diff options
| author | Krishnan Parthasarathi <kparthas@redhat.com> | 2013-05-11 14:36:38 +0530 |
|---|---|---|
| committer | Vijay Bellur <vbellur@redhat.com> | 2013-05-15 22:21:41 -0700 |
| commit | 4c0b149d8e7c574186a1ccefd9c74b79f8a06267 (patch) | |
| tree | c4b764cda3e67a08d48e4ecd2d5ea0e766db889d | |
| parent | 845aeb709e0e7e037a5b5afc7bc084d58e7e97ee (diff) | |
syncop: Remove task from synclock's waitq before 'wake'
Removing task from synclock's waitq after wake could result in
a subsequent unlock, wake'ing up the already running task.
This fix makes the removal from waitq and wake 'atomic'.
Change-Id: Ie51ccf9d38f2cee84471097644aab95496f488b1
BUG: 948686
Signed-off-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-on: http://review.gluster.org/4987
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
| -rw-r--r-- | libglusterfs/src/syncop.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/libglusterfs/src/syncop.c b/libglusterfs/src/syncop.c index 7dcdf3fefcb..98aee98dd85 100644 --- a/libglusterfs/src/syncop.c +++ b/libglusterfs/src/syncop.c @@ -529,12 +529,11 @@ __synclock_lock (struct synclock *lock) if (task) { /* called within a synctask */ list_add_tail (&task->waitq, &lock->waitq); - { - pthread_mutex_unlock (&lock->guard); - synctask_yield (task); - pthread_mutex_lock (&lock->guard); - } - list_del_init (&task->waitq); + pthread_mutex_unlock (&lock->guard); + synctask_yield (task); + /* task is removed from waitq in unlock, + * under lock->guard.*/ + pthread_mutex_lock (&lock->guard); } else { /* called by a non-synctask */ pthread_cond_wait (&lock->cond, &lock->guard); @@ -616,6 +615,7 @@ __synclock_unlock (synclock_t *lock) pthread_cond_signal (&lock->cond); if (!list_empty (&lock->waitq)) { task = list_entry (lock->waitq.next, struct synctask, waitq); + list_del_init (&task->waitq); synctask_wake (task); } |