1 files changed, 12 insertions, 7 deletions

diff --git a/fs/ioprio.c b/fs/ioprio.c
index 78b1deae3fa2..6dc6721d9e82 100644
--- a/fs/ioprio.c
+++ b/fs/ioprio.c
@@ -1,7 +1,7 @@
 /*
  * fs/ioprio.c
  *
- * Copyright (C) 2004 Jens Axboe <axboe@suse.de>
+ * Copyright (C) 2004 Jens Axboe <axboe@kernel.dk>
  *
  * Helper functions for setting/querying io priorities of processes. The
  * system calls closely mimmick getpriority/setpriority, see the man page for
@@ -47,8 +47,8 @@ static int set_task_ioprio(struct task_struct *task, int ioprio)
         /* see wmb() in current_io_context() */
         smp_read_barrier_depends();
 
-        if (ioc && ioc->set_ioprio)
-                ioc->set_ioprio(ioc, ioprio);
+        if (ioc)
+                ioc->ioprio_changed = 1;
 
         task_unlock(task);
         return 0;
@@ -81,7 +81,12 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
         }
 
         ret = -ESRCH;
-        read_lock_irq(&tasklist_lock);
+        /*
+         * We want IOPRIO_WHO_PGRP/IOPRIO_WHO_USER to be "atomic",
+         * so we can't use rcu_read_lock(). See re-copy of ->ioprio
+         * in copy_process().
+         */
+        read_lock(&tasklist_lock);
         switch (which) {
                 case IOPRIO_WHO_PROCESS:
                         if (!who)
@@ -124,7 +129,7 @@ free_uid:
                         ret = -EINVAL;
         }
 
-        read_unlock_irq(&tasklist_lock);
+        read_unlock(&tasklist_lock);
         return ret;
 }
 
@@ -170,7 +175,7 @@ asmlinkage long sys_ioprio_get(int which, int who)
         int ret = -ESRCH;
         int tmpio;
 
-        read_lock_irq(&tasklist_lock);
+        read_lock(&tasklist_lock);
         switch (which) {
                 case IOPRIO_WHO_PROCESS:
                         if (!who)
@@ -221,7 +226,7 @@ asmlinkage long sys_ioprio_get(int which, int who)
                         ret = -EINVAL;
         }
 
-        read_unlock_irq(&tasklist_lock);
+        read_unlock(&tasklist_lock);
         return ret;
 }