[3.8.y.z extended stable] Patch "md: avoid deadlock when md_set_badblocks." has been added to staging queue
Kamal Mostafa
kamal at canonical.com
Thu Nov 7 22:32:41 UTC 2013
This is a note to let you know that I have just added a patch titled
md: avoid deadlock when md_set_badblocks.
to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree
which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue
This patch is scheduled to be released in version 3.8.13.13.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From 9035f5798bf189e9cebe6eb21c4a33afe6180096 Mon Sep 17 00:00:00 2001
From: Bian Yu <bianyu at kedacom.com>
Date: Sat, 12 Oct 2013 01:10:03 -0400
Subject: md: avoid deadlock when md_set_badblocks.
commit 905b0297a9533d7a6ee00a01a990456636877dd6 upstream.
When operate harddisk and hit errors, md_set_badblocks is called after
scsi_restart_operations which already disabled the irq. but md_set_badblocks
will call write_sequnlock_irq and enable irq. so softirq can preempt the
current thread and that may cause a deadlock. I think this situation should
use write_sequnlock_irqsave/irqrestore instead.
I met the situation and the call trace is below:
[ 638.919974] BUG: spinlock recursion on CPU#0, scsi_eh_13/1010
[ 638.921923] lock: 0xffff8800d4d51fc8, .magic: dead4ead, .owner: scsi_eh_13/1010, .owner_cpu: 0
[ 638.923890] CPU: 0 PID: 1010 Comm: scsi_eh_13 Not tainted 3.12.0-rc5+ #37
[ 638.925844] Hardware name: To be filled by O.E.M. To be filled by O.E.M./MAHOBAY, BIOS 4.6.5 03/05/2013
[ 638.927816] ffff880037ad4640 ffff880118c03d50 ffffffff8172ff85 0000000000000007
[ 638.929829] ffff8800d4d51fc8 ffff880118c03d70 ffffffff81730030 ffff8800d4d51fc8
[ 638.931848] ffffffff81a72eb0 ffff880118c03d90 ffffffff81730056 ffff8800d4d51fc8
[ 638.933884] Call Trace:
[ 638.935867] <IRQ> [<ffffffff8172ff85>] dump_stack+0x55/0x76
[ 638.937878] [<ffffffff81730030>] spin_dump+0x8a/0x8f
[ 638.939861] [<ffffffff81730056>] spin_bug+0x21/0x26
[ 638.941836] [<ffffffff81336de4>] do_raw_spin_lock+0xa4/0xc0
[ 638.943801] [<ffffffff8173f036>] _raw_spin_lock+0x66/0x80
[ 638.945747] [<ffffffff814a73ed>] ? scsi_device_unbusy+0x9d/0xd0
[ 638.947672] [<ffffffff8173fb1b>] ? _raw_spin_unlock+0x2b/0x50
[ 638.949595] [<ffffffff814a73ed>] scsi_device_unbusy+0x9d/0xd0
[ 638.951504] [<ffffffff8149ec47>] scsi_finish_command+0x37/0xe0
[ 638.953388] [<ffffffff814a75e8>] scsi_softirq_done+0xa8/0x140
[ 638.955248] [<ffffffff8130e32b>] blk_done_softirq+0x7b/0x90
[ 638.957116] [<ffffffff8104fddd>] __do_softirq+0xfd/0x330
[ 638.958987] [<ffffffff810b964f>] ? __lock_release+0x6f/0x100
[ 638.960861] [<ffffffff8174a5cc>] call_softirq+0x1c/0x30
[ 638.962724] [<ffffffff81004c7d>] do_softirq+0x8d/0xc0
[ 638.964565] [<ffffffff8105024e>] irq_exit+0x10e/0x150
[ 638.966390] [<ffffffff8174ad4a>] smp_apic_timer_interrupt+0x4a/0x60
[ 638.968223] [<ffffffff817499af>] apic_timer_interrupt+0x6f/0x80
