[PATCH] cramfs mounts provide corrupted content since 2.6.15

Fix handling of cramfs images created by util-linux containing empty
regular files.  Images created by cramfstools 1.x were ok.

Fill out inode contents in cramfs_iget5_set() instead of get_cramfs_inode()
to prevent issues if cramfs_iget5_test() is called with I_LOCK|I_NEW still
set.
Signed-off-by: Dave Johnson <djohnson+linux-kernel@sw.starentnetworks.com>
Cc: Olaf Hering <olh@suse.de>
Cc: Chris Mason <mason@suse.com>
Cc: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/cramfs/inode.c

@@ -36,7 +36,7 @@ static DECLARE_MUTEX(read_mutex);
 
 /* These two macros may change in future, to provide better st_ino
    semantics. */
-#define CRAMINO(x)	((x)->offset?(x)->offset<<2:1)
+#define CRAMINO(x)	(((x)->offset && (x)->size)?(x)->offset<<2:1)
 #define OFFSET(x)	((x)->i_ino)
 
 
@@ -66,20 +66,8 @@ static int cramfs_iget5_test(struct inode *inode, void *opaque)
 
 static int cramfs_iget5_set(struct inode *inode, void *opaque)
 {
-	struct cramfs_inode *cramfs_inode = opaque;
-	inode->i_ino = CRAMINO(cramfs_inode);
-	return 0;
-}
-
-static struct inode *get_cramfs_inode(struct super_block *sb,
-				struct cramfs_inode * cramfs_inode)
-{
-	struct inode *inode = iget5_locked(sb, CRAMINO(cramfs_inode),
-					    cramfs_iget5_test, cramfs_iget5_set,
-					    cramfs_inode);
 	static struct timespec zerotime;
-
-	if (inode && (inode->i_state & I_NEW)) {
+	struct cramfs_inode *cramfs_inode = opaque;
 	inode->i_mode = cramfs_inode->mode;
 	inode->i_uid = cramfs_inode->uid;
 	inode->i_size = cramfs_inode->size;
@@ -108,6 +96,16 @@ static struct inode *get_cramfs_inode(struct super_block *sb,
 		init_special_inode(inode, inode->i_mode,
 			old_decode_dev(cramfs_inode->size));
 	}
+	return 0;
+}
+
+static struct inode *get_cramfs_inode(struct super_block *sb,
+				struct cramfs_inode * cramfs_inode)
+{
+	struct inode *inode = iget5_locked(sb, CRAMINO(cramfs_inode),
+					    cramfs_iget5_test, cramfs_iget5_set,
+					    cramfs_inode);
+	if (inode && (inode->i_state & I_NEW)) {
 		unlock_new_inode(inode);
 	}
 	return inode;