From: Tasos Sahanidis <tasos@tasossah.com>
To: linux-block@vger.kernel.org
Cc: axboe@kernel.dk, efremov@linux.com, jkosina@suse.cz, tasos@tasossah.com
Subject: [PATCH] floppy: Fix hang in watchdog when disk is ejected
Date: Fri, 3 Sep 2021 09:47:58 +0300 [thread overview]
Message-ID: <399e486c-6540-db27-76aa-7a271b061f76@tasossah.com> (raw)
When the watchdog detects a disk change, it calls cancel_activity(),
which in turn tries to cancel the fd_timer delayed work.
In the above scenario, fd_timer_fn is set to fd_watchdog(), meaning
it is trying to cancel its own work.
This results in a hang as cancel_delayed_work_sync() is waiting for the
watchdog (itself) to return, which never happens.
This can be reproduced relatively consistently by attempting to read a
broken floppy, and ejecting it while IO is being attempted and retried.
To resolve this, this patch calls cancel_delayed_work() instead, which
cancels the work without waiting for the watchdog to return and finish.
Before this regression was introduced, the code in this section used
del_timer(), and not del_timer_sync() to delete the watchdog timer.
Fixes: 070ad7e793dc ("floppy: convert to delayed work and single-thread wq")
Signed-off-by: Tasos Sahanidis <tasos@tasossah.com>
---
drivers/block/floppy.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index fef79ea52..85464d72d 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -1014,7 +1014,7 @@ static DECLARE_DELAYED_WORK(fd_timer, fd_timer_workfn);
static void cancel_activity(void)
{
do_floppy = NULL;
- cancel_delayed_work_sync(&fd_timer);
+ cancel_delayed_work(&fd_timer);
cancel_work_sync(&floppy_work);
}
--
2.25.1
next reply other threads:[~2021-09-03 6:50 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-03 6:47 Tasos Sahanidis [this message]
2021-09-18 22:33 ` [PATCH] floppy: Fix hang in watchdog when disk is ejected Denis Efremov
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=399e486c-6540-db27-76aa-7a271b061f76@tasossah.com \
--to=tasos@tasossah.com \
--cc=axboe@kernel.dk \
--cc=efremov@linux.com \
--cc=jkosina@suse.cz \
--cc=linux-block@vger.kernel.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;
as well as URLs for NNTP newsgroup(s).