[ 638.970079] <EOI> [<ffffffff810b964f>] ? __lock_release+0x6f/0x100
[ 638.971899] [<ffffffff8173fa6a>] ? _raw_spin_unlock_irq+0x3a/0x50
[ 638.973691] [<ffffffff8173fa60>] ? _raw_spin_unlock_irq+0x30/0x50
[ 638.975475] [<ffffffff81562393>] md_set_badblocks+0x1f3/0x4a0
[ 638.977243] [<ffffffff81566e07>] rdev_set_badblocks+0x27/0x80
[ 638.978988] [<ffffffffa00d97bb>] raid5_end_read_request+0x36b/0x4e0 [raid456]
[ 638.980723] [<ffffffff811b5a1d>] bio_endio+0x1d/0x40
[ 638.982463] [<ffffffff81304ff3>] req_bio_endio.isra.65+0x83/0xa0
[ 638.984214] [<ffffffff81306b9f>] blk_update_request+0x7f/0x350
[ 638.985967] [<ffffffff81306ea1>] blk_update_bidi_request+0x31/0x90
[ 638.987710] [<ffffffff813085e0>] __blk_end_bidi_request+0x20/0x50
[ 638.989439] [<ffffffff8130862f>] __blk_end_request_all+0x1f/0x30
[ 638.991149] [<ffffffff81308746>] blk_peek_request+0x106/0x250
[ 638.992861] [<ffffffff814a62a9>] ? scsi_kill_request.isra.32+0xe9/0x130
[ 638.994561] [<ffffffff814a633a>] scsi_request_fn+0x4a/0x3d0
[ 638.996251] [<ffffffff813040a7>] __blk_run_queue+0x37/0x50
[ 638.997900] [<ffffffff813045af>] blk_run_queue+0x2f/0x50
[ 638.999553] [<ffffffff814a5750>] scsi_run_queue+0xe0/0x1c0
[ 639.001185] [<ffffffff814a7721>] scsi_run_host_queues+0x21/0x40
[ 639.002798] [<ffffffff814a2e87>] scsi_restart_operations+0x177/0x200
[ 639.004391] [<ffffffff814a4fe9>] scsi_error_handler+0xc9/0xe0
[ 639.005996] [<ffffffff814a4f20>] ? scsi_unjam_host+0xd0/0xd0
[ 639.007600] [<ffffffff81072f6b>] kthread+0xdb/0xe0
[ 639.009205] [<ffffffff81072e90>] ? flush_kthread_worker+0x170/0x170
[ 639.010821] [<ffffffff81748cac>] ret_from_fork+0x7c/0xb0
[ 639.012437] [<ffffffff81072e90>] ? flush_kthread_worker+0x170/0x170
This bug was introduce in commit 2e8ac30312973dd20e68073653
(the first time rdev_set_badblock was call from interrupt context),
so this patch is appropriate for 3.5 and subsequent kernels.
Signed-off-by: Bian Yu <bianyu at kedacom.com>
Reviewed-by: Jianpeng Ma <majianpeng at gmail.com>
Signed-off-by: NeilBrown <neilb at suse.de>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
drivers/md/md.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 0411bde..a240f16 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8044,6 +8044,7 @@ static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
u64 *p;
int lo, hi;
int rv = 1;
+ unsigned long flags;
if (bb->shift < 0)
/* badblocks are disabled */
@@ -8058,7 +8059,7 @@ static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
sectors = next - s;
}
- write_seqlock_irq(&bb->lock);
+ write_seqlock_irqsave(&bb->lock, flags);
p = bb->page;
lo = 0;
@@ -8174,7 +8175,7 @@ static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
bb->changed = 1;
if (!acknowledged)
bb->unacked_exist = 1;
- write_sequnlock_irq(&bb->lock);
+ write_sequnlock_irqrestore(&bb->lock, flags);
return rv;
}
--
1.8.1.2
More information about the kernel-team
mailing list