fix do_emergency_remount()/umount() races
need list_for_each_entry_safe() here. Original didn't even
have restart logics, so if you race with umount() it blew up.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/super.c b/fs/super.c
index ccb2b5f..4df8233 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -602,10 +602,10 @@
static void do_emergency_remount(struct work_struct *work)
{
- struct super_block *sb;
+ struct super_block *sb, *n;
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;
sb->s_count++;
@@ -618,8 +618,8 @@
do_remount_sb(sb, MS_RDONLY, NULL, 1);
}
up_write(&sb->s_umount);
- put_super(sb);
spin_lock(&sb_lock);
+ __put_super(sb);
}
spin_unlock(&sb_lock);
kfree(work);