From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46167) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXtC8-0000OA-74 for qemu-devel@nongnu.org; Tue, 17 Mar 2015 11:14:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YXtC1-000593-Ql for qemu-devel@nongnu.org; Tue, 17 Mar 2015 11:14:12 -0400 Message-ID: <550844BB.6080702@redhat.com> Date: Tue, 17 Mar 2015 11:14:03 -0400 From: Max Reitz MIME-Version: 1.0 References: <1425528911-10300-1-git-send-email-jsnow@redhat.com> <1425528911-10300-2-git-send-email-jsnow@redhat.com> In-Reply-To: <1425528911-10300-2-git-send-email-jsnow@redhat.com> Content-Type: text/plain; charset=iso-8859-15; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 01/11] qapi: Add transaction support to block-dirty-bitmap operations List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: John Snow , qemu-block@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com, vsementsov@parallels.com, stefanha@redhat.com On 2015-03-04 at 23:15, John Snow wrote: > This adds two qmp commands to transactions. > > block-dirty-bitmap-add allows you to create a bitmap simultaneously > alongside a new full backup to accomplish a clean synchronization > point. > > block-dirty-bitmap-clear allows you to reset a bitmap back to as-if > it were new, which can also be used alongside a full backup to > accomplish a clean synchronization point. > > Signed-off-by: Fam Zheng > Signed-off-by: John Snow > --- > blockdev.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ > qapi-schema.json | 6 +++- > 2 files changed, 106 insertions(+), 1 deletion(-) > > diff --git a/blockdev.c b/blockdev.c > index e0671be..5120af1 100644 > --- a/blockdev.c > +++ b/blockdev.c > @@ -1664,6 +1664,96 @@ static void blockdev_backup_clean(BlkTransactionState *common) > } > } > > +typedef struct BlockDirtyBitmapState { > + BlkTransactionState common; > + BdrvDirtyBitmap *bitmap; > + BlockDriverState *bs; > + AioContext *aio_context; > + bool prepared; > +} BlockDirtyBitmapState; > + > +static void block_dirty_bitmap_add_prepare(BlkTransactionState *common, > + Error **errp) > +{ > + Error *local_err = NULL; > + 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, > + &local_err); > + > + if (!local_err) { > + state->prepared = true; > + } else { > + error_propagate(errp, local_err); > + } > +} > + > +static void block_dirty_bitmap_add_abort(BlkTransactionState *common) > +{ > + BlockDirtyBitmapAdd *action; > + BlockDirtyBitmapState *state = DO_UPCAST(BlockDirtyBitmapState, Indentation is still off. > + common, common); > + > + action = common->action->block_dirty_bitmap_add; > + /* Should not be able to fail: IF the bitmap was added via .prepare(), > + * then the node reference and bitmap name must have been valid. > + */ > + if (state->prepared) { > + qmp_block_dirty_bitmap_remove(action->node, action->name, &error_abort); > + } > +} > + > +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); This will need fix-up for v3 (and following, probably) of your transactionless series (&state->aio_context as the fourth parameter). > + 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); And this will probably need to be dropped for v4 of said series. Other than that, looks good. Max > +} > + > +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"); > @@ -1704,6 +1794,17 @@ static const BdrvActionOps actions[] = { > .abort = internal_snapshot_abort, > .clean = internal_snapshot_clean, > }, > + [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_ADD] = { > + .instance_size = sizeof(BlockDirtyBitmapState), > + .prepare = block_dirty_bitmap_add_prepare, > + .abort = block_dirty_bitmap_add_abort, > + }, > + [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..12c61f3 100644 > --- a/qapi-schema.json > +++ b/qapi-schema.json > @@ -1332,6 +1332,8 @@ > # 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-clear since 2.3 > ## > { 'union': 'TransactionAction', > 'data': { > @@ -1339,7 +1341,9 @@ > '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-clear': 'BlockDirtyBitmap' > } } > > ##