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Re: [Qemu-devel] [PATCH v2 8/9] qmp: Add support of "dirty-bitmap" sync
From: |
Benoît Canet |
Subject: |
Re: [Qemu-devel] [PATCH v2 8/9] qmp: Add support of "dirty-bitmap" sync mode for drive-backup |
Date: |
Thu, 13 Mar 2014 15:32:08 +0100 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
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 <address@hidden>
> ---
> 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
>
>
- [Qemu-devel] [PATCH v2 5/9] hbitmap: Add hbitmap_copy, (continued)
- [Qemu-devel] [PATCH v2 5/9] hbitmap: Add hbitmap_copy, Fam Zheng, 2014/03/12
- [Qemu-devel] [PATCH v2 6/9] block: Add bdrv_copy_dirty_bitmap and bdrv_reset_dirty_bitmap, Fam Zheng, 2014/03/12
- [Qemu-devel] [PATCH v2 7/9] qmp: Add dirty-bitmap-enable and dirty-bitmap-disable, Fam Zheng, 2014/03/12
- [Qemu-devel] [PATCH v2 8/9] qmp: Add support of "dirty-bitmap" sync mode for drive-backup, Fam Zheng, 2014/03/12
- Re: [Qemu-devel] [PATCH v2 8/9] qmp: Add support of "dirty-bitmap" sync mode for drive-backup,
Benoît Canet <=
- [Qemu-devel] [PATCH v2 9/9] qapi: Add transaction support to dirty-bitmap-{add, disable}, Fam Zheng, 2014/03/12