linux/kernel
Lai Jiangshan 5c529597e9 workqueue: avoid false negative WARN_ON() in destroy_workqueue()
destroy_workqueue() performs several sanity checks before proceeding
with destruction of a workqueue.  One of the checks verifies that
refcnt of each pwq (pool_workqueue) is over 1 as at that point there
should be no in-flight work items and the only holder of pwq refs is
the workqueue itself.

This worked fine as a workqueue used to hold only one reference to its
pwqs; however, since 4c16bd327c ("workqueue: implement NUMA affinity
for unbound workqueues"), a workqueue may hold multiple references to
its default pwq triggering this sanity check spuriously.

Fix it by not triggering the pwq->refcnt assertion on default pwqs.

An example spurious WARN trigger follows.

 WARNING: at kernel/workqueue.c:4201 destroy_workqueue+0x6a/0x13e()
 Hardware name: 4286C12
 Modules linked in: sdhci_pci sdhci mmc_core usb_storage i915 drm_kms_helper drm i2c_algo_bit i2c_core video
 Pid: 361, comm: umount Not tainted 3.9.0-rc5+ #29
 Call Trace:
  [<c04314a7>] warn_slowpath_common+0x7c/0x93
  [<c04314e0>] warn_slowpath_null+0x22/0x24
  [<c044796a>] destroy_workqueue+0x6a/0x13e
  [<c056dc01>] ext4_put_super+0x43/0x2c4
  [<c04fb7b8>] generic_shutdown_super+0x4b/0xb9
  [<c04fb848>] kill_block_super+0x22/0x60
  [<c04fb960>] deactivate_locked_super+0x2f/0x56
  [<c04fc41b>] deactivate_super+0x2e/0x31
  [<c050f1e6>] mntput_no_expire+0x103/0x108
  [<c050fdce>] sys_umount+0x2a2/0x2c4
  [<c050fe0e>] sys_oldumount+0x1e/0x20
  [<c085ba4d>] sysenter_do_call+0x12/0x38

