From 1aba9ab44409ccd32240de10141ae5ea4eccf554 Mon Sep 17 00:00:00 2001
From: Milan Broz <gmazyland@gmail.com>
Date: Wed, 19 Aug 2015 14:16:42 +0200
Subject: [PATCH] Cryptsetup resize will try resize also underlying device.

If encrypted device is file-backed, resize should try to resize
underlying loop device as well.
---
 lib/setup.c       |  8 ++++++++
 lib/utils_loop.c  | 23 +++++++++++++++++++++--
 lib/utils_loop.h  |  4 +++-
 tests/compat-test |  4 ++++
 4 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/lib/setup.c b/lib/setup.c
index 01e2c80a..bd0c1b84 100644
--- a/lib/setup.c
+++ b/lib/setup.c
@@ -1387,6 +1387,14 @@ int crypt_resize(struct crypt_device *cd, const char *name, uint64_t new_size)
 		goto out;
 	}
 
+	if (crypt_loop_device(crypt_get_device_name(cd))) {
+		log_dbg("Trying to resize underlying loop device %s.",
+			crypt_get_device_name(cd));
+		/* Here we always use default size not new_size */
+		if (crypt_loop_resize(crypt_get_device_name(cd)))
+			log_err(NULL, _("Cannot resize loop device.\n"));
+	}
+
 	r = device_block_adjust(cd, dmd.data_device, DEV_OK,
 				dmd.u.crypt.offset, &new_size, &dmd.flags);
 	if (r)
diff --git a/lib/utils_loop.c b/lib/utils_loop.c
index d7b03a13..ff30a27c 100644
--- a/lib/utils_loop.c
+++ b/lib/utils_loop.c
@@ -1,8 +1,8 @@
 /*
  * loopback block device utilities
  *
- * Copyright (C) 2011-2012, Red Hat, Inc. All rights reserved.
- * Copyright (C) 2009-2012, Milan Broz
+ * Copyright (C) 2011-2015, Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2009-2015, Milan Broz
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -42,6 +42,10 @@
 #define LOOP_CTL_GET_FREE 0x4C82
 #endif
 
+#ifndef LOOP_SET_CAPACITY
+#define LOOP_SET_CAPACITY 0x4C07
+#endif
+
 static char *crypt_loop_get_device_old(void)
 {
 	char dev[20];
@@ -157,6 +161,21 @@ int crypt_loop_detach(const char *loop)
 	return r;
 }
 
+int crypt_loop_resize(const char *loop)
+{
+	int loop_fd = -1, r = 1;
+
+	loop_fd = open(loop, O_RDONLY);
+	if (loop_fd < 0)
+                return 1;
+
+	if (!ioctl(loop_fd, LOOP_SET_CAPACITY, 0))
+		r = 0;
+
+	close(loop_fd);
+	return r;
+}
+
 static char *_ioctl_backing_file(const char *loop)
 {
 	struct loop_info64 lo64 = {0};
diff --git a/lib/utils_loop.h b/lib/utils_loop.h
index 052623d8..e8c2a5dd 100644
--- a/lib/utils_loop.h
+++ b/lib/utils_loop.h
@@ -1,7 +1,8 @@
 /*
  * loopback block device utilities
  *
- * Copyright (C) 2011-2012, Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2011-2015, Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2009-2015, Milan Broz
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -29,5 +30,6 @@ int crypt_loop_device(const char *loop);
 int crypt_loop_attach(const char *loop, const char *file, int offset,
 		      int autoclear, int *readonly);
 int crypt_loop_detach(const char *loop);
+int crypt_loop_resize(const char *loop);
 
 #endif /* _UTILS_LOOP_H */
diff --git a/tests/compat-test b/tests/compat-test
index 5247fd33..2dbc7c1b 100755
--- a/tests/compat-test
+++ b/tests/compat-test
@@ -361,6 +361,10 @@ $CRYPTSETUP -q resize  $DEV_NAME --size 100 || fail
 $CRYPTSETUP -q status  $DEV_NAME | grep "size:" | grep -q "100 sectors" || fail
 $CRYPTSETUP -q resize  $DEV_NAME || fail
 $CRYPTSETUP -q status  $DEV_NAME | grep "size:" | grep -q "19997 sectors" || fail
+# Resize underlying loop device as well
+truncate -s 16M $IMG || fail
+$CRYPTSETUP -q resize  $DEV_NAME || fail
+$CRYPTSETUP -q status  $DEV_NAME | grep "size:" | grep -q "32765 sectors" || fail
 $CRYPTSETUP -q remove  $DEV_NAME || fail
 $CRYPTSETUP -q status  $DEV_NAME >/dev/null && fail
 echo $PWD1 | $CRYPTSETUP create $DEV_NAME --hash sha1 $LOOPDEV || fail