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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 <famz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1429314609-29776-11-git-send-email-jsnow@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
John Snow 2015-04-17 19:49:58 -04:00 committed by Kevin Wolf
parent 9bd2b08f27
commit d58d845397
9 changed files with 181 additions and 33 deletions
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9
block.c
View File

@ -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);

155
block/backup.c
View File

@ -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);
}
}

4
block/mirror.c
View File

@ -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,

18
blockdev.c
View File

@ -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);

3
hmp.c
View File

@ -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);
}

1
include/block/block.h
View File

@ -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);

2
include/block/block_int.h
View File

@ -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,

14
qapi/block-core.json
View File

@ -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' } }

8
qmp-commands.hx
View File

@ -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)