There are various cleanup tasks required before this driver can be moved to fs/ and out of staging/. TODO attemps to start a list of what those tasks may be. The README delineates a history and provides credit to the module's original authors. I am not the original author, I have just ported it for upstream submission. Signed-off-by: Ethan Carter Edwards <ethan@xxxxxxxxxxxxxxxxx> --- drivers/staging/apfs/README.rst | 87 +++++++++++++++++++++++++++++++++++++++++ drivers/staging/apfs/TODO | 7 ++++ 2 files changed, 94 insertions(+) diff --git a/drivers/staging/apfs/README.rst b/drivers/staging/apfs/README.rst new file mode 100644 index 0000000000000000000000000000000000000000..0aa624e3a6eca4bbce5dac07ccd224ce4a67f690 --- /dev/null +++ b/drivers/staging/apfs/README.rst @@ -0,0 +1,87 @@ +=========================== +Apple File System for Linux +=========================== + +The Apple File System (APFS) is the copy-on-write filesystem currently used on +all Apple devices. This module provides a degree of experimental support on +Linux. + +To help test write support, a set of userland tools is also under development. +The git tree can be retrieved from https://github.com/eafer/apfsprogs.git. + +Known limitations +================= + +This module is the result of reverse engineering and testing has been limited. +If you make use of the write support, there is a real risk of data corruption. +Please report any issues that you find. + +Writes to fusion drives are not currently supported. +Encryption is also not yet implemented even in read-only mode. + +Reporting bugs +============== + +If you encounter any problem, the first thing you should do is run (as root):: + + dmesg | grep -i apfs + +to see all the error messages. If that doesn't help you, please report the +issue via email at lore.kernel.org. + +Mount +===== + +Like all filesystems, apfs is mounted with:: + + mount [-o options] device dir + +where ``device`` is the path to your device file or filesystem image, and +``dir`` is the mount point. The following options are accepted: + +============ ================================================================= +vol=n Volume number to mount. The default is volume 0. + +snap=label Volume snapshot to mount (in read-only mode). + +tier2=path Path to the tier 2 device. For fusion drives only. + +uid=n, gid=n Override on-disk inode ownership data with given uid/gid. + +cknodes Verify the checksum on all metadata nodes. Right now this has a + severe performance cost, so it's not recommended. + +readwrite Enable the experimental write support. This may corrupt your + container. +============ ================================================================= + +So for instance, if you want to mount volume number 2, and you want the metadata +to be checked, you should run (as root):: + + mount -o cknodes,vol=2 device dir + +To unmount it, run:: + + umount dir + +Credits +======= + +Originally written by Ernesto A. Fernández <ernesto@xxxxxxxxxxxxx>, with +several contributions from Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>, +Arnaud Ferraris <arnaud.ferraris@xxxxxxxxxxxxx> and Stan Skowronek +<skylark@xxxxxxxxxxxxxxxxxxxxxxx>. For attribution details see the historical +git tree at https://github.com/eafer/linux-apfs.git and +https://github.com/linux-apfs/linux-apfs-rw. + +The module was ported by Ethan Carter Edwards <ethan@xxxxxxxxxxxxxxxxx> to +mainline and submitted upstream in 2025. + +Work was first based on reverse engineering done by others [1]_ [2]_, and later +on the (very incomplete) official specification [3]_. Some parts of the code +imitate the ext2 module, and to a lesser degree xfs, udf, gfs2 and hfsplus. + +.. [1] Hansen, K.H., Toolan, F., Decoding the APFS file system, Digital + Investigation (2017), https://dx.doi.org/10.1016/j.diin.2017.07.003 +.. [2] https://github.com/sgan81/apfs-fuse +.. [3] https://developer.apple.com/support/apple-file-system/Apple-File-System-Reference.pdf diff --git a/drivers/staging/apfs/TODO b/drivers/staging/apfs/TODO new file mode 100644 index 0000000000000000000000000000000000000000..15d566a532688900e7b6234ee7b9600e3c0f4f88 --- /dev/null +++ b/drivers/staging/apfs/TODO @@ -0,0 +1,7 @@ +There are a couple things that should probably happen before this +module is moved to fs/ and out of staging/. Most notably is the +proper documentation of how APFS/this module works. Another is the +conversion from bufferheads/pages to folios. + +Another good task for newcomers is patches that make it so this +module conforms to current kernel coding standards. -- 2.48.1
