Re: Locking issue between NFSv4 and SMB client

Ralph Boehme
2021-09-24T03:46:37Z

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Am 24.09.21 um 05:35 schrieb Trond Myklebust:
> Not if you set the "kernel oplocks" parameter in the smb.conf file. We
> just added support for this in the Linux 5.14 kernel NFSv4 client.
>
> Now that said, "kernel oplocks" will currently only support basic level
> I oplocks, and cannot support level II or leases. According to the
> smb.conf manpage, this is due to some incompleteness in the current VFS
> lease implementation.
>
> I'd love to get some more info from the Samba team about what is
> missing from the kernel lease implementation that prevents us from
> implementing these more advanced oplock/lease features. From the
> description in Microsoft's docs, I'm pretty sure that NFSv4 delegations
> should be able to provide all the guarantees that are required.

leases can be shared among file handles. When someone requests a lease
he passes a cookie. Then when he opens the same file with the same
cookie the lease is not broken.

Maybe others can comment on the level II oplock problem. Afaik this was
more a lack of testing.

-slow

--
Ralph Boehme, Samba Team https://samba.org/
SerNet Samba Team Lead https://sernet.de/en/team-samba

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