On Thu, Dec 21, 2023 at 01:23:35PM +0000, David Howells wrote:
> Use netfslib's read and write iteration helpers, allowing netfslib to take
> over the management of the page cache for 9p files and to manage local disk
> caching. In particular, this eliminates write_begin, write_end, writepage
> and all mentions of struct page and struct folio from 9p.
>
> Note that netfslib now offers the possibility of write-through caching if
> that is desirable for 9p: just set the NETFS_ICTX_WRITETHROUGH flag in
> v9inode->netfs.flags in v9fs_set_netfs_context().
>
> Note also this is untested as I can't get ganesha.nfsd to correctly parse
> the config to turn on 9p support.
It looks like this patch has introduced a regression with autopkgtest,
see: https://bugs.launchpad.net/bugs/2056461
I haven't looked at the details yet, I just did some bisecting and
apparently reverting this one seems to fix the problem.
Let me know if you want me to test something in particular or if you
already have a potential fix. Otherwise I'll take a look.
Thanks,
-Andrea
Andrea Righi <[email protected]> wrote:
> On Thu, Dec 21, 2023 at 01:23:35PM +0000, David Howells wrote:
> > Use netfslib's read and write iteration helpers, allowing netfslib to take
> > over the management of the page cache for 9p files and to manage local disk
> > caching. In particular, this eliminates write_begin, write_end, writepage
> > and all mentions of struct page and struct folio from 9p.
> >
> > Note that netfslib now offers the possibility of write-through caching if
> > that is desirable for 9p: just set the NETFS_ICTX_WRITETHROUGH flag in
> > v9inode->netfs.flags in v9fs_set_netfs_context().
> >
> > Note also this is untested as I can't get ganesha.nfsd to correctly parse
> > the config to turn on 9p support.
>
> It looks like this patch has introduced a regression with autopkgtest,
> see: https://bugs.launchpad.net/bugs/2056461
>
> I haven't looked at the details yet, I just did some bisecting and
> apparently reverting this one seems to fix the problem.
>
> Let me know if you want me to test something in particular or if you
> already have a potential fix. Otherwise I'll take a look.
Do you have a reproducer?
I'll be at LSF next week, so if I can't fix it tomorrow, I won't be able to
poke at it until after that.
David
On Thu, May 09, 2024 at 10:33:37PM +0100, David Howells wrote:
> Andrea Righi <[email protected]> wrote:
>
> > On Thu, Dec 21, 2023 at 01:23:35PM +0000, David Howells wrote:
> > > Use netfslib's read and write iteration helpers, allowing netfslib to take
> > > over the management of the page cache for 9p files and to manage local disk
> > > caching. In particular, this eliminates write_begin, write_end, writepage
> > > and all mentions of struct page and struct folio from 9p.
> > >
> > > Note that netfslib now offers the possibility of write-through caching if
> > > that is desirable for 9p: just set the NETFS_ICTX_WRITETHROUGH flag in
> > > v9inode->netfs.flags in v9fs_set_netfs_context().
> > >
> > > Note also this is untested as I can't get ganesha.nfsd to correctly parse
> > > the config to turn on 9p support.
> >
> > It looks like this patch has introduced a regression with autopkgtest,
> > see: https://bugs.launchpad.net/bugs/2056461
> >
> > I haven't looked at the details yet, I just did some bisecting and
> > apparently reverting this one seems to fix the problem.
> >
> > Let me know if you want me to test something in particular or if you
> > already have a potential fix. Otherwise I'll take a look.
>
> Do you have a reproducer?
>
> I'll be at LSF next week, so if I can't fix it tomorrow, I won't be able to
> poke at it until after that.
>
> David
The only reproducer that I have at the moment is the autopkgtest command
mentioned in the bug, that is a bit convoluted, I'll try to see if I can
better isolate the problem and find a simpler reproducer, but I'll also
be travelling next week to a Canonical event.
At the moment I'll temporarily revert the commit (that seems to prevent
the issue from happening) and I'll keep you posted if I find something.
Thanks,
-Andrea
Andrea Righi <[email protected]> wrote:
> The only reproducer that I have at the moment is the autopkgtest command
> mentioned in the bug, that is a bit convoluted, I'll try to see if I can
> better isolate the problem and find a simpler reproducer, but I'll also
> be travelling next week to a Canonical event.
Note that the netfslib has some tracepoints that might help debug it.
David