrv_drain_all(void) |
| { |
| /* Always run first iteration so any pending completion BHs run */ |
| bool busy = true; |
| BlockDriverState *bs; |
| |
| while (busy) { |
| busy = false; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
| AioContext *aio_context = bdrv_get_aio_context(bs); |
| bool bs_busy; |
| |
| aio_context_acquire(aio_context); |
| bdrv_start_throttled_reqs(bs); |
| bs_busy = bdrv_requests_pending(bs); |
| bs_busy |= aio_poll(aio_context, bs_busy); |
| aio_context_release(aio_context); |
| |
| busy |= bs_busy; |
| } |
| } |
| } |
| |
| /* make a BlockDriverState anonymous by removing from bdrv_state and |
| * graph_bdrv_state list. |
| Also, NULL terminate the device_name to prevent double remove */ |
| void bdrv_make_anon(BlockDriverState *bs) |
| { |
| if (bs->device_name[0] != '\0') { |
| QTAILQ_REMOVE(&bdrv_states, bs, device_list); |
| } |
| bs->device_name[0] = '\0'; |
| if (bs->node_name[0] != '\0') { |
| QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list); |
| } |
| bs->node_name[0] = '\0'; |
| } |
| |
| static void bdrv_rebind(BlockDriverState *bs) |
| { |
| if (bs->drv && bs->drv->bdrv_rebind) { |
| bs->drv->bdrv_rebind(bs); |
| } |
| } |
| |
| static void bdrv_move_feature_fields(BlockDriverState *bs_dest, |
| BlockDriverState *bs_src) |
| { |
| /* move some fields that need to stay attached to the device */ |
| |
| /* dev info */ |
| bs_dest->dev_ops = bs_src->dev_ops; |
| bs_dest->dev_opaque = bs_src->dev_opaque; |
| bs_dest->dev = bs_src->dev; |
| bs_dest->guest_block_size = bs_src->guest_block_size; |
| bs_dest->copy_on_read = bs_src->copy_on_read; |
| |
| bs_dest->enable_write_cache = bs_src->enable_write_cache; |
| |
| /* i/o throttled req */ |
| memcpy(&bs_dest->throttle_state, |
| &bs_src->throttle_state, |
| sizeof(ThrottleState)); |
| bs_dest->throttled_reqs[0] = bs_src->throttled_reqs[0]; |
| bs_dest->throttled_reqs[1] = bs_src->throttled_reqs[1]; |
| bs_dest->io_limits_enabled = bs_src->io_limits_enabled; |
| |
| /* r/w error */ |
| bs_dest->on_read_error = bs_src->on_read_error; |
| bs_dest->on_write_error = bs_src->on_write_error; |
| |
| /* i/o status */ |
| bs_dest->iostatus_enabled = bs_src->iostatus_enabled; |
| bs_dest->iostatus = bs_src->iostatus; |
| |
| /* dirty bitmap */ |
| bs_dest->dirty_bitmaps = bs_src->dirty_bitmaps; |
| |
| /* reference count */ |
| bs_dest->refcnt = bs_src->refcnt; |
| |
| /* job */ |
| bs_dest->job = bs_src->job; |
| |
| /* keep the same entry in bdrv_states */ |
| pstrcpy(bs_dest->device_name, sizeof(bs_dest->device_name), |
| bs_src->device_name); |
| bs_dest->device_list = bs_src->device_list; |
| memcpy(bs_dest->op_blockers, bs_src->op_blockers, |
| sizeof(bs_dest->op_blockers)); |
| } |
| |
| /* |
| * Swap bs contents for two image chains while they are live, |
| * while keeping required fields on the BlockDriverState that is |
| * actually attached to a device. |
| * |
| * This will modify the BlockDriverState fields, and swap contents |
| * between bs_new and bs_old. Both bs_new and bs_old are modified. |
| * |
| * bs_new is required to be anonymous. |
| * |
| * This function does not create any image files. |
| */ |
| void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) |
| { |
| BlockDriverState tmp; |
| |
| /* The code needs to swap the node_name but simply swapping node_list won't |
| * work so first remove the nodes from the graph list, do the swap then |
| * insert them back if needed. |
| */ |
| if (bs_new->node_name[0] != '\0') { |
| QTAILQ_REMOVE(&graph_bdrv_states, bs_new, node_list); |
| } |
| if (bs_old->node_name[0] != '\0') { |
| QTAILQ_REMOVE(&graph_bdrv_states, bs_old, node_list); |
| } |
| |
| /* bs_new must be anonymous and shouldn't have anything fancy enabled */ |
| assert(bs_new->device_name[0] == '\0'); |
| assert(QLIST_EMPTY(&bs_new->dirty_bitmaps)); |
| assert(bs_new->job == NULL); |
| assert(bs_new->dev == NULL); |
| assert(bs_new->io_limits_enabled == false); |
| assert(!throttle_have_timer(&bs_new->throttle_state)); |
| |
| tmp = *bs_new; |
| *bs_new = *bs_old; |
| *bs_old = tmp; |
| |
| /* there are some fields that should not be swapped, move them back */ |
| bdrv_move_feature_fields(&tmp, bs_old); |
| bdrv_move_feature_fields(bs_old, bs_new); |
| bdrv_move_feature_fields(bs_new, &tmp); |
| |
| /* bs_new shouldn't be in bdrv_states even after the swap! */ |
| assert(bs_new->device_name[0] == '\0'); |
| |
| /* Check a few fields that should remain attached to the device */ |
| assert(bs_new->dev == NULL); |
| assert(bs_new->job == NULL); |
| assert(bs_new->io_limits_enabled == false); |
| assert(!throttle_have_timer(&bs_new->throttle_state)); |
| |
| /* insert the nodes back into the graph node list if needed */ |
| if (bs_new->node_name[0] != '\0') { |
| QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_new, node_list); |
| } |
| if (bs_old->node_name[0] != '\0') { |
| QTAILQ_INSERT_TAIL(&graph_bdrv_states, bs_old, node_list); |
| } |
| |
| bdrv_rebind(bs_new); |
| bdrv_rebind(bs_old); |
| } |
| |
| /* |
| * 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 is required to be anonymous. |
| * |
| * This function does not create any image files. |
| */ |
| void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) |
| { |
| bdrv_swap(bs_new, bs_top); |
| |
| /* The contents of 'tmp' will become bs_top, as we are |
| * swapping bs_new and bs_top contents. */ |
| bdrv_set_backing_hd(bs_top, bs_new); |
| } |
| |
| static void bdrv_delete(BlockDriverState *bs) |
| { |
| assert(!bs->dev); |
| assert(!bs->job); |
| assert(bdrv_op_blocker_is_empty(bs)); |
| assert(!bs->refcnt); |
| assert(QLIST_EMPTY(&bs->dirty_bitmaps)); |
| |
| bdrv_close(bs); |
| |
| /* remove from list, if necessary */ |
| bdrv_make_anon(bs); |
| |
| g_free(bs); |
| } |
| |
| int bdrv_attach_dev(BlockDriverState *bs, void *dev) |
| /* TODO change to DeviceState *dev when all users are qdevified */ |
| { |
| if (bs->dev) { |
| return -EBUSY; |
| } |
| bs->dev = dev; |
| bdrv_iostatus_reset(bs); |
| return 0; |
| } |
| |
| /* TODO qdevified devices don't use this, remove when devices are qdevified */ |
| void bdrv_attach_dev_nofail(BlockDriverState *bs, void *dev) |
| { |
| if (bdrv_attach_dev(bs, dev) < 0) { |
| abort(); |
| } |
| } |
| |
| void bdrv_detach_dev(BlockDriverState *bs, void *dev) |
| /* TODO change to DeviceState *dev when all users are qdevified */ |
| { |
| assert(bs->dev == dev); |
| bs->dev = NULL; |
| bs->dev_ops = NULL; |
| bs->dev_opaque = NULL; |
| bs->guest_block_size = 512; |
| } |
| |
| /* TODO change to return DeviceState * when all users are qdevified */ |
| void *bdrv_get_attached_dev(BlockDriverState *bs) |
| { |
| return bs->dev; |
| } |
| |
| void bdrv_set_dev_ops(BlockDriverState *bs, const BlockDevOps *ops, |
| void *opaque) |
| { |
| bs->dev_ops = ops; |
| bs->dev_opaque = opaque; |
| } |
| |
| void bdrv_emit_qmp_error_event(const BlockDriverState *bdrv, |
| enum MonitorEvent ev, |
| BlockErrorAction action, bool is_read) |
| { |
| QObject *data; |
| const char *action_str; |
| |
| switch (action) { |
| case BDRV_ACTION_REPORT: |
| action_str = "report"; |
| break; |
| case BDRV_ACTION_IGNORE: |
| action_str = "ignore"; |
| break; |
| case BDRV_ACTION_STOP: |
| action_str = "stop"; |
| break; |
| default: |
| abort(); |
| } |
| |
| data = qobject_from_jsonf("{ 'device': %s, 'action': %s, 'operation': %s }", |
| bdrv->device_name, |
| action_str, |
| is_read ? "read" : "write"); |
| monitor_protocol_event(ev, data); |
| |
| qobject_decref(data); |
| } |
| |
| static void bdrv_emit_qmp_eject_event(BlockDriverState *bs, bool ejected) |
| { |
| QObject *data; |
| |
| data = qobject_from_jsonf("{ 'device': %s, 'tray-open': %i }", |
| bdrv_get_device_name(bs), ejected); |
| monitor_protocol_event(QEVENT_DEVICE_TRAY_MOVED, data); |
| |
| qobject_decref(data); |
| } |
| |
| static void bdrv_dev_change_media_cb(BlockDriverState *bs, bool load) |
| { |
| if (bs->dev_ops && bs->dev_ops->change_media_cb) { |
| bool tray_was_closed = !bdrv_dev_is_tray_open(bs); |
| bs->dev_ops->change_media_cb(bs->dev_opaque, load); |
| if (tray_was_closed) { |
| /* tray open */ |
| bdrv_emit_qmp_eject_event(bs, true); |
| } |
| if (load) { |
| /* tray close */ |
| bdrv_emit_qmp_eject_event(bs, false); |
| } |
| } |
| } |
| |
| bool bdrv_dev_has_removable_media(BlockDriverState *bs) |
| { |
| return !bs->dev || (bs->dev_ops && bs->dev_ops->change_media_cb); |
| } |
| |
| void bdrv_dev_eject_request(BlockDriverState *bs, bool force) |
| { |
| if (bs->dev_ops && bs->dev_ops->eject_request_cb) { |
| bs->dev_ops->eject_request_cb(bs->dev_opaque, force); |
| } |
| } |
| |
| bool bdrv_dev_is_tray_open(BlockDriverState *bs) |
| { |
| if (bs->dev_ops && bs->dev_ops->is_tray_open) { |
| return bs->dev_ops->is_tray_open(bs->dev_opaque); |
| } |
| return false; |
| } |
| |
| static void bdrv_dev_resize_cb(BlockDriverState *bs) |
| { |
| if (bs->dev_ops && bs->dev_ops->resize_cb) { |
| bs->dev_ops->resize_cb(bs->dev_opaque); |
| } |
| } |
| |
| bool bdrv_dev_is_medium_locked(BlockDriverState *bs) |
| { |
| if (bs->dev_ops && bs->dev_ops->is_medium_locked) { |
| return bs->dev_ops->is_medium_locked(bs->dev_opaque); |
| } |
| return false; |
| } |
| |
| /* |
| * 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->bdrv_check == NULL) { |
| return -ENOTSUP; |
| } |
| |
| memset(res, 0, sizeof(*res)); |
| return bs->drv->bdrv_check(bs, res, fix); |
| } |
| |
| #define COMMIT_BUF_SECTORS 2048 |
| |
| /* commit COW file into the raw image */ |
| int bdrv_commit(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| int64_t sector, total_sectors, length, backing_length; |
| int n, ro, open_flags; |
| int ret = 0; |
| uint8_t *buf = NULL; |
| char filename[PATH_MAX]; |
| |
| if (!drv) |
| return -ENOMEDIUM; |
| |
| if (!bs->backing_hd) { |
| return -ENOTSUP; |
| } |
| |
| if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT, NULL) || |
| bdrv_op_is_blocked(bs->backing_hd, BLOCK_OP_TYPE_COMMIT, NULL)) { |
| return -EBUSY; |
| } |
| |
| ro = bs->backing_hd->read_only; |
| /* Use pstrcpy (not strncpy): filename must be NUL-terminated. */ |
| pstrcpy(filename, sizeof(filename), bs->backing_hd->filename); |
| open_flags = bs->backing_hd->open_flags; |
| |
| if (ro) { |
| if (bdrv_reopen(bs->backing_hd, open_flags | BDRV_O_RDWR, NULL)) { |
| return -EACCES; |
| } |
| } |
| |
| length = bdrv_getlength(bs); |
| if (length < 0) { |
| ret = length; |
| goto ro_cleanup; |
| } |
| |
| backing_length = bdrv_getlength(bs->backing_hd); |
| if (backing_length < 0) { |
| ret = backing_length; |
| goto ro_cleanup; |
| } |
| |
| /* If our top snapshot is larger than the backing file image, |
| * grow the backing file image if possible. If not possible, |
| * we must return an error */ |
| if (length > backing_length) { |
| ret = bdrv_truncate(bs->backing_hd, length); |
| if (ret < 0) { |
| goto ro_cleanup; |
| } |
| } |
| |
| total_sectors = length >> BDRV_SECTOR_BITS; |
| buf = g_malloc(COMMIT_BUF_SECTORS * BDRV_SECTOR_SIZE); |
| |
| for (sector = 0; sector < total_sectors; sector += n) { |
| ret = bdrv_is_allocated(bs, sector, COMMIT_BUF_SECTORS, &n); |
| if (ret < 0) { |
| goto ro_cleanup; |
| } |
| if (ret) { |
| ret = bdrv_read(bs, sector, buf, n); |
| if (ret < 0) { |
