[Virtio-fs] [PATCH v2 0/2] virtiofsd: Fix xattr and ACL

[Vivek Goyal]

On Tue, Jan 28, 2020 at 07:18:17PM +0900, Misono Tomohiro wrote:
> Hi,
> 
> This is a second version of xattr fix for virtiofsd.
> I included ACL fix (which introduces new option posix_acl) in this version
> too as ACL mostly depends on xattr.
> 
> I run xfstests with XFS backend using "-o xattr -o posix_acl" option and
> only new failure is generic/375 which checks if sgid bit is cleared after
> setfacl. I'll try to investigate it.
> 
> change in v1 -> v2
>  - rebased to current dev branch
> 
>  - Always chdir for xattr (1st patch)
>    In v1, I keep current implementation for regular file/dir since it
>    show better performance in my environment. But I notice opening file
>    for xattr causes seek sanity test fails (xfstest generic/285, 436).
> 
>    I'm not sure what is the fundamental problem here but I believe
>    performance can be improved by introducing some caching mechanism
>    in general.

Hi Misono,

How much is performance degradation due to fchdir(). If it is significant,
then I will be inclined to keep original code for dir/file till some
other mechanism is introduced to offset the perofrmance loss.

> So I change the code to always fchdir to avoid the
>    problem for now. This results in simpler code too.
> 
>  - Add ACL fix (2nd patch)
>    ACL mostly works if xattr option is enabled.
>    To support default ACL behavior, add new option posix_acl which
>    handles umasking in virtiofsd instead of guest kernel.

Ideally I would preferred ACL changes in a separapte patch series. We had
been discussing xattr related changes and it will be easier to test and
review xattr changes and then followed by ACL changes. Anyway, now you
have already posted these changes in smae patch series, I will review it.

But if you happen to post another patch series, then lets separate out
xattr changes and ACL changes in separate patch series.

Thanks
Vivek

> 
> Thanks,
> Misono
> 
> Misono Tomohiro (2):
>   virtiofsd: Fix xattr operations
>   virtiofsd: Add support of posix_acl
> 
>  tools/virtiofsd/fuse_virtio.c    |  13 +++
>  tools/virtiofsd/helper.c         |   3 +
>  tools/virtiofsd/passthrough_ll.c | 136 +++++++++++++++++++++----------
>  tools/virtiofsd/seccomp.c        |  11 ++-
>  4 files changed, 115 insertions(+), 48 deletions(-)
> 
> -- 
> 2.21.1
>