Re: [PATCH v2] docs: Remove outdated highuid.rst documentation

From: Jonathan Corbet
Date: Mon Mar 17 2025 - 18:46:12 EST


kth <kangtaeho2456@xxxxxxxxx> writes:

> The highuid.rst document describes a transition that is outdated and no
> longer relevant. Additionally, it references filesystems (ncpfs and smbfs),
> which have been removed or replaced.
>
> Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> Signed-off-by: Kang Taeho <kangtaeho2456@xxxxxxxxx>
> ---
> Documentation/admin-guide/highuid.rst | 80 ---------------------------
> Documentation/admin-guide/index.rst | 1 -
> 2 files changed, 81 deletions(-)
> delete mode 100644 Documentation/admin-guide/highuid.rst

OK, I have applied this, but it was some work. For future reference:

- When you do a v2 (or whatever), always include a description of what
changed since the previous version under the "---" line.

- Before sending another patch, email it to yourself and be sure that
you can apply what you receive. This patch was whitespace damaged,
but that is not all ...

>
> diff --git a/Documentation/admin-guide/highuid.rst b/Documentation/admin-guide/highuid.rst
> deleted file mode 100644
> index 9239067563a1..000000000000
> --- a/Documentation/admin-guide/highuid.rst
> +++ /dev/null
> @@ -1,80 +0,0 @@
> -===================================================
> -Notes on the change from 16-bit UIDs to 32-bit UIDs
> -===================================================
> -
> -:Author: Chris Wing <wingc@xxxxxxxxx>
> -:Last updated: January 11, 2000
> -
> -- kernel code MUST take into account __kernel_uid_t and __kernel_uid32_t
> - when communicating between user and kernel space in an ioctl or data
> - structure.
> -
> -- kernel code should use uid_t and gid_t in kernel-private structures and
> - code.
> -
> -What's left to be done for 32-bit UIDs on all Linux architectures:
> -
> -- Disk quotas have an interesting limitation that is not related to the
> - maximum UID/GID. They are limited by the maximum file size on the
> - underlying filesystem, because quota records are written at offsets
> - corresponding to the UID in question.
> - Further investigation is needed to see if the quota system can cope
> - properly with huge UIDs. If it can deal with 64-bit file offsets on all
> - architectures, this should not be a problem.
> -
> -- Decide whether or not to keep backwards compatibility with the system
> - accounting file, or if we should break it as the comments suggest
> - (currently, the old 16-bit UID and GID are still written to disk, and
> - part of the former pad space is used to store separate 32-bit UID and
> - GID)
> -
> -- Need to validate that OS emulation calls the 16-bit UID
> - compatibility syscalls, if the OS being emulated used 16-bit UIDs, or
> - uses the 32-bit UID system calls properly otherwise.
> -
> - This affects at least:
> -
> - - iBCS on Intel
> -
> - - sparc32 emulation on sparc64
> - (need to support whatever new 32-bit UID system calls are added to
> - sparc32)
> -
> -- Validate that all filesystems behave properly.
> -
> - At present, 32-bit UIDs _should_ work for:
> -
> - - ext2
> - - ufs
> - - isofs
> - - nfs
> - - coda
> - - udf
> -
> - Ioctl() fixups have been made for:
> -
> - - ncpfs
> - - smbfs
> -
> - Filesystems with simple fixups to prevent 16-bit UID wraparound:
> -
> - - minix
> - - sysv
> - - qnx4
> -
> - Other filesystems have not been checked yet.
> -
> -- The ncpfs and smbfs filesystems cannot presently use 32-bit UIDs in

This line here ^^^^^ contains your previous attempted fix; that,
too, caused the patch to fail to apply. I had to hand edit it to get
past that.

Thanks,

jon