Re: [PATCH] cifs: revalidate mapping prior to satisfying read_iter request with cache=loose

[Jeff Layton <jlayton-vpEMnDpepFuMZCB2o+C8xQ@public.gmane.org>]

On Fri, 23 May 2014 10:33:41 -0500
Steve French <smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:

> I pushed the other cifs patches to cifs-2.6.git for-next (and created
> a for-next-without-aio-iter branch that also includes the same set of
> cifs patch and also includes the older version of your revalidate
> patch that builds on current kernels) but your revalidate read_iter
> patch is not going to merge to for-next without me picking up at a
> minimum the patch that adds read_iter and write_iter to fs/cifs.
> Suggestions?
> 

Tough call...

I'm not sure how to handle that. One possibility would be to rebase
your for-next on top of Al's tree? Sort of icky, but I'm not sure what
else can be done...

> On Fri, May 23, 2014 at 9:52 AM, Steve French <smfrench-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> > Yes - makes sense.   I am rebuilding for-next branch of cifs-2.6.git
> > now.  I plan to put your patch on the tip of the branch - I may create
> > two branches, one with old and one with new version of the patch since
> > when I am testing latest cifs patches (and also the proposed SMB3
> > Posix extensions) don't have Al's series.
> >
> > On Fri, May 23, 2014 at 9:44 AM, Jeff Layton <jlayton-vpEMnDpepFuMZCB2o+C8xQ@public.gmane.org> wrote:
> >> On Fri, 23 May 2014 06:50:21 -0400
> >> Jeff Layton <jlayton-vpEMnDpepFuMZCB2o+C8xQ@public.gmane.org> wrote:
> >>
> >>> Before satisfying a read with cache=loose, we should always check
> >>> that the pagecache is valid before allowing a read to be satisfied
> >>> out of it.
> >>>
> >>> Reported-by: Tetsuo Handa <penguin-kernel-JPay3/Yim36HaxMnTkn67Xf5DAMn2ifp@public.gmane.org>
> >>> Signed-off-by: Jeff Layton <jlayton-vpEMnDpepFuMZCB2o+C8xQ@public.gmane.org>
> >>> ---
> >>>  fs/cifs/cifsfs.c | 17 +++++++++++++++--
> >>>  1 file changed, 15 insertions(+), 2 deletions(-)
> >>>
> >>> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> >>> index 2c90d07c0b3a..888398067420 100644
> >>> --- a/fs/cifs/cifsfs.c
> >>> +++ b/fs/cifs/cifsfs.c
> >>> @@ -725,6 +725,19 @@ out_nls:
> >>>       goto out;
> >>>  }
> >>>
> >>> +static ssize_t
> >>> +cifs_loose_read_iter(struct kiocb *iocb, struct iov_iter *iter)
> >>> +{
> >>> +     ssize_t rc;
> >>> +     struct inode *inode = file_inode(iocb->ki_filp);
> >>> +
> >>> +     rc = cifs_revalidate_mapping(inode);
> >>> +     if (rc)
> >>> +             return rc;
> >>> +
> >>> +     return generic_file_read_iter(iocb, iter);
> >>> +}
> >>> +
> >>>  static ssize_t cifs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
> >>>  {
> >>>       struct inode *inode = file_inode(iocb->ki_filp);
> >>> @@ -881,7 +894,7 @@ const struct inode_operations cifs_symlink_inode_ops = {
> >>>  const struct file_operations cifs_file_ops = {
> >>>       .read = new_sync_read,
> >>>       .write = new_sync_write,
> >>> -     .read_iter = generic_file_read_iter,
> >>> +     .read_iter = cifs_loose_read_iter,
> >>>       .write_iter = cifs_file_write_iter,
> >>>       .open = cifs_open,
> >>>       .release = cifs_close,
> >>> @@ -939,7 +952,7 @@ const struct file_operations cifs_file_direct_ops = {
> >>>  const struct file_operations cifs_file_nobrl_ops = {
> >>>       .read = new_sync_read,
> >>>       .write = new_sync_write,
> >>> -     .read_iter = generic_file_read_iter,
> >>> +     .read_iter = cifs_loose_read_iter,
> >>>       .write_iter = cifs_file_write_iter,
> >>>       .open = cifs_open,
> >>>       .release = cifs_close,
> >>
> >> Steve,
> >>
> >> This patch is a replacement for the last patch in the 4 patch series
> >> for handling reads when cache=loose. The reason for the respin is that
> >> aio_read has been replaced by read_iter in linux-next, so this is what
> >> we'll want for v3.16 (once Al's read_iter patches are merged).
> >>
> >> Thanks,
> >> --
> >> Jeff Layton <jlayton-vpEMnDpepFuMZCB2o+C8xQ@public.gmane.org>
> >
> >
> >
> > --
> > Thanks,
> >
> > Steve
> 
> 
> 


-- 
Jeff Layton <jlayton-vpEMnDpepFuMZCB2o+C8xQ@public.gmane.org>