fix: support alpine linux with musl libc and fuse 3.16

Alpine linux uses musl libc platform which has different macros for device major and minor numbers.
Additionally Fuse > 3.12 has ABI changes which mean Fuse 3 on latest Ubuntu and Alpine were broken.

Resolves: #26
Resolves: #27

.github/scripts/pre_install_alpine.sh

@@ -0,0 +1,11 @@
+#!/bin/ash
+
+echo "PreInstall Alpine Linux for FUSE_PKG=${FUSE_PKG}"
+
+#sudo chmod 666 /dev/fuse && ls -l /dev/fuse
+#sudo chown root:$USER /etc/fuse.conf && ls -l /etc/fuse.conf
+
+# Build lock file for this platform
+if [ ! -f Gemfile.lock ]; then
+  bundle lock
+fi

.github/workflows/build.yaml

@@ -15,11 +15,53 @@ on:
       - "!main"
       - "!release-please-action"
 jobs:
+  build-alpine:
+    if: ${{ !contains(github.event.head_commit.message, '[no build-alpine]') }}
+    strategy:
+      matrix:
+        fuse_pkg: ['fuse','fuse3']
+    runs-on: ubuntu-latest
+    env:
+      TERM: color # Pretty spec output
+      GIT_REF: ${{ inputs.ref || github.ref }}
+      GIT_BASE_REF: ${{ github.base_ref || 'undefined' }}
+      BUNDLE_PATH: vendor/bundle.alpine
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          ref: ${{ env.GIT_REF }}
+      - name: Setup Alpine Linux
+        uses: jirutka/setup-alpine@v1
+        with:
+          packages: >
+            build-base
+            ${{ matrix.fuse_pkg }}
+            ruby
+            ruby-dev
+            ruby-bundler
+      - name: Preinstall
+        env:
+          FUSE_PKG: ${{ matrix.fuse_pkg }}
+        run: .github/scripts/pre_install_alpine.sh
+        shell: alpine.sh {0}
+      - name: Cache gems
+        uses: actions/cache@v4
+        with:
+         path: ${{ env.BUNDLE_PATH }}
+         key: alpine-ruby-gems${{ hashFiles('**/Gemfile.lock','/etc/os-release') }}
+         restore-keys: |
+           alpine-ruby-gems-
+      - name: Run tests
+        run: bundle install && bundle exec rake test # only test, no rubocop etc..
+        shell: alpine.sh {0}
+
   build:
+    if: ${{ !contains(github.event.head_commit.message, '[no build]') }}
+
     strategy:
       matrix:
-        ruby-version: ['2.7' , '3.0', '3.1', '3.2']
-        os: ['ubuntu-latest'] # mac-os when/if Macfuse can be deployed on CI images
+        ruby-version: ['2.7','3.2','3.3']
+        os: ['ubuntu-latest','ubuntu-24.04'] # mac-os when/if Macfuse can be deployed on CI images
         fuse_pkg: ['fuse','fuse3']
 
     runs-on: ${{ matrix.os }}

.rubocop.yml

@@ -4,7 +4,7 @@ AllCops:
   NewCops: enable
   Exclude:
     - 'spec/**/*.rb'
-    - 'vendor/bundle/**/*'
+    - 'vendor/**/*'
 
 Gemspec/DevelopmentDependencies:
   EnforcedStyle: gemspec

Vagrantfile

@@ -8,17 +8,17 @@
 # backwards compatibility). Please don't change it unless you know what
 # you're doing.
 Vagrant.configure('2') do |config|
-  %w[focal impish].each do |dist|
+  %w[jammy].each do |dist|
     %w[fuse fuse3].each do |fuse_ver|
       config.vm.define "#{fuse_ver}-#{dist}", auto_start: false do |dist_config|
         dist_config.vm.box = "ubuntu/#{dist}64"
         dist_config.vm.provision :shell, inline: <<-SHELL
          apt-get update -y
-         apt-get install -y gnupg2 gcc make ruby ruby-dev libffi-dev ruby-bundler #{fuse_ver} lib#{fuse_ver}-dev
+         apt-get install -y gnupg2 gcc make libffi-dev #{fuse_ver} lib#{fuse_ver}-dev
         SHELL
         dist_config.vm.provision :shell, path: 'vagrant/install-rvm.sh', args: 'stable', privileged: false
         # TODO: extract rubies from github workflow
-        %w[2.7].each do |v|
+        %w[3.3.5].each do |v|
           dist_config.vm.provision :shell, path: 'vagrant/install-ruby.sh', args: [v, 'bundler'], privileged: false
         end
         dist_config.vm.provision :shell, inline: 'cd /vagrant; bundle install', privileged: false

lib/ffi/accessors.rb

@@ -427,18 +427,13 @@ def ffi_attr_fill(from, writers: self.class.ffi_attr_writers, **args)
       if from.is_a?(Hash)
         args.merge!(from)
       else
-        include_all = from.is_a?(Stat.class)
         writers.each do |w|
           r = w[0..-2] # strip trailing =
-          send(w, from.send(r)) if from.respond_to?(r, include_all)
+          send(w, from.public_send(r)) if from.respond_to?(r)
         end
       end
       args.transform_keys! { |k| :"#{k}=" }
 
