diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-12-23 21:47:28 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-12-23 21:47:28 -0800 |
| commit | a22681fabb1564d00d54e804ec95ba9330d857ed (patch) | |
| tree | cd1dd7d3027a0a1c25506e37c32579bc388c4287 | |
| parent | 6d451c578c7222c7e9305c2e776a654dc6ec06c3 (diff) | |
| parent | e30e2fdfe56288576ee9e04dbb06b4bd5f282203 (diff) | |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
VFS: Fix race between CPU hotplug and lglocks
| -rw-r--r-- | include/linux/lglock.h | 36 |
1 files changed, 32 insertions, 4 deletions
diff --git a/include/linux/lglock.h b/include/linux/lglock.h index f549056fb20..87f402ccec5 100644 --- a/include/linux/lglock.h +++ b/include/linux/lglock.h @@ -22,6 +22,7 @@ #include <linux/spinlock.h> #include <linux/lockdep.h> #include <linux/percpu.h> +#include <linux/cpu.h> /* can make br locks by using local lock for read side, global lock for write */ #define br_lock_init(name) name##_lock_init() @@ -72,9 +73,31 @@ #define DEFINE_LGLOCK(name) \ \ + DEFINE_SPINLOCK(name##_cpu_lock); \ + cpumask_t name##_cpus __read_mostly; \ DEFINE_PER_CPU(arch_spinlock_t, name##_lock); \ DEFINE_LGLOCK_LOCKDEP(name); \ \ + static int \ + name##_lg_cpu_callback(struct notifier_block *nb, \ + unsigned long action, void *hcpu) \ + { \ + switch (action & ~CPU_TASKS_FROZEN) { \ + case CPU_UP_PREPARE: \ + spin_lock(&name##_cpu_lock); \ + cpu_set((unsigned long)hcpu, name##_cpus); \ + spin_unlock(&name##_cpu_lock); \ + break; \ + case CPU_UP_CANCELED: case CPU_DEAD: \ + spin_lock(&name##_cpu_lock); \ + cpu_clear((unsigned long)hcpu, name##_cpus); \ + spin_unlock(&name##_cpu_lock); \ + } \ + return NOTIFY_OK; \ + } \ + static struct notifier_block name##_lg_cpu_notifier = { \ + .notifier_call = name##_lg_cpu_callback, \ + }; \ void name##_lock_init(void) { \ int i; \ LOCKDEP_INIT_MAP(&name##_lock_dep_map, #name, &name##_lock_key, 0); \ @@ -83,6 +106,11 @@ lock = &per_cpu(name##_lock, i); \ *lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; \ } \ + register_hotcpu_notifier(&name##_lg_cpu_notifier); \ + get_online_cpus(); \ + for_each_online_cpu(i) \ + cpu_set(i, name##_cpus); \ + put_online_cpus(); \ } \ EXPORT_SYMBOL(name##_lock_init); \ \ @@ -124,9 +152,9 @@ \ void name##_global_lock_online(void) { \ int i; \ - preempt_disable(); \ + spin_lock(&name##_cpu_lock); \ rwlock_acquire(&name##_lock_dep_map, 0, 0, _RET_IP_); \ - for_each_online_cpu(i) { \ + for_each_cpu(i, &name##_cpus) { \ arch_spinlock_t *lock; \ lock = &per_cpu(name##_lock, i); \ arch_spin_lock(lock); \ @@ -137,12 +165,12 @@ void name##_global_unlock_online(void) { \ int i; \ rwlock_release(&name##_lock_dep_map, 1, _RET_IP_); \ - for_each_online_cpu(i) { \ + for_each_cpu(i, &name##_cpus) { \ arch_spinlock_t *lock; \ lock = &per_cpu(name##_lock, i); \ arch_spin_unlock(lock); \ } \ - preempt_enable(); \ + spin_unlock(&name##_cpu_lock); \ } \ EXPORT_SYMBOL(name##_global_unlock_online); \ \ |