[GFS2] Clean up inode number handling

This patch cleans up the inode number handling code. The main difference
is that instead of looking up the inodes using a struct gfs2_inum_host
we now use just the no_addr member of this structure. The tests relating
to no_formal_ino can then be done by the calling code. This has
advantages in that we want to do different things in different code
paths if the no_formal_ino doesn't match. In the NFS patch we want to
return -ESTALE, but in the ->lookup() path, its a bug in the fs if the
no_formal_ino doesn't match and thus we can withdraw in this case.

In order to later fix bz #201012, we need to be able to look up an inode
without knowing no_formal_ino, as the only information that is known to
us is the on-disk location of the inode in question.

This patch will also help us to fix bz #236099 at a later date by
cleaning up a lot of the code in that area.

There are no user visible changes as a result of this patch and there
are no changes to the on-disk format either.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/ops_dentry.c b/fs/gfs2/ops_dentry.c
index a6fdc52..793e334 100644
--- a/fs/gfs2/ops_dentry.c
+++ b/fs/gfs2/ops_dentry.c
@@ -21,6 +21,7 @@
 #include "glock.h"
 #include "ops_dentry.h"
 #include "util.h"
+#include "inode.h"
 
 /**
  * gfs2_drevalidate - Check directory lookup consistency
@@ -40,14 +41,15 @@
 	struct gfs2_inode *dip = GFS2_I(parent->d_inode);
 	struct inode *inode = dentry->d_inode;
 	struct gfs2_holder d_gh;
-	struct gfs2_inode *ip;
-	struct gfs2_inum_host inum;
-	unsigned int type;
+	struct gfs2_inode *ip = NULL;
 	int error;
 	int had_lock=0;
 
-	if (inode && is_bad_inode(inode))
-		goto invalid;
+	if (inode) {
+		if (is_bad_inode(inode))
+			goto invalid;
+		ip = GFS2_I(inode);
+	}
 
 	if (sdp->sd_args.ar_localcaching)
 		goto valid;
@@ -59,7 +61,7 @@
 			goto fail;
 	} 
 
-	error = gfs2_dir_search(parent->d_inode, &dentry->d_name, &inum, &type);
+	error = gfs2_dir_check(parent->d_inode, &dentry->d_name, ip);
 	switch (error) {
 	case 0:
 		if (!inode)
@@ -73,16 +75,6 @@
 		goto fail_gunlock;
 	}
 
-	ip = GFS2_I(inode);
-
-	if (!gfs2_inum_equal(&ip->i_num, &inum))
-		goto invalid_gunlock;
-
-	if (IF2DT(ip->i_inode.i_mode) != type) {
-		gfs2_consist_inode(dip);
-		goto fail_gunlock;
-	}
-
 valid_gunlock:
 	if (!had_lock)
 		gfs2_glock_dq_uninit(&d_gh);