-      if (invalid = args.keys - writers).any?
-        raise ArgumentError, "Cannot fill #{self.class.name} using #{invalid}"
-      end
-
       args.each_pair { |k, v| send(k, v) }
       self
     end

lib/ffi/devt.rb

@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 
 require 'ffi'
-
 module FFI
   # Calculate major/minor device numbers for use with mknod etc..
   # @see makedev(3)
@@ -27,10 +26,13 @@ module Device
     #  @return [Integer] the minor component of dev
     attach_function :minor, :"#{prefix}minor", [:int], :int
   rescue FFI::NotFoundError
-    case Platform::NAME
-    when 'x86_64-darwin'
-      # From https://github.com/golang/go/issues/8106 these functions are not defined on Darwin.
-      class << self
+
+    class << self
+      # rubocop:disable Naming/MethodParameterName
+      case RUBY_PLATFORM
+      when 'x86_64-darwin'
+        # From https://github.com/golang/go/issues/8106 these functions are not defined on Darwin.
+
         # define	major(x)	((int32_t)(((u_int32_t)(x) >> 24) & 0xff))
         def major(dev)
           (dev >> 24) & 0xff
@@ -45,9 +47,33 @@ def minor(dev)
         def makedev(major, minor)
           (major << 24) | minor
         end
+
+      when 'x86_64-linux-musl' # eg alpine linux
+        # #define major(x) \
+        # 	((unsigned)( (((x)>>31>>1) & 0xfffff000) | (((x)>>8) & 0x00000fff) ))
+        def major(x)
+          ((x >> 31 >> 1) & 0xfffff000) | ((x >> 8) & 0x00000fff)
+        end
+
+        # #define minor(x) \
+        # 	((unsigned)( (((x)>>12) & 0xffffff00) | ((x) & 0x000000ff) ))
+        #
+        def minor(x)
+          ((x >> 12) & 0xffffff00) | (x & 0x000000ff)
+        end
+
+        # #define makedev(x,y) ( \
+        #         (((x)&0xfffff000ULL) << 32) | \
+        # 	(((x)&0x00000fffULL) << 8) | \
+        #         (((y)&0xffffff00ULL) << 12) | \
+        # 	(((y)&0x000000ffULL)) )
+        def makedev(x, y)
+          ((x & 0xfffff000) << 32) | ((x & 0x00000fff) << 8) | ((y & 0xffffff00) << 12) | (y & 0x000000ff)
+        end
+      else
+        raise
       end
-    else
-      raise
+      # rubocop:enable Naming/MethodParameterName
     end
   end
 end

lib/ffi/libfuse/adapter/context.rb

@@ -18,7 +18,7 @@ def fuse_wrappers(*wrappers)
           )
           return wrappers unless defined?(super)
 
-          super(*wrappers)
+          super
         end
 
         module_function

lib/ffi/libfuse/adapter/debug.rb

@@ -41,7 +41,7 @@ def fuse_wrappers(*wrappers)
           wrappers << proc { |fm, *args, &b| debug_callback(fm, *args, **conf, &b) } if debug?
           return wrappers unless defined?(super)
 
-          super(*wrappers)
+          super
         end
 
         # @!visibility private

lib/ffi/libfuse/adapter/fuse2_compat.rb

@@ -12,27 +12,27 @@ module Prepend
           if FUSE_MAJOR_VERSION == 2
             # @!visibility private
             def getattr(path, stat, fuse_file_info = nil)
-              super(path, stat, fuse_file_info)
+              super
             end
 
             def truncate(path, size, fuse_file_info = nil)
-              super(path, size, fuse_file_info)
+              super
             end
 
             def init(fuse_conn_info, fuse_config = nil)
-              super(fuse_conn_info, fuse_config)
+              super
             end
 
             def chown(path, uid, gid, fuse_file_info = nil)
-              super(path, uid, gid, fuse_file_info)
+              super
             end
 
             def chmod(path, mode, fuse_file_info = nil)
-              super(path, mode, fuse_file_info)
+              super
             end
 
             def utimens(path, times, fuse_file_info = nil)
-              super(path, times, fuse_file_info)
+              super
             end
 
             def readdir(path, buffer, filler, offset, fuse_file_info, fuse_readdir_flag = 0)
@@ -45,7 +45,7 @@ def fuse_respond_to?(fuse_method)
               # fgetattr and ftruncate already fallback to the respective basic method
               return false if %i[getdir fgetattr ftruncate].include?(fuse_method)
 
-              super(fuse_method)
+              super
             end
 
             def fuse_options(args)

lib/ffi/libfuse/adapter/fuse3_support.rb

@@ -24,24 +24,24 @@ def getattr(*args)
             fi = args.pop
             return fgetattr(*args, fi) if fi && fuse_super_respond_to?(:fgetattr)
 
-            super(*args)
+            super
           end
 
           def truncate(*args)
             fi = args.pop
             return ftruncate(*args, fi) if fi && fuse_super_respond_to?(:ftruncate)
 
