overlayfs: fix lockdep misannotation
In an overlay directory that shadows an empty lower directory, say
/mnt/a/empty102, do:
touch /mnt/a/empty102/x
unlink /mnt/a/empty102/x
rmdir /mnt/a/empty102
It's actually harmless, but needs another level of nesting between
I_MUTEX_CHILD and I_MUTEX_NORMAL.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 3fbf0d3..401f084 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -571,7 +571,7 @@
{
struct ovl_cache_entry *p;
- mutex_lock_nested(&upper->d_inode->i_mutex, I_MUTEX_PARENT);
+ mutex_lock_nested(&upper->d_inode->i_mutex, I_MUTEX_CHILD);
list_for_each_entry(p, list, l_node) {
struct dentry *dentry;