iget: stop CIFS from using iget() and read_inode()

Stop the CIFS filesystem from using iget() and read_inode().  Replace
cifs_read_inode() with cifs_iget(), and call that instead of iget().
cifs_iget() then uses iget_locked() directly and returns a proper error code
instead of an inode in the event of an error.

cifs_read_super() now returns any error incurred when getting the root inode
instead of ENOMEM.

cifs_iget() needs examining.  The comment "can not call macro FreeXid here
since in a void func" is no longer true.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Steven French <sfrench@us.ibm.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index e9f4ec7..fcc4342 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -147,10 +147,11 @@
 #endif
 	sb->s_blocksize = CIFS_MAX_MSGSIZE;
 	sb->s_blocksize_bits = 14;	/* default 2**14 = CIFS_MAX_MSGSIZE */
-	inode = iget(sb, ROOT_I);
+	inode = cifs_iget(sb, ROOT_I);
 
-	if (!inode) {
-		rc = -ENOMEM;
+	if (IS_ERR(inode)) {
+		rc = PTR_ERR(inode);
+		inode = NULL;
 		goto out_no_root;
 	}
 
@@ -520,7 +521,6 @@
 }
 
 static const struct super_operations cifs_super_ops = {
-	.read_inode = cifs_read_inode,
 	.put_super = cifs_put_super,
 	.statfs = cifs_statfs,
 	.alloc_inode = cifs_alloc_inode,