From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57332) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YMOQD-0003on-5i for qemu-devel@nongnu.org; Fri, 13 Feb 2015 17:09:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YMOQB-0004CO-QU for qemu-devel@nongnu.org; Fri, 13 Feb 2015 17:09:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34249) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YMOQB-0004C6-K0 for qemu-devel@nongnu.org; Fri, 13 Feb 2015 17:09:11 -0500 From: John Snow Date: Fri, 13 Feb 2015 17:08:51 -0500 Message-Id: <1423865338-8576-11-git-send-email-jsnow@redhat.com> In-Reply-To: <1423865338-8576-1-git-send-email-jsnow@redhat.com> References: <1423865338-8576-1-git-send-email-jsnow@redhat.com> Subject: [Qemu-devel] [PATCH v13 10/17] qapi: Add transaction support to block-dirty-bitmap operations List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, John Snow , armbru@redhat.com, mreitz@redhat.com, vsementsov@parallels.com, stefanha@redhat.com This adds four qmp commands to transactions. Users can stop a dirty bitmap, start backup of it, and start another dirty bitmap atomically, so that the dirty bitmap is tracked incrementally and we don't miss any write. For starting a new incremental backup chain, users can also chain together a bitmap clear and a full block backup. Signed-off-by: Fam Zheng Signed-off-by: John Snow --- blockdev.c | 170 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ qapi-schema.json | 10 +++- 2 files changed, 179 insertions(+), 1 deletion(-) diff --git a/blockdev.c b/blockdev.c index 8422e94..20fea62 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1675,6 +1675,153 @@ static void blockdev_backup_clean(BlkTransactionState *common) } } +typedef struct BlockDirtyBitmapState { + BlkTransactionState common; + BdrvDirtyBitmap *bitmap; + BlockDriverState *bs; + AioContext *aio_context; +} BlockDirtyBitmapState; + +static void block_dirty_bitmap_add_prepare(BlkTransactionState *common, + Error **errp) +{ + BlockDirtyBitmapAdd *action; + BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState, + common, common); + + action = common->action->block_dirty_bitmap_add; + /* AIO context taken within qmp_block_dirty_bitmap_add */ + qmp_block_dirty_bitmap_add(action->node, action->name, + action->has_granularity, action->granularity, + errp); + + state->bitmap = block_dirty_bitmap_lookup(action->node, action->name, + NULL, NULL); +} + +static void block_dirty_bitmap_add_abort(BlkTransactionState *common) +{ + BlockDirtyBitmapAdd *action; + BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState, + common, common); + + action = common->action->block_dirty_bitmap_add; + /* Should not fail meaningfully: IF the bitmap was added via .prepare(), + * then the node reference and bitmap name must have been valid. + * THUS: any failure here could only indicate the lack of a bitmap at all. + * We will use the presence of the bitmap field to check that we succeeded + * in the first place, though. + */ + if (state->bitmap) { + qmp_block_dirty_bitmap_remove(action->node, action->name, NULL); + } +} + +/** + * Enable and Disable re-use the same preparation. + */ +static void block_dirty_bitmap_toggle_prepare(BlkTransactionState *common, + Error **errp) +{ + BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState, + common, common); + BlockDirtyBitmap *action; + BlockDriverState *bs; + + /* We may be used by either enable or disable; + * We use the "enable" member of the union here, + * but "disable" should be functionally equivalent: */ + action = common->action->block_dirty_bitmap_enable; + assert(action == common->action->block_dirty_bitmap_disable); + + state->bitmap = block_dirty_bitmap_lookup(action->node, + action->name, + &bs, + errp); + if (!state->bitmap) { + return; + } + + if (bdrv_dirty_bitmap_frozen(state->bitmap)) { + error_setg(errp, "Cannot modify a frozen bitmap"); + return; + } + + /* AioContext is released in .clean() */ + state->aio_context = bdrv_get_aio_context(bs); + aio_context_acquire(state->aio_context); +} + +static