fix prune_dcache()/umount() race
... and get rid of the last __put_super_and_need_restart() caller
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/dcache.c b/fs/dcache.c
index 5afc499..d96047b 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -536,7 +536,7 @@
*/
static void prune_dcache(int count)
{
- struct super_block *sb;
+ struct super_block *sb, *n;
int w_count;
int unused = dentry_stat.nr_unused;
int prune_ratio;
@@ -545,13 +545,12 @@
if (unused == 0 || count == 0)
return;
spin_lock(&dcache_lock);
-restart:
if (count >= unused)
prune_ratio = 1;
else
prune_ratio = unused / count;
spin_lock(&sb_lock);
- list_for_each_entry(sb, &super_blocks, s_list) {
+ list_for_each_entry_safe(sb, n, &super_blocks, s_list) {
if (list_empty(&sb->s_instances))
continue;
if (sb->s_nr_dentry_unused == 0)
@@ -592,14 +591,10 @@
}
spin_lock(&sb_lock);
count -= pruned;
- /*
- * restart only when sb is no longer on the list and
- * we have more work to do.
- */
- if (__put_super_and_need_restart(sb) && count > 0) {
- spin_unlock(&sb_lock);
- goto restart;
- }
+ __put_super(sb);
+ /* more work left to do? */
+ if (count <= 0)
+ break;
}
spin_unlock(&sb_lock);
spin_unlock(&dcache_lock);