path: root/block/blk-merge.c
diff options
authorJens Axboe <axboe@kernel.dk>2019-01-27 06:35:28 -0700
committerJens Axboe <axboe@kernel.dk>2019-01-27 06:35:28 -0700
commit947b7ac135b16aa60f9141ff72bd494eda0edb5e (patch)
tree1b0d82a312636fdf683ef2eeab3b288df6f4f6fd /block/blk-merge.c
parent8367de2c99a13d35960a51d6084631c883e93a4d (diff)
Revert "block: cover another queue enter recursion via BIO_QUEUE_ENTERED"
We can't touch a bio after ->make_request_fn(), for all we know it could already have been completed by the time this function returns. This reverts commit 698cef173983b086977e633e46476e0f925ca01e. Reported-by: syzbot+4df6ca820108fd248943@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-merge.c')
1 files changed, 10 insertions, 0 deletions
diff --git a/block/blk-merge.c b/block/blk-merge.c
index d79a22f111d1..71e9ac03f621 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -272,6 +272,16 @@ 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);