From 947b7ac135b16aa60f9141ff72bd494eda0edb5e Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sun, 27 Jan 2019 06:35:28 -0700 Subject: 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 --- block/blk-merge.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'block/blk-merge.c') 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); generic_make_request(*bio); -- cgit 1.4.1