From 4c6dd53dd3674c310d7379c6b3273daa9fd95c79 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Wed, 27 May 2015 15:23:56 -0400 Subject: [PATCH] dm mpath: fix leak of dm_mpath_io structure in blk-mq .queue_rq error path Otherwise kmemleak reported: unreferenced object 0xffff88009b14e2b0 (size 16): comm "fio", pid 4274, jiffies 4294978034 (age 1253.210s) hex dump (first 16 bytes): 40 12 f3 99 01 88 ff ff 00 10 00 00 00 00 00 00 @............... backtrace: [] kmemleak_alloc+0x49/0xb0 [] kmem_cache_alloc+0xf8/0x160 [] mempool_alloc_slab+0x10/0x20 [] mempool_alloc+0x57/0x150 [] __multipath_map.isra.17+0xe1/0x220 [dm_multipath] [] multipath_clone_and_map+0x15/0x20 [dm_multipath] [] map_request.isra.39+0xd5/0x220 [dm_mod] [] dm_mq_queue_rq+0x134/0x240 [dm_mod] [] __blk_mq_run_hw_queue+0x1d5/0x380 [] blk_mq_run_hw_queue+0xc5/0x100 [] blk_sq_make_request+0x240/0x300 [] generic_make_request+0xc0/0x110 [] submit_bio+0x72/0x150 [] do_blockdev_direct_IO+0x1f3b/0x2da0 [] __blockdev_direct_IO+0x3e/0x40 [] ext4_direct_IO+0x1aa/0x390 Fixes: e5863d9ad ("dm: allocate requests in target when stacking on blk-mq devices") Reported-by: Bart Van Assche Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org # 4.0+ --- drivers/md/dm-mpath.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 63953477a07c..eff7bdd7731d 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -429,9 +429,11 @@ static int __multipath_map(struct dm_target *ti, struct request *clone, /* blk-mq request-based interface */ *__clone = blk_get_request(bdev_get_queue(bdev), rq_data_dir(rq), GFP_ATOMIC); - if (IS_ERR(*__clone)) + if (IS_ERR(*__clone)) { /* ENOMEM, requeue */ + clear_mapinfo(m, map_context); return r; + } (*__clone)->bio = (*__clone)->biotail = NULL; (*__clone)->rq_disk = bdev->bd_disk; (*__clone)->cmd_flags |= REQ_FAILFAST_TRANSPORT; -- 2.20.1