| goto ro_cleanup; |
| } |
| |
| ret = bdrv_write(bs->backing_hd, sector, buf, n); |
| if (ret < 0) { |
| goto ro_cleanup; |
| } |
| } |
| } |
| |
| if (drv->bdrv_make_empty) { |
| ret = drv->bdrv_make_empty(bs); |
| if (ret < 0) { |
| goto ro_cleanup; |
| } |
| bdrv_flush(bs); |
| } |
| |
| /* |
| * Make sure all data we wrote to the backing device is actually |
| * stable on disk. |
| */ |
| if (bs->backing_hd) { |
| bdrv_flush(bs->backing_hd); |
| } |
| |
| ret = 0; |
| ro_cleanup: |
| g_free(buf); |
| |
| if (ro) { |
| /* ignoring error return here */ |
| bdrv_reopen(bs->backing_hd, open_flags & ~BDRV_O_RDWR, NULL); |
| } |
| |
| return ret; |
| } |
| |
| int bdrv_commit_all(void) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
| AioContext *aio_context = bdrv_get_aio_context(bs); |
| |
| aio_context_acquire(aio_context); |
| if (bs->drv && bs->backing_hd) { |
| int ret = bdrv_commit(bs); |
| if (ret < 0) { |
| aio_context_release(aio_context); |
| return ret; |
| } |
| } |
| aio_context_release(aio_context); |
| } |
| return 0; |
| } |
| |
| /** |
| * Remove an active request from the tracked requests list |
| * |
| * This function should be called when a tracked request is completing. |
| */ |
| static void tracked_request_end(BdrvTrackedRequest *req) |
| { |
| if (req->serialising) { |
| req->bs->serialising_in_flight--; |
| } |
| |
| QLIST_REMOVE(req, list); |
| qemu_co_queue_restart_all(&req->wait_queue); |
| } |
| |
| /** |
| * Add an active request to the tracked requests list |
| */ |
| static void tracked_request_begin(BdrvTrackedRequest *req, |
| BlockDriverState *bs, |
| int64_t offset, |
| unsigned int bytes, bool is_write) |
| { |
| *req = (BdrvTrackedRequest){ |
| .bs = bs, |
| .offset = offset, |
| .bytes = bytes, |
| .is_write = is_write, |
| .co = qemu_coroutine_self(), |
| .serialising = false, |
| .overlap_offset = offset, |
| .overlap_bytes = bytes, |
| }; |
| |
| qemu_co_queue_init(&req->wait_queue); |
| |
| QLIST_INSERT_HEAD(&bs->tracked_requests, req, list); |
| } |
| |
| static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align) |
| { |
| int64_t overlap_offset = req->offset & ~(align - 1); |
| unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align) |
| - overlap_offset; |
| |
| if (!req->serialising) { |
| req->bs->serialising_in_flight++; |
| req->serialising = true; |
| } |
| |
| req->overlap_offset = MIN(req->overlap_offset, overlap_offset); |
| req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes); |
| } |
| |
| /** |
| * Round a region to cluster boundaries |
| */ |
| void bdrv_round_to_clusters(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| int64_t *cluster_sector_num, |
| int *cluster_nb_sectors) |
| { |
| BlockDriverInfo bdi; |
| |
| if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) { |
| *cluster_sector_num = sector_num; |
| *cluster_nb_sectors = nb_sectors; |
| } else { |
| int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE; |
| *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c); |
| *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num + |
| nb_sectors, c); |
| } |
| } |
| |
| static int bdrv_get_cluster_size(BlockDriverState *bs) |
| { |
| BlockDriverInfo bdi; |
| int ret; |
| |
| ret = bdrv_get_info(bs, &bdi); |
| if (ret < 0 || bdi.cluster_size == 0) { |
| return bs->request_alignment; |
| } else { |
| return bdi.cluster_size; |
| } |
| } |
| |
| static bool tracked_request_overlaps(BdrvTrackedRequest *req, |
| int64_t offset, unsigned int bytes) |
| { |
| /* aaaa bbbb */ |
| if (offset >= req->overlap_offset + req->overlap_bytes) { |
| return false; |
| } |
| /* bbbb aaaa */ |
| if (req->overlap_offset >= offset + bytes) { |
| return false; |
| } |
| return true; |
| } |
| |
| static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self) |
| { |
| BlockDriverState *bs = self->bs; |
| BdrvTrackedRequest *req; |
| bool retry; |
| bool waited = false; |
| |
| if (!bs->serialising_in_flight) { |
| return false; |
| } |
| |
| do { |
| retry = false; |
| QLIST_FOREACH(req, &bs->tracked_requests, list) { |
| if (req == self || (!req->serialising && !self->serialising)) { |
| continue; |
| } |
| if (tracked_request_overlaps(req, self->overlap_offset, |
| self->overlap_bytes)) |
| { |
| /* Hitting this means there was a reentrant request, for |
| * example, a block driver issuing nested requests. This must |
| * never happen since it means deadlock. |
| */ |
| assert(qemu_coroutine_self() != req->co); |
| |
| /* If the request is already (indirectly) waiting for us, or |
| * will wait for us as soon as it wakes up, then just go on |
| * (instead of producing a deadlock in the former case). */ |
| if (!req->waiting_for) { |
| self->waiting_for = req; |
| qemu_co_queue_wait(&req->wait_queue); |
| self->waiting_for = NULL; |
| retry = true; |
| waited = true; |
| break; |
| } |
| } |
| } |
| } while (retry); |
| |
| return waited; |
| } |
| |
| /* |
| * 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. |
| */ |
| BlockDriverState *bdrv_find_overlay(BlockDriverState *active, |
| BlockDriverState *bs) |
| { |
| BlockDriverState *overlay = NULL; |
| BlockDriverState *intermediate; |
| |
| assert(active != NULL); |
| assert(bs != NULL); |
| |
| /* if bs is the same as active, then by definition it has no overlay |
| */ |
| if (active == bs) { |
| return NULL; |
| } |
| |
| intermediate = active; |
| while (intermediate->backing_hd) { |
| if (intermediate->backing_hd == bs) { |
| overlay = intermediate; |
| break; |
| } |
| intermediate = intermediate->backing_hd; |
| } |
| |
| return overlay; |
| } |
| |
| typedef struct BlkIntermediateStates { |
| BlockDriverState *bs; |
| QSIMPLEQ_ENTRY(BlkIntermediateStates) entry; |
| } BlkIntermediateStates; |
| |
| |
| /* |
| * 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 |
| * |
| * Error conditions: |
| * if active == top, that is considered an error |
| * |
| */ |
| int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, |
| BlockDriverState *base) |
| { |
| BlockDriverState *intermediate; |
| BlockDriverState *base_bs = NULL; |
| BlockDriverState *new_top_bs = NULL; |
| BlkIntermediateStates *intermediate_state, *next; |
| int ret = -EIO; |
| |
| QSIMPLEQ_HEAD(states_to_delete, BlkIntermediateStates) states_to_delete; |
| QSIMPLEQ_INIT(&states_to_delete); |
| |
| 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_hd already pointing to base - nothing |
| * to do, no intermediate images */ |
| if (new_top_bs->backing_hd == base) { |
| ret = 0; |
| goto exit; |
| } |
| |
| intermediate = top; |
| |
| /* now we will go down through the list, and add each BDS we find |
| * into our deletion queue, until we hit the 'base' |
| */ |
| while (intermediate) { |
| intermediate_state = g_malloc0(sizeof(BlkIntermediateStates)); |
| intermediate_state->bs = intermediate; |
| QSIMPLEQ_INSERT_TAIL(&states_to_delete, intermediate_state, entry); |
| |
| if (intermediate->backing_hd == base) { |
| base_bs = intermediate->backing_hd; |
| break; |
| } |
| intermediate = intermediate->backing_hd; |
| } |
| if (base_bs == NULL) { |
| /* something went wrong, we did not end at the base. safely |
| * unravel everything, and exit with error */ |
| goto exit; |
| } |
| |
| /* success - we can delete the intermediate states, and link top->base */ |
| ret = bdrv_change_backing_file(new_top_bs, base_bs->filename, |
| base_bs->drv ? base_bs->drv->format_name : ""); |
| if (ret) { |
| goto exit; |
| } |
| bdrv_set_backing_hd(new_top_bs, base_bs); |
| |
| QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { |
| /* so that bdrv_close() does not recursively close the chain */ |
| bdrv_set_backing_hd(intermediate_state->bs, NULL); |
| bdrv_unref(intermediate_state->bs); |
| } |
| ret = 0; |
| |
| exit: |
| QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { |
| g_free(intermediate_state); |
| } |
| return ret; |
| } |
| |
| |
| static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset, |
| size_t size) |
| { |
| int64_t len; |
| |
| if (size > INT_MAX) { |
| return -EIO; |
| } |
| |
| if (!bdrv_is_inserted(bs)) |
| return -ENOMEDIUM; |
| |
| if (bs->growable) |
| return 0; |
| |
| len = bdrv_getlength(bs); |
| |
| if (offset < 0) |
| return -EIO; |
| |
| if ((offset > len) || (len - offset < size)) |
| return -EIO; |
| |
| return 0; |
| } |
| |
| static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors) |
| { |
| if (nb_sectors < 0 || nb_sectors > INT_MAX / BDRV_SECTOR_SIZE) { |
| return -EIO; |
| } |
| |
| return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE, |
| nb_sectors * BDRV_SECTOR_SIZE); |
| } |
| |
| typedef struct RwCo { |
| BlockDriverState *bs; |
| int64_t offset; |
| QEMUIOVector *qiov; |
| bool is_write; |
| int ret; |
| BdrvRequestFlags flags; |
| } RwCo; |
| |
| static void coroutine_fn bdrv_rw_co_entry(void *opaque) |
| { |
| RwCo *rwco = opaque; |
| |
| if (!rwco->is_write) { |
| rwco->ret = bdrv_co_do_preadv(rwco->bs, rwco->offset, |
| rwco->qiov->size, rwco->qiov, |
| rwco->flags); |
| } else { |
| rwco->ret = bdrv_co_do_pwritev(rwco->bs, rwco->offset, |
| rwco->qiov->size, rwco->qiov, |
| rwco->flags); |
| } |
| } |
| |
| /* |
| * Process a vectored synchronous request using coroutines |
| */ |
| static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset, |
| QEMUIOVector *qiov, bool is_write, |
| BdrvRequestFlags flags) |
| { |
| Coroutine *co; |
| RwCo rwco = { |
| .bs = bs, |
| .offset = offset, |
| .qiov = qiov, |
| .is_write = is_write, |
| .ret = NOT_DONE, |
| .flags = flags, |
| }; |
| |
| /** |
| * In sync call context, when the vcpu is blocked, this throttling timer |
| * will not fire; so the I/O throttling function has to be disabled here |
| * if it has been enabled. |
| */ |
| if (bs->io_limits_enabled) { |
| fprintf(stderr, "Disabling I/O throttling on '%s' due " |
| "to synchronous I/O.\n", bdrv_get_device_name(bs)); |
| bdrv_io_limits_disable(bs); |
| } |
| |
| if (qemu_in_coroutine()) { |
| /* Fast-path if already in coroutine context */ |
| bdrv_rw_co_entry(&rwco); |
| } else { |
| AioContext *aio_context = bdrv_get_aio_context(bs); |
| |
| co = qemu_coroutine_create(bdrv_rw_co_entry); |
| qemu_coroutine_enter(co, &rwco); |
| while (rwco.ret == NOT_DONE) { |
| aio_poll(aio_context, true); |
| } |
| } |
| return rwco.ret; |
| } |
| |
| /* |
| * Process a synchronous request using coroutines |
| */ |
| static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, |
| int nb_sectors, bool is_write, BdrvRequestFlags flags) |
| { |
| QEMUIOVector qiov; |
| struct iovec iov = { |
| .iov_base = (void *)buf, |
| .iov_len = nb_sectors * BDRV_SECTOR_SIZE, |
| }; |
| |
| if (nb_sectors < 0 || nb_sectors > INT_MAX / BDRV_SECTOR_SIZE) { |
| return -EINVAL; |
| } |
| |
| qemu_iovec_init_external(&qiov, &iov, 1); |
| return bdrv_prwv_co(bs, sector_num << BDRV_SECTOR_BITS, |
| &qiov, is_write, flags); |
| } |
| |
| /* return < 0 if error. See bdrv_write() for the return codes */ |
| int bdrv_read(BlockDriverState *bs, int64_t sector_num, |
| uint8_t *buf, int nb_sectors) |
| { |
| return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false, 0); |
| } |
| |
| /* Just like bdrv_read(), but with I/O throttling temporarily disabled */ |
| int bdrv_read_unthrottled(BlockDriverState *bs, int64_t sector_num, |
