From: Jia-Ju Bai <baijiaju1990@163.com>
To: kent.overstreet@gmail.com, shli@kernel.org, axboe@fb.com,
mchristi@redhat.com, git@linux.ewheeler.net, colyli@suse.de,
akpm@linux-foundation.org, wangyijing@huawei.com,
mingo@kernel.org, mhocko@suse.com
Cc: linux-bcache@vger.kernel.org, linux-raid@vger.kernel.org,
linux-kernel@vger.kernel.org, Jia-Ju Bai <baijiaju1990@163.com>
Subject: [PATCH] bcache: Fix a sleep-in-atomic bug
Date: Wed, 31 May 2017 15:23:40 +0800 [thread overview]
Message-ID: <1496215420-15819-1-git-send-email-baijiaju1990@163.com> (raw)
The driver may sleep under a spin lock, and the function call path is:
journal_wait_for_write (acquire the lock by spin_lock)
closure_sync
schedule --> may sleep
To fix it, the lock is released before "closure_sync", and the lock is
acquired again after this function.
Signed-off-by: Jia-Ju Bai <baijiaju1990@163.com>
---
drivers/md/bcache/journal.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index 1198e53..ad47c36 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -724,6 +724,7 @@ static struct journal_write *journal_wait_for_write(struct cache_set *c,
btree_flush_write(c);
}
+ spin_unlock(&c->journal.lock);
closure_sync(&cl);
spin_lock(&c->journal.lock);
wait = true;
--
1.7.9.5
next reply other threads:[~2017-05-31 7:23 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-31 7:23 Jia-Ju Bai [this message]
2017-05-31 7:52 ` [PATCH] bcache: Fix a sleep-in-atomic bug Kent Overstreet
2017-05-31 8:31 ` Jia-Ju Bai
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