From: Mikulas Patocka <mpatocka@redhat.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>,
Andrea Arcangeli <aarcange@redhat.com>, Jan Kara <jack@suse.cz>,
dm-devel@redhat.com, linux-kernel@vger.kernel.org,
Jeff Moyer <jmoyer@redhat.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
kosaki.motohiro@jp.fujitsu.com, linux-fsdevel@vger.kernel.org,
lwoodman@redhat.com, "Alasdair G. Kergon" <agk@redhat.com>
Subject: [PATCH 0/4] Fix a crash when block device is read and block size is changed at the same time
Date: Fri, 31 Aug 2012 14:40:26 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.4.64.1208311433480.2212@file.rdu.redhat.com> (raw)
In-Reply-To: <Pine.LNX.4.64.1208011601280.21832@file.rdu.redhat.com>
Hi
This is a series of patches to prevent a crash when when someone is
reading block device and block size is changed simultaneously. (the crash
is already happening in the production environment)
The first patch adds a rw-lock to struct block_device, but doesn't use the
lock anywhere. The reason why I submit this as a separate patch is that on
my computer adding an unused field to this structure affects performance
much more than any locking changes.
The second patch uses the rw-lock. The lock is locked for read when doing
I/O on the block device and it is locked for write when changing block
size.
The third patch converts the rw-lock to a percpu rw-lock for better
performance, to avoid cache line bouncing.
The fourth patch is an alternate percpu rw-lock implementation using RCU
by Eric Dumazet. It avoids any atomic instruction in the hot path.
Mikulas
next prev parent reply other threads:[~2012-08-31 18:40 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-28 3:04 Crash when IO is being submitted and block size is changed Mikulas Patocka
2012-06-28 11:15 ` Jan Kara
2012-06-28 15:44 ` Mikulas Patocka
2012-06-28 16:53 ` Jan Kara
2012-07-16 0:55 ` Mikulas Patocka
2012-07-17 19:19 ` Jeff Moyer
2012-07-19 2:27 ` Mikulas Patocka
2012-07-19 13:33 ` Jeff Moyer
2012-07-28 16:40 ` [PATCH 1/3] Fix " Mikulas Patocka
2012-07-28 16:41 ` [PATCH 2/3] Introduce percpu rw semaphores Mikulas Patocka
2012-07-28 16:42 ` [PATCH 3/3] blockdev: turn a rw semaphore into a percpu rw semaphore Mikulas Patocka
2012-07-28 20:44 ` [PATCH 2/3] Introduce percpu rw semaphores Eric Dumazet
2012-07-29 5:13 ` [dm-devel] " Mikulas Patocka
2012-07-29 10:10 ` Eric Dumazet
2012-07-29 18:36 ` Eric Dumazet
2012-08-01 20:07 ` Mikulas Patocka
2012-08-01 20:09 ` [PATCH 4/3] " Mikulas Patocka
2012-08-31 18:40 ` Mikulas Patocka [this message]
2012-08-31 18:41 ` [PATCH 1/4] Add a lock that will be needed by the next patch Mikulas Patocka
2012-08-31 18:42 ` [PATCH 2/4] blockdev: fix a crash when block size is changed and I/O is issued simultaneously Mikulas Patocka
2012-08-31 18:43 ` [PATCH 3/4] blockdev: turn a rw semaphore into a percpu rw semaphore Mikulas Patocka
2012-08-31 18:43 ` [PATCH 4/4] New percpu lock implementation Mikulas Patocka
2012-08-31 19:27 ` [PATCH 0/4] Fix a crash when block device is read and block size is changed at the same time Mikulas Patocka
2012-08-31 20:11 ` Jeff Moyer
2012-08-31 20:34 ` Mikulas Patocka
2012-09-17 21:19 ` Jeff Moyer
2012-09-17 21:19 ` Jeff Moyer
2012-09-18 17:04 ` Mikulas Patocka
2012-09-18 17:22 ` Jeff Moyer
2012-09-18 18:55 ` Mikulas Patocka
2012-09-18 18:58 ` Jeff Moyer
2012-09-18 20:11 ` Jeff Moyer
2012-09-25 17:49 ` Jeff Moyer
2012-09-25 17:59 ` Jens Axboe
2012-09-25 17:59 ` Jens Axboe
2012-09-25 18:11 ` Jens Axboe
2012-09-25 18:11 ` Jens Axboe
2012-09-25 22:49 ` [PATCH 1/2] " Mikulas Patocka
2012-09-26 5:48 ` Jens Axboe
2012-09-26 5:48 ` Jens Axboe
2012-11-16 22:02 ` Jeff Moyer
2012-09-25 22:50 ` [PATCH 2/2] " Mikulas Patocka
2012-09-25 22:58 ` [PATCH 0/4] " Mikulas Patocka
2012-09-26 13:47 ` Jeff Moyer
2012-09-26 14:35 ` Mikulas Patocka
2012-07-30 17:00 ` [dm-devel] [PATCH 2/3] Introduce percpu rw semaphores Paul E. McKenney
2012-07-31 0:00 ` Mikulas Patocka
2012-08-01 17:15 ` Paul E. McKenney
2012-06-29 6:25 ` Crash when IO is being submitted and block size is changed Vyacheslav Dubeyko
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