From: Hao Xu <haoxu@linux.alibaba.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: io-uring@vger.kernel.org, Pavel Begunkov <asml.silence@gmail.com>,
Joseph Qi <joseph.qi@linux.alibaba.com>
Subject: [PATCH 3/4] io-wq: fix worker->refcount when creating worker in work exit
Date: Sun, 12 Sep 2021 03:40:51 +0800 [thread overview]
Message-ID: <20210911194052.28063-4-haoxu@linux.alibaba.com> (raw)
In-Reply-To: <20210911194052.28063-1-haoxu@linux.alibaba.com>
We may enter the worker creation path from io_worker_exit(), and
refcount is already zero, which causes definite failure of worker
creation.
io_worker_exit
ref = 0
->io_wqe_dec_running
->io_queue_worker_create
->io_worker_get failure since ref is 0
Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
---
fs/io-wq.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/fs/io-wq.c b/fs/io-wq.c
index 0e1288a549eb..75e79571bdfd 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -188,7 +188,9 @@ static void io_worker_exit(struct io_worker *worker)
list_del_rcu(&worker->all_list);
acct->nr_workers--;
preempt_disable();
+ refcount_set(&worker->ref, 1);
io_wqe_dec_running(worker);
+ refcount_set(&worker->ref, 0);
worker->flags = 0;
current->flags &= ~PF_IO_WORKER;
preempt_enable();
--
2.24.4
next prev parent reply other threads:[~2021-09-11 19:41 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-11 19:40 [PATCH 0/4] iowq fix Hao Xu
2021-09-11 19:40 ` [PATCH 1/4] io-wq: tweak return value of io_wqe_create_worker() Hao Xu
2021-09-12 18:10 ` Jens Axboe
2021-09-12 19:02 ` Hao Xu
2021-09-12 21:34 ` Jens Axboe
2021-09-13 6:37 ` Hao Xu
2021-09-11 19:40 ` [PATCH 2/4] io-wq: code clean " Hao Xu
2021-09-12 18:18 ` Jens Axboe
2021-09-13 8:30 ` Hao Xu
2021-09-11 19:40 ` Hao Xu [this message]
2021-09-11 22:13 ` [PATCH 3/4] io-wq: fix worker->refcount when creating worker in work exit Jens Axboe
2021-09-12 9:04 ` Hao Xu
2021-09-12 18:07 ` Jens Axboe
2021-09-11 19:40 ` [PATCH 4/4] io-wq: fix potential race of acct->nr_workers Hao Xu
2021-09-12 18:23 ` Jens Axboe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210911194052.28063-4-haoxu@linux.alibaba.com \
--to=haoxu@linux.alibaba.com \
--cc=asml.silence@gmail.com \
--cc=axboe@kernel.dk \
--cc=io-uring@vger.kernel.org \
--cc=joseph.qi@linux.alibaba.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).