The Wednesday 12 Mar 2014 à 14:31:03 (+0800), Fam Zheng wrote : > 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. > > There are two bitmap use modes for sync=dirty-bitmap: > > - reset: backup job makes a copy of bitmap and resets the original > one. > - consume: back job makes the original anonymous (invisible to user) s/back job/backup job/ ?
> and releases it after use. > > Signed-off-by: Fam Zheng <f...@redhat.com> > --- > block/backup.c | 51 > ++++++++++++++++++++++++++++++++++++++++++++++- > block/mirror.c | 4 ++++ > blockdev.c | 9 ++++++++- > hmp.c | 4 +++- > include/block/block_int.h | 3 +++ > qapi-schema.json | 30 ++++++++++++++++++++++++---- > qmp-commands.hx | 7 ++++--- > 7 files changed, 98 insertions(+), 10 deletions(-) > > diff --git a/block/backup.c b/block/backup.c > index 15a2e55..6b05429 100644 > --- a/block/backup.c > +++ b/block/backup.c > @@ -37,6 +37,8 @@ typedef struct CowRequest { > typedef struct BackupBlockJob { > BlockJob common; > BlockDriverState *target; > + BdrvDirtyBitmap *sync_bitmap; > + int sync_bitmap_gran; Maybe a comment would help. Reading this variable name for the first time I wonder what the _gran suffix mean. > MirrorSyncMode sync_mode; > RateLimit limit; > BlockdevOnError on_source_error; > @@ -263,7 +265,7 @@ static void coroutine_fn backup_run(void *opaque) > job->common.busy = true; > } > } else { > - /* Both FULL and TOP SYNC_MODE's require copying.. */ > + /* FULL, TOP and DIRTY_BITMAP SYNC_MODE's require copying.. */ > for (; start < end; start++) { > bool error_is_read; > > @@ -317,7 +319,21 @@ static void coroutine_fn backup_run(void *opaque) > if (alloced == 0) { > continue; > } > + } else if (job->sync_mode == MIRROR_SYNC_MODE_DIRTY_BITMAP) { > + int i, dirty = 0; > + for (i = 0; i < BACKUP_SECTORS_PER_CLUSTER; > + i += job->sync_bitmap_gran) { Ok it's _gran for _granularity. > + if (bdrv_get_dirty(bs, job->sync_bitmap, > + start * BACKUP_SECTORS_PER_CLUSTER + i)) { > + dirty = 1; > + break; > + } > + } > + if (!dirty) { > + continue; > + } > } > + > /* FULL sync mode we copy the whole drive. */ > ret = backup_do_cow(bs, start * BACKUP_SECTORS_PER_CLUSTER, > BACKUP_SECTORS_PER_CLUSTER, &error_is_read); > @@ -341,6 +357,9 @@ 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) { > + bdrv_release_dirty_bitmap(bs, job->sync_bitmap); > + } > hbitmap_free(job->bitmap); > > bdrv_iostatus_disable(target); > @@ -351,12 +370,15 @@ static void coroutine_fn backup_run(void *opaque) > > void backup_start(BlockDriverState *bs, BlockDriverState *target, > int64_t speed, MirrorSyncMode sync_mode, > + BdrvDirtyBitmap *sync_bitmap, > + BitmapUseMode bitmap_mode, > BlockdevOnError on_source_error, > BlockdevOnError on_target_error, > BlockDriverCompletionFunc *cb, void *opaque, > Error **errp) > { > int64_t len; > + BdrvDirtyBitmap *original; > > assert(bs); > assert(target); > @@ -369,6 +391,28 @@ void backup_start(BlockDriverState *bs, BlockDriverState > *target, > return; > } > > + if (sync_mode == MIRROR_SYNC_MODE_DIRTY_BITMAP && !sync_bitmap) { > + error_setg(errp, "must provide a valid bitmap name for > \"dirty-bitmap\"" > + "sync mode"); > + return; > + } > + > + if (sync_bitmap) { > + switch (bitmap_mode) { > + case BITMAP_USE_MODE_RESET: > + original = sync_bitmap; > + sync_bitmap = bdrv_copy_dirty_bitmap(bs, sync_bitmap, NULL); > + bdrv_reset_dirty_bitmap(bs, original); > + break; > + case BITMAP_USE_MODE_CONSUME: > + bdrv_dirty_bitmap_make_anon(bs, sync_bitmap); > + break; > + default: > + assert(0); > + } > + bdrv_disable_dirty_bitmap(bs, sync_bitmap); > + } > + > len = bdrv_getlength(bs); > if (len < 0) { > error_setg_errno(errp, -len, "unable to get length for '%s'", > @@ -386,6 +430,11 @@ 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_bitmap; > + if (sync_bitmap) { > + job->sync_bitmap_gran = > + bdrv_dirty_bitmap_granularity(bs, job->sync_bitmap); > + } > job->common.len = len; > job->common.co = qemu_coroutine_create(backup_run); > qemu_coroutine_enter(job->common.co, job); > diff --git a/block/mirror.c b/block/mirror.c > index be8b2a1..6e4f3f3 100644 > --- a/block/mirror.c > +++ b/block/mirror.c > @@ -615,6 +615,10 @@ 