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authorMing Lei <ming.lei@redhat.com>2019-01-22 16:20:17 +0800
committerJens Axboe <axboe@kernel.dk>2019-01-22 10:24:08 -0700
commit698cef173983b086977e633e46476e0f925ca01e (patch)
tree57caf7c7c9ce231ce193c53ae663ac49bbe999c6 /block/blk-merge.c
parent8b9433eb4de3c26a9226c981c283f9f4896ae030 (diff)
downloadlinux-stericsson-698cef173983b086977e633e46476e0f925ca01e.tar.gz
block: cover another queue enter recursion via BIO_QUEUE_ENTERED
Except for blk_queue_split(), bio_split() is used for splitting bio too, then the remained bio is often resubmit to queue via generic_make_request(). So the same queue enter recursion exits in this case too. Unfortunatley commit cd4a4ae4683dc2 doesn't help this case. This patch covers the above case by setting BIO_QUEUE_ENTERED before calling q->make_request_fn. In theory the per-bio flag is used to simulate one stack variable, it is just fine to clear it after q->make_request_fn is returned. Especially the same bio can't be submitted from another context. Fixes: cd4a4ae4683dc2 ("block: don't use blocking queue entered for recursive bio submits") Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: NeilBrown <neilb@suse.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-merge.c')
-rw-r--r--block/blk-merge.c10
1 files changed, 0 insertions, 10 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 71e9ac03f621..d79a22f111d1 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -272,16 +272,6 @@ void blk_queue_split(struct request_queue *q, struct bio **bio)
/* there isn't chance to merge the splitted bio */
split->bi_opf |= REQ_NOMERGE;
- /*
- * Since we're recursing into make_request here, ensure
- * that we mark this bio as already having entered the queue.
- * If not, and the queue is going away, we can get stuck
- * forever on waiting for the queue reference to drop. But
- * that will never happen, as we're already holding a
- * reference to it.
- */
- bio_set_flag(*bio, BIO_QUEUE_ENTERED);
-
bio_chain(split, *bio);
trace_block_split(q, split, (*bio)->bi_iter.bi_sector);
generic_make_request(*bio);