Make sure that all callers of remount hold s_umount exclusive
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/super.c b/fs/super.c
index cb19fff..49f670c 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -579,7 +579,7 @@
list_for_each_entry(sb, &super_blocks, s_list) {
sb->s_count++;
spin_unlock(&sb_lock);
- down_read(&sb->s_umount);
+ down_write(&sb->s_umount);
if (sb->s_root && sb->s_bdev && !(sb->s_flags & MS_RDONLY)) {
/*
* ->remount_fs needs lock_kernel().
@@ -590,7 +590,8 @@
do_remount_sb(sb, MS_RDONLY, NULL, 1);
unlock_kernel();
}
- drop_super(sb);
+ up_write(&sb->s_umount);
+ put_super(sb);
spin_lock(&sb_lock);
}
spin_unlock(&sb_lock);