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 <f...@redhat.com>
Signed-off-by: John Snow <js...@redhat.com>
---
block.c | 9 +++
block/backup.c | 149 +++++++++++++++++++++++++++++++++++++++-------
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 | 13 ++--
qmp-commands.hx | 7 ++-
9 files changed, 172 insertions(+), 34 deletions(-)
diff --git a/block.c b/block.c
index 8d84ace..e93fceb 100644
--- a/block.c
+++ b/block.c
@@ -5648,6 +5648,15 @@ 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 1c535b1..bf8c0e7 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 +244,31 @@ 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 qemu_aio_flush() 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 void coroutine_fn backup_run(void *opaque)
{
BackupBlockJob *job = opaque;
@@ -254,13 +281,13 @@ static void coroutine_fn backup_run(void *opaque)
};
int64_t start, end;
int ret = 0;
+ bool error_is_read;
QLIST_INIT(&job->inflight_reqs);
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 +305,61 @@ 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) {
+ /* Dirty Bitmap sync has a slightly different iteration method */
+ HBitmapIter hbi;
+ int64_t sector;
+ int64_t cluster;
+ int64_t last_cluster = -1;
+ bool polyrhythmic;
+
+ bdrv_dirty_iter_init(bs, job->sync_bitmap, &hbi);
+ /* Does the granularity happen to match our backup cluster size? */
+ polyrhythmic = (bdrv_dirty_bitmap_granularity(job->sync_bitmap) !=
+ BACKUP_CLUSTER_SIZE);
+
+ /* Find the next dirty /sector/ and copy that /cluster/ */
+ while ((sector = hbitmap_iter_next(&hbi)) != -1) {
+ if (yield_and_check(job)) {
+ goto leave;
+ }
+ cluster = sector / BACKUP_SECTORS_PER_CLUSTER;
+
+ /* Play some catchup with the progress meter */
+ if (cluster != last_cluster + 1) {
+ job->common.offset += ((cluster - last_cluster - 1) *
+ BACKUP_CLUSTER_SIZE);
+ }
} 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 qemu_aio_flush() 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;
}
@@ -351,12 +411,26 @@ static void coroutine_fn backup_run(void *opaque)
}
}
+leave:
notifier_with_return_remove(&before_write);
/* wait until pending backup_do_cow() calls have completed */
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);
+ bdrv_enable_dirty_bitmap(job->sync_bitmap);
+ } 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 +443,7 @@ 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 +487,37 @@ 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 +526,15 @@ 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 77bd1ed..271dbf3 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 826d0c1..3f41e82 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1569,6 +1569,7 @@ 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);
@@ -2429,6 +2430,7 @@ 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)
@@ -2436,6 +2438,7 @@ 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;
@@ -2534,7 +2537,16 @@ 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);
@@ -2592,8 +2604,8 @@ 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 b47f331..015499f 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1027,7 +1027,8 @@ 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 b2d84d6..8589e77 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -469,6 +469,7 @@ 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 7ad1950..2233790 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -588,6 +588,7 @@ 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.
@@ -598,6 +599,7 @@ 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 940eff7..9c5a99c 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -508,10 +508,12 @@
#
# @none: only copy data written from now on
#
+# @dirty-bitmap: only copy data described by the dirty bitmap. Since: 2.3
+#
# Since: 1.3
##
{ 'enum': 'MirrorSyncMode',
- 'data': ['top', 'full', 'none'] }
+ 'data': ['top', 'full', 'none', 'dirty-bitmap'] }
##
# @BlockJobType:
@@ -686,14 +688,17 @@
# 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 2.3)
+#
# @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).
@@ -711,7 +716,7 @@
{ '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 ce7782f..5aa3845 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -1048,7 +1048,7 @@ 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,
},
@@ -1075,8 +1075,9 @@ 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 the dirty sectors in
+ the bitmap, or "none" to only replicate new I/O (MirrorSyncMode).
+- "bitmap": dirty bitmap name 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)
