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-rw-r--r--fs/ioprio.c30
1 files changed, 28 insertions, 2 deletions
diff --git a/fs/ioprio.c b/fs/ioprio.c
index 93aa5715f224..78b1deae3fa2 100644
--- a/fs/ioprio.c
+++ b/fs/ioprio.c
@@ -44,6 +44,9 @@ static int set_task_ioprio(struct task_struct *task, int ioprio)
task->ioprio = ioprio;
ioc = task->io_context;
+ /* see wmb() in current_io_context() */
+ smp_read_barrier_depends();
+
if (ioc && ioc->set_ioprio)
ioc->set_ioprio(ioc, ioprio);
@@ -111,9 +114,9 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
continue;
ret = set_task_ioprio(p, ioprio);
if (ret)
- break;
+ goto free_uid;
} while_each_thread(g, p);
-
+free_uid:
if (who)
free_uid(user);
break;
@@ -137,6 +140,29 @@ out:
return ret;
}
+int ioprio_best(unsigned short aprio, unsigned short bprio)
+{
+ unsigned short aclass = IOPRIO_PRIO_CLASS(aprio);
+ unsigned short bclass = IOPRIO_PRIO_CLASS(bprio);
+
+ if (!ioprio_valid(aprio))
+ return bprio;
+ if (!ioprio_valid(bprio))
+ return aprio;
+
+ if (aclass == IOPRIO_CLASS_NONE)
+ aclass = IOPRIO_CLASS_BE;
+ if (bclass == IOPRIO_CLASS_NONE)
+ bclass = IOPRIO_CLASS_BE;
+
+ if (aclass == bclass)
+ return min(aprio, bprio);
+ if (aclass > bclass)
+ return bprio;
+ else
+ return aprio;
+}
+
asmlinkage long sys_ioprio_get(int which, int who)
{
struct task_struct *g, *p;