[XFS] remove manual lookup from xfs_rename and simplify locking

->rename already gets the target inode passed if it exits. Pass it down to
xfs_rename so that we can avoid looking it up again. Also simplify locking
as the first lock section in xfs_rename can go away now: the isdir is an
invariant over the lifetime of the inode, and new_parent and the nlink
check are namespace topology protected by i_mutex in the VFS. The projid
check needs to move into the second lock section anyway to not be racy.

Also kill the now unused xfs_dir_lookup_int and remove the now-unused
first_locked argumet to xfs_lock_inodes.

SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30903a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
diff --git a/fs/xfs/xfs_dfrag.c b/fs/xfs/xfs_dfrag.c
index 3f53fad..5f3647c 100644
--- a/fs/xfs/xfs_dfrag.c
+++ b/fs/xfs/xfs_dfrag.c
@@ -162,7 +162,7 @@
 		ips[1] = ip;
 	}
 
-	xfs_lock_inodes(ips, 2, 0, lock_flags);
+	xfs_lock_inodes(ips, 2, lock_flags);
 	locked = 1;
 
 	/* Verify that both files have the same format */
@@ -265,7 +265,7 @@
 		locked = 0;
 		goto error0;
 	}
-	xfs_lock_inodes(ips, 2, 0, XFS_ILOCK_EXCL);
+	xfs_lock_inodes(ips, 2, XFS_ILOCK_EXCL);
 
 	/*
 	 * Count the number of extended attribute blocks