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>