From: Qu Wenruo <quwenruo@cn.fujitsu.com>
To: <linux-btrfs@vger.kernel.org>, <stephane_btrfs@lesimple.fr>
Subject: [PATCH 0/2] Btrfs: Fix a insane extent_buffer copy behavior for qgroup
Date: Fri, 25 Sep 2015 10:37:59 +0800 [thread overview]
Message-ID: <1443148681-3015-1-git-send-email-quwenruo@cn.fujitsu.com> (raw)
Stephane Lesimple reported an qgroup rescan bug:
[92098.841309] general protection fault: 0000 [#1] SMP
[92098.841338] Modules linked in: ...
[92098.841814] CPU: 1 PID: 24655 Comm: kworker/u4:12 Not tainted
4.3.0-rc1 #1
[92098.841868] Workqueue: btrfs-qgroup-rescan btrfs_qgroup_rescan_helper
[btrfs]
[92098.842261] Call Trace:
[92098.842277] [<ffffffffc035a5d8>] ? read_extent_buffer+0xb8/0x110
[btrfs]
[92098.842304] [<ffffffffc0396d00>] ? btrfs_find_all_roots+0x60/0x70
[btrfs]
[92098.842329] [<ffffffffc039af3d>]
btrfs_qgroup_rescan_worker+0x28d/0x5a0 [btrfs]
...
The triggering function btrfs_disk_key_to_cpu(), which should never
fail.
But it turned out that the extent_buffere being called on is memcpied
from an existing one.
Such behavior to copy a structure with page pointers and locks in it is
never a sane thing.
Fix it by do it in memory other than extent_buffer.
Qu Wenruo (2):
btrfs: Add support to do stack item key operation
btrfs: qgroup: Don't copy extent buffer to do qgroup rescan
fs/btrfs/ctree.h | 20 ++++++++++++++++++++
fs/btrfs/qgroup.c | 22 ++++++++++++----------
2 files changed, 32 insertions(+), 10 deletions(-)
--
2.5.3
next reply other threads:[~2015-09-25 2:38 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-25 2:37 Qu Wenruo [this message]
2015-09-25 2:38 ` [PATCH 1/2] btrfs: Add support to do stack item key operation Qu Wenruo
2015-10-01 16:46 ` David Sterba
2015-10-02 1:08 ` Qu Wenruo
2015-09-25 2:38 ` [PATCH 2/2] btrfs: qgroup: Don't copy extent buffer to do qgroup rescan Qu Wenruo
2015-09-25 22:35 ` [PATCH 0/2] Btrfs: Fix a insane extent_buffer copy behavior for qgroup Stéphane Lesimple
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