diff --git a/persistent-data/file_utils.cc b/persistent-data/file_utils.cc
index 2467079..4ed190e 100644
--- a/persistent-data/file_utils.cc
+++ b/persistent-data/file_utils.cc
@@ -8,11 +8,13 @@
 #include <unistd.h>
 
 using namespace base;
+using namespace bcache;
+using namespace persistent_data;
 
 //----------------------------------------------------------------
 
-persistent_data::block_address
-persistent_data::get_nr_blocks(string const &path)
+block_address
+persistent_data::get_nr_blocks(string const &path, block_address block_size)
 {
 	using namespace persistent_data;
 
@@ -24,7 +26,7 @@ persistent_data::get_nr_blocks(string const &path)
 		throw runtime_error("Couldn't stat dev path");
 
 	if (S_ISREG(info.st_mode) && info.st_size)
-		nr_blocks = div_up<block_address>(info.st_size, MD_BLOCK_SIZE);
+		nr_blocks = div_down<block_address>(info.st_size, block_size);
 
 	else if (S_ISBLK(info.st_mode)) {
 		// To get the size of a block device we need to
@@ -39,7 +41,7 @@ persistent_data::get_nr_blocks(string const &path)
 			throw runtime_error("ioctl BLKGETSIZE64 failed");
 		}
 		::close(fd);
-		nr_blocks = div_down<block_address>(nr_blocks, MD_BLOCK_SIZE);
+		nr_blocks = div_down<block_address>(nr_blocks, block_size);
 	} else
 		// FIXME: needs a better message
 		throw runtime_error("bad path");
@@ -47,10 +49,16 @@ persistent_data::get_nr_blocks(string const &path)
 	return nr_blocks;
 }
 
+block_address
+persistent_data::get_nr_metadata_blocks(string const &path)
+{
+	return get_nr_blocks(path, MD_BLOCK_SIZE);
+}
+
 persistent_data::block_manager<>::ptr
 persistent_data::open_bm(std::string const &dev_path, block_manager<>::mode m, bool excl)
 {
-	block_address nr_blocks = get_nr_blocks(dev_path);
+	block_address nr_blocks = get_nr_metadata_blocks(dev_path);
 	return block_manager<>::ptr(new block_manager<>(dev_path, nr_blocks, 1, m, excl));
 }
 
diff --git a/persistent-data/file_utils.h b/persistent-data/file_utils.h
index fcf203d..cb80bd4 100644
--- a/persistent-data/file_utils.h
+++ b/persistent-data/file_utils.h
@@ -9,7 +9,9 @@
 
 // FIXME: move to a different unit
 namespace persistent_data {
-	persistent_data::block_address get_nr_blocks(string const &path);
+	block_address get_nr_blocks(string const &path, block_address block_size);
+	block_address get_nr_metadata_blocks(string const &path);
+
 	block_manager<>::ptr open_bm(std::string const &dev_path,
 				     block_manager<>::mode m, bool excl = true);
 
diff --git a/thin-provisioning/thin_check.cc b/thin-provisioning/thin_check.cc
index 2451db2..4a3215c 100644
--- a/thin-provisioning/thin_check.cc
+++ b/thin-provisioning/thin_check.cc
@@ -43,7 +43,7 @@ using namespace thin_provisioning;
 namespace {
 	block_manager<>::ptr
 	open_bm(string const &path) {
-		block_address nr_blocks = get_nr_blocks(path);
+		block_address nr_blocks = get_nr_metadata_blocks(path);
 		block_manager<>::mode m = block_manager<>::READ_ONLY;
 		return block_manager<>::ptr(new block_manager<>(path, nr_blocks, 1, m));
 	}
diff --git a/thin-provisioning/thin_rmap.cc b/thin-provisioning/thin_rmap.cc
index 956fdf4..9f01255 100644
--- a/thin-provisioning/thin_rmap.cc
+++ b/thin-provisioning/thin_rmap.cc
@@ -23,7 +23,7 @@ using namespace thin_provisioning;
 namespace {
 	block_manager<>::ptr
 	open_bm(string const &path) {
-		block_address nr_blocks = get_nr_blocks(path);
+		block_address nr_blocks = get_nr_metadata_blocks(path);
 		block_manager<>::mode m = block_manager<>::READ_ONLY;
 		return block_manager<>::ptr(new block_manager<>(path, nr_blocks, 1, m));
 	}