| uint8_t *buf, int nb_sectors) |
| { |
| bool enabled; |
| int ret; |
| |
| enabled = bs->io_limits_enabled; |
| bs->io_limits_enabled = false; |
| ret = bdrv_read(bs, sector_num, buf, nb_sectors); |
| bs->io_limits_enabled = enabled; |
| return ret; |
| } |
| |
| /* Return < 0 if error. Important errors are: |
| -EIO generic I/O error (may happen for all errors) |
| -ENOMEDIUM No media inserted. |
| -EINVAL Invalid sector number or nb_sectors |
| -EACCES Trying to write a read-only device |
| */ |
| int bdrv_write(BlockDriverState *bs, int64_t sector_num, |
| const uint8_t *buf, int nb_sectors) |
| { |
| return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0); |
| } |
| |
| int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors, BdrvRequestFlags flags) |
| { |
| return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true, |
| BDRV_REQ_ZERO_WRITE | flags); |
| } |
| |
| /* |
| * Completely zero out a block device with the help of bdrv_write_zeroes. |
| * The operation is sped up by checking the block status and only writing |
| * zeroes to the device if they currently do not return zeroes. Optional |
| * flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP). |
| * |
| * Returns < 0 on error, 0 on success. For error codes see bdrv_write(). |
| */ |
| int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags) |
| { |
| int64_t target_size; |
| int64_t ret, nb_sectors, sector_num = 0; |
| int n; |
| |
| target_size = bdrv_getlength(bs); |
| if (target_size < 0) { |
| return target_size; |
| } |
| target_size /= BDRV_SECTOR_SIZE; |
| |
| for (;;) { |
| nb_sectors = target_size - sector_num; |
| if (nb_sectors <= 0) { |
| return 0; |
| } |
| if (nb_sectors > INT_MAX) { |
| nb_sectors = INT_MAX; |
| } |
| ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n); |
| if (ret < 0) { |
| error_report("error getting block status at sector %" PRId64 ": %s", |
| sector_num, strerror(-ret)); |
| return ret; |
| } |
| if (ret & BDRV_BLOCK_ZERO) { |
| sector_num += n; |
| continue; |
| } |
| ret = bdrv_write_zeroes(bs, sector_num, n, flags); |
| if (ret < 0) { |
| error_report("error writing zeroes at sector %" PRId64 ": %s", |
| sector_num, strerror(-ret)); |
| return ret; |
| } |
| sector_num += n; |
| } |
| } |
| |
| int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes) |
| { |
| QEMUIOVector qiov; |
| struct iovec iov = { |
| .iov_base = (void *)buf, |
| .iov_len = bytes, |
| }; |
| int ret; |
| |
| if (bytes < 0) { |
| return -EINVAL; |
| } |
| |
| qemu_iovec_init_external(&qiov, &iov, 1); |
| ret = bdrv_prwv_co(bs, offset, &qiov, false, 0); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| return bytes; |
| } |
| |
| int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov) |
| { |
| int ret; |
| |
| ret = bdrv_prwv_co(bs, offset, qiov, true, 0); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| return qiov->size; |
| } |
| |
| int bdrv_pwrite(BlockDriverState *bs, int64_t offset, |
| const void *buf, int bytes) |
| { |
| QEMUIOVector qiov; |
| struct iovec iov = { |
| .iov_base = (void *) buf, |
| .iov_len = bytes, |
| }; |
| |
| if (bytes < 0) { |
| return -EINVAL; |
| } |
| |
| qemu_iovec_init_external(&qiov, &iov, 1); |
| return bdrv_pwritev(bs, offset, &qiov); |
| } |
| |
| /* |
| * Writes to the file and ensures that no writes are reordered across this |
| * request (acts as a barrier) |
| * |
| * Returns 0 on success, -errno in error cases. |
| */ |
| int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset, |
| const void *buf, int count) |
| { |
| int ret; |
| |
| ret = bdrv_pwrite(bs, offset, buf, count); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| /* No flush needed for cache modes that already do it */ |
| if (bs->enable_write_cache) { |
| bdrv_flush(bs); |
| } |
| |
| return 0; |
| } |
| |
| static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) |
| { |
| /* Perform I/O through a temporary buffer so that users who scribble over |
| * their read buffer while the operation is in progress do not end up |
| * modifying the image file. This is critical for zero-copy guest I/O |
| * where anything might happen inside guest memory. |
| */ |
| void *bounce_buffer; |
| |
| BlockDriver *drv = bs->drv; |
| struct iovec iov; |
| QEMUIOVector bounce_qiov; |
| int64_t cluster_sector_num; |
| int cluster_nb_sectors; |
| size_t skip_bytes; |
| int ret; |
| |
| /* Cover entire cluster so no additional backing file I/O is required when |
| * allocating cluster in the image file. |
| */ |
| bdrv_round_to_clusters(bs, sector_num, nb_sectors, |
| &cluster_sector_num, &cluster_nb_sectors); |
| |
| trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, |
| cluster_sector_num, cluster_nb_sectors); |
| |
| iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE; |
| iov.iov_base = bounce_buffer = qemu_blockalign(bs, iov.iov_len); |
| qemu_iovec_init_external(&bounce_qiov, &iov, 1); |
| |
| ret = drv->bdrv_co_readv(bs, cluster_sector_num, cluster_nb_sectors, |
| &bounce_qiov); |
| if (ret < 0) { |
| goto err; |
| } |
| |
| if (drv->bdrv_co_write_zeroes && |
| buffer_is_zero(bounce_buffer, iov.iov_len)) { |
| ret = bdrv_co_do_write_zeroes(bs, cluster_sector_num, |
| cluster_nb_sectors, 0); |
| } else { |
| /* This does not change the data on the disk, it is not necessary |
| * to flush even in cache=writethrough mode. |
| */ |
| ret = drv->bdrv_co_writev(bs, cluster_sector_num, cluster_nb_sectors, |
| &bounce_qiov); |
| } |
| |
| if (ret < 0) { |
| /* It might be okay to ignore write errors for guest requests. If this |
| * is a deliberate copy-on-read then we don't want to ignore the error. |
| * Simply report it in all cases. |
| */ |
| goto err; |
| } |
| |
| skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE; |
| qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes, |
| nb_sectors * BDRV_SECTOR_SIZE); |
| |
| err: |
| qemu_vfree(bounce_buffer); |
| return ret; |
| } |
| |
| /* |
| * Forwards an already correctly aligned request to the BlockDriver. This |
| * handles copy on read and zeroing after EOF; any other features must be |
| * implemented by the caller. |
| */ |
| static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs, |
| BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, |
| int64_t align, QEMUIOVector *qiov, int flags) |
| { |
| BlockDriver *drv = bs->drv; |
| int ret; |
| |
| int64_t sector_num = offset >> BDRV_SECTOR_BITS; |
| unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS; |
| |
| assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); |
| assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); |
| |
| /* Handle Copy on Read and associated serialisation */ |
| if (flags & BDRV_REQ_COPY_ON_READ) { |
| /* If we touch the same cluster it counts as an overlap. This |
| * guarantees that allocating writes will be serialized and not race |
| * with each other for the same cluster. For example, in copy-on-read |
| * it ensures that the CoR read and write operations are atomic and |
| * guest writes cannot interleave between them. */ |
| mark_request_serialising(req, bdrv_get_cluster_size(bs)); |
| } |
| |
| wait_serialising_requests(req); |
| |
| if (flags & BDRV_REQ_COPY_ON_READ) { |
| int pnum; |
| |
| ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum); |
| if (ret < 0) { |
| goto out; |
| } |
| |
| if (!ret || pnum != nb_sectors) { |
| ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov); |
| goto out; |
| } |
| } |
| |
| /* Forward the request to the BlockDriver */ |
| if (!(bs->zero_beyond_eof && bs->growable)) { |
| ret = drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov); |
| } else { |
| /* Read zeros after EOF of growable BDSes */ |
| int64_t len, total_sectors, max_nb_sectors; |
| |
| len = bdrv_getlength(bs); |
| if (len < 0) { |
| ret = len; |
| goto out; |
| } |
| |
| total_sectors = DIV_ROUND_UP(len, BDRV_SECTOR_SIZE); |
| max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num), |
| align >> BDRV_SECTOR_BITS); |
| if (max_nb_sectors > 0) { |
| ret = drv->bdrv_co_readv(bs, sector_num, |
| MIN(nb_sectors, max_nb_sectors), qiov); |
| } else { |
| ret = 0; |
| } |
| |
| /* Reading beyond end of file is supposed to produce zeroes */ |
| if (ret == 0 && total_sectors < sector_num + nb_sectors) { |
| uint64_t offset = MAX(0, total_sectors - sector_num); |
| uint64_t bytes = (sector_num + nb_sectors - offset) * |
| BDRV_SECTOR_SIZE; |
| qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes); |
| } |
| } |
| |
| out: |
| return ret; |
| } |
| |
| /* |
| * Handle a read request in coroutine context |
| */ |
| static int coroutine_fn bdrv_co_do_preadv(BlockDriverState *bs, |
| int64_t offset, unsigned int bytes, QEMUIOVector *qiov, |
| BdrvRequestFlags flags) |
| { |
| BlockDriver *drv = bs->drv; |
| BdrvTrackedRequest req; |
| |
| /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ |
| uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); |
| uint8_t *head_buf = NULL; |
| uint8_t *tail_buf = NULL; |
| QEMUIOVector local_qiov; |
| bool use_local_qiov = false; |
| int ret; |
| |
| if (!drv) { |
| return -ENOMEDIUM; |
| } |
| if (bdrv_check_byte_request(bs, offset, bytes)) { |
| return -EIO; |
| } |
| |
| if (bs->copy_on_read) { |
| flags |= BDRV_REQ_COPY_ON_READ; |
| } |
| |
| /* throttling disk I/O */ |
| if (bs->io_limits_enabled) { |
| bdrv_io_limits_intercept(bs, bytes, false); |
| } |
| |
| /* Align read if necessary by padding qiov */ |
| if (offset & (align - 1)) { |
| head_buf = qemu_blockalign(bs, align); |
| qemu_iovec_init(&local_qiov, qiov->niov + 2); |
| qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1)); |
| qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); |
| use_local_qiov = true; |
| |
| bytes += offset & (align - 1); |
| offset = offset & ~(align - 1); |
| } |
| |
| if ((offset + bytes) & (align - 1)) { |
| if (!use_local_qiov) { |
| qemu_iovec_init(&local_qiov, qiov->niov + 1); |
| qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); |
| use_local_qiov = true; |
| } |
| tail_buf = qemu_blockalign(bs, align); |
| qemu_iovec_add(&local_qiov, tail_buf, |
| align - ((offset + bytes) & (align - 1))); |
| |
| bytes = ROUND_UP(bytes, align); |
| } |
| |
| tracked_request_begin(&req, bs, offset, bytes, false); |
| ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align, |
| use_local_qiov ? &local_qiov : qiov, |
| flags); |
| tracked_request_end(&req); |
| |
| if (use_local_qiov) { |
| qemu_iovec_destroy(&local_qiov); |
| qemu_vfree(head_buf); |
| qemu_vfree(tail_buf); |
| } |
| |
| return ret; |
| } |
| |
| static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, |
| BdrvRequestFlags flags) |
| { |
| if (nb_sectors < 0 || nb_sectors > (UINT_MAX >> BDRV_SECTOR_BITS)) { |
| return -EINVAL; |
| } |
| |
| return bdrv_co_do_preadv(bs, sector_num << BDRV_SECTOR_BITS, |
| nb_sectors << BDRV_SECTOR_BITS, qiov, flags); |
| } |
| |
| int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors, QEMUIOVector *qiov) |
| { |
| trace_bdrv_co_readv(bs, sector_num, nb_sectors); |
| |
| return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0); |
| } |
| |
| int coroutine_fn bdrv_co_copy_on_readv(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, QEMUIOVector *qiov) |
| { |
