From d58d84539784d27c826924a79d9436178b07ff69 Mon Sep 17 00:00:00 2001 From: John Snow Date: Fri, 17 Apr 2015 19:49:58 -0400 Subject: [PATCH] qmp: Add support of "dirty-bitmap" sync mode for drive-backup For "dirty-bitmap" sync mode, the block job will iterate through the given dirty bitmap to decide if a sector needs backup (backup all the dirty clusters and skip clean ones), just as allocation conditions of "top" sync mode. Signed-off-by: Fam Zheng Signed-off-by: John Snow Reviewed-by: Max Reitz Reviewed-by: Eric Blake Reviewed-by: Stefan Hajnoczi Message-id: 1429314609-29776-11-git-send-email-jsnow@redhat.com Signed-off-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block.c | 9 +++ block/backup.c | 155 ++++++++++++++++++++++++++++++++------ block/mirror.c | 4 + blockdev.c | 18 ++++- hmp.c | 3 +- include/block/block.h | 1 + include/block/block_int.h | 2 + qapi/block-core.json | 14 +++- qmp-commands.hx | 8 +- 9 files changed, 181 insertions(+), 33 deletions(-) diff --git a/block.c b/block.c index dffa9dedc0..9dc5c8cb1a 100644 --- a/block.c +++ b/block.c @@ -5783,6 +5783,15 @@ static void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector, } } +/** + * Advance an HBitmapIter to an arbitrary offset. + */ +void bdrv_set_dirty_iter(HBitmapIter *hbi, int64_t offset) +{ + assert(hbi->hb); + hbitmap_iter_init(hbi, hbi->hb, offset); +} + int64_t bdrv_get_dirty_count(BlockDriverState *bs, BdrvDirtyBitmap *bitmap) { return hbitmap_count(bitmap->bitmap); diff --git a/block/backup.c b/block/backup.c index 3312476d66..ddf9027995 100644 --- a/block/backup.c +++ b/block/backup.c @@ -37,6 +37,8 @@ typedef struct CowRequest { typedef struct BackupBlockJob { BlockJob common; BlockDriverState *target; + /* bitmap for sync=dirty-bitmap */ + BdrvDirtyBitmap *sync_bitmap; MirrorSyncMode sync_mode; RateLimit limit; BlockdevOnError on_source_error; @@ -242,6 +244,91 @@ static void backup_complete(BlockJob *job, void *opaque) g_free(data); } +static bool coroutine_fn yield_and_check(BackupBlockJob *job) +{ + if (block_job_is_cancelled(&job->common)) { + return true; + } + + /* we need to yield so that bdrv_drain_all() returns. + * (without, VM does not reboot) + */ + if (job->common.speed) { + uint64_t delay_ns = ratelimit_calculate_delay(&job->limit, + job->sectors_read); + job->sectors_read = 0; + block_job_sleep_ns(&job->common, QEMU_CLOCK_REALTIME, delay_ns); + } else { + block_job_sleep_ns(&job->common, QEMU_CLOCK_REALTIME, 0); + } + + if (block_job_is_cancelled(&job->common)) { + return true; + } + + return false; +} + +static int coroutine_fn backup_run_incremental(BackupBlockJob *job) +{ + bool error_is_read; + int ret = 0; + int clusters_per_iter; + uint32_t granularity; + int64_t sector; + int64_t cluster; + int64_t end; + int64_t last_cluster = -1; + BlockDriverState *bs = job->common.bs; + HBitmapIter hbi; + + granularity = bdrv_dirty_bitmap_granularity(job->sync_bitmap); + clusters_per_iter = MAX((granularity / BACKUP_CLUSTER_SIZE), 1); + bdrv_dirty_iter_init(bs, job->sync_bitmap, &hbi); + + /* Find the next dirty sector(s) */ + while ((sector = hbitmap_iter_next(&hbi)) != -1) { + cluster = sector / BACKUP_SECTORS_PER_CLUSTER; + + /* Fake progress updates for any clusters we skipped */ + if (cluster != last_cluster + 1) { + job->common.offset += ((cluster - last_cluster - 1) * + BACKUP_CLUSTER_SIZE); + } + + for (end = cluster + clusters_per_iter; cluster < end; cluster++) { + do { + if (yield_and_check(job)) { + return ret; + } + ret = backup_do_cow(bs, cluster * BACKUP_SECTORS_PER_CLUSTER, + BACKUP_SECTORS_PER_CLUSTER, &error_is_read); + if ((ret < 0) && + backup_error_action(job, error_is_read, -ret) == + BLOCK_ERROR_ACTION_REPORT) { + return ret; + } + } while (ret < 0); + } + + /* If the bitmap granularity is smaller than the