On Sat, Jun 29, 2024 at 06:18:42PM -0400, Chuck Lever wrote:
> > +
> > + /* nfs_fh -> svc_fh */
> > + if (nfs_fh->size > NFS4_FHSIZE) {
> > + status = -EINVAL;
> > + goto out;
> > + }
> > + fh_init(&fh, NFS4_FHSIZE);
> > + fh.fh_handle.fh_size = nfs_fh->size;
> > + memcpy(fh.fh_handle.fh_raw, nfs_fh->data, nfs_fh->size);
> > +
> > + if (fmode & FMODE_READ)
> > + mayflags |= NFSD_MAY_READ;
> > + if (fmode & FMODE_WRITE)
> > + mayflags |= NFSD_MAY_WRITE;
> > +
> > + beres = nfsd_file_acquire(rqstp, &fh, mayflags, &nf);
> > + if (beres) {
> > + status = nfs_stat_to_errno(be32_to_cpu(beres));
> > + goto out_fh_put;
> > + }
>
> So I'm wondering whether just calling fh_verify() and then
> nfsd_open_verified() would be simpler and/or good enough here. Is
> there a strong reason to use the file cache for locally opened
> files? Jeff, any thoughts?
> Will there be writeback ramifications for
> doing this? Maybe we need a comment here explaining how these files
> are garbage collected (just an fput by the local I/O client, I would
> guess).
OK, going back to this: Since right here we immediately call
nfsd_file_put(nf);
There are no writeback ramifications nor any need to comment about
garbage collection. But this still seems like a lot of (possibly
unnecessary) overhead for simply obtaining a struct file.
> > +
> > + *pfilp = get_file(nf->nf_file);
> > +
> > + nfsd_file_put(nf);
> > +out_fh_put:
> > + fh_put(&fh);
> > +
> > +out:
> > + nfsd_local_fakerqst_destroy(rqstp);
> > +out_revertcred:
> > + revert_creds(save_cred);
> > + return status;
> > +}
> > +EXPORT_SYMBOL_GPL(nfsd_open_local_fh);
--
Chuck Lever