tj: Rewrote description.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
2013-04-04 07:54:01 -07:00
..
debug KGDB/KDB fixes and cleanups 2013-03-02 08:31:39 -08:00
events perf: Generate EXIT event only once per task context 2013-03-18 09:47:33 +01:00
gcov kernel/gcov: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:39:33 -08:00
irq Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
power Driver core patches for 3.9-rc1 2013-02-21 12:05:51 -08:00
sched sched: replace PF_THREAD_BOUND with PF_NO_SETAFFINITY 2013-03-19 13:45:20 -07:00
time clockevents: Don't allow dummy broadcast timers 2013-03-07 17:16:11 +01:00
trace Merge branch 'tip/perf/urgent-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent 2013-03-18 09:48:29 +01:00
.gitignore
acct.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
async.c Merge branch 'for-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2013-02-19 22:01:33 -08:00
audit_tree.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
audit_watch.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
audit.c kernel/audit.c: avoid negative sleep durations 2013-01-11 14:54:56 -08:00
audit.h audit: optimize audit_compare_dname_path 2012-10-12 00:32:02 -04:00
auditfilter.c audit: fix auditfilter.c kernel-doc warnings 2013-01-10 14:35:23 -08:00
auditsc.c audit: catch possible NULL audit buffers 2013-01-11 14:54:55 -08:00
backtracetest.c
bounds.c
capability.c
cgroup_freezer.c cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free() 2012-11-19 08:13:38 -08:00
cgroup.c sched: replace PF_THREAD_BOUND with PF_NO_SETAFFINITY 2013-03-19 13:45:20 -07:00
compat.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-02-23 18:50:11 -08:00
configs.c
context_tracking.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 18:19:48 -08:00
cpu_pm.c
cpu.c Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:04:55 -08:00
cpuset.c sched: replace PF_THREAD_BOUND with PF_NO_SETAFFINITY 2013-03-19 13:45:20 -07:00
crash_dump.c
cred.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-18 10:55:28 -08:00
delayacct.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
dma.c
elfcore.c
exec_domain.c
exit.c Revert "lockdep: check that no locks held at freeze time" 2013-03-31 11:38:33 -07:00
extable.c
fork.c userns: Don't allow CLONE_NEWUSER | CLONE_FS 2013-03-13 15:00:20 -07:00
freezer.c freezer: change ptrace_stop/do_signal_stop to use freezable_schedule() 2012-10-26 14:27:49 -07:00
futex_compat.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal 2013-02-23 18:50:11 -08:00
futex.c futex: fix kernel-doc notation and spello 2013-03-12 20:42:10 -07:00
groups.c
hrtimer.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:05:45 -08:00
hung_task.c
irq_work.c Merge branch 'nohz/printk-v8' into irq/core 2013-02-05 00:48:46 +01:00
itimer.c
jump_label.c jump_label: Export jump_label_rate_limit() 2012-08-06 19:00:35 +03:00
kallsyms.c
kcmp.c kcmp: include linux/ptrace.h 2012-12-20 17:40:19 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking: Adjust spin lock inlining Kconfig options 2012-09-13 17:56:13 +02:00
Kconfig.preempt
kexec.c kexec: avoid freeing NULL pointer in image_crash_alloc() 2013-02-27 19:10:12 -08:00
kmod.c Merge branch 'master' into for-3.9-async 2013-01-23 09:31:01 -08:00
kprobes.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ksysfs.c Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-12-11 18:10:49 -08:00
kthread.c sched: replace PF_THREAD_BOUND with PF_NO_SETAFFINITY 2013-03-19 13:45:20 -07:00
latencytop.c
lglock.c
lockdep_internals.h
lockdep_proc.c lockdep: Use KSYM_NAME_LEN'ed buffer for __get_key_name() 2012-10-24 12:39:09 +02:00
lockdep_states.h
lockdep.c Revert "lockdep: check that no locks held at freeze time" 2013-03-31 11:38:33 -07:00
Makefile Merge branch 'akpm' (final batch from Andrew) 2013-02-27 20:58:09 -08:00
modsign_certificate.S MODSIGN: Avoid using .incbin in C source 2012-12-14 13:06:44 +10:30
modsign_pubkey.c keys: use keyring_alloc() to create module signing keyring 2012-12-20 17:40:21 -08:00
module_signing.c MODSIGN: Don't use enum-type bitfields in module signature info block 2012-12-05 11:27:24 +10:30
module-internal.h MODSIGN: Move the magic string to the end of a module and eliminate the search 2012-10-19 17:30:40 -07:00
module.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
mutex-debug.c
mutex-debug.h
mutex.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
mutex.h
notifier.c
nsproxy.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
padata.c padata: use __this_cpu_read per-cpu helper 2012-12-06 17:16:23 +08:00
