APFS module for linux, with experimental write support (out-of-tree repository)

While preparing to add this kernel module to NixOS, I tried to build it for all kernels in Nixpkgs and it failed for three kernel versions. The README states, that this is supposed to work with kernel version 4.9 or before but it fails to build on 4.4.273, 4.9.273 and 4.14.237. The error message for Linux 4.14.237 boils down to

/build/source/dir.c:652:2: error: implicit declaration of function 'discard_new_inode'
  652 |  discard_new_inode(inode);
      |  ^~~~~~~~~~~~~~~~~

and the error message for Linux 4.4.273 and 4.9.273:

   23 |  SB_RDONLY = MS_RDONLY;
      |  ^~~~~~~~~
/build/source/apfs.h:23:2: error: type defaults to 'int' in declaration of 'SB_RDONLY'

I don't really care about those kernels. You should decide if you want to fix this or not as I can of course just exclude building this module with those old kernels in Nixpkgs. Please either fix the compilation or update the README. As always, I'm happy to try to compile any patches you may develop.

The latest commit from the develop branch does not compile on Linux 5.14.1. Here is the relevant build log:

/build/source/inode.c: In function 'apfs_do_ioc_setflags':
/build/source/inode.c:1807:8: error: implicit declaration of function 'vfs_ioc_setflags_prepare' [8;;https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wimplicit-function-declaration-Werror=implicit-function-declaration8;;]
 1807 |  err = vfs_ioc_setflags_prepare(inode, oldflags, newflags);
      |        ^~~~~~~~~~~~~~~~~~~~~~~~
/build/source/inode.c: In function 'apfs_ioc_setflags':
/build/source/inode.c:1844:30: error: passing argument 1 of 'inode_owner_or_capable' from incompatible pointer type [8;;https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html#index-Wincompatible-pointer-types-Werror=incompatible-pointer-types8;;]
 1844 |  if (!inode_owner_or_capable(inode))
      |                              ^~~~~
      |                              |
      |                              struct inode *
In file included from /nix/store/iswyx074r0h6k9dlbf53mhwddwjb1ri8-linux-5.14.1-dev/lib/modules/5.14.1/source/include/linux/buffer_head.h:12,
                 from /build/source/inode.c:7:
/nix/store/iswyx074r0h6k9dlbf53mhwddwjb1ri8-linux-5.14.1-dev/lib/modules/5.14.1/source/include/linux/fs.h:1888:52: note: expected 'struct user_namespace *' but argument is of type 'struct inode *'
 1888 | bool inode_owner_or_capable(struct user_namespace *mnt_userns,
      |                             ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
/build/source/inode.c:1844:7: error: too few arguments to function 'inode_owner_or_capable'
 1844 |  if (!inode_owner_or_capable(inode))
      |       ^~~~~~~~~~~~~~~~~~~~~~
In file included from /nix/store/iswyx074r0h6k9dlbf53mhwddwjb1ri8-linux-5.14.1-dev/lib/modules/5.14.1/source/include/linux/buffer_head.h:12,
                 from /build/source/inode.c:7:
/nix/store/iswyx074r0h6k9dlbf53mhwddwjb1ri8-linux-5.14.1-dev/lib/modules/5.14.1/source/include/linux/fs.h:1888:6: note: declared here
 1888 | bool inode_owner_or_capable(struct user_namespace *mnt_userns,
      |      ^~~~~~~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors

Let me know if I can provide any additional information.

I'm trying to build this on NixOS with Linux 5.12.11 but the build fails. I don't think this issue has to do with NixOS as it compiled fine with an older kernel (5.11.x). Here is the build output from nix-build:

