This patch actually implements the transactional callback system
for the drive_backup transaction.
(1) We manually pick up a reference to the bitmap if present to allow
its cleanup to be delayed until after all drive_backup jobs launched
by the transaction have fully completed.
(2) We create a functional closure that envelops the original drive_backup
callback, to be able to intercept the completion status and return code
for the job.
(3) We add the drive_backup_cb method for the drive_backup action, which
unpacks the completion information and invokes the final cleanup.
(4) backup_transaction_complete will perform the final cleanup on the
backup job.
(5) In the case of transaction cancellation, drive_backup_cb is still
responsible for cleaning up the mess we may have already made.
Signed-off-by: John Snow <address@hidden>
---
block/backup.c | 9 +++++++
blockdev.c | 64 ++++++++++++++++++++++++++++++++++++++---------
include/block/block_int.h | 8 ++++++
3 files changed, 69 insertions(+), 12 deletions(-)
diff --git a/block/backup.c b/block/backup.c
index 4332df4..3673fb0 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -233,6 +233,15 @@ typedef struct {
int ret;
} BackupCompleteData;
+void backup_transaction_complete(BlockJob *job, int ret)
+{
+ BackupBlockJob *s = container_of(job, BackupBlockJob, common);
+
+ if (s->sync_bitmap) {
+ bdrv_dirty_bitmap_decref(job->bs, s->sync_bitmap, ret, NULL);
+ }
+}
+
static void backup_complete(BlockJob *job, void *opaque)
{
BackupBlockJob *s = container_of(job, BackupBlockJob, common);
diff --git a/blockdev.c b/blockdev.c
index 9e3b9e9..3ff14a7 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1363,14 +1363,6 @@ static void transaction_callback(void *opaque, int ret)
typedef void (CallbackFn)(void *opaque, int ret);
-/* Temporary. Removed in the next patch. */
-CallbackFn *new_transaction_wrapper(BlkTransactionState *common,
- void *opaque,
- void (*callback)(void *, int),
- void **new_opaque);
-
-void undo_transaction_wrapper(BlkTransactionState *common);
-
/**
* Create a new transactional callback wrapper.
*
@@ -1389,7 +1381,7 @@ void undo_transaction_wrapper(BlkTransactionState
*common);
*
* @return The callback to be used instead of @callback.
*/
-CallbackFn *new_transaction_wrapper(BlkTransactionState *common,
+static CallbackFn *new_transaction_wrapper(BlkTransactionState *common,
void *opaque,
CallbackFn *callback,
void **new_opaque)
@@ -1416,7 +1408,7 @@ CallbackFn *new_transaction_wrapper(BlkTransactionState
*common,
/**
* Undo any actions performed by the above call.
*/
-void undo_transaction_wrapper(BlkTransactionState *common)
+static void undo_transaction_wrapper(BlkTransactionState *common)
{
BlkTransactionList *btl = common->list;
BlkTransactionState *bts;
@@ -1449,6 +1441,7 @@ void undo_transaction_wrapper(BlkTransactionState *common)
blk_put_transaction_state(common);
}
+static void block_job_cb(void *opaque, int ret);
static void _drive_backup(const char *device, const char *target,
bool has_format, const char *format,
enum MirrorSyncMode sync,
@@ -1767,6 +1760,9 @@ static void drive_backup_prepare(BlkTransactionState
*common, Error **errp)
BlockDriverState *bs;
DriveBackup *backup;
Error *local_err = NULL;
+ CallbackFn *cb;
+ void *opaque;
+ BdrvDirtyBitmap *bmap = NULL;
assert(common->action->kind == TRANSACTION_ACTION_KIND_DRIVE_BACKUP);
backup = common->action->drive_backup;
@@ -1777,6 +1773,19 @@ static void drive_backup_prepare(BlkTransactionState
*common, Error **errp)
return;
}
+ /* BackupBlockJob is opaque to us, so look up the bitmap ourselves */
+ if (backup->has_bitmap) {
+ bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap);
+ if (!bmap) {
+ error_setg(errp, "Bitmap '%s' could not be found", backup->bitmap);
+ return;
+ }
+ }
+
+ /* Create our transactional callback wrapper,
+ and register that we'd like to call .cb() later. */
+ cb = new_transaction_wrapper(common, bs, block_job_cb, &opaque);
+
/* AioContext is released in .clean() */
state->aio_context = bdrv_get_aio_context(bs);
aio_context_acquire(state->aio_context);
@@ -1789,7 +1798,7 @@ static void drive_backup_prepare(BlkTransactionState
*common, Error **errp)
backup->has_bitmap, backup->bitmap,
backup->has_on_source_error, backup->on_source_error,
backup->has_on_target_error, backup->on_target_error,
- NULL, NULL,
+ cb, opaque,
&local_err);
if (local_err) {
error_propagate(errp, local_err);
@@ -1798,6 +1807,11 @@ static void drive_backup_prepare(BlkTransactionState
*common, Error **errp)
state->bs = bs;
state->job = state->bs->job;
+ /* Keep the job alive until .cb(), too. */
+ block_job_incref(state->job);
+ if (bmap) {
+ bdrv_dirty_bitmap_incref(bmap);
+ }
}
static void drive_backup_abort(BlkTransactionState *common)
@@ -1809,6 +1823,10 @@ static void drive_backup_abort(BlkTransactionState
*common)
if (bs && bs->job && bs->job == state->job) {
block_job_cancel_sync(bs->job);
}
+
+ /* Undo any callback actions we may have done. Putting down references
+ * obtained during prepare() is handled by cb(). */
+ undo_transaction_wrapper(common);
}
static void drive_backup_clean(BlkTransactionState *common)
@@ -1820,6 +1838,27 @@ static void drive_backup_clean(BlkTransactionState
*common)
}
}
+static void drive_backup_cb(BlkTransactionState *common)
+{
+ BlkTransactionData *btd = common->opaque;
+ BlockDriverState *bs = btd->opaque;
+ DriveBackupState *state = DO_UPCAST(DriveBackupState, common, common);
+
+ assert(state->bs == bs);
+ if (bs->job) {
+ assert(state->job == bs->job);
+ }
+
+ state->aio_context = bdrv_get_aio_context(bs);
+ aio_context_acquire(state->aio_context);
+
+ /* Note: We also have the individual job's return code in btd->ret */
+ backup_transaction_complete(state->job, common->list->status);
+ block_job_decref(state->job);
+
+ aio_context_release(state->aio_context);
+}
+
typedef struct BlockdevBackupState {
BlkTransactionState common;
BlockDriverState *bs;
@@ -2004,7 +2043,8 @@ static const BdrvActionOps actions[] = {
.instance_size = sizeof(DriveBackupState),
.prepare = drive_backup_prepare,
.abort = drive_backup_abort,
- .clean = drive_backup_clean
+ .clean = drive_backup_clean,
+ .cb = drive_backup_cb
},
[TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP] = {
.instance_size = sizeof(BlockdevBackupState),
diff --git a/include/block/block_int.h b/include/block/block_int.h
index e0d5561..731684d 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -619,6 +619,14 @@ void backup_start(BlockDriverState *bs, BlockDriverState
*target,
BlockCompletionFunc *cb, void *opaque,
Error **errp);
+/*
+ * backup_transaction_complete
+ * @job The BackupJob that was associated with a transaction