ovl: simplify arguments to ovl_check_origin_fh()

Pass the fs instance with lower_layers array instead of the dentry
lowerstack array to ovl_check_origin_fh(), because the dentry members
of lowerstack play no role in this helper.

This change simplifies the argument list of ovl_check_origin(),
ovl_cleanup_index() and ovl_verify_index().
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

fs/overlayfs/namei.c

@@ -291,17 +291,15 @@ static int ovl_lookup_layer(struct dentry *base, struct ovl_lookup_data *d,
 }
 
 
-static int ovl_check_origin_fh(struct ovl_fh *fh, struct dentry *upperdentry,
-			       struct ovl_path *lower, unsigned int numlower,
+static int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh,
+			       struct dentry *upperdentry,
 			       struct ovl_path **stackp)
 {
-	struct vfsmount *mnt;
 	struct dentry *origin = NULL;
 	int i;
 
-	for (i = 0; i < numlower; i++) {
-		mnt = lower[i].layer->mnt;
-		origin = ovl_decode_fh(fh, mnt);
+	for (i = 0; i < ofs->numlower; i++) {
+		origin = ovl_decode_fh(fh, ofs->lower_layers[i].mnt);
 		if (origin)
 			break;
 	}
@@ -321,7 +319,10 @@ static int ovl_check_origin_fh(struct ovl_fh *fh, struct dentry *upperdentry,
 		dput(origin);
 		return -ENOMEM;
 	}
-	**stackp = (struct ovl_path){.dentry = origin, .layer = lower[i].layer};
+	**stackp = (struct ovl_path){
+		.dentry = origin,
+		.layer = &ofs->lower_layers[i]
+	};
 
 	return 0;
 
@@ -333,8 +334,7 @@ static int ovl_check_origin_fh(struct ovl_fh *fh, struct dentry *upperdentry,
 	return -EIO;
 }
 
-static int ovl_check_origin(struct dentry *upperdentry,
-			    struct ovl_path *lower, unsigned int numlower,
+static int ovl_check_origin(struct ovl_fs *ofs, struct dentry *upperdentry,
 			    struct ovl_path **stackp, unsigned int *ctrp)
 {
 	struct ovl_fh *fh = ovl_get_origin_fh(upperdentry);
@@ -343,7 +343,7 @@ static int ovl_check_origin(struct dentry *upperdentry,
 	if (IS_ERR_OR_NULL(fh))
 		return PTR_ERR(fh);
 
-	err = ovl_check_origin_fh(fh, upperdentry, lower, numlower, stackp);
+	err = ovl_check_origin_fh(ofs, fh, upperdentry, stackp);
 	kfree(fh);
 
 	if (err) {
@@ -423,8 +423,7 @@ int ovl_verify_origin(struct dentry *dentry, struct dentry *origin,
  * OVL_XATTR_ORIGIN and that origin file handle can be decoded to lower path.
  * Return 0 on match, -ESTALE on mismatch or stale origin, < 0 on error.
  */
-int ovl_verify_index(struct dentry *index, struct ovl_path *lower,
-		     unsigned int numlower)
+int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index)
 {
 	struct ovl_fh *fh = NULL;
 	size_t len;
@@ -471,7 +470,7 @@ int ovl_verify_index(struct dentry *index, struct ovl_path *lower,
 	if (err)
 		goto fail;
 
-	err = ovl_check_origin_fh(fh, index, lower, numlower, &stack);
+	err = ovl_check_origin_fh(ofs, fh, index, &stack);
 	if (err)
 		goto fail;
 
@@ -689,8 +688,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
 			 * number - it's the same as if we held a reference
 			 * to a dentry in lower layer that was moved under us.
 			 */
-			err = ovl_check_origin(upperdentry, roe->lowerstack,
-					       roe->numlower, &stack, &ctr);
+			err = ovl_check_origin(ofs, upperdentry, &stack, &ctr);
 			if (err)
 				goto out_put_upper;
 		}

fs/overlayfs/overlayfs.h

@@ -251,11 +251,11 @@ static inline bool ovl_is_impuredir(struct dentry *dentry)
 /* namei.c */
 int ovl_verify_origin(struct dentry *dentry, struct dentry *origin,
 		      bool is_upper, bool set);
-int ovl_verify_index(struct dentry *index, struct ovl_path *lower,
-		     unsigned int numlower);
+int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index);
 int ovl_get_index_name(struct dentry *origin, struct qstr *name);
 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);
+struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
+			  unsigned int flags);
 bool ovl_lower_positive(struct dentry *dentry);
 
 /* readdir.c */
@@ -267,8 +267,7 @@ void ovl_dir_cache_free(struct inode *inode);
 int ovl_check_d_type_supported(struct path *realpath);
 void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
 			 struct dentry *dentry, int level);
-int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
-			 struct ovl_path *lower, unsigned int numlower);
+int ovl_indexdir_cleanup(struct ovl_fs *ofs);
 
 /* inode.c */
 int ovl_set_nlink_upper(struct dentry *dentry);

fs/overlayfs/readdir.c

@@ -1030,13 +1030,13 @@ void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
 	}
 }
 
-int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
-			 struct ovl_path *lower, unsigned int numlower)
+int ovl_indexdir_cleanup(struct ovl_fs *ofs)
 {
 	int err;
+	struct dentry *indexdir = ofs->indexdir;
 	struct dentry *index = NULL;
-	struct inode *dir = dentry->d_inode;
-	struct path path = { .mnt = mnt, .dentry = dentry };
+	struct inode *dir = indexdir->d_inode;
+	struct path path = { .mnt = ofs->upper_mnt, .dentry = indexdir };
 	LIST_HEAD(list);
 	struct rb_root root = RB_ROOT;
 	struct ovl_cache_entry *p;
@@ -1060,13 +1060,13 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
 			if (p->len == 2 && p->name[1] == '.')
 				continue;
 		}
-		index = lookup_one_len(p->name, dentry, p->len);
+		index = lookup_one_len(p->name, indexdir, p->len);
 		if (IS_ERR(index)) {
 			err = PTR_ERR(index);
 			index = NULL;
 			break;
 		}
-		err = ovl_verify_index(index, lower, numlower);
+		err = ovl_verify_index(ofs, index);
 		/* Cleanup stale and orphan index entries */
 		if (err && (err == -ESTALE || err == -ENOENT))
 			err = ovl_cleanup(dir, index);

fs/overlayfs/super.c

@@ -1057,10 +1057,7 @@ static int ovl_get_indexdir(struct ovl_fs *ofs, struct ovl_entry *oe,
 
 		/* Cleanup bad/stale/orphan index entries */
 		if (!err)
-			err = ovl_indexdir_cleanup(ofs->indexdir,
-						   ofs->upper_mnt,
-						   oe->lowerstack,
-						   oe->numlower);
+			err = ovl_indexdir_cleanup(ofs);
 	}
 	if (err || !ofs->indexdir)
 		pr_warn("overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index.\n");