ocfs2: Implement compat_ioctl()

We need this to support 32 bit system calls on 64 bit kernels.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

fs/ocfs2/file.c

@@ -1853,6 +1853,9 @@ const struct file_operations ocfs2_fops = {
 	.aio_read	= ocfs2_file_aio_read,
 	.aio_write	= ocfs2_file_aio_write,
 	.ioctl		= ocfs2_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = ocfs2_compat_ioctl,
+#endif
 	.splice_read	= ocfs2_file_splice_read,
 	.splice_write	= ocfs2_file_splice_write,
 };
@@ -1862,4 +1865,7 @@ const struct file_operations ocfs2_dops = {
 	.readdir	= ocfs2_readdir,
 	.fsync		= ocfs2_sync_file,
 	.ioctl		= ocfs2_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl   = ocfs2_compat_ioctl,
+#endif
 };

fs/ocfs2/ioctl.c

@@ -134,3 +134,26 @@ int ocfs2_ioctl(struct inode * inode, struct file * filp,
 	}
 }
 
+#ifdef CONFIG_COMPAT
+long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	int ret;
+
+	switch (cmd) {
+	case OCFS2_IOC32_GETFLAGS:
+		cmd = OCFS2_IOC_GETFLAGS;
+		break;
+	case OCFS2_IOC32_SETFLAGS:
+		cmd = OCFS2_IOC_SETFLAGS;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+
+	lock_kernel();
+	ret = ocfs2_ioctl(inode, file, cmd, arg);
+	unlock_kernel();
+	return ret;
+}
+#endif

fs/ocfs2/ioctl.h

@@ -12,5 +12,6 @@
 
 int ocfs2_ioctl(struct inode * inode, struct file * filp,
 	unsigned int cmd, unsigned long arg);
+long ocfs2_compat_ioctl(struct file *file, unsigned cmd, unsigned long arg);
 
 #endif /* OCFS2_IOCTL_H */

fs/ocfs2/ocfs2_fs.h

@@ -166,6 +166,8 @@
  */
 #define OCFS2_IOC_GETFLAGS	_IOR('f', 1, long)
 #define OCFS2_IOC_SETFLAGS	_IOW('f', 2, long)
+#define OCFS2_IOC32_GETFLAGS	_IOR('f', 1, int)
+#define OCFS2_IOC32_SETFLAGS	_IOW('f', 2, int)
 
 /*
  * Journal Flags (ocfs2_dinode.id1.journal1.i_flags)