The old aio context check is hacky because when it was added we didn't
have the permission system to enforce a general rule. It only checks if
the target BDS has a BB, which is in fact insufficient because there may
be other BBs in the graph that cannot handle the aio context change.
Do this through blk_set_aio_context interface, in backup_job_create()
which is a central place for both drive-backup and blockdev-backup, to
take care of the compatibility check.
Also the bdrv_set_aio_context in do_drive_backup could have been
conditional, to save a recursion when possible.
Signed-off-by: Fam Zheng <f...@redhat.com>
---
block/backup.c | 9 +++++++++
blockdev.c | 14 --------------
2 files changed, 9 insertions(+), 14 deletions(-)
diff --git a/block/backup.c b/block/backup.c
index 546c5c5..9136f91 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -564,6 +564,7 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
BlockDriverInfo bdi;
BackupBlockJob *job = NULL;
int ret;
+ AioContext *aio_context, *target_context;
assert(bs);
assert(target);
@@ -644,6 +645,14 @@ BlockJob *backup_job_create(const char *job_id,
BlockDriverState *bs,
goto error;
}
+ aio_context = bdrv_get_aio_context(bs);
+ target_context = bdrv_get_aio_context(target);
+ if (target_context != aio_context) {
+ aio_context_acquire(target_context);
+ blk_set_aio_context(job->target, aio_context);
+ aio_context_release(target_context);
+ }
+
job->on_source_error = on_source_error;
job->on_target_error = on_target_error;
job->sync_mode = sync_mode;
diff --git a/blockdev.c b/blockdev.c
index 4927914..dfd1385 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3259,8 +3259,6 @@ static BlockJob *do_drive_backup(DriveBackup *backup,
BlockJobTxn *txn,
goto out;
}
- bdrv_set_aio_context(target_bs, aio_context);
-
if (backup->has_bitmap) {
bmap = bdrv_find_dirty_bitmap(bs, backup->bitmap);
if (!bmap) {
@@ -3337,18 +3335,6 @@ BlockJob *do_blockdev_backup(BlockdevBackup *backup,
BlockJobTxn *txn,
if (!target_bs) {
goto out;
}
-
- if (bdrv_get_aio_context(target_bs) != aio_context) {
- if (!bdrv_has_blk(target_bs)) {
- /* The target BDS is not attached, we can safely move it to another
- * AioContext. */
- bdrv_set_aio_context(target_bs, aio_context);
- } else {
- error_setg(errp, "Target is attached to a different thread from "
- "source.");
- goto out;
- }
- }
job = backup_job_create(backup->job_id, bs, target_bs, backup->speed,
backup->sync, NULL, backup->compress,
backup->on_source_error, backup->on_target_error,
--
2.9.3
