2 files changed, 8 insertions, 0 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e176f8c551f7..1c665ebe47e0 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -173,6 +173,9 @@ static int btrfs_csum_sizes[] = { 4, 0 };
 #define BTRFS_FT_XATTR          8
 #define BTRFS_FT_MAX            9
 
+/* ioprio of readahead is set to idle */
+#define BTRFS_IOPRIO_READA (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_IDLE, 0))
+
 /*
  * The key defines the order in the tree, and so it also defines (optimal)
  * block layout.
diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index ac5d01085884..48a4882d8ad5 100644
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -718,13 +718,18 @@ static void reada_start_machine_worker(struct btrfs_work *work)
 {
         struct reada_machine_work *rmw;
         struct btrfs_fs_info *fs_info;
+        int old_ioprio;
 
         rmw = container_of(work, struct reada_machine_work, work);
         fs_info = rmw->fs_info;
 
         kfree(rmw);
 
+        old_ioprio = IOPRIO_PRIO_VALUE(task_nice_ioclass(current),
+                                       task_nice_ioprio(current));
+        set_task_ioprio(current, BTRFS_IOPRIO_READA);
         __reada_start_machine(fs_info);
+        set_task_ioprio(current, old_ioprio);
 }
 
 static void __reada_start_machine(struct btrfs_fs_info *fs_info)