| trace_bdrv_co_copy_on_readv(bs, sector_num, nb_sectors); |
| |
| return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, |
| BDRV_REQ_COPY_ON_READ); |
| } |
| |
| /* if no limit is specified in the BlockLimits use a default |
| * of 32768 512-byte sectors (16 MiB) per request. |
| */ |
| #define MAX_WRITE_ZEROES_DEFAULT 32768 |
| |
| static int coroutine_fn bdrv_co_do_write_zeroes(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, BdrvRequestFlags flags) |
| { |
| BlockDriver *drv = bs->drv; |
| QEMUIOVector qiov; |
| struct iovec iov = {0}; |
| int ret = 0; |
| |
| int max_write_zeroes = bs->bl.max_write_zeroes ? |
| bs->bl.max_write_zeroes : MAX_WRITE_ZEROES_DEFAULT; |
| |
| while (nb_sectors > 0 && !ret) { |
| int num = nb_sectors; |
| |
| /* Align request. Block drivers can expect the "bulk" of the request |
| * to be aligned. |
| */ |
| if (bs->bl.write_zeroes_alignment |
| && num > bs->bl.write_zeroes_alignment) { |
| if (sector_num % bs->bl.write_zeroes_alignment != 0) { |
| /* Make a small request up to the first aligned sector. */ |
| num = bs->bl.write_zeroes_alignment; |
| num -= sector_num % bs->bl.write_zeroes_alignment; |
| } else if ((sector_num + num) % bs->bl.write_zeroes_alignment != 0) { |
| /* Shorten the request to the last aligned sector. num cannot |
| * underflow because num > bs->bl.write_zeroes_alignment. |
| */ |
| num -= (sector_num + num) % bs->bl.write_zeroes_alignment; |
| } |
| } |
| |
| /* limit request size */ |
| if (num > max_write_zeroes) { |
| num = max_write_zeroes; |
| } |
| |
| ret = -ENOTSUP; |
| /* First try the efficient write zeroes operation */ |
| if (drv->bdrv_co_write_zeroes) { |
| ret = drv->bdrv_co_write_zeroes(bs, sector_num, num, flags); |
| } |
| |
| if (ret == -ENOTSUP) { |
| /* Fall back to bounce buffer if write zeroes is unsupported */ |
| iov.iov_len = num * BDRV_SECTOR_SIZE; |
| if (iov.iov_base == NULL) { |
| iov.iov_base = qemu_blockalign(bs, num * BDRV_SECTOR_SIZE); |
| memset(iov.iov_base, 0, num * BDRV_SECTOR_SIZE); |
| } |
| qemu_iovec_init_external(&qiov, &iov, 1); |
| |
| ret = drv->bdrv_co_writev(bs, sector_num, num, &qiov); |
| |
| /* Keep bounce buffer around if it is big enough for all |
| * all future requests. |
| */ |
| if (num < max_write_zeroes) { |
| qemu_vfree(iov.iov_base); |
| iov.iov_base = NULL; |
| } |
| } |
| |
| sector_num += num; |
| nb_sectors -= num; |
| } |
| |
| qemu_vfree(iov.iov_base); |
| return ret; |
| } |
| |
| /* |
| * Forwards an already correctly aligned write request to the BlockDriver. |
| */ |
| static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs, |
| BdrvTrackedRequest *req, int64_t offset, unsigned int bytes, |
| QEMUIOVector *qiov, int flags) |
| { |
| BlockDriver *drv = bs->drv; |
| bool waited; |
| int ret; |
| |
| int64_t sector_num = offset >> BDRV_SECTOR_BITS; |
| unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS; |
| |
| assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0); |
| assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0); |
| |
| waited = wait_serialising_requests(req); |
| assert(!waited || !req->serialising); |
| assert(req->overlap_offset <= offset); |
| assert(offset + bytes <= req->overlap_offset + req->overlap_bytes); |
| |
| ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req); |
| |
| if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF && |
| !(flags & BDRV_REQ_ZERO_WRITE) && drv->bdrv_co_write_zeroes && |
| qemu_iovec_is_zero(qiov)) { |
| flags |= BDRV_REQ_ZERO_WRITE; |
| if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) { |
| flags |= BDRV_REQ_MAY_UNMAP; |
| } |
| } |
| |
| if (ret < 0) { |
| /* Do nothing, write notifier decided to fail this request */ |
| } else if (flags & BDRV_REQ_ZERO_WRITE) { |
| BLKDBG_EVENT(bs, BLKDBG_PWRITEV_ZERO); |
| ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags); |
| } else { |
| BLKDBG_EVENT(bs, BLKDBG_PWRITEV); |
| ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov); |
| } |
| BLKDBG_EVENT(bs, BLKDBG_PWRITEV_DONE); |
| |
| if (ret == 0 && !bs->enable_write_cache) { |
| ret = bdrv_co_flush(bs); |
| } |
| |
| bdrv_set_dirty(bs, sector_num, nb_sectors); |
| |
| if (bs->wr_highest_sector < sector_num + nb_sectors - 1) { |
| bs->wr_highest_sector = sector_num + nb_sectors - 1; |
| } |
| if (bs->growable && ret >= 0) { |
| bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Handle a write request in coroutine context |
| */ |
| static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs, |
| int64_t offset, unsigned int bytes, QEMUIOVector *qiov, |
| BdrvRequestFlags flags) |
| { |
| BdrvTrackedRequest req; |
| /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */ |
| uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment); |
| uint8_t *head_buf = NULL; |
| uint8_t *tail_buf = NULL; |
| QEMUIOVector local_qiov; |
| bool use_local_qiov = false; |
| int ret; |
| |
| if (!bs->drv) { |
| return -ENOMEDIUM; |
| } |
| if (bs->read_only) { |
| return -EACCES; |
| } |
| if (bdrv_check_byte_request(bs, offset, bytes)) { |
| return -EIO; |
| } |
| |
| /* throttling disk I/O */ |
| if (bs->io_limits_enabled) { |
| bdrv_io_limits_intercept(bs, bytes, true); |
| } |
| |
| /* |
| * Align write if necessary by performing a read-modify-write cycle. |
| * Pad qiov with the read parts and be sure to have a tracked request not |
| * only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle. |
| */ |
| tracked_request_begin(&req, bs, offset, bytes, true); |
| |
| if (offset & (align - 1)) { |
| QEMUIOVector head_qiov; |
| struct iovec head_iov; |
| |
| mark_request_serialising(&req, align); |
| wait_serialising_requests(&req); |
| |
| head_buf = qemu_blockalign(bs, align); |
| head_iov = (struct iovec) { |
| .iov_base = head_buf, |
| .iov_len = align, |
| }; |
| qemu_iovec_init_external(&head_qiov, &head_iov, 1); |
| |
| BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_HEAD); |
| ret = bdrv_aligned_preadv(bs, &req, offset & ~(align - 1), align, |
| align, &head_qiov, 0); |
| if (ret < 0) { |
| goto fail; |
| } |
| BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD); |
| |
| qemu_iovec_init(&local_qiov, qiov->niov + 2); |
| qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1)); |
| qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); |
| use_local_qiov = true; |
| |
| bytes += offset & (align - 1); |
| offset = offset & ~(align - 1); |
| } |
| |
| if ((offset + bytes) & (align - 1)) { |
| QEMUIOVector tail_qiov; |
| struct iovec tail_iov; |
| size_t tail_bytes; |
| bool waited; |
| |
| mark_request_serialising(&req, align); |
| waited = wait_serialising_requests(&req); |
| assert(!waited || !use_local_qiov); |
| |
| tail_buf = qemu_blockalign(bs, align); |
| tail_iov = (struct iovec) { |
| .iov_base = tail_buf, |
| .iov_len = align, |
| }; |
| qemu_iovec_init_external(&tail_qiov, &tail_iov, 1); |
| |
| BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_TAIL); |
| ret = bdrv_aligned_preadv(bs, &req, (offset + bytes) & ~(align - 1), align, |
| align, &tail_qiov, 0); |
| if (ret < 0) { |
| goto fail; |
| } |
| BLKDBG_EVENT(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL); |
| |
| if (!use_local_qiov) { |
| qemu_iovec_init(&local_qiov, qiov->niov + 1); |
| qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size); |
| use_local_qiov = true; |
| } |
| |
| tail_bytes = (offset + bytes) & (align - 1); |
| qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes); |
| |
| bytes = ROUND_UP(bytes, align); |
| } |
| |
| ret = bdrv_aligned_pwritev(bs, &req, offset, bytes, |
| use_local_qiov ? &local_qiov : qiov, |
| flags); |
| |
| fail: |
| tracked_request_end(&req); |
| |
| if (use_local_qiov) { |
| qemu_iovec_destroy(&local_qiov); |
| } |
| qemu_vfree(head_buf); |
| qemu_vfree(tail_buf); |
| |
| return ret; |
| } |
| |
| static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, |
| BdrvRequestFlags flags) |
| { |
| if (nb_sectors < 0 || nb_sectors > (INT_MAX >> BDRV_SECTOR_BITS)) { |
| return -EINVAL; |
| } |
| |
| return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS, |
| nb_sectors << BDRV_SECTOR_BITS, qiov, flags); |
| } |
| |
| int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors, QEMUIOVector *qiov) |
| { |
| trace_bdrv_co_writev(bs, sector_num, nb_sectors); |
| |
| return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0); |
| } |
| |
| int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| BdrvRequestFlags flags) |
| { |
| trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags); |
| |
| if (!(bs->open_flags & BDRV_O_UNMAP)) { |
| flags &= ~BDRV_REQ_MAY_UNMAP; |
| } |
| |
| return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL, |
| BDRV_REQ_ZERO_WRITE | flags); |
| } |
| |
| /** |
| * Truncate file to 'offset' bytes (needed only for file protocols) |
| */ |
| int bdrv_truncate(BlockDriverState *bs, int64_t offset) |
| { |
| BlockDriver *drv = bs->drv; |
| int ret; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (!drv->bdrv_truncate) |
| return -ENOTSUP; |
| if (bs->read_only) |
| return -EACCES; |
| if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, NULL)) { |
| return -EBUSY; |
| } |
| ret = drv->bdrv_truncate(bs, offset); |
| if (ret == 0) { |
| ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); |
| bdrv_dev_resize_cb(bs); |
| } |
| 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); |
| } |
| return -ENOTSUP; |
| } |
| |
| /** |
| * Length of a file in bytes. Return < 0 if error or unknown. |
| */ |
| int64_t bdrv_getlength(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 * 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 length; |
| length = bdrv_getlength(bs); |
| if (length < 0) |
| length = 0; |
| else |
| length = length >> BDRV_SECTOR_BITS; |
| *nb_sectors_ptr = length; |
| } |
| |
| void bdrv_set_on_error(BlockDriverState *bs, BlockdevOnError on_read_error, |
| BlockdevOnError on_write_error) |
| { |
| bs->on_read_error = on_read_error; |
| bs->on_write_error = on_write_error; |
| } |
| |
| BlockdevOnError bdrv_get_on_error(BlockDriverState *bs, bool is_read) |
| { |
| return is_read ? bs->on_read_error : bs->on_write_error; |
| } |
| |
| BlockErrorAction bdrv_get_error_action(BlockDriverState *bs, bool is_read, int error) |
| { |
| BlockdevOnError on_err = is_read ? bs->on_read_error : bs->on_write_error; |
| |
| switch (on_err) { |
| case BLOCKDEV_ON_ERROR_ENOSPC: |
| return (error == ENOSPC) ? BDRV_ACTION_STOP : BDRV_ACTION_REPORT; |
| case BLOCKDEV_ON_ERROR_STOP: |
| return BDRV_ACTION_STOP; |
| case BLOCKDEV_ON_ERROR_REPORT: |
| return BDRV_ACTION_REPORT; |
| case BLOCKDEV_ON_ERROR_IGNORE: |
| return BDRV_ACTION_IGNORE; |
| default: |
| abort(); |
| } |
| } |
| |
| /* This is done by device models because, while the block layer knows |
| * about the error, it does not know whether an operation comes from |
| * the device or the block layer (from a job, for example). |
| */ |
| void bdrv_error_action(BlockDriverState *bs, BlockErrorAction action, |
| bool is_read, int error) |
| { |
| assert(error >= 0); |
| bdrv_emit_qmp_error_event(bs, QEVENT_BLOCK_IO_ERROR, action, is_read); |
| if (action == BDRV_ACTION_STOP) { |
| vm_stop(RUN_STATE_IO_ERROR); |
| bdrv_iostatus_set_err(bs, error); |
| } |
| } |
| |
| int bdrv_is_read_only(BlockDriverState *bs) |