this derivation will be built:
  /nix/store/mq0rxj1qff8ak2r08l8i9nw6n9af7axv-apfs-unstable-2020-08-06-5.12.11.drv
building '/nix/store/mq0rxj1qff8ak2r08l8i9nw6n9af7axv-apfs-unstable-2020-08-06-5.12.11.drv'...
unpacking sources
unpacking source archive /nix/store/0br698lgx8dm5bss6n25ls4llfv2q0zj-source
source root is source
setting SOURCE_DATE_EPOCH to timestamp 1624192656 of file source/xfield.c
patching sources
applying patch /nix/store/20r89d87xwycl20cfcsv4d884qlcp0gq-9.patch
patching file Makefile
configuring
no configure script, doing nothing
building
build flags: SHELL=/nix/store/kxj6cblcsd1qcbbxlmbswwrn89zcmgd6-bash-4.4-p23/bin/bash KERNELRELEASE=5.12.11 KERNEL_DIR=/nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/build INSTALL_MOD_PATH=\$\(out\)
make -C /nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/build M=/build/source
make[1]: Entering directory '/nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/build'
  CC [M]  /build/source/btree.o
  CC [M]  /build/source/compress.o
  CC [M]  /build/source/dir.o
  CC [M]  /build/source/extents.o
  CC [M]  /build/source/file.o
  CC [M]  /build/source/inode.o
  CC [M]  /build/source/key.o
  CC [M]  /build/source/message.o
  CC [M]  /build/source/namei.o
  CC [M]  /build/source/node.o
  CC [M]  /build/source/object.o
  CC [M]  /build/source/spaceman.o
  CC [M]  /build/source/super.o
/build/source/super.c: In function 'apfs_attach_nxi':
/build/source/super.c:1128:9: error: too few arguments to function 'lookup_bdev'
 1128 |  bdev = lookup_bdev(dev_name);
      |         ^~~~~~~~~~~
In file included from /nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/source/include/linux/backing-dev.h:15,
                 from /build/source/super.c:6:
/nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/source/include/linux/blkdev.h:1984:5: note: declared here
 1984 | int lookup_bdev(const char *pathname, dev_t *dev);
      |     ^~~~~~~~~~~
make[3]: *** [/nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/source/scripts/Makefile.build:271: /build/source/super.o] Error 1
make[2]: *** [/nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/source/Makefile:1856: /build/source] Error 2
make[1]: *** [/nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/source/Makefile:215: __sub-make] Error 2
make[1]: Leaving directory '/nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/build'
make: *** [Makefile:16: default] Error 2
error: builder for '/nix/store/mq0rxj1qff8ak2r08l8i9nw6n9af7axv-apfs-unstable-2020-08-06-5.12.11.drv' failed with exit code 2;
       last 10 log lines:
       > In file included from /nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/source/include/linux/backing-dev.h:15,
       >                  from /build/source/super.c:6:
       > /nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/source/include/linux/blkdev.h:1984:5: note: declared here
       >  1984 | int lookup_bdev(const char *pathname, dev_t *dev);
       >       |     ^~~~~~~~~~~
       > make[3]: *** [/nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/source/scripts/Makefile.build:271: /build/source/super.o] Error 1
       > make[2]: *** [/nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/source/Makefile:1856: /build/source] Error 2
       > make[1]: *** [/nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/source/Makefile:215: __sub-make] Error 2
       > make[1]: Leaving directory '/nix/store/23gik70gdmadraqxzas87fy40dvg13ph-linux-5.12.11-dev/lib/modules/5.12.11/build'
       > make: *** [Makefile:16: default] Error 2
       For full logs, run 'nix log /nix/store/mq0rxj1qff8ak2r08l8i9nw6n9af7axv-apfs-unstable-2020-08-06-5.12.11.drv'.

This looks like something has changed in the kernel to which linux-apfs needs to be adapted to.

Source files currently contain headers with SPDX-License-Identifier: GPL-2.0. However, as per https://spdx.org/licenses/, there is no such license identifier, I am assuming it was meant to be "GPL-2.0-only" or "GPL-2.0-or-later". Please clarify which version is used by this project.

The last missing piece for perfect NixOS integration is a NixOS module. This will allow awesome things like specifying

fileSystems."/mnt/apfs" = {
  device = "/dev/disk/by-partlabel/apfs";
  fsType = "apfs";
}

in the configuration, which is all that is required to automatically mount the filesystem during boot, no need to install anything or configure anything else. As part of writing a NixOS module, it is good practice to write a test for a basic sanity check and to gain some confidence, that at least the basic stuff all works as expected. Here is how the test looks currently:

import ./make-test-python.nix ({ pkgs, ... }: {
  name = "apfs";
  meta.maintainers = with pkgs.lib.maintainers; [ Luflosi ];

  machine = { pkgs, ... }: {
    virtualisation.emptyDiskImages = [ 1024 ];

    boot.supportedFilesystems = [ "apfs" ];
  };

  testScript = ''
    machine.wait_for_unit("basic.target")
    machine.succeed("mkdir /tmp/mnt")

    with subtest("mkapfs refuses to work with a label that is too long"):
      machine.fail( "mkapfs -L '000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F303132333435363738393A3B3C3D3E3F404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7F' /dev/vdb")

