Btrfs: Fix the multi-bio code to save the original bio for completion
The multi-bio code is responsible for duplicating blocks in raid1 and
single spindle duplication. It has counters to make sure all of
the locations for a given extent are properly written before io completion
is returned to the higher layers.
But, it didn't always complete the same bio it was given, sometimes a
clone was completed instead. This lead to problems with the async
work queues because they saved a pointer to the bio in a struct off
bi_private.
The fix is to remember the original bio and only complete that one.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 48a44f7..c50e505 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -95,6 +95,7 @@
struct btrfs_multi_bio {
atomic_t stripes_pending;
bio_end_io_t *end_io;
+ struct bio *orig_bio;
void *private;
atomic_t error;
int max_errors;
