make nfs_follow_remote_path() handle ERR_PTR() passed as root_mnt

... rather than duplicating that in callers

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 73d87f9..0e6dd56 100644 (file)
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2787,11 +2787,15 @@ static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
                const char *export_path)
 {
        struct dentry *dentry;
-       int ret = nfs_referral_loop_protect();
+       int err;
 
-       if (ret) {
+       if (IS_ERR(root_mnt))
+               return ERR_CAST(root_mnt);
+
+       err = nfs_referral_loop_protect();
+       if (err) {
                mntput(root_mnt);
-               return ERR_PTR(ret);
+               return ERR_PTR(err);
        }
 
        dentry = mount_subtree(root_mnt, export_path);
@@ -2815,9 +2819,7 @@ static struct dentry *nfs4_try_mount(int flags, const char *dev_name,
                        data->nfs_server.hostname);
        data->nfs_server.export_path = export_path;
 
-       res = ERR_CAST(root_mnt);
-       if (!IS_ERR(root_mnt))
-               res = nfs_follow_remote_path(root_mnt, export_path);
+       res = nfs_follow_remote_path(root_mnt, export_path);
 
        dfprintk(MOUNT, "<-- nfs4_try_mount() = %ld%s\n",
                        IS_ERR(res) ? PTR_ERR(res) : 0,
@@ -3078,9 +3080,7 @@ static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
                        flags, data, data->hostname);
        data->mnt_path = export_path;
 
-       res = ERR_CAST(root_mnt);
-       if (!IS_ERR(root_mnt))
-               res = nfs_follow_remote_path(root_mnt, export_path);
+       res = nfs_follow_remote_path(root_mnt, export_path);
        dprintk("<-- nfs4_referral_mount() = %ld%s\n",
                        IS_ERR(res) ? PTR_ERR(res) : 0,
                        IS_ERR(res) ? " [error]" : "");