btrfs: reada: limit max works count

[linux-2.6-block.git] / fs / btrfs / reada.c

diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index 9157d789ae86c2e483fcdc2e0fec2f5b531afdfe..e97bc8eb01e22eb184c276d8c90f4ccedd9689c1 100644 (file)
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -748,6 +748,8 @@ static void reada_start_machine_worker(struct btrfs_work *work)
        set_task_ioprio(current, BTRFS_IOPRIO_READA);
        __reada_start_machine(fs_info);
        set_task_ioprio(current, old_ioprio);
+
+       atomic_dec(&fs_info->reada_works_cnt);
 }
 
 static void __reada_start_machine(struct btrfs_fs_info *fs_info)
@@ -779,8 +781,12 @@ static void __reada_start_machine(struct btrfs_fs_info *fs_info)
         * enqueue to workers to finish it. This will distribute the load to
         * the cores.
         */
-       for (i = 0; i < 2; ++i)
+       for (i = 0; i < 2; ++i) {
                reada_start_machine(fs_info);
+               if (atomic_read(&fs_info->reada_works_cnt) >
+                   BTRFS_MAX_MIRRORS * 2)
+                       break;
+       }
 }
 
 static void reada_start_machine(struct btrfs_fs_info *fs_info)
@@ -797,6 +803,7 @@ static void reada_start_machine(struct btrfs_fs_info *fs_info)
        rmw->fs_info = fs_info;
 
        btrfs_queue_work(fs_info->readahead_workers, &rmw->work);
+       atomic_inc(&fs_info->reada_works_cnt);
 }
 
 #ifdef DEBUG