Merge branch 'work.misc-set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull misc user access cleanups from Al Viro:
 "The first pile is assorted getting rid of cargo-culted access_ok(),
  cargo-culted set_fs() and field-by-field copyouts.

  The same description applies to a lot of stuff in other branches -
  this is just the stuff that didn't fit into a more specific topical
  branch"

* 'work.misc-set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  Switch flock copyin/copyout primitives to copy_{from,to}_user()
  fs/fcntl: return -ESRCH in f_setown when pid/pgid can't be found
  fs/fcntl: f_setown, avoid undefined behaviour
  fs/fcntl: f_setown, allow returning error
  lpfc debugfs: get rid of pointless access_ok()
  adb: get rid of pointless access_ok()
  isdn: get rid of pointless access_ok()
  compat statfs: switch to copy_to_user()
  fs/locks: don't mess with the address limit in compat_fcntl64
  nfsd_readlink(): switch to vfs_get_link()
  drbd: ->sendpage() never needed set_fs()
  fs/locks: pass kernel struct flock to fcntl_getlk/setlk
  fs: locks: Fix some troubles at kernel-doc comments

1 files changed, 16 insertions, 23 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 2be32955d7f2..6eef95c585e3 100644
--- a/fs/nfsd/vfs.c
+++ b/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);
+	link = vfs_get_link(path.dentry, &done);
+	if (IS_ERR(link))
+		return nfserrno(PTR_ERR(link));
 
-	if (host_err < 0)
-		goto out_nfserr;
-	*lenp = host_err;
-	err = 0;
-out:
-	return err;
-
-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;
 }
 
 /*