| { |
| return bs->read_only; |
| } |
| |
| int bdrv_is_sg(BlockDriverState *bs) |
| { |
| return bs->sg; |
| } |
| |
| int bdrv_enable_write_cache(BlockDriverState *bs) |
| { |
| return bs->enable_write_cache; |
| } |
| |
| void bdrv_set_enable_write_cache(BlockDriverState *bs, bool wce) |
| { |
| bs->enable_write_cache = wce; |
| |
| /* so a reopen() will preserve wce */ |
| if (wce) { |
| bs->open_flags |= BDRV_O_CACHE_WB; |
| } else { |
| bs->open_flags &= ~BDRV_O_CACHE_WB; |
| } |
| } |
| |
| int bdrv_is_encrypted(BlockDriverState *bs) |
| { |
| if (bs->backing_hd && bs->backing_hd->encrypted) |
| return 1; |
| return bs->encrypted; |
| } |
| |
| int bdrv_key_required(BlockDriverState *bs) |
| { |
| BlockDriverState *backing_hd = bs->backing_hd; |
| |
| if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key) |
| return 1; |
| return (bs->encrypted && !bs->valid_key); |
| } |
| |
| int bdrv_set_key(BlockDriverState *bs, const char *key) |
| { |
| int ret; |
| if (bs->backing_hd && bs->backing_hd->encrypted) { |
| ret = bdrv_set_key(bs->backing_hd, 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 = 0; |
| } else if (!bs->valid_key) { |
| bs->valid_key = 1; |
| /* call the change callback now, we skipped it on open */ |
| bdrv_dev_change_media_cb(bs, true); |
| } |
| return ret; |
| } |
| |
| const char *bdrv_get_format_name(BlockDriverState *bs) |
| { |
| return bs->drv ? bs->drv->format_name : NULL; |
| } |
| |
| void bdrv_iterate_format(void (*it)(void *opaque, const char *name), |
| void *opaque) |
| { |
| BlockDriver *drv; |
| int count = 0; |
| 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_realloc(formats, (count + 1) * sizeof(char *)); |
| formats[count++] = drv->format_name; |
| it(opaque, drv->format_name); |
| } |
| } |
| } |
| g_free(formats); |
| } |
| |
| /* This function is to find block backend bs */ |
| BlockDriverState *bdrv_find(const char *name) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
| if (!strcmp(name, bs->device_name)) { |
| return bs; |
| } |
| } |
| return NULL; |
| } |
| |
| /* 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(void) |
| { |
| BlockDeviceInfoList *list, *entry; |
| BlockDriverState *bs; |
| |
| list = NULL; |
| QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) { |
| entry = g_malloc0(sizeof(*entry)); |
| entry->value = bdrv_block_device_info(bs); |
| entry->next = list; |
| list = entry; |
| } |
| |
| return list; |
| } |
| |
| BlockDriverState *bdrv_lookup_bs(const char *device, |
| const char *node_name, |
| Error **errp) |
| { |
| BlockDriverState *bs = NULL; |
| |
| if (device) { |
| bs = bdrv_find(device); |
| |
| if (bs) { |
| 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; |
| } |
| |
| BlockDriverState *bdrv_next(BlockDriverState *bs) |
| { |
| if (!bs) { |
| return QTAILQ_FIRST(&bdrv_states); |
| } |
| return QTAILQ_NEXT(bs, device_list); |
| } |
| |
| void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
| it(opaque, bs); |
| } |
| } |
| |
| const char *bdrv_get_device_name(BlockDriverState *bs) |
| { |
| return bs->device_name; |
| } |
| |
| int bdrv_get_flags(BlockDriverState *bs) |
| { |
| return bs->open_flags; |
| } |
| |
| int bdrv_flush_all(void) |
| { |
| BlockDriverState *bs; |
| int result = 0; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
| AioContext *aio_context = bdrv_get_aio_context(bs); |
| int ret; |
| |
| aio_context_acquire(aio_context); |
| ret = bdrv_flush(bs); |
| if (ret < 0 && !result) { |
| result = ret; |
| } |
| aio_context_release(aio_context); |
| } |
| |
| return result; |
| } |
| |
| 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_hd) { |
| 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_hd) { |
| 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->backing_hd || !(bs->open_flags & BDRV_O_UNMAP)) { |
| return false; |
| } |
| |
| if (bdrv_get_info(bs, &bdi) == 0) { |
| return bdi.can_write_zeroes_with_unmap; |
| } |
| |
| return false; |
| } |
| |
| typedef struct BdrvCoGetBlockStatusData { |
| BlockDriverState *bs; |
| BlockDriverState *base; |
| int64_t sector_num; |
| int nb_sectors; |
| int *pnum; |
| int64_t ret; |
| bool done; |
| } BdrvCoGetBlockStatusData; |
| |
| /* |
| * Returns true iff the specified sector is present in the disk image. Drivers |
| * not implementing the functionality are assumed to not support backing files, |
| * hence all their sectors are reported as allocated. |
| * |
| * If 'sector_num' is beyond the end of the disk image the return value is 0 |
| * and 'pnum' is set to 0. |
| * |
| * 'pnum' is set to the number of sectors (including and immediately following |
| * the specified sector) that are known to be in the same |
| * allocated/unallocated state. |
| * |
| * 'nb_sectors' is the max value 'pnum' should be set to. If nb_sectors goes |
| * beyond the end of the disk image it will be clamped. |
| */ |
| static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs, |
| int64_t sector_num, |
| int nb_sectors, int *pnum) |
| { |
| int64_t length; |
| int64_t n; |
| int64_t ret, ret2; |
| |
| length = bdrv_getlength(bs); |
| if (length < 0) { |
| return length; |
| } |
| |
| if (sector_num >= (length >> BDRV_SECTOR_BITS)) { |
| *pnum = 0; |
| return 0; |
| } |
| |
| n = bs->total_sectors - sector_num; |
| if (n < nb_sectors) { |
| nb_sectors = n; |
| } |
| |
| if (!bs->drv->bdrv_co_get_block_status) { |
| *pnum = nb_sectors; |
| ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED; |
| if (bs->drv->protocol_name) { |
| ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE); |
| } |
| return ret; |
| } |
| |
| ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum); |
| if (ret < 0) { |
| *pnum = 0; |
| return ret; |
| } |
| |
| if (ret & BDRV_BLOCK_RAW) { |
| assert(ret & BDRV_BLOCK_OFFSET_VALID); |
| return bdrv_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS, |
| *pnum, pnum); |
| } |
| |
| if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) { |
| ret |= BDRV_BLOCK_ALLOCATED; |
| } |
| |
| if (!(ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO)) { |
| if (bdrv_unallocated_blocks_are_zero(bs)) { |
| ret |= BDRV_BLOCK_ZERO; |
| } else if (bs->backing_hd) { |
| BlockDriverState *bs2 = bs->backing_hd; |
| int64_t length2 = bdrv_getlength(bs2); |
| if (length2 >= 0 && sector_num >= (length2 >> BDRV_SECTOR_BITS)) { |
| ret |= BDRV_BLOCK_ZERO; |
| } |
| } |
| } |
| |
| if (bs->file && |
| (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) && |
| (ret & BDRV_BLOCK_OFFSET_VALID)) { |
| ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS, |
| *pnum, pnum); |
| if (ret2 >= 0) { |
| /* Ignore errors. This is just providing extra information, it |
| * is useful but not necessary. |
| */ |
| ret |= (ret2 & BDRV_BLOCK_ZERO); |
| } |
| } |
| |
| return ret; |
| } |
| |
| /* Coroutine wrapper for bdrv_get_block_status() */ |
| static void coroutine_fn bdrv_get_block_status_co_entry(void *opaque) |
| { |
| BdrvCoGetBlockStatusData *data = opaque; |
| BlockDriverState *bs = data->bs; |
| |
| data->ret = bdrv_co_get_block_status(bs, data->sector_num, data->nb_sectors, |
| data->pnum); |
| data->done = true; |
| } |
| |
| /* |
| * Synchronous wrapper around bdrv_co_get_block_status(). |
| * |
| * See bdrv_co_get_block_status() for details. |
| */ |
| int64_t bdrv_get_block_status(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors, int *pnum) |
| { |
| Coroutine *co; |
| BdrvCoGetBlockStatusData data = { |
| .bs = bs, |
| .sector_num = sector_num, |
| .nb_sectors = nb_sectors, |
| .pnum = pnum, |
| .done = false, |
| }; |
| |
| if (qemu_in_coroutine()) { |
| /* Fast-path if already in coroutine context */ |
| bdrv_get_block_status_co_entry(&data); |
| } else { |
| AioContext *aio_context = bdrv_get_aio_context(bs); |
| |
| co = qemu_coroutine_create(bdrv_get_block_status_co_entry); |
| qemu_coroutine_enter(co, &data); |
| while (!data.done) { |
| aio_poll(aio_context, true); |
| } |
| } |
| return data.ret; |
| } |
| |
| int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors, int *pnum) |
| { |
| int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum); |
| if (ret < 0) { |
| return ret; |
| } |
| return (ret & BDRV_BLOCK_ALLOCATED); |
| } |
| |
| /* |
| * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP] |
| * |
| * Return true if the given sector is allocated in any image between |
| * BASE and TOP (inclusive). BASE can be NULL to check if the given |
| * sector is allocated in any image of the chain. Return false otherwise. |
| * |
| * 'pnum' is set to the number of sectors (including and immediately following |
| * the specified sector) that are known to be in the same |
| * allocated/unallocated state. |
| * |
| */ |
| int bdrv_is_allocated_above(BlockDriverState *top, |
| BlockDriverState *base, |
| int64_t sector_num, |
| int nb_sectors, int *pnum) |
| { |
| BlockDriverState *intermediate; |
| int ret, n = nb_sectors; |
| |
| intermediate = top; |
| while (intermediate && intermediate != base) { |
| int pnum_inter; |
| ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors, |
| &pnum_inter); |
| if (ret < 0) { |
| return ret; |
| } else if (ret) { |
| *pnum = pnum_inter; |
| return 1; |
| } |
| |
| /* |
| * [sector_num, nb_sectors] is unallocated on top but intermediate |
| * might have |
| * |
| * [sector_num+x, nr_sectors] allocated. |
| */ |
| if (n > pnum_inter && |
| (intermediate == top || |
| sector_num + pnum_inter < intermediate->total_sectors)) { |
| n = pnum_inter; |
| } |
| |
| intermediate = intermediate->backing_hd; |
| } |
| |
| *pnum = n; |
| return 0; |
| } |
| |
| const char *bdrv_get_encrypted_filename(BlockDriverState *bs) |
| { |
| if (bs->backing_hd && bs->backing_hd->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_write_compressed(BlockDriverState *bs, int64_t sector_num, |
| const uint8_t *buf, int nb_sectors) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (!drv->bdrv_write_compressed) |
| return -ENOTSUP; |
| if (bdrv_check_request(bs, sector_num, nb_sectors)) |
| return -EIO; |
| |
| assert(QLIST_EMPTY(&bs->dirty_bitmaps)); |
| |
| return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors); |
| } |
| |
| 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; |
| } |
| |
| int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf, |
| int64_t pos, int size) |
| { |
| QEMUIOVector qiov; |
| struct iovec iov = { |
| .iov_base = (void *) buf, |
| .iov_len = size, |
| }; |
| |
| qemu_iovec_init_external(&qiov, &iov, 1); |
| return bdrv_writev_vmstate(bs, &qiov, pos); |
| } |
| |
| int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (!drv) { |
| return -ENOMEDIUM; |
| } else if (drv->bdrv_save_vmstate) { |
| return drv->bdrv_save_vmstate(bs, qiov, pos); |
| } else if (bs->file) { |
| return bdrv_writev_vmstate(bs->file, qiov, pos); |
| } |
| |
| return -ENOTSUP; |
| } |
| |
| int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf, |
| int64_t pos, int size) |
| { |
| BlockDriver *drv = bs->drv; |
| if (!drv) |
| return -ENOMEDIUM; |
| if (drv->bdrv_load_vmstate) |
| return drv->bdrv_load_vmstate(bs, buf, pos, size); |
| if (bs->file) |
| return bdrv_load_vmstate(bs->file, buf, pos, size); |
| return -ENOTSUP; |
| } |
| |
| 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; |