    with subtest("mkapfs works with the maximum label length"):
      machine.succeed("mkapfs -L '000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F303132333435363738393A3B3C3D3E3F404142434445464748494A4B4C4D4E4F505152535455565758595A5B5C5D5E5F606162636465666768696A6B6C6D6E6F707172737475767778797A7B7C7D7E7' /dev/vdb")

    with subtest("Enable case sensitivity and normalization sensitivity"):
      machine.succeed(
          "mkapfs -s -z /dev/vdb",
          # Triggers a bug, see https://github.com/linux-apfs/linux-apfs-rw/issues/15
          # "mount -o cknodes,readwrite /dev/vdb /tmp/mnt",
          "mount -o readwrite /dev/vdb /tmp/mnt",
          "echo 'Hello World 1' > /tmp/mnt/test.txt",
          "[ ! -f /tmp/mnt/TeSt.TxT ] || false", # Test case sensitivity
          "echo 'Hello World 1' | diff - /tmp/mnt/test.txt",
          "echo 'Hello World 2' > /tmp/mnt/\u0061\u0301.txt",
          "echo 'Hello World 2' | diff - /tmp/mnt/\u0061\u0301.txt",
          "[ ! -f /tmp/mnt/\u00e1.txt ] || false", # Test Unicode normalization sensitivity
          "umount /tmp/mnt",
          "apfsck /dev/vdb",
      )
    with subtest("Disable case sensitivity and normalization sensitivity"):
      machine.succeed(
          "mkapfs /dev/vdb",
          "mount -o readwrite /dev/vdb /tmp/mnt",
          "echo 'Hello World Hello World Hello World' > /tmp/mnt/Test.txt",
          "echo -n 'Hello World' > /tmp/mnt/test.txt",
          "echo ' 1' >> /tmp/mnt/TEST.TXT",
          "umount /tmp/mnt",
          "apfsck /dev/vdb",
          "mount -o readwrite /dev/vdb /tmp/mnt",
          "echo 'Hello World 1' | diff - /tmp/mnt/TeSt.TxT", # Test case insensitivity
          "echo 'Hello World 2' > /tmp/mnt/\u0061\u0301.txt",
          "echo 'Hello World 2' | diff - /tmp/mnt/\u0061\u0301.txt",
          "echo 'Hello World 2' | diff - /tmp/mnt/\u00e1.txt", # Test Unicode normalization
          "umount /tmp/mnt",
          "apfsck /dev/vdb",
      )
  '';
})

Most of the space in the file is taken up by a Python script. The strings passed to machine.succeed() are shell script one-liners that all need to succeed for the test to succeed. The test builds a qemu VM with an empty 1GB disk image, loads the APFS kernel module and then executes the tests. Here is the NixOS test for ZFS. It basically tests smb file sharing, encryption and forefully importing a pool on a machine with a different host ID, for two versions of ZFS and the Linux kernel. I'd like to hear your feedback, if you think this is an adequate amount of testing or if you would test more or test less? Should I maybe reboot the VM somewhere during the test? Maybe test long filenames? Call apfsck more often? Create a whole bunch of files and see if any disappear? Something else entirely?

I am on Arch, so I simply downloaded linux-headers from pacman, cloned the repo, cd'd into the repo, ran make and got this error:

make -C /lib/modules/5.13.9-arch1-1/build M=/home/nate/linux-apfs-rw
make[1]: *** /lib/modules/5.13.9-arch1-1/build: No such file or directory.  Stop.
make: *** [Makefile:15: default] Error 2

Did I miss something?

EDIT: in /lib/modules I have a folder called 5.13.12-arch1-1... Do I need that specific version for this to work?

The label of an APFS filesystem does not seem to show up anywhere. The steps I tried:

1. modprobe apfs
2. truncate -s 1G /tmp/test.img
3. losetup -f /tmp/test.img
4. mkapfs -L testing /dev/loop0
5. lsblk -f does not show a label for loop0
6. ls -la /dev/disk/by-label does not show loop0
7. mounting the filesystem does not change the situation

I don't think this is a problem with mkapfs because an APFS filesystem created with macOS also does not show a label in Linux and copying /tmp/test.img to a macOS machine and mounting it does show the label.

This issue is probably very low on your TODO list. I just wanted to know if it is a known issue and if I did something wrong or if this is supposed to work.

