fix: duf reports odd sizes due to using bsize instead of frsize

This is arguably a bug in `duf`, but the `bsize` value reported by
DwarFS isn't that relevant, so we might just change it here.

Author: mhx

src/dwarfs/metadata_v2.cpp

@@ -983,7 +983,7 @@ metadata_<LoggerPolicy>::info_as_dynamic(int detail_level,
   }
 
   if (detail_level > 0) {
-    info["block_size"] = stbuf.bsize;
+    info["block_size"] = meta_.block_size();
     info["block_count"] = fsinfo.block_count;
     info["inode_count"] = stbuf.files;
     if (auto ps = meta_.preferred_path_separator()) {
@@ -1710,7 +1710,9 @@ template <typename LoggerPolicy>
 int metadata_<LoggerPolicy>::statvfs(vfs_stat* stbuf) const {
   ::memset(stbuf, 0, sizeof(*stbuf));
 
-  stbuf->bsize = meta_.block_size();
+  // Make sure bsize and frsize are the same, as doing otherwise can confuse
+  // some applications (such as `duf`).
+  stbuf->bsize = 1UL;
   stbuf->frsize = 1UL;
   stbuf->blocks = meta_.total_fs_size();
   if (!options_.enable_nlink) {

test/compat_test.cpp

@@ -404,7 +404,7 @@ char const* reference_v0_2 = R"(
   },
   "statvfs": {
     "f_blocks": 10614,
-    "f_bsize": 1024,
+    "f_bsize": 1,
     "f_files": 33
   }
 }
@@ -777,7 +777,7 @@ char const* reference = R"(
   },
   "statvfs": {
     "f_blocks": 10614,
-    "f_bsize": 1024,
+    "f_bsize": 1,
     "f_files": 36
   }
 }
@@ -822,7 +822,7 @@ void check_compat(logger& lgr, filesystem_v2 const& fs,
   vfs_stat vfsbuf;
   fs.statvfs(&vfsbuf);
 
-  EXPECT_EQ(1024, vfsbuf.bsize);
+  EXPECT_EQ(1, vfsbuf.bsize);
   EXPECT_EQ(1, vfsbuf.frsize);
   EXPECT_EQ(10614, vfsbuf.blocks);
   EXPECT_EQ(33 + 3 * has_devices, vfsbuf.files);

test/dwarfs_test.cpp

@@ -227,7 +227,7 @@ void basic_end_to_end_test(std::string const& compressor,
   vfs_stat vfsbuf;
   fs.statvfs(&vfsbuf);
 
-  EXPECT_EQ(1 << block_size_bits, vfsbuf.bsize);
+  EXPECT_EQ(1, vfsbuf.bsize);
   EXPECT_EQ(1, vfsbuf.frsize);
   if (enable_nlink) {
     EXPECT_EQ(access_fail ? 2046934 : 2056934, vfsbuf.blocks);