diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2015-12-18 15:19:16 +1100 |
|---|---|---|
| committer | NeilBrown <neilb@suse.com> | 2015-12-18 15:19:16 +1100 |
| commit | 0dc10e50f219db3f7fd66d35e5d95860ecde4213 (patch) | |
| tree | cbff7c61541a7645eb6e0c3a568a96aea6a52679 | |
| parent | 9b15603dbd98ad1003355ef6ac7d682c75df81c1 (diff) | |
| download | linux-0dc10e50f219db3f7fd66d35e5d95860ecde4213.tar.bz2 | |
md: fix bug due to nested suspend
The patch c7bfced9a6716ff66c9d61f934bb60af08d4688c committed to 4.4-rc
causes crash in LVM test shell/lvchange-raid.sh. The kernel crashes with
this BUG, the reason is that we attempt to suspend a device that is
already suspended. See also
https://bugzilla.redhat.com/show_bug.cgi?id=1283491
This patch fixes the bug by changing functions mddev_suspend and
mddev_resume to always nest.
The number of nested calls to mddev_nested_suspend is kept in the
variable mddev->suspended.
[neilb: made mddev_suspend() always nest instead of introduce mddev_nested_suspend]
kernel BUG at drivers/md/md.c:317!
CPU: 3 PID: 32754 Comm: lvm Not tainted 4.4.0-rc2 #1
task: 0000000047076040 ti: 0000000047014000 task.ti: 0000000047014000
YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI
PSW: 00001000000001000000000000001111 Not tainted
r00-03 000000000804000f 00000000102c5280 0000000010c7522c 000000007e3d1810
r04-07 0000000010c6f000 000000004ef37f20 000000007e3d1dd0 000000007e3d1810
r08-11 000000007c9f1600 0000000000000000 0000000000000001 ffffffffffffffff
r12-15 0000000010c1d000 0000000000000041 00000000f98d63c8 00000000f98e49e4
r16-19 00000000f98e49e4 00000000c138fd06 00000000f98d63c8 0000000000000001
r20-23 0000000000000002 000000004ef37f00 00000000000000b0 00000000000001d1
r24-27 00000000424783a0 000000007e3d1dd0 000000007e3d1810 00000000102b2000
r28-31 0000000000000001 0000000047014840 0000000047014930 0000000000000001
sr00-03 0000000007040800 0000000000000000 0000000000000000 0000000007040800
sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000
IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000102c538c 00000000102c5390
IIR: 03ffe01f ISR: 0000000000000000 IOR: 00000000102b2748
CPU: 3 CR30: 0000000047014000 CR31: 0000000000000000
ORIG_R28: 00000000000000b0
IAOQ[0]: mddev_suspend+0x10c/0x160 [md_mod]
IAOQ[1]: mddev_suspend+0x110/0x160 [md_mod]
RP(r2): raid1_add_disk+0xd4/0x2c0 [raid1]
Backtrace:
[<0000000010c7522c>] raid1_add_disk+0xd4/0x2c0 [raid1]
[<0000000010c20078>] raid_resume+0x390/0x418 [dm_raid]
[<00000000105833e8>] dm_table_resume_targets+0xc0/0x188 [dm_mod]
[<000000001057f784>] dm_resume+0x144/0x1e0 [dm_mod]
[<0000000010587dd4>] dev_suspend+0x1e4/0x568 [dm_mod]
[<0000000010589278>] ctl_ioctl+0x1e8/0x428 [dm_mod]
[<0000000010589518>] dm_compat_ctl_ioctl+0x18/0x68 [dm_mod]
[<0000000040377b88>] compat_SyS_ioctl+0xd0/0x1558
Fixes: c7bfced9a671 ("md: suspend i/o during runtime blk_integrity_unregister")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
| -rw-r--r-- | drivers/md/md.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 874c843e72fb..b79b95784e46 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -314,8 +314,8 @@ static blk_qc_t md_make_request(struct request_queue *q, struct bio *bio) */ void mddev_suspend(struct mddev *mddev) { - BUG_ON(mddev->suspended); - mddev->suspended = 1; + if (mddev->suspended++) + return; synchronize_rcu(); wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0); mddev->pers->quiesce(mddev, 1); @@ -326,7 +326,8 @@ EXPORT_SYMBOL_GPL(mddev_suspend); void mddev_resume(struct mddev *mddev) { - mddev->suspended = 0; + if (--mddev->suspended) + return; wake_up(&mddev->sb_wait); mddev->pers->quiesce(mddev, 0); |