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make elv_register() output atomic

Booting 2.6.21-rc3-g45592145 I noticed the following on one of my
machines in the bootlog:

io scheduler noop registered<6>Time: jiffies clocksource has been installed.

io scheduler deadline registered (default)

Looking at block/elevator.c, it appears that elv_register() uses two
consecutive printks in a non-atomic way, leading to the above glitch. The
attached trivial patch fixes this issue, by using a single printk.

Signed-off-by: Thibaut VARENE <varenet@parisc-linux.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Thibaut VARENE 18 years ago
parent
commit
1ffb96c587
1 changed files with 4 additions and 3 deletions
  1. 4 3
      block/elevator.c

+ 4 - 3
block/elevator.c

@@ -964,17 +964,18 @@ void elv_unregister_queue(struct request_queue *q)
 
 
 int elv_register(struct elevator_type *e)
 int elv_register(struct elevator_type *e)
 {
 {
+	char *def = "";
 	spin_lock_irq(&elv_list_lock);
 	spin_lock_irq(&elv_list_lock);
 	BUG_ON(elevator_find(e->elevator_name));
 	BUG_ON(elevator_find(e->elevator_name));
 	list_add_tail(&e->list, &elv_list);
 	list_add_tail(&e->list, &elv_list);
 	spin_unlock_irq(&elv_list_lock);
 	spin_unlock_irq(&elv_list_lock);
 
 
-	printk(KERN_INFO "io scheduler %s registered", e->elevator_name);
 	if (!strcmp(e->elevator_name, chosen_elevator) ||
 	if (!strcmp(e->elevator_name, chosen_elevator) ||
 			(!*chosen_elevator &&
 			(!*chosen_elevator &&
 			 !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED)))
 			 !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED)))
-				printk(" (default)");
-	printk("\n");
+				def = " (default)";
+
+	printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name, def);
 	return 0;
 	return 0;
 }
 }
 EXPORT_SYMBOL_GPL(elv_register);
 EXPORT_SYMBOL_GPL(elv_register);