Since kernel commit 549c7297717c ("fs: make helpers idmap mount aware") extended the exisiting inode method to let filesystems be aware of idmapped mounts, compiling apfs module with linux v5.12 failed:

make make -C /lib/modules/5.12.0-custom/build M=/root/rw make[1]: Entering directory '/root/linux' CC [M] /root/linux-apfs-rw/dir.o /root/linux-apfs-rw/dir.c:644:5: error: conflicting types for apfs_mknod 644 | int apfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) | ^~~~~~~~~~ In file included from /root/linux-apfs-rw/dir.c:8: /root/linux-apfs-rw/apfs.h:642:12: note: previous declaration of apfs_mknod was here 642 | extern int apfs_mknod(struct user_namespace *mnt_userns, struct inode *dir, | ^~~~~~~~~~ /root/linux-apfs-rw/dir.c:649:5: error: conflicting types for apfs_mkdir 649 | int apfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) | ^~~~~~~~~~ In file included from /root/linux-apfs-rw/dir.c:8: /root/linux-apfs-rw/apfs.h:644:12: note: previous declaration of apfs_mkdir was here 644 | extern int apfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir, | ^~~~~~~~~~ /root/linux-apfs-rw/dir.c:654:5: error: conflicting types for apfs_create 654 | int apfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, | ^~~~~~~~~~~ In file included from /root/linux-apfs-rw/dir.c:8: /root/linux-apfs-rw/apfs.h:649:12: note: previous declaration of apfs_create was here 649 | extern int apfs_create(struct user_namespace *mnt_userns, struct inode *dir, | ^~~~~~~~~~~ /root/linux-apfs-rw/dir.c:1197:5: error: conflicting types for apfs_rename 1197 | int apfs_rename(struct inode *old_dir, struct dentry *old_dentry, | ^~~~~~~~~~~ In file included from /root/linux-apfs-rw/dir.c:8: /root/linux-apfs-rw/apfs.h:646:12: note: previous declaration of apfs_rename was here 646 | extern int apfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir, | ^~~~~~~~~~~ make[2]: *** [scripts/Makefile.build:271: /root/linux-apfs-rw/dir.o] Error 1 make[1]: *** [Makefile:1851: /root/rw] Error 2 make[1]: Leaving directory '/root/linux' make: *** [Makefile:14: default] Error 2

Although keeping forward and backward compatibilities is painful, add awful preprocessors to let compilation pass.

Signed-off-by: Su Yue [email protected]

Hey @eafer, I'm very very keen on using this!

[[email protected] ~]$ yay apfs
5 aur/linux-apfs-git 1:r6.2a598f1-1 (+2 0.68) (Installed: 1:r8.0e35d97-1)
    Experimental APFS kernel module (DKMS)
4 aur/apfsprogs-git r304.26f3461-1 (+3 0.68) (Installed: r331.8ecdb0b-1)
    Experimental APFS tools for linux
3 aur/linux-apfs-dkms-git 1:r5.277a34e-1 (+5 0.68) (Installed: 1:r8.0e35d97-1)
    Experimental APFS kernel module (DKMS)
2 aur/apfs-fuse-git r77.670e45e-1 (+9 0.79) (Installed: r92.ee71aa5-1)
    FUSE driver for APFS (Apple File System)

# dkms status
linux-apfs, 0.1, 5.10.26-1-lts, x86_64: installed
linux-apfs, 0.1, 5.11.10-arch1-1, x86_64: installed (original_module exists)

Install over your existing linux-apfs-dkms-git? https://github.com/linux-apfs/linux-apfs-rw/commit/cb4f9d2514ea0d4913ddc2ce3b4fe95258b22587

sudo pacman -Rns linux-apfs-dkms-git linux-apfs-git
yay --getpkgbuild linux-apfs-dkms-git
cd linux-apfs-dkms-git
sed -i -e s/oot/rw/ PKGBUILD
makepkg -si

I have a 50GB raw disk image, made with https://github.com/sickcodes/Docker-OSX

It is APFS + Unencrypted + Case Sensitive:

export IMAGE="${PWD}/mac_hdd_ng_nonqcow.img"
sudo mkdir -p "/media/${USER}/macos"
fdisk -l ${IMAGE}

Disk ./mac_hdd_ng_nonqcow.img: 50 GiB, 53687091200 bytes, 104857600 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 5C21B10B-9C3E-4AE9-8482-F4C321A8094D