-            super(*args)
+            super
           end
 
           def chown(*args)
             args.pop
-            super(*args)
+            super
           end
 
           def chmod(*args)
             args.pop
-            super(*args)
+            super
           end
 
           # TODO: Fuse3 deprecated flag utime_omit_ok - which meant that UTIME_OMIT and UTIME_NOW are passed through
@@ -50,14 +50,14 @@ def chmod(*args)
           #  but there is no way to handle OMIT
           def utimens(*args)
             args.pop
-            super(*args) if defined?(super)
+            super if defined?(super)
           end
 
           def init(*args)
             args.pop
 
             # TODO: populate FuseConfig with output from fuse_flags/FuseConnInfo where appropriate
-            super(*args)
+            super
           end
 
           def readdir(*args, &block)
@@ -71,7 +71,7 @@ def readdir(*args, &block)
               proc { |buf, name, stat, off| a.call(buf, name, stat, off, 0) }
             end
 
-            super(*args, &block)
+            super
           end
 
           def fuse_respond_to(fuse_callback)

lib/ffi/libfuse/adapter/interrupt.rb

@@ -20,7 +20,7 @@ def fuse_wrappers(*wrappers)
           }
           return wrappers unless defined?(super)
 
-          super(*wrappers)
+          super
         end
 
         module_function

lib/ffi/libfuse/adapter/pathname.rb

@@ -15,7 +15,7 @@ def fuse_wrappers(*wrappers)
           }
           return wrappers unless defined?(super)
 
-          super(*wrappers)
+          super
         end
       end
     end

lib/ffi/libfuse/adapter/ruby.rb

@@ -338,7 +338,7 @@ def utimens(path, times, *fuse3_args)
 
           # Calls super if defined and storing result to protect from GC until {#destroy}
           def init(*args)
-            o = super(*args) if fuse_super_respond_to?(:init)
+            o = super if fuse_super_respond_to?(:init)
             handles << o if o
           end
 

lib/ffi/libfuse/adapter/safe.rb

@@ -23,7 +23,7 @@ def fuse_wrappers(*wrappers)
           }
           return wrappers unless defined?(super)
 
-          super(*wrappers)
+          super
         end
 
         # @return [Integer] the default errno to return for rescued errors.  ENOTRECOVERABLE unless overridden

lib/ffi/libfuse/filesystem/virtual_dir.rb

@@ -41,7 +41,7 @@ class VirtualDir < VirtualNode
 
         def initialize(accounting: Accounting.new)
           @entries = {}
-          super(accounting: accounting)
+          super
         end
 
         # @!endgroup
@@ -157,7 +157,7 @@ def create(path, mode = FuseContext.get.mask(0o644), ffi = nil, &file)
             # TODO: Strictly should understand setgid and sticky bits of this dir's mode when creating new files
             new_file = file ? file.call(name) : new_file(name)
             if entry_fuse_respond_to?(new_file, :create)
-              new_file.public_send(:create, '/', mode, ffi)
+              new_file.create('/', mode, ffi)
             else
               # TODO: generate a sensible device number
               entry_send(new_file, :mknod, '/', mode, 0)

lib/ffi/libfuse/filesystem/virtual_file.rb

@@ -20,7 +20,7 @@ module VirtualFile
 
           # Create an empty synthetic file
           def initialize(accounting: nil)
-            super(accounting: accounting)
+            super
           end
 
           # @!group FUSE Callbacks

lib/ffi/libfuse/filesystem/virtual_link.rb

@@ -12,7 +12,7 @@ module VirtualLink
           include VirtualNode
           def initialize(accounting: nil)
             @target = target
-            super(accounting: accounting)
+            super
           end
 
           def readlink(_path, size)

lib/ffi/libfuse/fuse3.rb

@@ -145,8 +145,8 @@ def io
 
       private
 
-      def native_fuse_loop_mt(max_idle_threads: 10, **_options)
-        Libfuse.fuse_loop_mt3(@fuse, FuseLoopConfig.new.fill(max_idle_threads: max_idle_threads))
+      def native_fuse_loop_mt(**options)
+        Libfuse.fuse_loop_mt3(@fuse, FuseLoopConfig.create(**options))
       end
 
       def unmount

lib/ffi/libfuse/fuse_cmdline_opts.rb

@@ -31,15 +31,17 @@ class FuseCmdlineOpts < FFI::Struct
         show_version: :bool_int,
         show_help: :bool_int,
         clone_fd: :bool_int,
-        max_idle_threads: :int
+        max_idle_threads: :uint
       }
+      spec[:max_threads] = :uint if FUSE_MINOR_VERSION >= 12
 
       layout(spec)
 
       bool, = spec.partition { |_, v| v == :bool_int }
       ffi_attr_reader(*bool.map { |k, _| "#{k}?" })
 
       ffi_attr_reader(:max_idle_threads, :mountpoint)
+      ffi_attr_reader(:max_threads) if FUSE_MINOR_VERSION >= 12
     end
   end
 end