xen-blkback: fix dispatch_rw_block_io() error path Commit 7708992 ("xen/blkback: Seperate the bio allocation and the bio submission") consolidated the pendcnt updates to just a single write, neglecting the fact that the error path relied on it getting set to 1 up front (such that the decrement in __end_block_io_op() would actually drop the count to zero, triggering the necessary cleanup actions). Also remove a misleading and a stale (after said commit) comment. Signed-off-by: Jan Beulich --- drivers/block/xen-blkback/blkback.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) --- 3.9-rc2/drivers/block/xen-blkback/blkback.c +++ 3.9-rc2-xen-blkback-error-path-refcnt/drivers/block/xen-blkback/blkback.c @@ -977,13 +977,7 @@ static int dispatch_rw_block_io(struct x bio->bi_end_io = end_block_io_op; } - /* - * We set it one so that the last submit_bio does not have to call - * atomic_inc. - */ atomic_set(&pending_req->pendcnt, nbio); - - /* Get a reference count for the disk queue and start sending I/O */ blk_start_plug(&plug); for (i = 0; i < nbio; i++) @@ -1011,6 +1005,7 @@ static int dispatch_rw_block_io(struct x fail_put_bio: for (i = 0; i < nbio; i++) bio_put(biolist[i]); + atomic_set(&pending_req->pendcnt, 1); __end_block_io_op(pending_req, -EINVAL); msleep(1); /* back off a bit */ return -EIO;