diff options
authorKeith Busch <keith.busch@intel.com>2015-01-12 15:04:06 -0500
committerJens Axboe <axboe@fb.com>2015-01-28 09:44:15 -0700
commit77a086890173c0958515f7322880e4680cf12f8e (patch)
parent7fb4898e0cd6e7eba7419790921391e53848a35d (diff)
block: keep established cmd_flags when cloning into a blk-mq request
blk_mq_alloc_request() may establish REQ_MQ_INFLIGHT in addition to incrementing the hctx->nr_active count. Any cmd_flags that are established in the newly allocated clone request must be preserved in addition to the cmd_flags that are later copied over from the original request as part of blk_rq_prep_clone(). Otherwise, if REQ_MQ_INFLIGHT isn't set in the clone request the hctx->nr_active count won't get decremented via blk_mq_free_request(). The only consumer of blk_rq_prep_clone() is request-based DM, which uses blk_rq_init() prior to calling blk_rq_prep_clone() for the non-blk-mq case. Given the cloned request's cmd_flags will be 0 it is safe to OR them with the original request's cmd_flags for both the non-blk-mq and blk-mq cases. Reported-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-core.c b/block/blk-core.c
index c81f02cd17d4..b5e0cc381458 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2914,7 +2914,7 @@ EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
static void __blk_rq_prep_clone(struct request *dst, struct request *src)
dst->cpu = src->cpu;
- dst->cmd_flags = (src->cmd_flags & REQ_CLONE_MASK) | REQ_NOMERGE;
+ dst->cmd_flags |= (src->cmd_flags & REQ_CLONE_MASK) | REQ_NOMERGE;
dst->cmd_type = src->cmd_type;
dst->__sector = blk_rq_pos(src);
dst->__data_len = blk_rq_bytes(src);