nfsd_readlink(): switch to vfs_get_link()

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

fs/nfsd/vfs.c

@@ -1464,41 +1464,34 @@ do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
 __be32
 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
 {
-	mm_segment_t	oldfs;
 	__be32		err;
-	int		host_err;
+	const char *link;
 	struct path path;
+	DEFINE_DELAYED_CALL(done);
+	int len;
 
 	err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
-	if (err)
-		goto out;
+	if (unlikely(err))
+		return err;
 
 	path.mnt = fhp->fh_export->ex_path.mnt;
 	path.dentry = fhp->fh_dentry;
 
-	err = nfserr_inval;
-	if (!d_is_symlink(path.dentry))
-		goto out;
+	if (unlikely(!d_is_symlink(path.dentry)))
+		return nfserr_inval;
 
 	touch_atime(&path);
-	/* N.B. Why does this call need a get_fs()??
-	 * Remove the set_fs and watch the fireworks:-) --okir
-	 */
-
-	oldfs = get_fs(); set_fs(KERNEL_DS);
-	host_err = vfs_readlink(path.dentry, (char __user *)buf, *lenp);
-	set_fs(oldfs);
 
-	if (host_err < 0)
-		goto out_nfserr;
-	*lenp = host_err;
-	err = 0;
-out:
-	return err;
+	link = vfs_get_link(path.dentry, &done);
+	if (IS_ERR(link))
+		return nfserrno(PTR_ERR(link));
 
-out_nfserr:
-	err = nfserrno(host_err);
-	goto out;
+	len = strlen(link);
+	if (len < *lenp)
+		*lenp = len;
+	memcpy(buf, link, *lenp);
+	do_delayed_call(&done);
+	return 0;
 }
 
 /*