Re: NFS delegations behavior analysis
Trond Myklebust <[email protected]>
| Newsgroups | gmane.linux.nfs |
|---|---|
| Message-ID | <[email protected]> |
On Tue, 2026-06-23 at 09:32 -0400, Benjamin Coddington wrote: > On 23 Jun 2026, at 9:11, Benjamin Coddington wrote: > > > .... er - so with directory delegations, can we simply re-hydrate > > the dentry > > cache from the directory page mappings if the delegation is still > > valid? > > Does the directory delegation pin the mapping? Clearly I need to > > look at > > the code.. > > .. right - we don't keep the file attributes in the mappings today. > And, > more to the point - the directory delegation doesn't protect those > file > attributes either. We'd need NOTIFY4_CHANGE_CHILD_ATTRIBUTES > implemented. > > Ben Unlike delegations, notifications are asynchronous by design. Upon reception of a notification, you may deduce that you should revalidate the attributes on a file. However the absence of that notification is insufficient to deduce that it is safe not to revalidate those attributes. So when it comes to informing the client whether to use READDIR or READDIRPLUS, I'm sceptical concerning the value of throwing NOTIFY4_CHANGE_CHILD_ATTRS at the problem. -- Trond Myklebust Linux NFS client maintainer, Hammerspace [email protected], trond.myklebust-F/[email protected]