• Bian Yu's avatar
    md: avoid deadlock when md_set_badblocks. · 905b0297
    Bian Yu authored
    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  2e8ac303
    (the first time rdev_set_badblock was call from interrupt context),
    so this patch is appropriate for 3.5 and subsequent kernels.
    
    Cc: <stable@vger.kernel.org> (3.5+)
    Signed-off-by: default avatarBian Yu <bianyu@kedacom.com>
    Reviewed-by: default avatarJianpeng Ma <majianpeng@gmail.com>
    Signed-off-by: default avatarNeilBrown <neilb@suse.de>
    905b0297
md.c 224 KB