| } |
| |
| 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; |
| } |
| |
| 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; |
| } |
| |
| 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; |
| } |
| |
| if (bs && bs->drv && bs->drv->bdrv_debug_is_suspended) { |
| return bs->drv->bdrv_debug_is_suspended(bs, tag); |
| } |
| |
| return false; |
| } |
| |
| int bdrv_is_snapshot(BlockDriverState *bs) |
| { |
| return !!(bs->open_flags & BDRV_O_SNAPSHOT); |
| } |
| |
| /* 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; |
| |
| 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_hd; curr_bs = curr_bs->backing_hd) { |
| |
| /* 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_hd; |
| break; |
| } |
| } 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_hd; |
| 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_hd) { |
| return 0; |
| } |
| |
| return 1 + bdrv_get_backing_file_depth(bs->backing_hd); |
| } |
| |
| BlockDriverState *bdrv_find_base(BlockDriverState *bs) |
| { |
| BlockDriverState *curr_bs = NULL; |
| |
| if (!bs) { |
| return NULL; |
| } |
| |
| curr_bs = bs; |
| |
| while (curr_bs->backing_hd) { |
| curr_bs = curr_bs->backing_hd; |
| } |
| return curr_bs; |
| } |
| |
| /**************************************************************/ |
| /* async I/Os */ |
| |
| BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num, |
| QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque); |
| |
| return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0, |
| cb, opaque, false); |
| } |
| |
| BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num, |
| QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque); |
| |
| return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0, |
| cb, opaque, true); |
| } |
| |
| BlockDriverAIOCB *bdrv_aio_write_zeroes(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, BdrvRequestFlags flags, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| trace_bdrv_aio_write_zeroes(bs, sector_num, nb_sectors, flags, opaque); |
| |
| return bdrv_co_aio_rw_vector(bs, sector_num, NULL, nb_sectors, |
| BDRV_REQ_ZERO_WRITE | flags, |
| cb, opaque, true); |
| } |
| |
| |
| typedef struct MultiwriteCB { |
| int error; |
| int num_requests; |
| int num_callbacks; |
| struct { |
| BlockDriverCompletionFunc *cb; |
| void *opaque; |
| QEMUIOVector *free_qiov; |
| } callbacks[]; |
| } MultiwriteCB; |
| |
| static void multiwrite_user_cb(MultiwriteCB *mcb) |
| { |
| int i; |
| |
| for (i = 0; i < mcb->num_callbacks; i++) { |
| mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error); |
| if (mcb->callbacks[i].free_qiov) { |
| qemu_iovec_destroy(mcb->callbacks[i].free_qiov); |
| } |
| g_free(mcb->callbacks[i].free_qiov); |
| } |
| } |
| |
| static void multiwrite_cb(void *opaque, int ret) |
| { |
| MultiwriteCB *mcb = opaque; |
| |
| trace_multiwrite_cb(mcb, ret); |
| |
| if (ret < 0 && !mcb->error) { |
| mcb->error = ret; |
| } |
| |
| mcb->num_requests--; |
| if (mcb->num_requests == 0) { |
| multiwrite_user_cb(mcb); |
| g_free(mcb); |
| } |
| } |
| |
| static int multiwrite_req_compare(const void *a, const void *b) |
| { |
| const BlockRequest *req1 = a, *req2 = b; |
| |
| /* |
| * Note that we can't simply subtract req2->sector from req1->sector |
| * here as that could overflow the return value. |
| */ |
| if (req1->sector > req2->sector) { |
| return 1; |
| } else if (req1->sector < req2->sector) { |
| return -1; |
| } else { |
| return 0; |
| } |
| } |
| |
| /* |
| * Takes a bunch of requests and tries to merge them. Returns the number of |
| * requests that remain after merging. |
| */ |
| static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs, |
| int num_reqs, MultiwriteCB *mcb) |
| { |
| int i, outidx; |
| |
| // Sort requests by start sector |
| qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare); |
| |
| // Check if adjacent requests touch the same clusters. If so, combine them, |
| // filling up gaps with zero sectors. |
| outidx = 0; |
| for (i = 1; i < num_reqs; i++) { |
| int merge = 0; |
| int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors; |
| |
| // Handle exactly sequential writes and overlapping writes. |
| if (reqs[i].sector <= oldreq_last) { |
| merge = 1; |
| } |
| |
| if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) { |
| merge = 0; |
| } |
| |
| if (merge) { |
| size_t size; |
| QEMUIOVector *qiov = g_malloc0(sizeof(*qiov)); |
| qemu_iovec_init(qiov, |
| reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1); |
| |
| // Add the first request to the merged one. If the requests are |
| // overlapping, drop the last sectors of the first request. |
| size = (reqs[i].sector - reqs[outidx].sector) << 9; |
| qemu_iovec_concat(qiov, reqs[outidx].qiov, 0, size); |
| |
| // We should need to add any zeros between the two requests |
| assert (reqs[i].sector <= oldreq_last); |
| |
| // Add the second request |
| qemu_iovec_concat(qiov, reqs[i].qiov, 0, reqs[i].qiov->size); |
| |
| reqs[outidx].nb_sectors = qiov->size >> 9; |
| reqs[outidx].qiov = qiov; |
| |
| mcb->callbacks[i].free_qiov = reqs[outidx].qiov; |
| } else { |
| outidx++; |
| reqs[outidx].sector = reqs[i].sector; |
| reqs[outidx].nb_sectors = reqs[i].nb_sectors; |
| reqs[outidx].qiov = reqs[i].qiov; |
| } |
| } |
| |
| return outidx + 1; |
| } |
| |
| /* |
| * Submit multiple AIO write requests at once. |
| * |
| * On success, the function returns 0 and all requests in the reqs array have |
| * been submitted. In error case this function returns -1, and any of the |
| * requests may or may not be submitted yet. In particular, this means that the |
| * callback will be called for some of the requests, for others it won't. The |
| * caller must check the error field of the BlockRequest to wait for the right |
| * callbacks (if error != 0, no callback will be called). |
| * |
| * The implementation may modify the contents of the reqs array, e.g. to merge |
| * requests. However, the fields opaque and error are left unmodified as they |
| * are used to signal failure for a single request to the caller. |
| */ |
| int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) |
| { |
| MultiwriteCB *mcb; |
| int i; |
| |
| /* don't submit writes if we don't have a medium */ |
| if (bs->drv == NULL) { |
| for (i = 0; i < num_reqs; i++) { |
| reqs[i].error = -ENOMEDIUM; |
| } |
| return -1; |
| } |
| |
| if (num_reqs == 0) { |
| return 0; |
| } |
| |
| // Create MultiwriteCB structure |
| mcb = g_malloc0(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks)); |
| mcb->num_requests = 0; |
| mcb->num_callbacks = num_reqs; |
| |
| for (i = 0; i < num_reqs; i++) { |
| mcb->callbacks[i].cb = reqs[i].cb; |
| mcb->callbacks[i].opaque = reqs[i].opaque; |
| } |
| |
| // Check for mergable requests |
| num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb); |
| |
| trace_bdrv_aio_multiwrite(mcb, mcb->num_callbacks, num_reqs); |
| |
| /* Run the aio requests. */ |
| mcb->num_requests = num_reqs; |
| for (i = 0; i < num_reqs; i++) { |
| bdrv_co_aio_rw_vector(bs, reqs[i].sector, reqs[i].qiov, |
| reqs[i].nb_sectors, reqs[i].flags, |
| multiwrite_cb, mcb, |
| true); |
| } |
| |
| return 0; |
| } |
| |
| void bdrv_aio_cancel(BlockDriverAIOCB *acb) |
| { |
| acb->aiocb_info->cancel(acb); |
| } |
| |
| /**************************************************************/ |
| /* async block device emulation */ |
| |
| typedef struct BlockDriverAIOCBSync { |
| BlockDriverAIOCB common; |
| QEMUBH *bh; |
| int ret; |
| /* vector translation state */ |
| QEMUIOVector *qiov; |
| uint8_t *bounce; |
| int is_write; |
| } BlockDriverAIOCBSync; |
| |
| static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb) |
| { |
| BlockDriverAIOCBSync *acb = |
| container_of(blockacb, BlockDriverAIOCBSync, common); |
| qemu_bh_delete(acb->bh); |
| acb->bh = NULL; |
| qemu_aio_release(acb); |
| } |
| |
| static const AIOCBInfo bdrv_em_aiocb_info = { |
| .aiocb_size = sizeof(BlockDriverAIOCBSync), |
| .cancel = bdrv_aio_cancel_em, |
| }; |
| |
| static void bdrv_aio_bh_cb(void *opaque) |
| { |
| BlockDriverAIOCBSync *acb = opaque; |
| |
| if (!acb->is_write) |
| qemu_iovec_from_buf(acb->qiov, 0, acb->bounce, acb->qiov->size); |
| qemu_vfree(acb->bounce); |
| acb->common.cb(acb->common.opaque, acb->ret); |
| qemu_bh_delete(acb->bh); |
| acb->bh = NULL; |
| qemu_aio_release(acb); |
| } |
| |
| static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs, |
| int64_t sector_num, |
| QEMUIOVector *qiov, |
| int nb_sectors, |
| BlockDriverCompletionFunc *cb, |
| void *opaque, |
| int is_write) |
| |
| { |
| BlockDriverAIOCBSync *acb; |
| |
| acb = qemu_aio_get(&bdrv_em_aiocb_info, bs, cb, opaque); |
| acb->is_write = is_write; |
| acb->qiov = qiov; |
| acb->bounce = qemu_blockalign(bs, qiov->size); |
| acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_aio_bh_cb, acb); |
| |
| if (is_write) { |
| qemu_iovec_to_buf(acb->qiov, 0, acb->bounce, qiov->size); |
| acb->ret = bs->drv->bdrv_write(bs, sector_num, acb->bounce, nb_sectors); |
| } else { |
| acb->ret = bs->drv->bdrv_read(bs, sector_num, acb->bounce, nb_sectors); |
| } |
| |
| qemu_bh_schedule(acb->bh); |
| |
| return &acb->common; |
| } |
| |
| static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs, |
| int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0); |
| } |
| |
| static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs, |
| int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1); |
| } |
| |
| |
| typedef struct BlockDriverAIOCBCoroutine { |
| BlockDriverAIOCB common; |
| BlockRequest req; |
| bool is_write; |
| bool *done; |
| QEMUBH* bh; |
| } BlockDriverAIOCBCoroutine; |
| |
| static void bdrv_aio_co_cancel_em(BlockDriverAIOCB *blockacb) |
| { |
| AioContext *aio_context = bdrv_get_aio_context(blockacb->bs); |
| BlockDriverAIOCBCoroutine *acb = |
| container_of(blockacb, BlockDriverAIOCBCoroutine, common); |
| bool done = false; |
| |
| acb->done = &done; |
| while (!done) { |
| aio_poll(aio_context, true); |
| } |
| } |
| |
| static const AIOCBInfo bdrv_em_co_aiocb_info = { |
| .aiocb_size = sizeof(BlockDriverAIOCBCoroutine), |
| .cancel = bdrv_aio_co_cancel_em, |
| }; |
| |
| static void bdrv_co_em_bh(void *opaque) |
| { |
| BlockDriverAIOCBCoroutine *acb = opaque; |
| |
| acb->common.cb(acb->common.opaque, acb->req.error); |
| |
| if (acb->done) { |
| *acb->done = true; |
| } |
| |
| qemu_bh_delete(acb->bh); |
| qemu_aio_release(acb); |
| } |
| |
| /* Invoke bdrv_co_do_readv/bdrv_co_do_writev */ |
| static void coroutine_fn bdrv_co_do_rw(void *opaque) |
| { |
| BlockDriverAIOCBCoroutine *acb = opaque; |
| BlockDriverState *bs = acb->common.bs; |
| |
| if (!acb->is_write) { |
| acb->req.error = bdrv_co_do_readv(bs, acb->req.sector, |
| acb->req.nb_sectors, acb->req.qiov, acb->req.flags); |
| } else { |
| acb->req.error = bdrv_co_do_writev(bs, acb->req.sector, |
| acb->req.nb_sectors, acb->req.qiov, acb->req.flags); |
| } |
| |
| acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb); |
| qemu_bh_schedule(acb->bh); |
| } |
| |
| static BlockDriverAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs, |
| int64_t sector_num, |
| QEMUIOVector *qiov, |
| int nb_sectors, |
| BdrvRequestFlags flags, |
