[test] Simplify struct test

Author: mxmlnkn

.github/workflows/tests.yml

@@ -66,6 +66,7 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     strategy:
+      fail-fast: false
       matrix:
         # https://endoflife.date/python
         include:
@@ -206,6 +207,9 @@ jobs:
            - os: netbsd
              version: '10.1'
              display_name: NetBSD
+           - os: netbsd
+             version: '9.4'
+             display_name: NetBSD
 
     steps:
       - name: Check out repository

mfusepy.py

@@ -742,7 +742,58 @@ class c_flock_t(ctypes.Structure):  # type: ignore
 #  - 3.14.1 -> 3.16.2: no change
 _fuse_int32 = ctypes.c_int32 if (fuse_version_major, fuse_version_minor) >= (3, 17) else ctypes.c_int
 _fuse_uint32 = ctypes.c_uint32 if (fuse_version_major, fuse_version_minor) >= (3, 17) else ctypes.c_uint
-if fuse_version_major == 2:
+if _system == 'NetBSD':
+    # NetBSD has its own FUSE library reimplementation with mismatching struct layouts!
+    # writepage is a bitfield (as in libFUSE 3.x), but the fh_old member still exists and the reported version is 2.9!
+    # https://www.netbsd.org/docs/puffs/
+    # https://github.com/NetBSD/src/blob/netbsd-11/lib/librefuse/fuse.h#L100-L129
+    # https://github.com/NetBSD/src/blob/netbsd-10/lib/librefuse/fuse.h#L100-L129
+    #  - fuse_file_info is unchanged between 10 and 11
+    #  - FUSE_USE_VERSION is not set, but is set to _REFUSE_VERSION_ (3.10) with a warning if not set!
+    #  - However, the CI prints FUSE version 2.9?!
+    #  - Seems there is no sane way to get the correct compiled version! This is again an absolute shit show!
+    # https://github.com/NetBSD/src/blob/netbsd-9/lib/librefuse/fuse.h#L51-L61
+    #  - fuse_file_info looks quite different and version is specified as 2.6!
+    #  - #define FUSE_USE_VERSION 26
+    fuse_version = (fuse_version_major, fuse_version_minor)
+    _fuse_file_info_fields_: list[FieldsEntry] = [
+        ('flags', ctypes.c_int32),
+        ('fh_old', ctypes.c_uint32),
+    ]
+
+    _fuse_file_info_fields_bitfield: list[FieldsEntry] = []
+
+    if fuse_version >= (2, 9):
+        _fuse_file_info_fields_bitfield += [('writepage', ctypes.c_int32, 1)]
+    else:
+        _fuse_file_info_fields_ += [('writepage', ctypes.c_int32)]
+
+    _fuse_file_info_fields_bitfield += [
+        ('direct_io', ctypes.c_uint32, 1),  # Introduced in FUSE 2.4
+        ('keep_cache', ctypes.c_uint32, 1),  # Introduced in FUSE 2.4
+        ('flush', ctypes.c_uint32, 1),  # Introduced in FUSE 2.6
+    ]
+    if fuse_version >= (2, 9):
+        _fuse_file_info_fields_bitfield += [
+            ('nonseekable', ctypes.c_uint, 1),  # Introduced in FUSE 2.8
+            ('flock_release', ctypes.c_uint, 1),  # Introduced in FUSE 2.9
+            ('cache_readdir', ctypes.c_uint, 1),  # Introduced in FUSE 3.5
+        ]
+
+    _fuse_file_info_flag_count = sum(x[2] for x in _fuse_file_info_fields_bitfield)
+    assert _fuse_file_info_flag_count < ctypes.sizeof(_fuse_uint32) * 8
+
+    _fuse_file_info_fields_ += _fuse_file_info_fields_bitfield
+    _fuse_file_info_fields_ += [
+        ('padding', _fuse_uint32, ctypes.sizeof(_fuse_uint32) * 8 - _fuse_file_info_flag_count),
+        ('fh', ctypes.c_uint64),
+        ('lock_owner', ctypes.c_uint64),
+    ]
+
+    if fuse_version >= (2, 9):
+        _fuse_file_info_fields_ += [('poll_events', ctypes.c_uint32)]
+
+elif fuse_version_major == 2:
     _fh_old_type = ctypes.c_uint if _system == 'OpenBSD' else ctypes.c_ulong
     _fuse_file_info_fields_: list[FieldsEntry] = [
         ('flags', ctypes.c_int),