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 introducing functions mddev_nested_suspend and mddev_nested_resume that can be called when the device is already suspended. The number of calls to mddev_nested_suspend is kept in the variable mddev->suspended. 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@xxxxxxxxxx> --- drivers/md/md.c | 19 +++++++++++++++++++ drivers/md/md.h | 2 ++ drivers/md/multipath.c | 4 ++-- drivers/md/raid1.c | 4 ++-- drivers/md/raid10.c | 4 ++-- 5 files changed, 27 insertions(+), 6 deletions(-) Index: linux-4.4-rc2/drivers/md/md.c =================================================================== --- linux-4.4-rc2.orig/drivers/md/md.c 2015-11-25 18:05:11.000000000 +0100 +++ linux-4.4-rc2/drivers/md/md.c 2015-11-25 18:05:31.000000000 +0100 @@ -336,6 +336,25 @@ void mddev_resume(struct mddev *mddev) } EXPORT_SYMBOL_GPL(mddev_resume); +void mddev_nested_suspend(struct mddev *mddev) +{ + if (mddev->suspended) + mddev->suspended++; + else + mddev_suspend(mddev); +} +EXPORT_SYMBOL_GPL(mddev_nested_suspend); + +void mddev_nested_resume(struct mddev *mddev) +{ + BUG_ON(!mddev->suspended); + if (mddev->suspended > 1) + mddev->suspended--; + else + mddev_resume(mddev); +} +EXPORT_SYMBOL_GPL(mddev_nested_resume); + int mddev_congested(struct mddev *mddev, int bits) { struct md_personality *pers = mddev->pers; Index: linux-4.4-rc2/drivers/md/md.h =================================================================== --- linux-4.4-rc2.orig/drivers/md/md.h 2015-11-25 18:04:08.000000000 +0100 +++ linux-4.4-rc2/drivers/md/md.h 2015-11-25 18:05:21.000000000 +0100 @@ -665,6 +665,8 @@ extern void md_rdev_clear(struct md_rdev extern void mddev_suspend(struct mddev *mddev); extern void mddev_resume(struct mddev *mddev); +extern void mddev_nested_suspend(struct mddev *mddev); +extern void mddev_nested_resume(struct mddev *mddev); extern struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask, struct mddev *mddev); extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs, Index: linux-4.4-rc2/drivers/md/multipath.c =================================================================== --- linux-4.4-rc2.orig/drivers/md/multipath.c 2015-11-25 18:05:11.000000000 +0100 +++ linux-4.4-rc2/drivers/md/multipath.c 2015-11-25 18:05:21.000000000 +0100 @@ -264,9 +264,9 @@ static int multipath_add_disk(struct mdd spin_unlock_irq(&conf->device_lock); rcu_assign_pointer(p->rdev, rdev); err = 0; - mddev_suspend(mddev); + mddev_nested_suspend(mddev); md_integrity_add_rdev(rdev, mddev); - mddev_resume(mddev); + mddev_nested_resume(mddev); break; } Index: linux-4.4-rc2/drivers/md/raid1.c =================================================================== --- linux-4.4-rc2.orig/drivers/md/raid1.c 2015-11-25 18:05:11.000000000 +0100 +++ linux-4.4-rc2/drivers/md/raid1.c 2015-11-25 18:05:21.000000000 +0100 @@ -1632,9 +1632,9 @@ static int raid1_add_disk(struct mddev * break; } } - mddev_suspend(mddev); + mddev_nested_suspend(mddev); md_integrity_add_rdev(rdev, mddev); - mddev_resume(mddev); + mddev_nested_resume(mddev); if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev))) queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); print_conf(conf); Index: linux-4.4-rc2/drivers/md/raid10.c =================================================================== --- linux-4.4-rc2.orig/drivers/md/raid10.c 2015-11-25 18:05:11.000000000 +0100 +++ linux-4.4-rc2/drivers/md/raid10.c 2015-11-25 18:05:21.000000000 +0100 @@ -1739,9 +1739,9 @@ static int raid10_add_disk(struct mddev rcu_assign_pointer(p->rdev, rdev); break; } - mddev_suspend(mddev); + mddev_nested_suspend(mddev); md_integrity_add_rdev(rdev, mddev); - mddev_resume(mddev); + mddev_nested_resume(mddev); if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev))) queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
