From: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-mm@kvack.org, linux-block@vger.kernel.org
Subject: [PATCH v2] block: avoid incorrect bdi_unregiter call
Date: Fri, 2 Dec 2016 14:08:34 +0900 [thread overview]
Message-ID: <584101D2.4090200@jp.fujitsu.com> (raw)
bdi_unregister() should be called after bdi_register() is called,
so we should check whether WB_registered flag is set.
For example of the situation, error path in device driver may call
blk_cleanup_queue() before the driver calls bdi_register().
Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
---
mm/backing-dev.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 8fde443..f8b07d4 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -853,6 +853,9 @@ static void bdi_remove_from_list(struct backing_dev_info *bdi)
void bdi_unregister(struct backing_dev_info *bdi)
{
+ if (!test_bit(WB_registered, &bdi->wb.state))
+ return;
+
/* make sure nobody finds us on the bdi_list anymore */
bdi_remove_from_list(bdi);
wb_shutdown(&bdi->wb);
--
1.8.3.1
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next reply other threads:[~2016-12-02 5:09 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-02 5:08 Masayoshi Mizuma [this message]
2016-12-16 5:00 ` Masayoshi Mizuma
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=584101D2.4090200@jp.fujitsu.com \
--to=m.mizuma@jp.fujitsu.com \
--cc=axboe@kernel.dk \
--cc=linux-block@vger.kernel.org \
--cc=linux-mm@kvack.org \
/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