| BlockDriverCompletionFunc *cb, |
| void *opaque, |
| bool is_write) |
| { |
| Coroutine *co; |
| BlockDriverAIOCBCoroutine *acb; |
| |
| acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); |
| acb->req.sector = sector_num; |
| acb->req.nb_sectors = nb_sectors; |
| acb->req.qiov = qiov; |
| acb->req.flags = flags; |
| acb->is_write = is_write; |
| acb->done = NULL; |
| |
| co = qemu_coroutine_create(bdrv_co_do_rw); |
| qemu_coroutine_enter(co, acb); |
| |
| return &acb->common; |
| } |
| |
| static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque) |
| { |
| BlockDriverAIOCBCoroutine *acb = opaque; |
| BlockDriverState *bs = acb->common.bs; |
| |
| acb->req.error = bdrv_co_flush(bs); |
| acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb); |
| qemu_bh_schedule(acb->bh); |
| } |
| |
| BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| trace_bdrv_aio_flush(bs, opaque); |
| |
| Coroutine *co; |
| BlockDriverAIOCBCoroutine *acb; |
| |
| acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); |
| acb->done = NULL; |
| |
| co = qemu_coroutine_create(bdrv_aio_flush_co_entry); |
| qemu_coroutine_enter(co, acb); |
| |
| return &acb->common; |
| } |
| |
| static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque) |
| { |
| BlockDriverAIOCBCoroutine *acb = opaque; |
| BlockDriverState *bs = acb->common.bs; |
| |
| acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors); |
| acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb); |
| qemu_bh_schedule(acb->bh); |
| } |
| |
| BlockDriverAIOCB *bdrv_aio_discard(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| Coroutine *co; |
| BlockDriverAIOCBCoroutine *acb; |
| |
| trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque); |
| |
| acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque); |
| acb->req.sector = sector_num; |
| acb->req.nb_sectors = nb_sectors; |
| acb->done = NULL; |
| co = qemu_coroutine_create(bdrv_aio_discard_co_entry); |
| qemu_coroutine_enter(co, acb); |
| |
| return &acb->common; |
| } |
| |
| void bdrv_init(void) |
| { |
| module_call_init(MODULE_INIT_BLOCK); |
| } |
| |
| void bdrv_init_with_whitelist(void) |
| { |
| use_bdrv_whitelist = 1; |
| bdrv_init(); |
| } |
| |
| void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| BlockDriverAIOCB *acb; |
| |
| acb = g_slice_alloc(aiocb_info->aiocb_size); |
| acb->aiocb_info = aiocb_info; |
| acb->bs = bs; |
| acb->cb = cb; |
| acb->opaque = opaque; |
| return acb; |
| } |
| |
| void qemu_aio_release(void *p) |
| { |
| BlockDriverAIOCB *acb = p; |
| g_slice_free1(acb->aiocb_info->aiocb_size, acb); |
| } |
| |
| /**************************************************************/ |
| /* Coroutine block device emulation */ |
| |
| typedef struct CoroutineIOCompletion { |
| Coroutine *coroutine; |
| int ret; |
| } CoroutineIOCompletion; |
| |
| static void bdrv_co_io_em_complete(void *opaque, int ret) |
| { |
| CoroutineIOCompletion *co = opaque; |
| |
| co->ret = ret; |
| qemu_coroutine_enter(co->coroutine, NULL); |
| } |
| |
| static int coroutine_fn bdrv_co_io_em(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors, QEMUIOVector *iov, |
| bool is_write) |
| { |
| CoroutineIOCompletion co = { |
| .coroutine = qemu_coroutine_self(), |
| }; |
| BlockDriverAIOCB *acb; |
| |
| if (is_write) { |
| acb = bs->drv->bdrv_aio_writev(bs, sector_num, iov, nb_sectors, |
| bdrv_co_io_em_complete, &co); |
| } else { |
| acb = bs->drv->bdrv_aio_readv(bs, sector_num, iov, nb_sectors, |
| bdrv_co_io_em_complete, &co); |
| } |
| |
| trace_bdrv_co_io_em(bs, sector_num, nb_sectors, is_write, acb); |
| if (!acb) { |
| return -EIO; |
| } |
| qemu_coroutine_yield(); |
| |
| return co.ret; |
| } |
| |
| static int coroutine_fn bdrv_co_readv_em(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| QEMUIOVector *iov) |
| { |
| return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, false); |
| } |
| |
| static int coroutine_fn bdrv_co_writev_em(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, |
| QEMUIOVector *iov) |
| { |
| return bdrv_co_io_em(bs, sector_num, nb_sectors, iov, true); |
| } |
| |
| static void coroutine_fn bdrv_flush_co_entry(void *opaque) |
| { |
| RwCo *rwco = opaque; |
| |
| rwco->ret = bdrv_co_flush(rwco->bs); |
| } |
| |
| int coroutine_fn bdrv_co_flush(BlockDriverState *bs) |
| { |
| int ret; |
| |
| if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs)) { |
| return 0; |
| } |
| |
| /* Write back cached data to the OS even with cache=unsafe */ |
| BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS); |
| if (bs->drv->bdrv_co_flush_to_os) { |
| ret = bs->drv->bdrv_co_flush_to_os(bs); |
| if (ret < 0) { |
| return ret; |
| } |
| } |
| |
| /* But don't actually force it to the disk with cache=unsafe */ |
| if (bs->open_flags & BDRV_O_NO_FLUSH) { |
| goto flush_parent; |
| } |
| |
| BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK); |
| if (bs->drv->bdrv_co_flush_to_disk) { |
| ret = bs->drv->bdrv_co_flush_to_disk(bs); |
| } else if (bs->drv->bdrv_aio_flush) { |
| BlockDriverAIOCB *acb; |
| CoroutineIOCompletion co = { |
| .coroutine = qemu_coroutine_self(), |
| }; |
| |
| acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co); |
| if (acb == NULL) { |
| ret = -EIO; |
| } else { |
| qemu_coroutine_yield(); |
| ret = co.ret; |
| } |
| } else { |
| /* |
| * Some block drivers always operate in either writethrough or unsafe |
| * mode and don't support bdrv_flush therefore. Usually qemu doesn't |
| * know how the server works (because the behaviour is hardcoded or |
| * depends on server-side configuration), so we can't ensure that |
| * everything is safe on disk. Returning an error doesn't work because |
| * that would break guests even if the server operates in writethrough |
| * mode. |
| * |
| * Let's hope the user knows what he's doing. |
| */ |
| ret = 0; |
| } |
| if (ret < 0) { |
| return ret; |
| } |
| |
| /* Now flush the underlying protocol. It will also have BDRV_O_NO_FLUSH |
| * in the case of cache=unsafe, so there are no useless flushes. |
| */ |
| flush_parent: |
| return bdrv_co_flush(bs->file); |
| } |
| |
| void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) |
| { |
| Error *local_err = NULL; |
| int ret; |
| |
| if (!bs->drv) { |
| return; |
| } |
| |
| if (bs->drv->bdrv_invalidate_cache) { |
| bs->drv->bdrv_invalidate_cache(bs, &local_err); |
| } else if (bs->file) { |
| bdrv_invalidate_cache(bs->file, &local_err); |
| } |
| if (local_err) { |
| error_propagate(errp, local_err); |
| return; |
| } |
| |
| ret = refresh_total_sectors(bs, bs->total_sectors); |
| if (ret < 0) { |
| 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; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
| 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; |
| } |
| } |
| } |
| |
| void bdrv_clear_incoming_migration_all(void) |
| { |
| BlockDriverState *bs; |
| |
| QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
| AioContext *aio_context = bdrv_get_aio_context(bs); |
| |
| aio_context_acquire(aio_context); |
| bs->open_flags = bs->open_flags & ~(BDRV_O_INCOMING); |
| aio_context_release(aio_context); |
| } |
| } |
| |
| int bdrv_flush(BlockDriverState *bs) |
| { |
| Coroutine *co; |
| RwCo rwco = { |
| .bs = bs, |
| .ret = NOT_DONE, |
| }; |
| |
| if (qemu_in_coroutine()) { |
| /* Fast-path if already in coroutine context */ |
| bdrv_flush_co_entry(&rwco); |
| } else { |
| AioContext *aio_context = bdrv_get_aio_context(bs); |
| |
| co = qemu_coroutine_create(bdrv_flush_co_entry); |
| qemu_coroutine_enter(co, &rwco); |
| while (rwco.ret == NOT_DONE) { |
| aio_poll(aio_context, true); |
| } |
| } |
| |
| return rwco.ret; |
| } |
| |
| typedef struct DiscardCo { |
| BlockDriverState *bs; |
| int64_t sector_num; |
| int nb_sectors; |
| int ret; |
| } DiscardCo; |
| static void coroutine_fn bdrv_discard_co_entry(void *opaque) |
| { |
| DiscardCo *rwco = opaque; |
| |
| rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors); |
| } |
| |
| /* if no limit is specified in the BlockLimits use a default |
| * of 32768 512-byte sectors (16 MiB) per request. |
| */ |
| #define MAX_DISCARD_DEFAULT 32768 |
| |
| int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num, |
| int nb_sectors) |
| { |
| int max_discard; |
| |
| if (!bs->drv) { |
| return -ENOMEDIUM; |
| } else if (bdrv_check_request(bs, sector_num, nb_sectors)) { |
| return -EIO; |
| } else if (bs->read_only) { |
| return -EROFS; |
| } |
| |
| bdrv_reset_dirty(bs, sector_num, nb_sectors); |
| |
| /* Do nothing if disabled. */ |
| if (!(bs->open_flags & BDRV_O_UNMAP)) { |
| return 0; |
| } |
| |
| if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_aio_discard) { |
| return 0; |
| } |
| |
| max_discard = bs->bl.max_discard ? bs->bl.max_discard : MAX_DISCARD_DEFAULT; |
| while (nb_sectors > 0) { |
| int ret; |
| int num = nb_sectors; |
| |
| /* align request */ |
| if (bs->bl.discard_alignment && |
| num >= bs->bl.discard_alignment && |
| sector_num % bs->bl.discard_alignment) { |
| if (num > bs->bl.discard_alignment) { |
| num = bs->bl.discard_alignment; |
| } |
| num -= sector_num % bs->bl.discard_alignment; |
| } |
| |
| /* limit request size */ |
| if (num > max_discard) { |
| num = max_discard; |
| } |
| |
| if (bs->drv->bdrv_co_discard) { |
| ret = bs->drv->bdrv_co_discard(bs, sector_num, num); |
| } else { |
| BlockDriverAIOCB *acb; |
| CoroutineIOCompletion co = { |
| .coroutine = qemu_coroutine_self(), |
| }; |
| |
| acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors, |
| bdrv_co_io_em_complete, &co); |
| if (acb == NULL) { |
| return -EIO; |
| } else { |
| qemu_coroutine_yield(); |
| ret = co.ret; |
| } |
| } |
| if (ret && ret != -ENOTSUP) { |
| return ret; |
| } |
| |
| sector_num += num; |
| nb_sectors -= num; |
| } |
| return 0; |
| } |
| |
| int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) |
| { |
| Coroutine *co; |
| DiscardCo rwco = { |
| .bs = bs, |
| .sector_num = sector_num, |
| .nb_sectors = nb_sectors, |
| .ret = NOT_DONE, |
| }; |
| |
| if (qemu_in_coroutine()) { |
| /* Fast-path if already in coroutine context */ |
| bdrv_discard_co_entry(&rwco); |
| } else { |
| AioContext *aio_context = bdrv_get_aio_context(bs); |
| |
| co = qemu_coroutine_create(bdrv_discard_co_entry); |
| qemu_coroutine_enter(co, &rwco); |
| while (rwco.ret == NOT_DONE) { |
| aio_poll(aio_context, true); |
| } |
| } |
| |
| return rwco.ret; |
| } |
| |
| /**************************************************************/ |
| /* removable device support */ |
| |
| /** |
| * Return TRUE if the media is present |
| */ |
| int bdrv_is_inserted(BlockDriverState *bs) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (!drv) |
| return 0; |
| if (!drv->bdrv_is_inserted) |
| return 1; |
| return drv->bdrv_is_inserted(bs); |
| } |
| |
| /** |
| * 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); |
| } |
| |
| if (bs->device_name[0] != '\0') { |
| bdrv_emit_qmp_eject_event(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); |
| } |
| } |
| |
| /* needed for generic scsi interface */ |
| |
| int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (drv && drv->bdrv_ioctl) |
| return drv->bdrv_ioctl(bs, req, buf); |
| return -ENOTSUP; |
| } |
| |
| BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, |
