Re: [PATCH 4/4] change sb_writers to use percpu_rw_semaphore

[Oleg Nesterov <oleg@redhat.com>]

On 07/22, Oleg Nesterov wrote:
>
> +static void sb_freeze_unlock(struct super_block *sb)
> +{
> +	int level;
> +
> +	for (level = 0; level < SB_FREEZE_LEVELS; ++level)
> +		percpu_up_write(sb->s_writers.rw_sem + level);
>  }

OK, this is not exactly right, see the fix below.

Otherwise seems to work, but see another email I'll send in reply to 0/4.

Oleg.

--- a/fs/super.c
+++ b/fs/super.c
@@ -1237,7 +1237,7 @@ static void sb_freeze_unlock(struct super_block *sb)
 {
 	int level;
 
-	for (level = 0; level < SB_FREEZE_LEVELS; ++level)
+	for (level = SB_FREEZE_LEVELS; --level >= 0; )
 		percpu_up_write(sb->s_writers.rw_sem + level);
 }