Device                                                   Start      End  Sectors  Size Type
./mac_hdd_ng_nonqcow.img1     40   409639   409600  200M EFI System
./mac_hdd_ng_nonqcow.img2 409640 48174215 47764576 22.8G Apple APFS

apfs-fuse works fine (read-only)

sudo apfs-fuse -o allow_other "$IMAGE" "/media/${USER}/macos"
ls "/media/${USER}/macos"
# private-dir  root

sudo touch "/media/${USER}/macos/root/ok"
# touch: cannot touch '/media/user/macos/root/ok': Read-only file system
sudo umount "/media/${USER}/macos"

When I try mount your new one, I get the bad superblock error :(

[[email protected] test]$ sudo mount -t apfs -o cknodes,vol=1 "$IMAGE" "/media/${USER}/macos"
mount: /media/${USER}/macos: wrong fs type, bad option, bad superblock on /dev/loop0, missing codepage or helper program, or other error.

[[email protected] test]$ stat /dev/loop0 
  File: /dev/loop0
  Size: 0         	Blocks: 0          IO Block: 4096   block special file
Device: 5h/5d	Inode: 801         Links: 1     Device type: 7,0
Access: (0660/brw-rw----)  Uid: (    0/    root)   Gid: (  994/    disk)
Access: 2021-04-04 00:22:50.183666683 +0000
Modify: 2021-04-04 00:22:50.183666683 +0000
Change: 2021-04-04 00:22:50.183666683 +0000
 Birth: -

sudo losetup -d /dev/loop0

[[email protected] ~]$ sudo losetup -d /dev/loop0
losetup: /dev/loop0: detach failed: No such device or address

Since I can still apfs-fuse, I need to remove all and install ONLY this -rw repo instead of -oot?

Also, perhaps change https://github.com/linux-apfs/linux-apfs-rw/blob/master/dkms.conf to

PACKAGE_NAME="linux-apfs-rw"
PACKAGE_VERSION="0.2"

BUILT_MODULE_NAME[0]="apfsrw"
DEST_MODULE_LOCATION[0]="/extra"

Or will you merge into linux-apfs soon?

Should I try the non-dkms version?

Executing echo test > test.txt twice on a readwrite mounted APFS filesystem prints "operation not supported: test.txt" and does not overwrite the file.

Is this something you plan to support in the future? How much work would it be to implement this?

I will use this to make packaging the kernel module on NixOS easier. Executing this target will automatically compress apfs.ko and put it into the correct directory, $out/lib/modules/kernel-version-here/extra/ in the case of NixOS. I have not tested this on any other Linux distro.

When I was trying to compile this, it reports that there was an error in super.c.

make -C /lib/modules/5.14.0-70.13.1.el9_0.x86_64/build M=/home/tienyu/linux-apfs-rw
make[1]: Entering directory '/usr/src/kernels/5.14.0-70.13.1.el9_0.x86_64'
  CC [M]  /home/tienyu/linux-apfs-rw/btree.o
  CC [M]  /home/tienyu/linux-apfs-rw/compress.o
  CC [M]  /home/tienyu/linux-apfs-rw/dir.o
  CC [M]  /home/tienyu/linux-apfs-rw/extents.o
  CC [M]  /home/tienyu/linux-apfs-rw/file.o
  CC [M]  /home/tienyu/linux-apfs-rw/inode.o
  CC [M]  /home/tienyu/linux-apfs-rw/key.o
  CC [M]  /home/tienyu/linux-apfs-rw/message.o
  CC [M]  /home/tienyu/linux-apfs-rw/namei.o
  CC [M]  /home/tienyu/linux-apfs-rw/node.o
  CC [M]  /home/tienyu/linux-apfs-rw/object.o
  CC [M]  /home/tienyu/linux-apfs-rw/spaceman.o
  CC [M]  /home/tienyu/linux-apfs-rw/super.o
/home/tienyu/linux-apfs-rw/super.c: In function 'apfs_setup_bdi':
/home/tienyu/linux-apfs-rw/super.c:1073:31: error: 'struct block_device' has no member named 'bd_bdi'
 1073 |         bdi_dev = nxi->nx_bdev->bd_bdi;
      |                               ^~
make[2]: *** [scripts/Makefile.build:271: /home/tienyu/linux-apfs-rw/super.o] Error 1
make[1]: *** [Makefile:1862: /home/tienyu/linux-apfs-rw] Error 2
make[1]: Leaving directory '/usr/src/kernels/5.14.0-70.13.1.el9_0.x86_64'
make: *** [Makefile:16: default] Error 2

However I looked into super.c then and found a piece of code which detects kernel version:

#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0)
        bdi_dev = nxi->nx_bdev->bd_bdi;
#else
        bdi_dev = nxi->nx_bdev->bd_disk->bdi;
#endif

I tried deleting the whole part and use bdi_dev = nxi->nx_bdev->bd_disk->bdi; (i.e. the one for Linux 5.15+) only and it compiled successfully. That's pretty wired since I'm on Red Hat Enterprise Linux 9 and my kernel version is 5.14.0.