backup granularity, + * we need to advance the iterator pointer to the next cluster. */ + if (granularity < BACKUP_CLUSTER_SIZE) { + bdrv_set_dirty_iter(&hbi, cluster * BACKUP_SECTORS_PER_CLUSTER); + } + + last_cluster = cluster - 1; + } + + /* Play some final catchup with the progress meter */ + end = DIV_ROUND_UP(job->common.len, BACKUP_CLUSTER_SIZE); + if (last_cluster + 1 < end) { + job->common.offset += ((end - last_cluster - 1) * BACKUP_CLUSTER_SIZE); + } + + return ret; +} + static void coroutine_fn backup_run(void *opaque) { BackupBlockJob *job = opaque; @@ -259,8 +346,7 @@ static void coroutine_fn backup_run(void *opaque) qemu_co_rwlock_init(&job->flush_rwlock); start = 0; - end = DIV_ROUND_UP(job->common.len / BDRV_SECTOR_SIZE, - BACKUP_SECTORS_PER_CLUSTER); + end = DIV_ROUND_UP(job->common.len, BACKUP_CLUSTER_SIZE); job->bitmap = hbitmap_alloc(end, 0); @@ -278,28 +364,13 @@ static void coroutine_fn backup_run(void *opaque) qemu_coroutine_yield(); job->common.busy = true; } + } else if (job->sync_mode == MIRROR_SYNC_MODE_DIRTY_BITMAP) { + ret = backup_run_incremental(job); } else { /* Both FULL and TOP SYNC_MODE's require copying.. */ for (; start < end; start++) { bool error_is_read; - - if (block_job_is_cancelled(&job->common)) { - break; - } - - /* we need to yield so that bdrv_drain_all() returns. - * (without, VM does not reboot) - */ - if (job->common.speed) { - uint64_t delay_ns = ratelimit_calculate_delay( - &job->limit, job->sectors_read); - job->sectors_read = 0; - block_job_sleep_ns(&job->common, QEMU_CLOCK_REALTIME, delay_ns); - } else { - block_job_sleep_ns(&job->common, QEMU_CLOCK_REALTIME, 0); - } - - if (block_job_is_cancelled(&job->common)) { + if (yield_and_check(job)) { break; } @@ -357,6 +428,18 @@ static void coroutine_fn backup_run(void *opaque) qemu_co_rwlock_wrlock(&job->flush_rwlock); qemu_co_rwlock_unlock(&job->flush_rwlock); + if (job->sync_bitmap) { + BdrvDirtyBitmap *bm; + if (ret < 0) { + /* Merge the successor back into the parent, delete nothing. */ + bm = bdrv_reclaim_dirty_bitmap(bs, job->sync_bitmap, NULL); + assert(bm); + } else { + /* Everything is fine, delete this bitmap and install the backup. */ + bm = bdrv_dirty_bitmap_abdicate(bs, job->sync_bitmap, NULL); + assert(bm); + } + } hbitmap_free(job->bitmap); bdrv_iostatus_disable(target); @@ -369,6 +452,7 @@ static void coroutine_fn backup_run(void *opaque) void backup_start(BlockDriverState *bs, BlockDriverState *target, int64_t speed, MirrorSyncMode sync_mode, + BdrvDirtyBitmap *sync_bitmap, BlockdevOnError on_source_error, BlockdevOnError on_target_error, BlockCompletionFunc *cb, void *opaque, @@ -412,17 +496,36 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target, return; } + if (sync_mode == MIRROR_SYNC_MODE_DIRTY_BITMAP) { + if (!sync_bitmap) { + error_setg(errp, "must provide a valid bitmap name for " + "\"dirty-bitmap\" sync mode"); + return; + } + + /* Create a new bitmap, and freeze/disable this one. */ + if (bdrv_dirty_bitmap_create_successor(bs, sync_bitmap, errp) < 0) { + return; + } + } else if (sync_bitmap) { + error_setg(errp, + "a sync_bitmap was provided to backup_run, " + "but received an incompatible sync_mode (%s)", + MirrorSyncMode_lookup[sync_mode]); + return; + } + len = bdrv_getlength(bs); if (len < 0) { error_setg_errno(errp, -len, "unable to get length for '%s'", bdrv_get_device_name(bs)); - return; + goto error; } BackupBlockJob *job = block_job_create(&backup_job_driver, bs, speed, cb, opaque, errp); if (!job) { - return; + goto error; } bdrv_op_block_all(target, job->common.blocker); @@ -431,7 +534,15 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target, job->on_target_error = on_target_error; job->target = target; job->sync_mode = sync_mode; + job->sync_bitmap = sync_mode == MIRROR_SYNC_MODE_DIRTY_BITMAP ? + sync_bitmap : NULL; job->common.len = len; job->common.co = qemu_coroutine_create(backup_run); qemu_coroutine_enter(job->common.co, job); + return; + + error: + if (sync_bitmap) { + bdrv_reclaim_dirty_bitmap(bs, sync_bitmap, NULL); + } } diff --git a/block/mirror.c b/block/mirror.c index 29c45453c9..898f8ce8a1 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -718,6 +718,10 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target, bool is_none_mode; BlockDriverState *base; + if (mode == MIRROR_SYNC_MODE_DIRTY_BITMAP) { + error_setg(errp, "Sync mode 'dirty-bitmap' not supported"); + return; + } is_none_mode = mode == MIRROR_SYNC_MODE_NONE; base = mode == MIRROR_SYNC_MODE_TOP ? bs->backing_hd : NULL; mirror_start_job(bs, target, replaces, diff --git a/blockdev.c b/blockdev.c index e8b712e7e2..62d862cf01 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1585,6 +1585,7 @@ static void drive_backup_prepare(BlkTransactionState *common, Error **errp) backup->sync, backup->has_mode, backup->mode, backup->has_speed, backup->speed, + backup->has_bitmap, backup->bitmap, backup->has_on_source_error, backup->on_source_error, backup->has_on_target_error, backup->on_target_error, &local_err); @@ -2395,6 +2396,7 @@ void qmp_drive_backup(const char *device, const char *target, enum MirrorSyncMode sync, bool has_mode, enum NewImageMode mode, bool has_speed, int64_t speed, + bool has_bitmap, const char *bitmap, bool has_on_source_error, BlockdevOnError on_source_error, bool has_on_target_error, BlockdevOnError on_target_error, Error **errp) @@ -2403,6 +2405,7 @@ void qmp_drive_backup(const char *device, const char *target, BlockDriverState *bs; BlockDriverState *target_bs; BlockDriverState *source = NULL; + BdrvDirtyBitmap *bmap = NULL; AioContext *aio_context; BlockDriver *drv = NULL; Error *local_err = NULL; @@ -2502,7 +2505,16 @@ void qmp_drive_backup(const char *device, const char *target, bdrv_set_aio_context(target_bs, aio_context); - backup_start(bs, target_bs, speed, sync, on_source_error, on_target_error, + if (has_bitmap) { + bmap = bdrv_find_dirty_bitmap(bs, bitmap); + if (!bmap) { + error_setg(errp, "Bitmap '%s' could not be found", bitmap); + goto out; + } + } + + backup_start(bs, target_bs, speed, sync, bmap, + on_source_error, on_target_error, block_job_cb, bs, &local_err); if (local_err != NULL) { bdrv_unref(target_bs); @@ -2563,8 +2575,8 @@ void qmp_blockdev_backup(const char *device, const char *target, bdrv_ref(target_bs); bdrv_set_aio_context(target_bs, aio_context); - backup_start(bs, target_bs, speed, sync, on_source_error, on_target_error, - block_job_cb, bs, &local_err); + backup_start(bs, target_bs, speed, sync, NULL, on_source_error, + on_target_error, block_job_cb, bs, &local_err); if (local_err != NULL) { bdrv_unref(target_bs); error_propagate(errp, local_err); diff --git a/hmp.c b/hmp.c index f31ae2796a..d85d913a79 100644 --- a/hmp.c +++ b/hmp.c @@ -1061,7 +1061,8 @@ void hmp_drive_backup(Monitor *mon, const QDict *qdict) qmp_drive_backup(device, filename, !!format, format, full ? MIRROR_SYNC_MODE_FULL : MIRROR_SYNC_MODE_TOP, - true, mode, false, 0, false, 0, false, 0, &err); + true, mode, false, 0, false, NULL, + false, 0, false, 0, &err); hmp_handle_error(mon, &err); } diff --git a/include/block/block.h b/include/block/block.h index 1635c227f3..035cf7bb4c 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -481,6 +481,7 @@ void bdrv_reset_dirty_bitmap(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, int64_t cur_sector, int nr_sectors); void bdrv_dirty_iter_init(BlockDriverState *bs, BdrvDirtyBitmap *bitmap, struct HBitmapIter *hbi); +void bdrv_set_dirty_iter(struct HBitmapIter *hbi, int64_t offset); int64_t bdrv_get_dirty_count(BlockDriverState *bs, BdrvDirtyBitmap *bitmap); void