Commit 91ffe7be authored by Amir Goldstein's avatar Amir Goldstein Committed by Miklos Szeredi
Browse files

ovl: factor out ovl_get_index_fh() helper 



The helper is needed to lookup an index by file handle for NFS export.

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 24f0b172

fs/overlayfs/namei.c

+49 −10
Original line number Diff line number Diff line
@@ -585,6 +585,21 @@ int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index) 
	goto out;

}



static int ovl_get_index_name_fh(struct ovl_fh *fh, struct qstr *name)

{

	char *n, *s;



	n = kzalloc(fh->len * 2, GFP_KERNEL);

	if (!n)

		return -ENOMEM;



	s  = bin2hex(n, fh, fh->len);

	*name = (struct qstr) QSTR_INIT(n, s - n);



	return 0;



}



/*

 * Lookup in indexdir for the index entry of a lower real inode or a copy up

 * origin inode. The index entry name is the hex representation of the lower
@@ -602,25 +617,49 @@ int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index) 
 */

int ovl_get_index_name(struct dentry *origin, struct qstr *name)

{

	int err;

	struct ovl_fh *fh;

	char *n, *s;

	int err;



	fh = ovl_encode_fh(origin, false);

	if (IS_ERR(fh))

		return PTR_ERR(fh);



	err = -ENOMEM;

	n = kzalloc(fh->len * 2, GFP_KERNEL);

	if (n) {

		s  = bin2hex(n, fh, fh->len);

		*name = (struct qstr) QSTR_INIT(n, s - n);

		err = 0;

	}

	kfree(fh);

	err = ovl_get_index_name_fh(fh, name);



	kfree(fh);

	return err;

}



/* Lookup index by file handle for NFS export */

struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh)

{

	struct dentry *index;

	struct qstr name;

	int err;



	err = ovl_get_index_name_fh(fh, &name);

	if (err)

		return ERR_PTR(err);



	index = lookup_one_len_unlocked(name.name, ofs->indexdir, name.len);

	kfree(name.name);

	if (IS_ERR(index)) {

		if (PTR_ERR(index) == -ENOENT)

			index = NULL;

		return index;

	}



	if (d_is_negative(index))

		err = 0;

	else if (ovl_is_whiteout(index))

		err = -ESTALE;

	else if (ovl_dentry_weird(index))

		err = -EIO;

	else

		return index;



	dput(index);

	return ERR_PTR(err);

}



static struct dentry *ovl_lookup_index(struct dentry *dentry,

fs/overlayfs/overlayfs.h

+1 −0
Original line number Diff line number Diff line
@@ -257,6 +257,7 @@ int ovl_verify_set_fh(struct dentry *dentry, const char *name, 
		      struct dentry *real, bool is_upper, bool set);

int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);

int ovl_get_index_name(struct dentry *origin, struct qstr *name);

struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh);

int ovl_path_next(int idx, struct dentry *dentry, struct path *path);

struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,

			  unsigned int flags);