diff options
| author | Miklos Szeredi <miklos@szeredi.hu> | 2014-10-27 15:42:01 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2014-10-28 23:32:47 +0100 |
| commit | d1b72cc6d8cb766c802fdc70a5edc2f0ba8a2b57 (patch) | |
| tree | 35e1ed80b8a78b53538d73bd99525d17def9a7f5 | |
| parent | ovl: fix check for cursor (diff) | |
| download | linux-d1b72cc6d8cb766c802fdc70a5edc2f0ba8a2b57.tar.xz linux-d1b72cc6d8cb766c802fdc70a5edc2f0ba8a2b57.zip | |
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>
| -rw-r--r-- | fs/namei.c | 2 | ||||
| -rw-r--r-- | fs/overlayfs/readdir.c | 2 | ||||
| -rw-r--r-- | include/linux/fs.h | 9 |
3 files changed, 8 insertions, 5 deletions
diff --git a/fs/namei.c b/fs/namei.c index 42df664e95e5..922f27068c4c 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2497,7 +2497,7 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2) } mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT2); return NULL; } EXPORT_SYMBOL(lock_rename); diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index 3fbf0d306e12..401f0840f5cc 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -571,7 +571,7 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list) { 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; diff --git a/include/linux/fs.h b/include/linux/fs.h index 4e41a4a331bb..01036262095f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -639,11 +639,13 @@ static inline int inode_unhashed(struct inode *inode) * 2: child/target * 3: xattr * 4: second non-directory - * The last is for certain operations (such as rename) which lock two + * 5: second parent (when locking independent directories in rename) + * + * I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two * non-directories at once. * * The locking order between these classes is - * parent -> child -> normal -> xattr -> second non-directory + * parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory */ enum inode_i_mutex_lock_class { @@ -651,7 +653,8 @@ enum inode_i_mutex_lock_class I_MUTEX_PARENT, I_MUTEX_CHILD, I_MUTEX_XATTR, - I_MUTEX_NONDIR2 + I_MUTEX_NONDIR2, + I_MUTEX_PARENT2, }; void lock_two_nondirectories(struct inode *, struct inode*); |