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, speed, granularity, buf_size, > diff --git a/blockdev.c b/blockdev.c > index aa3ee55..4120dee 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -1384,6 +1384,8 @@ 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_bitmap_use_mode, backup->bitmap_use_mode, > backup->has_on_source_error, backup->on_source_error, > backup->has_on_target_error, backup->on_target_error, > &local_err); > @@ -2032,6 +2034,8 @@ 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_bitmap_use_mode, enum BitmapUseMode > bitmap_mode, > bool has_on_source_error, BlockdevOnError > on_source_error, > bool has_on_target_error, BlockdevOnError > on_target_error, > Error **errp) > @@ -2129,7 +2133,10 @@ void qmp_drive_backup(const char *device, const char > *target, > return; > } > > - backup_start(bs, target_bs, speed, sync, on_source_error, > on_target_error, > + backup_start(bs, target_bs, speed, sync, > + has_bitmap ? bdrv_find_dirty_bitmap(bs, bitmap) : NULL, > + has_bitmap_use_mode ? bitmap_mode : BITMAP_USE_MODE_RESET, > + on_source_error, on_target_error, > block_job_cb, bs, &local_err); > if (local_err != NULL) { > bdrv_unref(target_bs); > diff --git a/hmp.c b/hmp.c > index 2f279c4..2c84377 100644 > --- a/hmp.c > +++ b/hmp.c > @@ -950,7 +950,9 @@ 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, &errp); > + true, mode, false, 0, false, NULL, > + false, 0, > + false, 0, false, 0, &errp); > hmp_handle_error(mon, &errp); > } > > diff --git a/include/block/block_int.h b/include/block/block_int.h > index 0bcf1c9..d02c090 100644 > --- a/include/block/block_int.h > +++ b/include/block/block_int.h > @@ -484,6 +484,7 @@ 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. > @@ -494,6 +495,8 @@ void mirror_start(BlockDriverState *bs, BlockDriverState > *target, > */ > void backup_start(BlockDriverState *bs, BlockDriverState *target, > int64_t speed, MirrorSyncMode sync_mode, > + BdrvDirtyBitmap *sync_bitmap, > + BitmapUseMode bitmap_mode, > BlockdevOnError on_source_error, > BlockdevOnError on_target_error, > BlockDriverCompletionFunc *cb, void *opaque, > diff --git a/qapi-schema.json b/qapi-schema.json > index f8cd6b8..e4e66cb 100644 > --- a/qapi-schema.json > +++ b/qapi-schema.json > @@ -1503,7 +1503,7 @@ > # Since: 1.3 > ## > { 'enum': 'MirrorSyncMode', > - 'data': ['top', 'full', 'none'] } > + 'data': ['top', 'full', 'none', 'dirty-bitmap'] } > > ## > # @BlockJobType: > @@ -1879,6 +1879,22 @@ > 'data': { 'device': 'str', 'name': 'str' } } > > ## > +# @BitmapUseMode > +# > +# An enumeration that tells QEMU what operation to take when consuming a > bitmap > +# a new image file. > +# > +# @consume: QEMU should just consume the bitmap and release it after using > +# > +# @reset: QEMU should keep an internal copy of the bitmap and reset the > +# dirty record from original one > +# > +# Since: 2.1 > +## > +{ 'enum': 'BitmapUseMode', > + 'data': [ 'consume', 'reset' ] } > + > +## > # @DriveBackup > # > # @device: the name of the device which should be copied. > @@ -1891,14 +1907,19 @@ > # 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" (Since 2.1) > +# > +# @bitmap-use-mode: #optional which operation to take when consuming @bitmap, > +# default is reset. (Since 2.1) > +# > # @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). > @@ -1916,7 +1937,8 @@ > { 'type': 'DriveBackup', > 'data': { 'device': 'str', 'target': 'str', '*format': 'str', > 'sync': 'MirrorSyncMode', '*mode': 'NewImageMode', > - '*speed': 'int', > + '*speed': 'int', '*bitmap': 'str', > + '*bitmap-use-mode': 'BitmapUseMode', > '*on-source-error': 'BlockdevOnError', > '*on-target-error': 'BlockdevOnError' } } > > diff --git a/qmp-commands.hx b/qmp-commands.hx > index 205343b..4d8271a 100644 > --- a/qmp-commands.hx > +++ b/qmp-commands.hx > @@ -1031,7 +1031,7 @@ 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, > }, > > @@ -1058,8 +1058,9 @@ 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 sync the dirty > + sectors in the bitmap, or "none" to only replicate new I/O > (MirrorSyncMode). > +- "bitmap": bitmap name to use for sync==dirty-bitmap > - "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) > -- > 1.9.0 > >