[Samba] How samba guarantee close-to-open consistency?

[jie wang]

If we only open file for read, and when we close it, do we also need to
signall all other smbds to drop cache ?

"But if you really want to cache on the server side, you could signal all
other smbds with a message to drop the cache when you process the close
in your VFS module."

On Wed, Jun 29, 2022 at 6:09 PM jie wang <yjxxtd12 at gmail.com> wrote:

> Thanks the reply, I'm interested in the DOS attributes, how can we avoid
> storing an xattr ?
>
> "Another question would be which metadata your shooting for? stat info?
> DOS attributes? For the latter we have some design ideas to avoid the
> need to store an xattr with the DOS attributes for the default case."
>
> On Thu, Jun 23, 2022 at 10:37 PM Ralph Boehme <slow at samba.org> wrote:
>
>> On 6/23/22 15:54, jie wang wrote:
>> > Yes, we implement a vfs module which has cache. And we want to get
>> > attributes from cache when samba calls openat.
>>
>> well, I guess the correct way to tackle this would be to let the
>> *clients* do the caching with leases for file data and with directory
>> leases for file metadata.
>>
>> But if you really want to cache on the server side, you could signal all
>> other smbds with a message to drop the cache when you process the close
>> in your VFS module.
>>
>> Another question would be which metadata your shooting for? stat info?
>> DOS attributes? For the latter we have some design ideas to avoid the
>> need to store an xattr with the DOS attributes for the default case.
>>
>> Cheers!
>> -slow
>>
>> --
>> Ralph Boehme, Samba Team                 https://samba.org/
>> SerNet Samba Team Lead      https://sernet.de/en/team-samba
>>
>