On Fri, Sep 24, 2021 at 04:13:23AM +0000, Trond Myklebust wrote:
On Fri, 2021-09-24 at 05:46 +0200, Ralph Boehme wrote:
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.
Right, but that is easily solved in user space by having the cookie act
as a key that references the file descriptor that holds the lease. This
is how we typically implement NFSv4 delegations as well.
How does this work in multi-process situations ?
When you say "file descriptor", if the fd was passed
between processes would the lease state transfer ?
