From: Jan Kara <jack@suse.cz>
To: stable@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org
Subject: Revert commit 310ca162d77
Date: Wed, 20 Mar 2019 13:58:06 +0100 [thread overview]
Message-ID: <20190320125806.GD9485@quack2.suse.cz> (raw)
Hello,
commit 310ca162d77 "block/loop: Use global lock for ioctl() operation." has
been pushed to multiple stable trees. This patch is a part of larger series
that overhauls the locking inside loopback device upstream and for 4.4,
4.9, and 4.14 stable trees only this patch from the series is applied. Our
testing now has shown [1] that the patch alone makes present deadlocks
inside loopback driver more likely (the openqa test in our infrastructure
didn't hit the deadlock before whereas with the new kernel it hits it
reliably every time). So I would suggest we revert 310ca162d77 from 4.4,
4.9, and 4.14 kernels.
Another option would be to backport other locking fixes for the loop
device but honestly I don't think that's a stable material - never heard
of real users hitting problems, only syzkaller could, and we are still
fixing up some small glitches resulting from that rework...
Honza
[1] https://bugzilla.suse.com/show_bug.cgi?id=1129739
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next reply other threads:[~2019-03-20 12:58 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-20 12:58 Jan Kara [this message]
2019-03-20 15:12 ` Revert commit 310ca162d77 Greg KH
2019-03-20 15:16 ` Greg KH
2019-03-21 10:41 ` Jan Kara
2019-03-20 15:16 ` Greg KH
2019-03-21 10:26 ` Jan Kara
2019-04-29 12:05 ` Salvatore Bonaccorso
2019-04-29 14:04 ` Greg KH
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