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From: Jens Axboe <[email protected]>
To: [email protected]
Cc: [email protected], Jens Axboe <[email protected]>
Subject: [PATCH 5/7] io_uring: Fix leaking linked timeouts
Date: Wed, 20 Nov 2019 13:09:35 -0700	[thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>

From: Pavel Begunkov <[email protected]>

let have a dependant link: REQ -> LINK_TIMEOUT -> LINK_TIMEOUT

1. submission stage: submission references for REQ and LINK_TIMEOUT
are dropped. So, references respectively (1,1,2)

2. io_put(REQ) + FAIL_LINKS stage: calls io_fail_links(), which for all
linked timeouts will call cancel_timeout() and drop 1 reference.
So, references after: (0,0,1). That's a leak.

Make it treat only the first linked timeout as such, and pass others
through __io_double_put_req().

Signed-off-by: Pavel Begunkov <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
---
 fs/io_uring.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 8d25e157b4d8..a79ef43367b1 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -937,6 +937,7 @@ static void io_fail_links(struct io_kiocb *req)
 		if ((req->flags & REQ_F_LINK_TIMEOUT) &&
 		    link->submit.sqe->opcode == IORING_OP_LINK_TIMEOUT) {
 			io_link_cancel_timeout(link);
+			req->flags &= ~REQ_F_LINK_TIMEOUT;
 		} else {
 			io_cqring_fill_event(link, -ECANCELED);
 			__io_double_put_req(link);
-- 
2.24.0


  parent reply	other threads:[~2019-11-20 20:10 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-20 20:09 [PATCHSET 0/2] io_uring: close lookup gap for dependent work Jens Axboe
2019-11-20 20:09 ` [PATCH 1/7] io-wq: wait for io_wq_create() to setup necessary workers Jens Axboe
2019-11-20 20:09 ` [PATCH 1/2] io_uring: allow finding next link independent of req reference count Jens Axboe
2019-11-20 20:09 ` [PATCH 2/7] io-wq: remove extra space characters Jens Axboe
2019-11-20 20:09 ` [PATCH 2/2] io_uring: close lookup gap for dependent next work Jens Axboe
2019-11-20 20:09 ` [PATCH 3/7] io_uring: break links for failed defer Jens Axboe
2019-11-20 20:09 ` [PATCH 4/7] io_uring: remove redundant check Jens Axboe
2019-11-20 20:09 ` Jens Axboe [this message]
2019-11-20 20:09 ` [PATCH 6/7] io_uring: io_fail_links() should only consider first linked timeout Jens Axboe
2019-11-20 20:09 ` [PATCH 7/7] io_uring: Always REQ_F_FREE_SQE for allocated sqe Jens Axboe
2019-11-20 20:11 ` [PATCHSET 0/2] io_uring: close lookup gap for dependent work Jens Axboe

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