Re: [PATCH V4 0/6] shmem: Add user and group quota support for tmpfs

[Carlos Maiolino <cem@kernel.org>]

On Wed, Apr 26, 2023 at 12:20:02PM +0200, cem@kernel.org wrote:
> From: Carlos Maiolino <cem@kernel.org>
> 
> Hello folks.
> 
> This is the final version of the quota support from tmpfs, with all the issues
> addressed, and now including RwB tags on all patches, and should be ready for
> merge. Details are within each patch, and the original cover-letter below.
> 

Ping? Can somebody manage to pickup these patches?

Thanks!

> Hi folks. this work has been done originally by Lukas, but he left the company,
> so I'm taking over his work from where he left it of. This series is virtually
> done, and he had updated it with comments from the last version, but, I'm
> initially posting it as a RFC because it's been a while since he posted the
> last version.
> Most of what I did here was rebase his last work on top of current Linus's tree.
> 
> Honza, there is one patch from you in this series, which I believe you had it
> suggested to Lukas on a previous version.
> 
> The original cover-letter follows...
> 
> people have been asking for quota support in tmpfs many times in the past
> mostly to avoid one malicious user, or misbehaving user/program to consume
> all of the system memory. This has been partially solved with the size
> mount option, but some problems still prevail.
> 
> One of the problems is the fact that /dev/shm is still generally unprotected
> with this and another is administration overhead of managing multiple tmpfs
> mounts and lack of more fine grained control.
> 
> Quota support can solve all these problems in a somewhat standard way
> people are already familiar with from regular file systems. It can give us
> more fine grained control over how much memory user/groups can consume.
> Additionally it can also control number of inodes and with special quota
> mount options introduced with a second patch we can set global limits
> allowing us to replace the size mount option with quota entirely.
> 
> Currently the standard userspace quota tools (quota, xfs_quota) are only
> using quotactl ioctl which is expecting a block device. I patched quota [1]
> and xfs_quota [2] to use quotactl_fd in case we want to run the tools on
> mount point directory to work nicely with tmpfs.
> 
> The implementation was tested on patched version of xfstests [3].
> 
> [1] https://github.com/lczerner/quota/tree/quotactl_fd_support
> [2] https://github.com/lczerner/xfsprogs/tree/quotactl_fd_support
> [3] https://github.com/lczerner/xfstests/tree/tmpfs_quota_support
> 
> 
> Jan Kara (1):
>   quota: Check presence of quota operation structures instead of
>     ->quota_read and ->quota_write callbacks
> 
> Lukas Czerner (5):
>   shmem: make shmem_inode_acct_block() return error
>   shmem: make shmem_get_inode() return ERR_PTR instead of NULL
>   shmem: prepare shmem quota infrastructure
>   shmem: quota support
>   Add default quota limit mount options
> 
>  Documentation/filesystems/tmpfs.rst |  31 ++
>  fs/Kconfig                          |  12 +
>  fs/quota/dquot.c                    |   2 +-
>  include/linux/shmem_fs.h            |  28 ++
>  include/uapi/linux/quota.h          |   1 +
>  mm/Makefile                         |   2 +-
>  mm/shmem.c                          | 465 +++++++++++++++++++++-------
>  mm/shmem_quota.c                    | 350 +++++++++++++++++++++
>  8 files changed, 783 insertions(+), 108 deletions(-)
>  create mode 100644 mm/shmem_quota.c
> 
> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
> --
> 2.30.2
> 

-- 
Carlos Maiolino