Dan Williams 5fd3a17ed4 md: fix deadlock when stopping arrays ... Resolve a deadlock when stopping redundant arrays, i.e. ones that require a call to sysfs_remove_group when shutdown. The deadlock is summarized below: Thread1 Thread2 ------- ------- read sysfs attribute stop array take mddev lock sysfs_remove_group sysfs_get_active wait for mddev lock wait for active Sysrq-w: -------- mdmon S 00000017 2212 4163 1 f1982ea8 00000046 2dcf6b85 00000017 c0b23100 f2f83ed0 c0b23100 f2f8413c c0b23100 c0b23100 c0b1fb98 f2f8413c 00000000 f2f8413c c0b23100 f2291ecc 00000002 c0b23100 00000000 00000017 f2f83ed0 f1982eac 00000046 c044d9dd Call Trace: [<c044d9dd>] ? debug_mutex_add_waiter+0x1d/0x58 [<c06ef451>] __mutex_lock_common+0x1d9/0x338 [<c06ef451>] ? __mutex_lock_common+0x1d9/0x338 [<c06ef5e3>] mutex_lock_interruptible_nested+0x33/0x3a [<c0634553>] ? mddev_lock+0x14/0x16 [<c0634553>] mddev_lock+0x14/0x16 [<c0634eda>] md_attr_show+0x2a/0x49 [<c04e9997>] sysfs_read_file+0x93/0xf9 mdadm D 00000017 2812 4177 1 f0401d78 00000046 430456f8 00000017 f0401d58 f0401d20 c0b23100 f2da2c4c c0b23100 c0b23100 c0b1fb98 f2da2c4c 0a10fc36 00000000 c0b23100 f0401d70 00000003 c0b23100 00000000 00000017 f2da29e0 00000001 00000002 00000000 Call Trace: [<c06eed1b>] schedule_timeout+0x1b/0x95 [<c06eed1b>] ? schedule_timeout+0x1b/0x95 [<c06eeb97>] ? wait_for_common+0x34/0xdc [<c044fa8a>] ? trace_hardirqs_on_caller+0x18/0x145 [<c044fbc2>] ? trace_hardirqs_on+0xb/0xd [<c06eec03>] wait_for_common+0xa0/0xdc [<c0428c7c>] ? default_wake_function+0x0/0x12 [<c06eeccc>] wait_for_completion+0x17/0x19 [<c04ea620>] sysfs_addrm_finish+0x19f/0x1d1 [<c04e920e>] sysfs_hash_and_remove+0x42/0x55 [<c04eb4db>] sysfs_remove_group+0x57/0x86 [<c0638086>] do_md_stop+0x13a/0x499 This has been there for a while, but is easier to trigger now that mdmon is closely watching sysfs. Cc: <stable@kernel.org> Reported-by: Jacek Danecki <jacek.danecki@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>		2009-03-04 00:57:25 -07:00
..
raid6test
.gitignore
bitmap.c	md: use list_for_each_entry macro directly	2009-01-09 08:31:08 +11:00
dm-bio-list.h
dm-bio-record.h
dm-crypt.c	dm: consolidate target deregistration error handling	2009-01-06 03:04:58 +00:00
dm-delay.c	dm: consolidate target deregistration error handling	2009-01-06 03:04:58 +00:00
dm-exception-store.c	dm snapshot: extend exception store functions	2009-01-06 03:05:19 +00:00
dm-exception-store.h	dm snapshot: extend exception store functions	2009-01-06 03:05:19 +00:00
dm-io.c	block: fix bad definition of BIO_RW_SYNC	2009-02-18 10:32:00 +01:00
dm-ioctl.c	dm table: rework reference counting	2009-01-06 03:05:10 +00:00
dm-kcopyd.c	block: fix bad definition of BIO_RW_SYNC	2009-02-18 10:32:00 +01:00
dm-linear.c	dm: support barriers on simple devices	2009-01-06 03:05:09 +00:00
dm-log.c	dm log: ensure log bitmap fits on log device	2009-01-06 03:05:02 +00:00
dm-mpath.c	dm mpath: move trigger_event to system workqueue	2009-01-06 03:05:13 +00:00
dm-mpath.h
dm-path-selector.c
dm-path-selector.h
dm-raid1.c	dm log: move region_size validation	2009-01-06 03:05:01 +00:00
dm-region-hash.c
dm-round-robin.c
dm-snap-persistent.c	dm snapshot: extend exception store functions	2009-01-06 03:05:19 +00:00
dm-snap-transient.c	dm snapshot: extend exception store functions	2009-01-06 03:05:19 +00:00
dm-snap.c	dm snapshot: extend exception store functions	2009-01-06 03:05:19 +00:00
dm-snap.h	dm snapshot: extend exception store functions	2009-01-06 03:05:19 +00:00
dm-stripe.c	dm: consolidate target deregistration error handling	2009-01-06 03:04:58 +00:00
dm-sysfs.c	dm: add name and uuid to sysfs	2009-01-06 03:05:12 +00:00
dm-table.c	dm table: rework reference counting	2009-01-06 03:05:10 +00:00
dm-target.c	dm: consolidate target deregistration error handling	2009-01-06 03:04:58 +00:00
dm-uevent.c
dm-uevent.h
dm-zero.c	dm: consolidate target deregistration error handling	2009-01-06 03:04:58 +00:00
dm.c	dm: add name and uuid to sysfs	2009-01-06 03:05:12 +00:00
dm.h	dm: add name and uuid to sysfs	2009-01-06 03:05:12 +00:00
faulty.c	md: use list_for_each_entry macro directly	2009-01-09 08:31:08 +11:00
Kconfig
linear.c	md: Fix a bug in linear.c causing which_dev() to return the wrong device.	2009-02-06 15:10:52 +11:00
Makefile	dm snapshot: split out exception store implementations	2009-01-06 03:05:17 +00:00
md.c	md: fix deadlock when stopping arrays	2009-03-04 00:57:25 -07:00
mktables.c
multipath.c	md: use list_for_each_entry macro directly	2009-01-09 08:31:08 +11:00
raid0.c	md: use list_for_each_entry macro directly	2009-01-09 08:31:08 +11:00
raid1.c	md: avoid races when stopping resync.	2009-02-25 13:18:47 +11:00
raid5.c	md: use list_for_each_entry macro directly	2009-01-09 08:31:08 +11:00
raid6.h
raid6algos.c
raid6altivec.uc
raid6int.uc
raid6mmx.c
raid6recov.c
raid6sse1.c
raid6sse2.c
raid6x86.h
raid10.c	md: avoid races when stopping resync.	2009-02-25 13:18:47 +11:00
unroll.pl