From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39761) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gXwgN-0000p8-Ji for qemu-devel@nongnu.org; Fri, 14 Dec 2018 18:15:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gXwgL-0002cz-Hi for qemu-devel@nongnu.org; Fri, 14 Dec 2018 18:15:47 -0500 From: John Snow Date: Fri, 14 Dec 2018 18:15:06 -0500 Message-Id: <20181214231512.5295-2-jsnow@redhat.com> In-Reply-To: <20181214231512.5295-1-jsnow@redhat.com> References: <20181214231512.5295-1-jsnow@redhat.com> Subject: [Qemu-devel] [PATCH v3 1/7] blockdev: abort transactions in reverse order List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org, qemu-devel@nongnu.org Cc: vsementsov@virtuozzo.com, Markus Armbruster , eblake@redhat.com, Max Reitz , Kevin Wolf , John Snow Presently, we abort transactions in the same order they were processed in. Bitmap commands, though, attempt to restore backup data structures on abort. To that end, though, they need to be aborted in reverse chronological order. Replace the QSIMPLEQ data structure with a QTAILQ one, so we can iterate in reverse for the abort phase of the transaction. Signed-off-by: John Snow Reviewed-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy --- blockdev.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/blockdev.c b/blockdev.c index 81f95d920b..1ba706df8b 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1341,7 +1341,7 @@ struct BlkActionState { const BlkActionOps *ops; JobTxn *block_job_txn; TransactionProperties *txn_props; - QSIMPLEQ_ENTRY(BlkActionState) entry; + QTAILQ_ENTRY(BlkActionState) entry; }; /* internal snapshot private data */ @@ -2269,8 +2269,8 @@ void qmp_transaction(TransactionActionList *dev_list, BlkActionState *state, *next; Error *local_err = NULL; - QSIMPLEQ_HEAD(snap_bdrv_states, BlkActionState) snap_bdrv_states; - QSIMPLEQ_INIT(&snap_bdrv_states); + QTAILQ_HEAD(snap_bdrv_states, BlkActionState) snap_bdrv_states; + QTAILQ_INIT(&snap_bdrv_states); /* Does this transaction get canceled as a group on failure? * If not, we don't really need to make a JobTxn. @@ -2301,7 +2301,7 @@ void qmp_transaction(TransactionActionList *dev_list, state->action = dev_info; state->block_job_txn = block_job_txn; state->txn_props = props; - QSIMPLEQ_INSERT_TAIL(&snap_bdrv_states, state, entry); + QTAILQ_INSERT_TAIL(&snap_bdrv_states, state, entry); state->ops->prepare(state, &local_err); if (local_err) { @@ -2310,7 +2310,7 @@ void qmp_transaction(TransactionActionList *dev_list, } } - QSIMPLEQ_FOREACH(state, &snap_bdrv_states, entry) { + QTAILQ_FOREACH(state, &snap_bdrv_states, entry) { if (state->ops->commit) { state->ops->commit(state); } @@ -2321,13 +2321,13 @@ void qmp_transaction(TransactionActionList *dev_list, delete_and_fail: /* failure, and it is all-or-none; roll back all operations */ - QSIMPLEQ_FOREACH(state, &snap_bdrv_states, entry) { + QTAILQ_FOREACH_REVERSE(state, &snap_bdrv_states, snap_bdrv_states, entry) { if (state->ops->abort) { state->ops->abort(state); } } exit: - QSIMPLEQ_FOREACH_SAFE(state, &snap_bdrv_states, entry, next) { + QTAILQ_FOREACH_SAFE(state, &snap_bdrv_states, entry, next) { if (state->ops->clean) { state->ops->clean(state); } -- 2.17.2