From: Mikulas Patocka If barrier request was returned with DM_ENDIO_REQUEUE, requeue it in dm_wq_work instead of dec_pending. This allows us to correctly handle a situation when some targets are asking for a requeue and other targets signal an error. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon --- drivers/md/dm.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) Index: linux-2.6.30/drivers/md/dm.c =================================================================== --- linux-2.6.30.orig/drivers/md/dm.c +++ linux-2.6.30/drivers/md/dm.c @@ -536,9 +536,11 @@ static void dec_pending(struct dm_io *io * Target requested pushing back the I/O. */ spin_lock_irqsave(&md->deferred_lock, flags); - if (__noflush_suspending(md)) - bio_list_add_head(&md->deferred, io->bio); - else + if (__noflush_suspending(md)) { + if (!bio_barrier(io->bio)) + bio_list_add_head(&md->deferred, + io->bio); + } else /* noflush suspend was interrupted. */ io->error = -EIO; spin_unlock_irqrestore(&md->deferred_lock, flags); @@ -1458,6 +1460,11 @@ static void process_barrier(struct mappe if (md->barrier_error != DM_ENDIO_REQUEUE) bio_endio(bio, md->barrier_error); + else { + spin_lock_irq(&md->deferred_lock); + bio_list_add_head(&md->deferred, bio); + spin_unlock_irq(&md->deferred_lock); + } } /*