nfs: propagate devname to nfs{,4}_get_root()

step 1 of ->mnt_devname fixes: make sure we have the value of devname
available in ..._get_root().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/nfs/getroot.c

@@ -75,7 +75,8 @@ static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *i
 /*
  * get an NFS2/NFS3 root dentry from the root filehandle
  */
-struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh)
+struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh,
+			    const char *devname)
 {
 	struct nfs_server *server = NFS_SB(sb);
 	struct nfs_fsinfo fsinfo;
@@ -169,7 +170,8 @@ int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh)
 /*
  * get an NFS4 root dentry from the root filehandle
  */
-struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh)
+struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh,
+			     const char *devname)
 {
 	struct nfs_server *server = NFS_SB(sb);
 	struct nfs_fattr *fattr = NULL;

fs/nfs/internal.h

@@ -254,9 +254,11 @@ extern char *nfs_path(const char *base,
 extern struct vfsmount *nfs_d_automount(struct path *path);
 
 /* getroot.c */
-extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *);
+extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *,
+				   const char *);
 #ifdef CONFIG_NFS_V4
-extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *);
+extern struct dentry *nfs4_get_root(struct super_block *, struct nfs_fh *,
+				    const char *);
 
 extern int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh);
 #endif

fs/nfs/super.c

@@ -2336,7 +2336,7 @@ static int nfs_get_sb(struct file_system_type *fs_type,
 			s, data ? data->fscache_uniq : NULL, NULL);
 	}
 
-	mntroot = nfs_get_root(s, mntfh);
+	mntroot = nfs_get_root(s, mntfh, dev_name);
 	if (IS_ERR(mntroot)) {
 		error = PTR_ERR(mntroot);
 		goto error_splat_super;
@@ -2450,7 +2450,7 @@ nfs_xdev_mount(struct file_system_type *fs_type, int flags,
 		nfs_fscache_get_super_cookie(s, NULL, data);
 	}
 
-	mntroot = nfs_get_root(s, data->fh);
+	mntroot = nfs_get_root(s, data->fh, dev_name);
 	if (IS_ERR(mntroot)) {
 		error = PTR_ERR(mntroot);
 		goto error_splat_super;
@@ -2718,7 +2718,7 @@ nfs4_remote_mount(struct file_system_type *fs_type, int flags,
 			s, data ? data->fscache_uniq : NULL, NULL);
 	}
 
-	mntroot = nfs4_get_root(s, mntfh);
+	mntroot = nfs4_get_root(s, mntfh, dev_name);
 	if (IS_ERR(mntroot)) {
 		error = PTR_ERR(mntroot);
 		goto error_splat_super;
@@ -3033,7 +3033,7 @@ nfs4_xdev_mount(struct file_system_type *fs_type, int flags,
 		nfs_fscache_get_super_cookie(s, NULL, data);
 	}
 
-	mntroot = nfs4_get_root(s, data->fh);
+	mntroot = nfs4_get_root(s, data->fh, dev_name);
 	if (IS_ERR(mntroot)) {
 		error = PTR_ERR(mntroot);
 		goto error_splat_super;
@@ -3120,7 +3120,7 @@ nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
 		nfs_fscache_get_super_cookie(s, NULL, data);
 	}
 
-	mntroot = nfs4_get_root(s, mntfh);
+	mntroot = nfs4_get_root(s, mntfh, dev_name);
 	if (IS_ERR(mntroot)) {
 		error = PTR_ERR(mntroot);
 		goto error_splat_super;