---

yaml
---
r: 30110
b: refs/heads/master
c: 6b97fd3
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9cdb3883c38f883436a84c2353a4cf964ff890a2
+refs/heads/master: 6b97fd3da1eab2cc490cfe884c7d4956522eaf8b

trunk/fs/nfs/inode.c

@@ -888,7 +888,10 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
 				set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode));
 			/* Deal with crossing mountpoints */
 			if (!nfs_fsid_equal(&NFS_SB(sb)->fsid, &fattr->fsid)) {
-				inode->i_op = &nfs_mountpoint_inode_operations;
+				if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
+					inode->i_op = &nfs_referral_inode_operations;
+				else
+					inode->i_op = &nfs_mountpoint_inode_operations;
 				inode->i_fop = NULL;
 			}
 		} else if (S_ISLNK(inode->i_mode))

trunk/fs/nfs/namespace.c

@@ -58,7 +58,10 @@ static void * nfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
 	if (err != 0)
 		goto out_err;
 
-	mnt = nfs_do_submount(nd->mnt, nd->dentry, &fh, &fattr);
+	if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL)
+		mnt = nfs_do_refmount(nd->mnt, nd->dentry);
+	else
+		mnt = nfs_do_submount(nd->mnt, nd->dentry, &fh, &fattr);
 	err = PTR_ERR(mnt);
 	if (IS_ERR(mnt))
 		goto out_err;
@@ -94,6 +97,10 @@ struct inode_operations nfs_mountpoint_inode_operations = {
 	.getattr	= nfs_getattr,
 };
 
+struct inode_operations nfs_referral_inode_operations = {
+	.follow_link	= nfs_follow_mountpoint,
+};
+
 static void nfs_expire_automounts(void *data)
 {
 	struct list_head *list = (struct list_head *)data;

trunk/fs/nfs/nfs4proc.c

@@ -1462,6 +1462,50 @@ static int nfs4_proc_get_root(struct nfs_server *server, struct nfs_fh *fhandle,
 	return nfs4_map_errors(status);
 }
 
+/*
+ * Get locations and (maybe) other attributes of a referral.
+ * Note that we'll actually follow the referral later when
+ * we detect fsid mismatch in inode revalidation
+ */
+static int nfs4_get_referral(struct inode *dir, struct qstr *name, struct nfs_fattr *fattr, struct nfs_fh *fhandle)
+{
+	int status = -ENOMEM;
+	struct page *page = NULL;
+	struct nfs4_fs_locations *locations = NULL;
+	struct dentry dentry = {};
+
+	page = alloc_page(GFP_KERNEL);
+	if (page == NULL)
+		goto out;
+	locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
+	if (locations == NULL)
+		goto out;
+
+	dentry.d_name.name = name->name;
+	dentry.d_name.len = name->len;
+	status = nfs4_proc_fs_locations(dir, &dentry, locations, page);
+	if (status != 0)
+		goto out;
+	/* Make sure server returned a different fsid for the referral */
+	if (nfs_fsid_equal(&NFS_SERVER(dir)->fsid, &locations->fattr.fsid)) {
+		dprintk("%s: server did not return a different fsid for a referral at %s\n", __FUNCTION__, name->name);
+		status = -EIO;
+		goto out;
+	}
+
+	memcpy(fattr, &locations->fattr, sizeof(struct nfs_fattr));
+	fattr->valid |= NFS_ATTR_FATTR_V4_REFERRAL;
+	if (!fattr->mode)
+		fattr->mode = S_IFDIR;
+	memset(fhandle, 0, sizeof(struct nfs_fh));
+out:
+	if (page)
+		__free_page(page);
+	if (locations)
+		kfree(locations);
+	return status;
+}
+
 static int _nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle, struct nfs_fattr *fattr)
 {
 	struct nfs4_getattr_arg args = {
@@ -1566,6 +1610,8 @@ static int _nfs4_proc_lookup(struct inode *dir, struct qstr *name,
 
 	dprintk("NFS call  lookup %s\n", name->name);
 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
+	if (status == -NFS4ERR_MOVED)
+		status = nfs4_get_referral(dir, name, fattr, fhandle);
 	dprintk("NFS reply lookup: %d\n", status);
 	return status;
 }

trunk/include/linux/nfs_fs.h

@@ -409,6 +409,7 @@ extern void nfs_unregister_sysctl(void);
  */
 extern struct list_head nfs_automount_list;
 extern struct inode_operations nfs_mountpoint_inode_operations;
+extern struct inode_operations nfs_referral_inode_operations;
 extern int nfs_mountpoint_expiry_timeout;
 extern void nfs_release_automount_timer(void);
 

trunk/include/linux/nfs_xdr.h

@@ -63,6 +63,7 @@ struct nfs_fattr {
 #define NFS_ATTR_FATTR		0x0002		/* post-op attributes */
 #define NFS_ATTR_FATTR_V3	0x0004		/* NFSv3 attributes */
 #define NFS_ATTR_FATTR_V4	0x0008		/* NFSv4 change attribute */
+#define NFS_ATTR_FATTR_V4_REFERRAL	0x0010		/* NFSv4 referral */
 
 /*
  * Info on the file system