diff options
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 1 | ||||
| -rw-r--r-- | fs/overlayfs/super.c | 21 |
2 files changed, 22 insertions, 0 deletions
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index d39eaa8f5e47..d176b679f526 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -135,6 +135,7 @@ void ovl_dentry_version_inc(struct dentry *dentry); void ovl_path_upper(struct dentry *dentry, struct path *path); void ovl_path_lower(struct dentry *dentry, struct path *path); enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); +int ovl_path_next(int idx, struct dentry *dentry, struct path *path); struct dentry *ovl_dentry_upper(struct dentry *dentry); struct dentry *ovl_dentry_lower(struct dentry *dentry); struct dentry *ovl_dentry_real(struct dentry *dentry); diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 460d866b97a2..07e4c576e93e 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -305,6 +305,27 @@ static inline struct dentry *ovl_lookup_real(struct dentry *dir, return dentry; } +/* + * Returns next layer in stack starting from top. + * Returns -1 if this is the last layer. + */ +int ovl_path_next(int idx, struct dentry *dentry, struct path *path) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + BUG_ON(idx < 0); + if (idx == 0) { + ovl_path_upper(dentry, path); + if (path->dentry) + return oe->numlower ? 1 : -1; + idx++; + } + BUG_ON(idx > oe->numlower); + *path = oe->lowerstack[idx - 1]; + + return (idx < oe->numlower) ? idx + 1 : -1; +} + struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { |