[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_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 322ba09..308dfff 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -1982,7 +1982,7 @@
 
 		ips[0] = ip;
 		ips[1] = dp;
-		xfs_lock_inodes(ips, 2, 0, XFS_ILOCK_EXCL);
+		xfs_lock_inodes(ips, 2, XFS_ILOCK_EXCL);
 	}
 	/* else	 e_inum == dp->i_ino */
 	/*     This can happen if we're asked to lock /x/..
@@ -2030,7 +2030,6 @@
 xfs_lock_inodes(
 	xfs_inode_t	**ips,
 	int		inodes,
-	int		first_locked,
 	uint		lock_mode)
 {
 	int		attempts = 0, i, j, try_lock;
@@ -2038,13 +2037,8 @@
 
 	ASSERT(ips && (inodes >= 2)); /* we need at least two */
 
-	if (first_locked) {
-		try_lock = 1;
-		i = 1;
-	} else {
-		try_lock = 0;
-		i = 0;
-	}
+	try_lock = 0;
+	i = 0;
 
 again:
 	for (; i < inodes; i++) {
@@ -2406,7 +2400,7 @@
 		ips[1] = sip;
 	}
 
-	xfs_lock_inodes(ips, 2, 0, XFS_ILOCK_EXCL);
+	xfs_lock_inodes(ips, 2, XFS_ILOCK_EXCL);
 
 	/*
 	 * Increment vnode ref counts since xfs_trans_commit &