kernel_optimize_test/drivers/md
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 md: raid6: clean up the style of raid6test/test.c 2008-02-06 10:41:18 -08:00
.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_list macro renaming 2007-10-20 02:01:11 +01:00
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 mpath: remove is_active from struct dm_path 2008-10-10 13:36:58 +01:00
dm-path-selector.c dm: remove dm header from targets 2008-10-21 17:44:59 +01:00
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 raid1: separate region_hash interface part1 2008-10-21 17:45:06 +01:00
dm-round-robin.c dm: remove dm header from targets 2008-10-21 17:44:59 +01:00
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 md: replace remaining __FUNCTION__ occurrences 2008-04-28 08:58:42 -07:00
dm-uevent.h dm: uevent generate events 2007-10-20 02:01:26 +01:00
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 raid, fastboot: hide RAID autodetect option if MD is compiled as a module 2008-10-12 08:25:14 -07:00
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 md: raid6: Fix mktable.c 2008-02-06 10:41:18 -08:00
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 md: Remove unnecessary #includes, #defines, and function declarations. 2008-10-13 11:55:12 +11:00
raid6algos.c drivers/md: use time_before, time_before_eq, etc 2008-04-28 08:58:42 -07:00
raid6altivec.uc
raid6int.uc
raid6mmx.c x86 merge fallout: uml 2007-10-29 07:41:32 -07:00
raid6recov.c
raid6sse1.c x86 merge fallout: uml 2007-10-29 07:41:32 -07:00
raid6sse2.c x86 merge fallout: uml 2007-10-29 07:41:32 -07:00
raid6x86.h x86 merge fallout: uml 2007-10-29 07:41:32 -07:00
raid10.c md: avoid races when stopping resync. 2009-02-25 13:18:47 +11:00
unroll.pl