bdrv_enable_copy_on_read(BlockDriverState *bs); diff --git a/include/block/block_int.h b/include/block/block_int.h index fb9e1002ba..e0d5561678 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -602,6 +602,7 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target, * @target: Block device to write to. * @speed: The maximum speed, in bytes per second, or 0 for unlimited. * @sync_mode: What parts of the disk image should be copied to the destination. + * @sync_bitmap: The dirty bitmap if sync_mode is MIRROR_SYNC_MODE_DIRTY_BITMAP. * @on_source_error: The action to take upon error reading from the source. * @on_target_error: The action to take upon error writing to the target. * @cb: Completion function for the job. @@ -612,6 +613,7 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target, */ void backup_start(BlockDriverState *bs, BlockDriverState *target, int64_t speed, MirrorSyncMode sync_mode, + BdrvDirtyBitmap *sync_bitmap, BlockdevOnError on_source_error, BlockdevOnError on_target_error, BlockCompletionFunc *cb, void *opaque, diff --git a/qapi/block-core.json b/qapi/block-core.json index f3b92d80c9..8a4c7f21fc 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -512,10 +512,12 @@ # # @none: only copy data written from now on # +# @dirty-bitmap: only copy data described by the dirty bitmap. Since: 2.4 +# # Since: 1.3 ## { 'enum': 'MirrorSyncMode', - 'data': ['top', 'full', 'none'] } + 'data': ['top', 'full', 'none', 'dirty-bitmap'] } ## # @BlockJobType: @@ -690,14 +692,18 @@ # probe if @mode is 'existing', else the format of the source # # @sync: what parts of the disk image should be copied to the destination -# (all the disk, only the sectors allocated in the topmost image, or -# only new I/O). +# (all the disk, only the sectors allocated in the topmost image, from a +# dirty bitmap, or only new I/O). # # @mode: #optional whether and how QEMU should create a new image, default is # 'absolute-paths'. # # @speed: #optional the maximum speed, in bytes per second # +# @bitmap: #optional the name of dirty bitmap if sync is "dirty-bitmap". +# Must be present if sync is "dirty-bitmap", must NOT be present +# otherwise. (Since 2.4) +# # @on-source-error: #optional the action to take on an error on the source, # default 'report'. 'stop' and 'enospc' can only be used # if the block device supports io-status (see BlockInfo). @@ -715,7 +721,7 @@ { 'type': 'DriveBackup', 'data': { 'device': 'str', 'target': 'str', '*format': 'str', 'sync': 'MirrorSyncMode', '*mode': 'NewImageMode', - '*speed': 'int', + '*speed': 'int', '*bitmap': 'str', '*on-source-error': 'BlockdevOnError', '*on-target-error': 'BlockdevOnError' } } diff --git a/qmp-commands.hx b/qmp-commands.hx index 1aeab504aa..9b10d3d2e8 100644 --- a/qmp-commands.hx +++ b/qmp-commands.hx @@ -1110,7 +1110,7 @@ EQMP { .name = "drive-backup", .args_type = "sync:s,device:B,target:s,speed:i?,mode:s?,format:s?," - "on-source-error:s?,on-target-error:s?", + "bitmap:s?,on-source-error:s?,on-target-error:s?", .mhandler.cmd_new = qmp_marshal_input_drive_backup, }, @@ -1137,8 +1137,10 @@ Arguments: (json-string, optional) - "sync": what parts of the disk image should be copied to the destination; possibilities include "full" for all the disk, "top" for only the sectors - allocated in the topmost image, or "none" to only replicate new I/O - (MirrorSyncMode). + allocated in the topmost image, "dirty-bitmap" for only the dirty sectors in + the bitmap, or "none" to only replicate new I/O (MirrorSyncMode). +- "bitmap": dirty bitmap name for sync==dirty-bitmap. Must be present if sync + is "dirty-bitmap", must NOT be present otherwise. - "mode": whether and how QEMU should create a new image (NewImageMode, optional, default 'absolute-paths') - "speed": the maximum speed, in bytes per second (json-int, optional)