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Commit 5ef88da5 authored by Miklos Szeredi's avatar Miklos Szeredi
Browse files

ovl: helper to iterate layers 



Add helper to iterate through all the layers, starting from the upper layer
(if exists) and continuing down through the lower layers.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
parent dd662667

fs/overlayfs/overlayfs.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

fs/overlayfs/super.c

+21 −0
Original line number Diff line number Diff line
@@ -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)

{