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| author | Tejun Heo <tj@kernel.org> | 2011-11-03 18:52:11 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2011-11-03 18:52:11 +0100 |
| commit | 6dd9ad7df2019b1e33a372a501907db293ebcd0d (patch) | |
| tree | 1a07cfde1f3ea94b3f5f62e688d21668ff7831e4 /mm | |
| parent | blk-throttle: use queue_is_locked() instead of lockdep_is_held() (diff) | |
| download | linux-6dd9ad7df2019b1e33a372a501907db293ebcd0d.tar.xz linux-6dd9ad7df2019b1e33a372a501907db293ebcd0d.zip | |
block: don't call blk_drain_queue() if elevator is not up
blk_cleanup_queue() may be called before elevator is set up on a
queue which triggers the following oops.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff8125a69c>] elv_drain_elevator+0x1c/0x70
...
Pid: 830, comm: kworker/0:2 Not tainted 3.1.0-next-20111025_64+ #1590
Bochs Bochs
RIP: 0010:[<ffffffff8125a69c>] [<ffffffff8125a69c>] elv_drain_elevator+0x1c/0x70
...
Call Trace:
[<ffffffff8125da92>] blk_drain_queue+0x42/0x70
[<ffffffff8125db90>] blk_cleanup_queue+0xd0/0x1c0
[<ffffffff81469640>] md_free+0x50/0x70
[<ffffffff8126f43b>] kobject_release+0x8b/0x1d0
[<ffffffff81270d56>] kref_put+0x36/0xa0
[<ffffffff8126f2b7>] kobject_put+0x27/0x60
[<ffffffff814693af>] mddev_delayed_delete+0x2f/0x40
[<ffffffff81083450>] process_one_work+0x100/0x3b0
[<ffffffff8108527f>] worker_thread+0x15f/0x3a0
[<ffffffff81089937>] kthread+0x87/0x90
[<ffffffff81621834>] kernel_thread_helper+0x4/0x10
Fix it by making blk_cleanup_queue() check whether q->elevator is set
up before invoking blk_drain_queue.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'mm')
0 files changed, 0 insertions, 0 deletions