| unsigned long int req, void *buf, |
| BlockDriverCompletionFunc *cb, void *opaque) |
| { |
| BlockDriver *drv = bs->drv; |
| |
| if (drv && drv->bdrv_aio_ioctl) |
| return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque); |
| return NULL; |
| } |
| |
| void bdrv_set_guest_block_size(BlockDriverState *bs, int align) |
| { |
| bs->guest_block_size = align; |
| } |
| |
| void *qemu_blockalign(BlockDriverState *bs, size_t size) |
| { |
| return qemu_memalign(bdrv_opt_mem_align(bs), size); |
| } |
| |
| /* |
| * Check if all memory in this vector is sector aligned. |
| */ |
| bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov) |
| { |
| int i; |
| size_t alignment = bdrv_opt_mem_align(bs); |
| |
| for (i = 0; i < qiov->niov; i++) { |
| if ((uintptr_t) qiov->iov[i].iov_base % alignment) { |
| return false; |
| } |
| if (qiov->iov[i].iov_len % alignment) { |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| BdrvDirtyBitmap *bdrv_create_dirty_bitmap(BlockDriverState *bs, int granularity, |
| Error **errp) |
| { |
| int64_t bitmap_size; |
| BdrvDirtyBitmap *bitmap; |
| |
| assert((granularity & (granularity - 1)) == 0); |
| |
| granularity >>= BDRV_SECTOR_BITS; |
| assert(granularity); |
| bitmap_size = bdrv_getlength(bs); |
| if (bitmap_size < 0) { |
| error_setg_errno(errp, -bitmap_size, "could not get length of device"); |
| errno = -bitmap_size; |
| return NULL; |
| } |
| bitmap_size >>= BDRV_SECTOR_BITS; |
| bitmap = g_malloc0(sizeof(BdrvDirtyBitmap)); |
| bitmap->bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1); |
| QLIST_INSERT_HEAD(&bs->dirty_bitmaps, bitmap, list); |
| return bitmap; |
| } |
| |
| void bdrv_release_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap) |
| { |
| BdrvDirtyBitmap *bm, *next; |
| QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) { |
| if (bm == bitmap) { |
| QLIST_REMOVE(bitmap, list); |
| hbitmap_free(bitmap->bitmap); |
| g_free(bitmap); |
| return; |
| } |
| } |
| } |
| |
| BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs) |
| { |
| BdrvDirtyBitmap *bm; |
| BlockDirtyInfoList *list = NULL; |
| BlockDirtyInfoList **plist = &list; |
| |
| QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) { |
| BlockDirtyInfo *info = g_malloc0(sizeof(BlockDirtyInfo)); |
| BlockDirtyInfoList *entry = g_malloc0(sizeof(BlockDirtyInfoList)); |
| info->count = bdrv_get_dirty_count(bs, bm); |
| info->granularity = |
| ((int64_t) BDRV_SECTOR_SIZE << hbitmap_granularity(bm->bitmap)); |
| entry->value = info; |
| *plist = entry; |
| plist = &entry->next; |
| } |
| |
| return list; |
| } |
| |
| int bdrv_get_dirty(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t sector) |
| { |
| if (bitmap) { |
| return hbitmap_get(bitmap->bitmap, sector); |
| } else { |
| return 0; |
| } |
| } |
| |
| void bdrv_dirty_iter_init(BlockDriverState *bs, |
| BdrvDirtyBitmap *bitmap, HBitmapIter *hbi) |
| { |
| hbitmap_iter_init(hbi, bitmap->bitmap, 0); |
| } |
| |
| void bdrv_set_dirty(BlockDriverState *bs, int64_t cur_sector, |
| int nr_sectors) |
| { |
| BdrvDirtyBitmap *bitmap; |
| QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { |
| hbitmap_set(bitmap->bitmap, cur_sector, nr_sectors); |
| } |
| } |
| |
| void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, int nr_sectors) |
| { |
| BdrvDirtyBitmap *bitmap; |
| QLIST_FOREACH(bitmap, &bs->dirty_bitmaps, list) { |
| hbitmap_reset(bitmap->bitmap, cur_sector, nr_sectors); |
| } |
| } |
| |
| int64_t bdrv_get_dirty_count(BlockDriverState *bs, BdrvDirtyBitmap *bitmap) |
| { |
| return hbitmap_count(bitmap->bitmap); |
| } |
| |
| /* 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) |
| { |
| 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) { |
| error_setg(errp, "Device '%s' is busy: %s", |
| bs->device_name, error_get_pretty(blocker->reason)); |
| } |
| 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_malloc0(sizeof(BdrvOpBlocker)); |
| 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_iostatus_enable(BlockDriverState *bs) |
| { |
| bs->iostatus_enabled = true; |
| bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; |
| } |
| |
| /* The I/O status is only enabled if the drive explicitly |
| * enables it _and_ the VM is configured to stop on errors */ |
| bool bdrv_iostatus_is_enabled(const BlockDriverState *bs) |
| { |
| return (bs->iostatus_enabled && |
| (bs->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC || |
| bs->on_write_error == BLOCKDEV_ON_ERROR_STOP || |
| bs->on_read_error == BLOCKDEV_ON_ERROR_STOP)); |
| } |
| |
| void bdrv_iostatus_disable(BlockDriverState *bs) |
| { |
| bs->iostatus_enabled = false; |
| } |
| |
| void bdrv_iostatus_reset(BlockDriverState *bs) |
| { |
| if (bdrv_iostatus_is_enabled(bs)) { |
| bs->iostatus = BLOCK_DEVICE_IO_STATUS_OK; |
| if (bs->job) { |
| block_job_iostatus_reset(bs->job); |
| } |
| } |
| } |
| |
| void bdrv_iostatus_set_err(BlockDriverState *bs, int error) |
| { |
| assert(bdrv_iostatus_is_enabled(bs)); |
| if (bs->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { |
| bs->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : |
| BLOCK_DEVICE_IO_STATUS_FAILED; |
| } |
| } |
| |
| void |
| bdrv_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie, int64_t bytes, |
| enum BlockAcctType type) |
| { |
| assert(type < BDRV_MAX_IOTYPE); |
| |
| cookie->bytes = bytes; |
| cookie->start_time_ns = get_clock(); |
| cookie->type = type; |
| } |
| |
| void |
| bdrv_acct_done(BlockDriverState *bs, BlockAcctCookie *cookie) |
| { |
| assert(cookie->type < BDRV_MAX_IOTYPE); |
| |
| bs->nr_bytes[cookie->type] += cookie->bytes; |
| bs->nr_ops[cookie->type]++; |
| bs->total_time_ns[cookie->type] += get_clock() - cookie->start_time_ns; |
| } |
| |
| 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) |
| { |
| QEMUOptionParameter *param = NULL, *create_options = NULL; |
| QEMUOptionParameter *backing_fmt, *backing_file, *size; |
| BlockDriver *drv, *proto_drv; |
| BlockDriver *backing_drv = NULL; |
| 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); |
| if (!proto_drv) { |
| error_setg(errp, "Unknown protocol '%s'", filename); |
| return; |
| } |
| |
| create_options = append_option_parameters(create_options, |
| drv->create_options); |
| create_options = append_option_parameters(create_options, |
| proto_drv->create_options); |
| |
| /* Create parameter list with default values */ |
| param = parse_option_parameters("", create_options, param); |
| |
| set_option_parameter_int(param, BLOCK_OPT_SIZE, img_size); |
| |
| /* Parse -o options */ |
| if (options) { |
| param = parse_option_parameters(options, create_options, param); |
| if (param == NULL) { |
| error_setg(errp, "Invalid options for file format '%s'.", fmt); |
| goto out; |
| } |
| } |
| |
| if (base_filename) { |
| if (set_option_parameter(param, BLOCK_OPT_BACKING_FILE, |
| base_filename)) { |
| error_setg(errp, "Backing file not supported for file format '%s'", |
| fmt); |
| goto out; |
| } |
| } |
| |
| if (base_fmt) { |
| if (set_option_parameter(param, BLOCK_OPT_BACKING_FMT, base_fmt)) { |
| error_setg(errp, "Backing file format not supported for file " |
| "format '%s'", fmt); |
| goto out; |
| } |
| } |
| |
| backing_file = get_option_parameter(param, BLOCK_OPT_BACKING_FILE); |
| if (backing_file && backing_file->value.s) { |
| if (!strcmp(filename, backing_file->value.s)) { |
| error_setg(errp, "Error: Trying to create an image with the " |
| "same filename as the backing file"); |
| goto out; |
| } |
| } |
| |
| backing_fmt = get_option_parameter(param, BLOCK_OPT_BACKING_FMT); |
| if (backing_fmt && backing_fmt->value.s) { |
| backing_drv = bdrv_find_format(backing_fmt->value.s); |
| if (!backing_drv) { |
| error_setg(errp, "Unknown backing file format '%s'", |
| backing_fmt->value.s); |
| goto out; |
| } |
| } |
| |
| // 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 = get_option_parameter(param, BLOCK_OPT_SIZE); |
| if (size && size->value.n == -1) { |
| if (backing_file && backing_file->value.s) { |
| BlockDriverState *bs; |
| uint64_t size; |
| char buf[32]; |
| int back_flags; |
| |
| /* backing files always opened read-only */ |
| back_flags = |
| flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); |
| |
| bs = NULL; |
| ret = bdrv_open(&bs, backing_file->value.s, NULL, NULL, back_flags, |
| backing_drv, &local_err); |
| if (ret < 0) { |
| error_setg_errno(errp, -ret, "Could not open '%s': %s", |
| backing_file->value.s, |
| error_get_pretty(local_err)); |
| error_free(local_err); |
| local_err = NULL; |
| goto out; |
| } |
| bdrv_get_geometry(bs, &size); |
| size *= 512; |
| |
| snprintf(buf, sizeof(buf), "%" PRId64, size); |
| set_option_parameter(param, BLOCK_OPT_SIZE, buf); |
| |
| bdrv_unref(bs); |
| } else { |
| error_setg(errp, "Image creation needs a size parameter"); |
| goto out; |
| } |
| } |
| |
| if (!quiet) { |
| printf("Formatting '%s', fmt=%s ", filename, fmt); |
| print_option_parameters(param); |
| puts(""); |
| } |
| ret = bdrv_create(drv, filename, param, &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 (get_option_parameter(create_options, BLOCK_OPT_CLUSTER_SIZE)) { |
| 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: |
| free_option_parameters(create_options); |
| free_option_parameters(param); |
| |
| if (local_err) { |
| error_propagate(errp, local_err); |
| } |
| } |
| |
| AioContext *bdrv_get_aio_context(BlockDriverState *bs) |
| { |
| return bs->aio_context; |
| } |
| |
| void bdrv_detach_aio_context(BlockDriverState *bs) |
| { |
| if (!bs->drv) { |
| return; |
| } |
| |
| if (bs->io_limits_enabled) { |
| throttle_detach_aio_context(&bs->throttle_state); |
| } |
| if (bs->drv->bdrv_detach_aio_context) { |
| bs->drv->bdrv_detach_aio_context(bs); |
| } |
| if (bs->file) { |
| bdrv_detach_aio_context(bs->file); |
| } |
| if (bs->backing_hd) { |
| bdrv_detach_aio_context(bs->backing_hd); |
| } |
| |
| bs->aio_context = NULL; |
| } |
| |
| void bdrv_attach_aio_context(BlockDriverState *bs, |
| AioContext *new_context) |
| { |
| if (!bs->drv) { |
| return; |
| } |
| |
| bs->aio_context = new_context; |
| |
| if (bs->backing_hd) { |
| bdrv_attach_aio_context(bs->backing_hd, new_context); |
| } |
| if (bs->file) { |
| bdrv_attach_aio_context(bs->file, new_context); |
| } |
| if (bs->drv->bdrv_attach_aio_context) { |
| bs->drv->bdrv_attach_aio_context(bs, new_context); |
| } |
| if (bs->io_limits_enabled) { |
| throttle_attach_aio_context(&bs->throttle_state, new_context); |
| } |
| } |
| |
| void bdrv_set_aio_context(BlockDriverState *bs, AioContext *new_context) |
| { |
| bdrv_drain_all(); /* 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_before_write_notifier(BlockDriverState *bs, |
| NotifierWithReturn *notifier) |
| { |
| notifier_with_return_list_add(&bs->before_write_notifiers, notifier); |
| } |
| |
| int bdrv_amend_options(BlockDriverState *bs, QEMUOptionParameter *options) |
| { |
| if (bs->drv->bdrv_amend_options == NULL) { |
| return -ENOTSUP; |
| } |
| return bs->drv->bdrv_amend_options(bs, options); |
| } |
| |
| /* 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; |
| |
| /* walk down the bs forest recursively */ |
| QTAILQ_FOREACH(bs, &bdrv_states, device_list) { |
| 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; |
| } |