void block_dirty_bitmap_enable_commit(BlkTransactionState *common) +{ + BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState, + common, common); + bdrv_enable_dirty_bitmap(state->bitmap); +} + +static void block_dirty_bitmap_disable_commit(BlkTransactionState *common) +{ + BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState, + common, common); + bdrv_disable_dirty_bitmap(state->bitmap); +} + +static void block_dirty_bitmap_toggle_clean(BlkTransactionState *common) +{ + BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState, + common, common); + + if (state->aio_context) { + aio_context_release(state->aio_context); + } +} + +static void block_dirty_bitmap_clear_prepare(BlkTransactionState *common, + Error **errp) +{ + BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState, + common, common); + BlockDirtyBitmap *action; + + action = common->action->block_dirty_bitmap_clear; + state->bitmap = block_dirty_bitmap_lookup(action->node, + action->name, + &state->bs, + errp); + if (!state->bitmap) { + return; + } + + if (bdrv_dirty_bitmap_frozen(state->bitmap)) { + error_setg(errp, "Cannot modify a frozen bitmap"); + return; + } else if (!bdrv_dirty_bitmap_enabled(state->bitmap)) { + error_setg(errp, "Cannot clear a disabled bitmap"); + return; + } + + /* AioContext is released in .clean() */ + state->aio_context = bdrv_get_aio_context(state->bs); + aio_context_acquire(state->aio_context); +} + +static void block_dirty_bitmap_clear_commit(BlkTransactionState *common) +{ + BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState, + common, common); + bdrv_clear_dirty_bitmap(state->bitmap); +} + +static void block_dirty_bitmap_clear_clean(BlkTransactionState *common) +{ + BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState, + common, common); + + if (state->aio_context) { + aio_context_release(state->aio_context); + } +} + static void abort_prepare(BlkTransactionState *common, Error **errp) { error_setg(errp, "Transaction aborted using Abort action"); @@ -1715,6 +1862,29 @@ static const BdrvActionOps actions[] = { .abort = internal_snapshot_abort, .clean = internal_snapshot_clean, }, + [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ADD] = { + .instance_size = sizeof(BlkTransactionState), + .prepare = block_dirty_bitmap_add_prepare, + .abort = block_dirty_bitmap_add_abort, + }, + [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ENABLE] = { + .instance_size = sizeof(BlockDirtyBitmapState), + .prepare = block_dirty_bitmap_toggle_prepare, + .commit = block_dirty_bitmap_enable_commit, + .clean = block_dirty_bitmap_toggle_clean, + }, + [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_DISABLE] = { + .instance_size = sizeof(BlockDirtyBitmapState), + .prepare = block_dirty_bitmap_toggle_prepare, + .commit = block_dirty_bitmap_disable_commit, + .clean = block_dirty_bitmap_toggle_clean, + }, + [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_CLEAR] = { + .instance_size = sizeof(BlockDirtyBitmapState), + .prepare = block_dirty_bitmap_clear_prepare, + .commit = block_dirty_bitmap_clear_commit, + .clean = block_dirty_bitmap_clear_clean, + } }; /* diff --git a/qapi-schema.json b/qapi-schema.json index e16f8eb..0c31203 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -1332,6 +1332,10 @@ # abort since 1.6 # blockdev-snapshot-internal-sync since 1.7 # blockdev-backup since 2.3 +# block-dirty-bitmap-add since 2.3 +# block-dirty-bitmap-enable since 2.3 +# block-dirty-bitmap-disable since 2.3 +# block-dirty-bitmap-clear since 2.3 ## { 'union': 'TransactionAction', 'data': { @@ -1339,7 +1343,11 @@ 'drive-backup': 'DriveBackup', 'blockdev-backup': 'BlockdevBackup', 'abort': 'Abort', - 'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal' + 'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal', + 'block-dirty-bitmap-add': 'BlockDirtyBitmapAdd', + 'block-dirty-bitmap-enable': 'BlockDirtyBitmap', + 'block-dirty-bitmap-disable': 'BlockDirtyBitmap', + 'block-dirty-bitmap-clear': 'BlockDirtyBitmap' } } ## -- 1.9.3