panic.c taint: add explicit flag to show whether lock dep is still OK. 2013-01-21 17:17:57 +10:30
params.c
pid_namespace.c pid: Handle the exit of a multi-threaded init. 2013-03-26 03:41:23 -07:00
pid.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
posix-cpu-timers.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 19:05:45 -08:00
posix-timers.c posix-timers: convert to idr_alloc() 2013-02-27 19:10:19 -08:00
printk.c printk: Provide a wake_up_klogd() off-case 2013-03-22 16:41:20 -07:00
profile.c profiling: Remove unused timer hook 2013-01-24 15:37:26 +01:00
ptrace.c uprobes: Add exports for module use 2013-02-08 17:47:13 +01:00
range.c
rcu.h rcu: Provide RCU CPU stall warnings for tiny RCU 2013-01-28 22:06:21 -08:00
rcupdate.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutiny_plugin.h rcu: Provide RCU CPU stall warnings for tiny RCU 2013-01-28 22:06:21 -08:00
rcutiny.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutorture.c rcu: Allow rcutorture to be built at low optimization levels 2013-02-04 12:18:20 -08:00
rcutree_plugin.h rcu: Make rcu_nocb_poll an early_param instead of module_param 2013-01-08 14:12:19 -08:00
rcutree_trace.c rcu: Separate accounting of callbacks from callback-free CPUs 2012-11-16 10:05:57 -08:00
rcutree.c Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
rcutree.h Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD 2013-01-28 22:25:21 -08:00
relay.c new helper: file_inode(file) 2013-02-22 23:31:31 -05:00
res_counter.c res_counter: return amount of charges after res_counter_uncharge() 2012-12-18 15:02:12 -08:00
resource.c kernel/resource.c: fix stack overflow in __reserve_region_with_split() 2012-10-06 03:05:31 +09:00
rtmutex_common.h
rtmutex-debug.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex-debug.h
rtmutex-tester.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
rtmutex.h
rwsem.c lockdep, rwsem: provide down_write_nest_lock() 2013-01-11 14:54:55 -08:00
seccomp.c seccomp: Make syscall skipping and nr changes more consistent 2012-10-02 21:14:29 +10:00
semaphore.c
signal.c kernel/signal.c: use __ARCH_HAS_SA_RESTORER instead of SA_RESTORER 2013-03-13 15:21:45 -07:00
smp.c smp: make smp_call_function_many() use logic similar to smp_call_function_single() 2013-02-21 17:22:20 -08:00
smpboot.c Revert parts of "hlist: drop the node parameter from iterators" 2013-03-08 15:05:34 -08:00
smpboot.h smpboot: Provide infrastructure for percpu hotplug threads 2012-08-13 17:01:07 +02:00
softirq.c Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-03-05 18:10:04 -08:00
spinlock.c
srcu.c srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock() 2013-02-07 15:19:36 -08:00
stacktrace.c
stop_machine.c stop_machine: Mark per cpu stopper enabled early 2013-02-26 22:25:17 +01:00
sys_ni.c module: add syscall to load module from fd 2012-12-14 13:05:22 +10:30
sys.c poweroff: change orderly_poweroff() to use schedule_work() 2013-03-22 16:41:20 -07:00
sysctl_binary.c sysctl: fix null checking in bin_dn_node_address() 2013-02-27 19:10:21 -08:00
sysctl.c Initial ARC Linux port with some fixes on top for 3.9-rc1 2013-03-02 07:58:56 -08:00
task_work.c task_work: task_work_add() should not succeed after exit_task_work() 2012-09-13 16:47:34 +02:00
taskstats.c taskstats: cgroupstats_user_cmd() may leak on error 2012-10-06 03:05:31 +09:00
test_kprobes.c
time.c time: don't inline EXPORT_SYMBOL functions 2013-02-21 17:22:19 -08:00
timeconst.bc kernel: Replace timeconst.pl with a bc script 2013-02-16 23:17:25 +01:00
timer.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-19 18:19:48 -08:00
tracepoint.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
tsacct.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
uid16.c
up.c
user_namespace.c userns: Restrict when proc and sysfs can be mounted 2013-03-27 07:50:08 -07:00
user-return-notifier.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
user.c userns: Restrict when proc and sysfs can be mounted 2013-03-27 07:50:08 -07:00
utsname_sysctl.c kernel/utsname_sysctl.c: put get/get_uts() into CONFIG_PROC_SYSCTL code block 2013-02-27 19:10:22 -08:00
utsname.c kernel/utsname.c: fix wrong comment about clone_uts_ns() 2013-02-27 19:10:22 -08:00
wait.c propagate name change to comments in kernel source 2012-12-06 10:39:54 +01:00
watchdog.c Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-02-22 19:25:09 -08:00
workqueue_internal.h workqueue: directly restore CPU affinity of workers from CPU_ONLINE 2013-03-19 13:45:21 -07:00
workqueue.c workqueue: avoid false negative WARN_ON() in destroy_workqueue() 2013-04-04 07:54:01 -07:00