diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-06 08:30:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-06 08:30:03 -0700 |
| commit | a7c56ebac1bce799b583230595b4de9ccb8162d0 (patch) | |
| tree | 000aa9f3f7aef65ecd918c012c1f9b86445cb135 /drivers/md/md.c | |
| parent | 538d2882213ef4f076108f3edda2c39a584c4c2b (diff) | |
| parent | 01f96c0a9922cd9919baf9d16febdf7016177a12 (diff) | |
Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md:
md: Avoid waking up a thread after it has been freed.
Diffstat (limited to 'drivers/md/md.c')
| -rw-r--r-- | drivers/md/md.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 5404b229582..5c95ccb5950 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -61,6 +61,11 @@ static void autostart_arrays(int part); #endif +/* pers_list is a list of registered personalities protected + * by pers_lock. + * pers_lock does extra service to protect accesses to + * mddev->thread when the mutex cannot be held. + */ static LIST_HEAD(pers_list); static DEFINE_SPINLOCK(pers_lock); @@ -739,7 +744,12 @@ static void mddev_unlock(mddev_t * mddev) } else mutex_unlock(&mddev->reconfig_mutex); + /* was we've dropped the mutex we need a spinlock to + * make sur the thread doesn't disappear + */ + spin_lock(&pers_lock); md_wakeup_thread(mddev->thread); + spin_unlock(&pers_lock); } static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr) @@ -6429,11 +6439,18 @@ mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev, return thread; } -void md_unregister_thread(mdk_thread_t *thread) +void md_unregister_thread(mdk_thread_t **threadp) { + mdk_thread_t *thread = *threadp; if (!thread) return; dprintk("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk)); + /* Locking ensures that mddev_unlock does not wake_up a + * non-existent thread + */ + spin_lock(&pers_lock); + *threadp = NULL; + spin_unlock(&pers_lock); kthread_stop(thread->tsk); kfree(thread); @@ -7340,8 +7357,7 @@ static void reap_sync_thread(mddev_t *mddev) mdk_rdev_t *rdev; /* resync has finished, collect result */ - md_unregister_thread(mddev->sync_thread); - mddev->sync_thread = NULL; + md_unregister_thread(&mddev->sync_thread); if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery) && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { /* success...*/ |