1 files changed, 12 insertions, 22 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 2009cea65d89..f8220ec02036 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -222,11 +222,8 @@ int btrfs_pin_log_trans(struct btrfs_root *root)
 void btrfs_end_log_trans(struct btrfs_root *root)
 {
         if (atomic_dec_and_test(&root->log_writers)) {
-                /*
-                 * Implicit memory barrier after atomic_dec_and_test
-                 */
-                if (waitqueue_active(&root->log_writer_wait))
-                        wake_up(&root->log_writer_wait);
+                /* atomic_dec_and_test implies a barrier */
+                cond_wake_up_nomb(&root->log_writer_wait);
         }
 }
 
@@ -2988,11 +2985,8 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
 
         mutex_lock(&log_root_tree->log_mutex);
         if (atomic_dec_and_test(&log_root_tree->log_writers)) {
-                /*
-                 * Implicit memory barrier after atomic_dec_and_test
-                 */
-                if (waitqueue_active(&log_root_tree->log_writer_wait))
-                        wake_up(&log_root_tree->log_writer_wait);
+                /* atomic_dec_and_test implies a barrier */
+                cond_wake_up_nomb(&log_root_tree->log_writer_wait);
         }
 
         if (ret) {
@@ -3116,13 +3110,11 @@ out_wake_log_root:
         mutex_unlock(&log_root_tree->log_mutex);
 
         /*
-         * The barrier before waitqueue_active is needed so all the updates
-         * above are seen by the woken threads. It might not be necessary, but
-         * proving that seems to be hard.
+         * The barrier before waitqueue_active (in cond_wake_up) is needed so
+         * all the updates above are seen by the woken threads. It might not be
+         * necessary, but proving that seems to be hard.
          */
-        smp_mb();
-        if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
-                wake_up(&log_root_tree->log_commit_wait[index2]);
+        cond_wake_up(&log_root_tree->log_commit_wait[index2]);
 out:
         mutex_lock(&root->log_mutex);
         btrfs_remove_all_log_ctxs(root, index1, ret);
@@ -3131,13 +3123,11 @@ out:
         mutex_unlock(&root->log_mutex);
 
         /*
-         * The barrier before waitqueue_active is needed so all the updates
-         * above are seen by the woken threads. It might not be necessary, but
-         * proving that seems to be hard.
+         * The barrier before waitqueue_active (in cond_wake_up) is needed so
+         * all the updates above are seen by the woken threads. It might not be
+         * necessary, but proving that seems to be hard.
          */
-        smp_mb();
-        if (waitqueue_active(&root->log_commit_wait[index1]))
-                wake_up(&root->log_commit_wait[index1]);
+        cond_wake_up(&root->log_commit_wait[index1]);
         return ret;
 }