Linux TienyusRHEL 5.14.0-70.13.1.el9_0.x86_64 #1 SMP PREEMPT Thu Apr 14 12:42:38 EDT 2022 x86_64 x86_64 x86_64 GNU/Linux

Is there any way to work it out? Thank you for your work!

DKMS make.log for linux-apfs-rw-0.2 for kernel 5.18.3-arch1-1 (x86_64)
Mon Jun 13 23:06:19 PDT 2022
make: Entering directory '/usr/lib/modules/5.18.3-arch1-1/build'
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/btree.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/compress.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/dir.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/extents.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/file.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/inode.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/message.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/key.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/namei.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/node.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/object.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/spaceman.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/super.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/symlink.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/transaction.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/unicode.o
  CC [M]  /var/lib/dkms/linux-apfs-rw/0.2/build/xattr.o
/var/lib/dkms/linux-apfs-rw/0.2/build/inode.c:524:10: error: ‘const struct address_space_operations’ has no member named ‘invalidatepage’; did you mean ‘invalidate_folio’?
  524 |         .invalidatepage = apfs_noop_invalidatepage,
      |          ^~~~~~~~~~~~~~
      |          invalidate_folio
/var/lib/dkms/linux-apfs-rw/0.2/build/inode.c:524:27: error: initialization of ‘sector_t (*)(struct address_space *, sector_t)’ {aka ‘long long unsigned int (*)(struct address_space *, long long unsigned int)’} from incompatible pointer type ‘void (*)(struct page *, unsigned int,  unsigned int)’ [-Werror=incompatible-pointer-types]
  524 |         .invalidatepage = apfs_noop_invalidatepage,
      |                           ^~~~~~~~~~~~~~~~~~~~~~~~
/var/lib/dkms/linux-apfs-rw/0.2/build/inode.c:524:27: note: (near initialization for ‘apfs_aops.bmap’)
cc1: some warnings being treated as errors
make[1]: *** [scripts/Makefile.build:288: /var/lib/dkms/linux-apfs-rw/0.2/build/inode.o] Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [Makefile:1834: /var/lib/dkms/linux-apfs-rw/0.2/build] Error 2
make: Leaving directory '/usr/lib/modules/5.18.3-arch1-1/build'

Same git revision worked for 5.17.x kernels.

mounting apfs looks ok ...but the files inside the tree structure are almost empty I have mac's rootfs from a working virtual mac (I can play jessica rhaye singing bob dylan on youtube ; so it is really working) all the filenames in directory tree look quite normal ... but its contents are simply 0 I have just followed prescription make; modprobe libcrc... and insmod apfs.ko I am not aiming at modifying files in apfs ,but just willing to clone a apfs_mojave back into hfs_mojave using tar between the 2 filesytems under linux instead of using CCC carbone clone copy thank you

Thanks for this effort you are making by enabling apfs on Linux. I used your other tool to format an external hard disk, and everything seems to work. When I mount the newly formatted partition with:

sudo mount -o readwrite /dev/sdc1 Backup 

And I try to create anything either with sudo or as a regular user; it does not let me do that.

mkdir: cannot create directory ‘hola’: Read-only file system

PS. This is on Debian Unstable.

While writing a simple test for NixOS, I experimented a bit and found a problem. This is what I did:

1. truncate -s 1G /tmp/tmp.img
2. losetup -f /tmp/tmp.img
3. mkapfs /dev/loop0
4. mkdir /mnt/tmp
5. mount -o cknodes,readwrite /dev/loop0 /mnt/tmp
6. touch /mnt/tmp/testfile fails with "touch: cannot touch '/mnt/tmp/testfile': Bad message"
7. "APFS (86g): bad checksum for the space manager" and "APFS (86g): aborting transaction" appear in dmesg

Is this a known problem?