From d7a0d860b93484634e35eaadb8ccf5e526420c3d Mon Sep 17 00:00:00 2001
From: Milan Broz <gmazyland@gmail.com>
Date: Wed, 26 Jul 2017 14:32:21 +0200
Subject: [PATCH] Use getvfs for block size of filesytem if available.

---
 configure.ac       |  2 +-
 lib/utils_device.c | 29 +++++++++++++++++++++++++++--
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/configure.ac b/configure.ac
index 4dbcd6a7..29823fb1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -37,7 +37,7 @@ PKG_PROG_PKG_CONFIG
 AC_HEADER_DIRENT
 AC_HEADER_STDC
 AC_CHECK_HEADERS(fcntl.h malloc.h inttypes.h sys/ioctl.h sys/mman.h \
-	sys/sysmacros.h ctype.h unistd.h locale.h byteswap.h endian.h)
+	sys/sysmacros.h sys/statvfs.h ctype.h unistd.h locale.h byteswap.h endian.h)
 
 AC_CHECK_HEADERS(uuid/uuid.h,,[AC_MSG_ERROR([You need the uuid library.])])
 AC_CHECK_HEADER(libdevmapper.h,,[AC_MSG_ERROR([You need the device-mapper library.])])
diff --git a/lib/utils_device.c b/lib/utils_device.c
index ea83311c..b62d5875 100644
--- a/lib/utils_device.c
+++ b/lib/utils_device.c
@@ -33,6 +33,9 @@
 #ifdef HAVE_SYS_SYSMACROS_H
 # include <sys/sysmacros.h>     /* for major, minor */
 #endif
+#ifdef HAVE_SYS_STATVFS_H
+# include <sys/statvfs.h>
+#endif
 #include "internal.h"
 
 struct device {
@@ -49,6 +52,28 @@ struct device {
 	size_t block_size;
 };
 
+static size_t device_fs_block_size(const char *path)
+{
+#ifdef HAVE_SYS_STATVFS_H
+	struct statvfs buf;
+
+	if (!statvfs(path, &buf) && buf.f_bsize)
+		return (size_t)buf.f_bsize;
+#endif
+	return crypt_getpagesize();
+}
+
+static size_t device_fs_block_size_fd(int fd)
+{
+#ifdef HAVE_SYS_STATVFS_H
+	struct statvfs buf;
+
+	if (!fstatvfs(fd, &buf) && buf.f_bsize)
+		return (size_t)buf.f_bsize;
+#endif
+	return crypt_getpagesize();
+}
+
 static size_t device_block_size_fd(int fd, size_t *min_size)
 {
 	struct stat st;
@@ -59,7 +84,7 @@ static size_t device_block_size_fd(int fd, size_t *min_size)
 		return 0;
 
 	if (S_ISREG(st.st_mode))
-		bsize = crypt_getpagesize();
+		bsize = device_fs_block_size_fd(fd);
 	else {
 		if (ioctl(fd, BLKSSZGET, &arg) < 0)
 			bsize = crypt_getpagesize();
@@ -338,7 +363,7 @@ size_t device_block_size(struct device *device)
 		return device->block_size;
 
 	if (device->file_path)
-		device->block_size = crypt_getpagesize();
+		device->block_size = device_fs_block_size(device->file_path);
 	else {
 		fd = open(device->path, O_RDONLY);
 		if (fd >= 0) {