Jeff Layton <jlayton@xxxxxxxxxx> wrote:
> > (7) If stored data is culled from the local cache, we must set zero_point
> > above that if the data also got written to the server.
>
> When you say culled here, it sounds like you're just throwing out the
> dirty cache without writing the data back. That shouldn't be allowed
> though, so I must be misunderstanding what you mean here. Can you
> explain?
I meant fscache specifically. Too many caches - and some of them with the
same names!
> > (8) If dirty data is written back to the server, but not the local cache,
> > we must set zero_point above that.
>
> How do you write back without writing to the local cache? I'm guessing
> this means you're doing a non-buffered write?
I meant fscache. fscache can decline to honour a request to store data.
> > + if (size != i_size) {
> > + truncate_pagecache(&vnode->netfs.inode, size);
> > + netfs_resize_file(&vnode->netfs, size);
> > + fscache_resize_cookie(afs_vnode_cache(vnode), size);
> > + }
>
> Isn't this an existing bug? AFS is not setting remote_i_size in the
> setattr path currently? I think this probably ought to be done in a
> preliminary AFS patch.
It is being set. afs_apply_status() sets it. This is called by
afs_vnode_commit_status() which is called from afs_setattr_success(). The
value isn't updated until we get the return status from the server that
includes the new value.
> > + loff_t zero_point; /* Size after which we assume there's no data
> > + * on the server */
>
> While I understand the concept, I'm not yet sure I understand how this
> new value will be used. It might be better to merge this patch in with
> the patch that adds the first user of this data.
I'll consider it. At least it might make sense to move them adjacent to each
other in the series.
David
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