NFSv4: Eliminate nfs4_path_walk()

All we really want is the ability to retrieve the root file handle. We no
longer need the ability to walk down the path, since that is now done in
nfs_follow_remote_path().
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/client.c

@@ -1364,7 +1364,7 @@ struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
 		goto error;
 
 	/* Probe the root fh to retrieve its FSID */
-	error = nfs4_path_walk(server, mntfh, data->nfs_server.export_path);
+	error = nfs4_get_rootfh(server, mntfh);
 	if (error < 0)
 		goto error;
 
@@ -1443,7 +1443,7 @@ struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
 	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
 
 	/* Probe the root fh to retrieve its FSID and filehandle */
-	error = nfs4_path_walk(server, mntfh, data->mnt_path);
+	error = nfs4_get_rootfh(server, mntfh);
 	if (error < 0)
 		goto error;
 

fs/nfs/getroot.c

@@ -122,115 +122,44 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh)
 
 #ifdef CONFIG_NFS_V4
 
-/*
- * Do a simple pathwalk from the root FH of the server to the nominated target
- * of the mountpoint
- * - give error on symlinks
- * - give error on ".." occurring in the path
- * - follow traversals
- */
-int nfs4_path_walk(struct nfs_server *server,
-		   struct nfs_fh *mntfh,
-		   const char *path)
+int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh)
 {
 	struct nfs_fsinfo fsinfo;
-	struct nfs_fattr fattr;
-	struct nfs_fh lastfh;
-	struct qstr name;
-	int ret;
+	int ret = -ENOMEM;
 
-	dprintk("--> nfs4_path_walk(,,%s)\n", path);
+	dprintk("--> nfs4_get_rootfh()\n");
 
-	fsinfo.fattr = &fattr;
-	nfs_fattr_init(&fattr);
-
-	/* Eat leading slashes */
-	while (*path == '/')
-		path++;
+	fsinfo.fattr = nfs_alloc_fattr();
+	if (fsinfo.fattr == NULL)
+		goto out;
 
 	/* Start by getting the root filehandle from the server */
 	ret = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
 	if (ret < 0) {
-		dprintk("nfs4_get_root: getroot error = %d\n", -ret);
-		return ret;
+		dprintk("nfs4_get_rootfh: getroot error = %d\n", -ret);
+		goto out;
 	}
 
-	if (!S_ISDIR(fattr.mode)) {
-		printk(KERN_ERR "nfs4_get_root:"
+	if (!(fsinfo.fattr->valid & NFS_ATTR_FATTR_MODE)
+			|| !S_ISDIR(fsinfo.fattr->mode)) {
+		printk(KERN_ERR "nfs4_get_rootfh:"
 		       " getroot encountered non-directory\n");
-		return -ENOTDIR;
+		ret = -ENOTDIR;
+		goto out;
 	}
 
-	/* FIXME: It is quite valid for the server to return a referral here */
-	if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) {
-		printk(KERN_ERR "nfs4_get_root:"
+	if (fsinfo.fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
+		printk(KERN_ERR "nfs4_get_rootfh:"
 		       " getroot obtained referral\n");
-		return -EREMOTE;
+		ret = -EREMOTE;
+		goto out;
 	}
 
-next_component:
-	dprintk("Next: %s\n", path);
-
-	/* extract the next bit of the path */
-	if (!*path)
-		goto path_walk_complete;
-
-	name.name = path;
-	while (*path && *path != '/')
-		path++;
-	name.len = path - (const char *) name.name;
-
-	if (name.len > NFS4_MAXNAMLEN)
-		return -ENAMETOOLONG;
-
-eat_dot_dir:
-	while (*path == '/')
-		path++;
-
-	if (path[0] == '.' && (path[1] == '/' || !path[1])) {
-		path += 2;
-		goto eat_dot_dir;
-	}
-
-	/* FIXME: Why shouldn't the user be able to use ".." in the path? */
-	if (path[0] == '.' && path[1] == '.' && (path[2] == '/' || !path[2])
-	    ) {
-		printk(KERN_ERR "nfs4_get_root:"
-		       " Mount path contains reference to \"..\"\n");
-		return -EINVAL;
-	}
-
-	/* lookup the next FH in the sequence */
-	memcpy(&lastfh, mntfh, sizeof(lastfh));
-
-	dprintk("LookupFH: %*.*s [%s]\n", name.len, name.len, name.name, path);
-
-	ret = server->nfs_client->rpc_ops->lookupfh(server, &lastfh, &name,
-						    mntfh, &fattr);
-	if (ret < 0) {
-		dprintk("nfs4_get_root: getroot error = %d\n", -ret);
-		return ret;
-	}
-
-	if (!S_ISDIR(fattr.mode)) {
-		printk(KERN_ERR "nfs4_get_root:"
-		       " lookupfh encountered non-directory\n");
-		return -ENOTDIR;
-	}
-
-	/* FIXME: Referrals are quite valid here too */
-	if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) {
-		printk(KERN_ERR "nfs4_get_root:"
-		       " lookupfh obtained referral\n");
-		return -EREMOTE;
-	}
-
-	goto next_component;
-
-path_walk_complete:
-	memcpy(&server->fsid, &fattr.fsid, sizeof(server->fsid));
-	dprintk("<-- nfs4_path_walk() = 0\n");
-	return 0;
+	memcpy(&server->fsid, &fsinfo.fattr->fsid, sizeof(server->fsid));
+out:
+	nfs_free_fattr(fsinfo.fattr);
+	dprintk("<-- nfs4_get_rootfh() = %d\n", ret);
+	return ret;
 }
 
 /*

fs/nfs/internal.h

@@ -244,9 +244,7 @@ extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *);
 #ifdef CONFIG_NFS_V4
 extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *);
 
-extern int nfs4_path_walk(struct nfs_server *server,
-			  struct nfs_fh *mntfh,
-			  const char *path);
+extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh);
 #endif
 
 /* read.c */