1 files changed, 39 insertions, 19 deletions

diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index 08b9c93675da..348b535cd786 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -7,6 +7,7 @@
  * NFS namespace
  */
 
+#include <linux/module.h>
 #include <linux/dcache.h>
 #include <linux/gfp.h>
 #include <linux/mount.h>
@@ -32,6 +33,7 @@ int nfs_mountpoint_expiry_timeout = 500 * HZ;
  * @dentry - pointer to dentry
  * @buffer - result buffer
  * @buflen - length of buffer
+ * @flags - options (see below)
  *
  * Helper function for constructing the server pathname
  * by arbitrary hashed dentry.
@@ -39,8 +41,14 @@ int nfs_mountpoint_expiry_timeout = 500 * HZ;
  * This is mainly for use in figuring out the path on the
  * server side when automounting on top of an existing partition
  * and in generating /proc/mounts and friends.
+ *
+ * Supported flags:
+ * NFS_PATH_CANONICAL: ensure there is exactly one slash after
+ *		       the original device (export) name
+ *		       (if unset, the original name is returned verbatim)
  */
-char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen)
+char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen,
+	       unsigned flags)
 {
 	char *end;
 	int namelen;
@@ -73,7 +81,7 @@ rename_retry:
 		rcu_read_unlock();
 		goto rename_retry;
 	}
-	if (*end != '/') {
+	if ((flags & NFS_PATH_CANONICAL) && *end != '/') {
 		if (--buflen < 0) {
 			spin_unlock(&dentry->d_lock);
 			rcu_read_unlock();
@@ -90,9 +98,11 @@ rename_retry:
 		return end;
 	}
 	namelen = strlen(base);
-	/* Strip off excess slashes in base string */
-	while (namelen > 0 && base[namelen - 1] == '/')
-		namelen--;
+	if (flags & NFS_PATH_CANONICAL) {
+		/* Strip off excess slashes in base string */
+		while (namelen > 0 && base[namelen - 1] == '/')
+			namelen--;
+	}
 	buflen -= namelen;
 	if (buflen < 0) {
 		spin_unlock(&dentry->d_lock);
@@ -112,6 +122,7 @@ Elong_unlock:
 Elong:
 	return ERR_PTR(-ENAMETOOLONG);
 }
+EXPORT_SYMBOL_GPL(nfs_path);
 
 /*
  * nfs_d_automount - Handle crossing a mountpoint on the server
@@ -166,11 +177,31 @@ out_nofree:
 	return mnt;
 }
 
+static int
+nfs_namespace_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+{
+	if (NFS_FH(dentry->d_inode)->size != 0)
+		return nfs_getattr(mnt, dentry, stat);
+	generic_fillattr(dentry->d_inode, stat);
+	return 0;
+}
+
+static int
+nfs_namespace_setattr(struct dentry *dentry, struct iattr *attr)
+{
+	if (NFS_FH(dentry->d_inode)->size != 0)
+		return nfs_setattr(dentry, attr);
+	return -EACCES;
+}
+
 const struct inode_operations nfs_mountpoint_inode_operations = {
 	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
 };
 
 const struct inode_operations nfs_referral_inode_operations = {
+	.getattr	= nfs_namespace_getattr,
+	.setattr	= nfs_namespace_setattr,
 };
 
 static void nfs_expire_automounts(struct work_struct *work)
@@ -195,20 +226,7 @@ static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server,
 					   const char *devname,
 					   struct nfs_clone_mount *mountdata)
 {
-#ifdef CONFIG_NFS_V4
-	struct vfsmount *mnt = ERR_PTR(-EINVAL);
-	switch (server->nfs_client->rpc_ops->version) {
-		case 2:
-		case 3:
-			mnt = vfs_kern_mount(&nfs_xdev_fs_type, 0, devname, mountdata);
-			break;
-		case 4:
-			mnt = vfs_kern_mount(&nfs4_xdev_fs_type, 0, devname, mountdata);
-	}
-	return mnt;
-#else
 	return vfs_kern_mount(&nfs_xdev_fs_type, 0, devname, mountdata);
-#endif
 }
 
 /**
@@ -253,6 +271,7 @@ out:
 	dprintk("<-- nfs_do_submount() = %p\n", mnt);
 	return mnt;
 }
+EXPORT_SYMBOL_GPL(nfs_do_submount);
 
 struct vfsmount *nfs_submount(struct nfs_server *server, struct dentry *dentry,
 			      struct nfs_fh *fh, struct nfs_fattr *fattr)
@@ -261,10 +280,11 @@ struct vfsmount *nfs_submount(struct nfs_server *server, struct dentry *dentry,
 	struct dentry *parent = dget_parent(dentry);
 
 	/* Look it up again to get its attributes */
-	err = server->nfs_client->rpc_ops->lookup(parent->d_inode, &dentry->d_name, fh, fattr);
+	err = server->nfs_client->rpc_ops->lookup(parent->d_inode, &dentry->d_name, fh, fattr, NULL);
 	dput(parent);
 	if (err != 0)
 		return ERR_PTR(err);
 
 	return nfs_do_submount(dentry, fh, fattr, server->client->cl_auth->au_flavor);
 }
+EXPORT_SYMBOL_GPL(nfs_submount);