Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik...

[sfrench/cifs-2.6.git] / fs / ioprio.c

diff --git a/fs/ioprio.c b/fs/ioprio.c
index 78b1deae3fa2e1a9aaa4142fa83050b434840b90..10d2c211d18b28414aa8b0f26dcfe489fa0ddfe9 100644 (file)
--- 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;
@@ -60,6 +60,7 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
        int data = IOPRIO_PRIO_DATA(ioprio);
        struct task_struct *p, *g;
        struct user_struct *user;
+       struct pid *pgrp;
        int ret;
 
        switch (class) {
@@ -81,7 +82,12 @@ 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)
@@ -93,12 +99,14 @@ asmlinkage long sys_ioprio_set(int which, int who, int ioprio)
                        break;
                case IOPRIO_WHO_PGRP:
                        if (!who)
-                               who = process_group(current);
-                       do_each_task_pid(who, PIDTYPE_PGID, p) {
+                               pgrp = task_pgrp(current);
+                       else
+                               pgrp = find_pid(who);
+                       do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
                                ret = set_task_ioprio(p, ioprio);
                                if (ret)
                                        break;
-                       } while_each_task_pid(who, PIDTYPE_PGID, p);
+                       } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
                        break;
                case IOPRIO_WHO_USER:
                        if (!who)
@@ -124,7 +132,7 @@ free_uid:
                        ret = -EINVAL;
        }
 
-       read_unlock_irq(&tasklist_lock);
+       read_unlock(&tasklist_lock);
        return ret;
 }
 
@@ -145,11 +153,6 @@ 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)
@@ -167,10 +170,11 @@ asmlinkage long sys_ioprio_get(int which, int who)
 {
        struct task_struct *g, *p;
        struct user_struct *user;
+       struct pid *pgrp;
        int ret = -ESRCH;
        int tmpio;
 
-       read_lock_irq(&tasklist_lock);
+       read_lock(&tasklist_lock);
        switch (which) {
                case IOPRIO_WHO_PROCESS:
                        if (!who)
@@ -182,8 +186,10 @@ asmlinkage long sys_ioprio_get(int which, int who)
                        break;
                case IOPRIO_WHO_PGRP:
                        if (!who)
-                               who = process_group(current);
-                       do_each_task_pid(who, PIDTYPE_PGID, p) {
+                               pgrp = task_pgrp(current);
+                       else
+                               pgrp = find_pid(who);
+                       do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
                                tmpio = get_task_ioprio(p);
                                if (tmpio < 0)
                                        continue;
@@ -191,7 +197,7 @@ asmlinkage long sys_ioprio_get(int which, int who)
                                        ret = tmpio;
                                else
                                        ret = ioprio_best(ret, tmpio);
-                       } while_each_task_pid(who, PIDTYPE_PGID, p);
+                       } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
                        break;
                case IOPRIO_WHO_USER:
                        if (!who)
@@ -221,7 +227,7 @@ asmlinkage long sys_ioprio_get(int which, int who)
                        ret = -EINVAL;
        }
 
-       read_unlock_irq(&tasklist_lock);
+       read_unlock(&tasklist_lock);
        return ret;
 }