Commit e7fe0585 authored by Al Viro's avatar Al Viro
Browse files

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: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 6754af64

fs/super.c

+3 −3
Original line number Diff line number Diff line
@@ -602,10 +602,10 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force) 


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 @@ static void do_emergency_remount(struct work_struct *work) 
			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);