[Linux-cifsd-devel] [PATCH] cifsd: make xattr format of ksmbd compatible with samba's one

[Namjae Jeon]

> Hi Namjae,
Hi Metze,
>
> I played with this today and found a few things.
Great. Thanks for your check!
>
>>>> Samba team request that ksmbd should make xattr format of ksmbd
>>>> compatible
>>>> with samba's one. When user replace samba with ksmbd or replace ksmbd
>>>> with samba, The written attribute and ACLs of xattr in file should be
>>>> used
>>>> on both server. This patch work the following ones.
>>>>  1. make xattr prefix compaible.
>>>>     - rename creation.time and file.attribute to DOSATTRIB.
>
> I just noticed that you use xattr_DosInfo3 instead of xattr_DosInfo4,
> Samba uses xattr_DosInfo4, starting from samba-4.11.0, so all supported
> Samba releases write xattr_DosInfo4. All versions from 3.5-4.10 wrote
> xattr_DosInfo3. Versions before 3.5 only stored the hex-string.
>
> So it would be good to read hex-string-only, xattr_DosInfo3 and
> xattr_DosInfo4 and write
> xattr_DosInfo4.
Okay, I will add xattr_DosInfo4 support. but I don't think that ksmbd
support the structure of too old samba version.
>
>>>>     - rename stream. to DosStream.
>
> I noticed that "vfs objects = acl_xattr" is allowed,
>
> "vfs objects = streams_xattr acl_xattr" is not handled at all,
> even acl_xattr isn't detected in that case.
ksmbd supports it under a different name. It would be better to change
it to the name used by samba.
>
>>>>     - rename sd. to NTACL.
>
> There seems to be a problem, when a new file inherits acls from the parent
> directory. There I see a strange owner sid:
Hm... I'll try to reproduce it when I go to office.

Thanks!
>
>                         owner_sid                : *
>                             owner_sid                : S-21-2276714256
> and
>
> WARNING! 20 unread bytes
> [0000] 00 00 00 00 00 00 00 00   00 00 00 00 00 00 00 00   ........
> ........
> [0010] 00 00 00 00
>
> I used this command to analyze this:
>
> getfattr -n security.NTACL WHATSNEW.txt | grep security.NTACL| sed -e
> 's!security.NTACL=0s!!' | ndrdump --base64-input xattr xattr_NTACL struct
> 2>&1 |less
>
> metze
>
>