On Thu, 2022-04-07 at 11:33 -0400, Jeff Layton wrote:
> On Thu, 2022-04-07 at 22:41 +0800, xiubli@xxxxxxxxxx wrote:
> > From: Xiubo Li <xiubli@xxxxxxxxxx>
> >
> > When truncating the file size the MDS will help update the last
> > encrypted block, and during this we need to make sure the client
> > won't fill the pagecaches.
> >
> > Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
> > ---
> > fs/ceph/inode.c | 7 ++++++-
> > 1 file changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
> > index f4059d73edd5..cc1829ab497d 100644
> > --- a/fs/ceph/inode.c
> > +++ b/fs/ceph/inode.c
> > @@ -2647,9 +2647,12 @@ int __ceph_setattr(struct inode *inode, struct iattr *attr, struct ceph_iattr *c
> > req->r_num_caps = 1;
> > req->r_stamp = attr->ia_ctime;
> > if (fill_fscrypt) {
> > + filemap_invalidate_lock(inode->i_mapping);
> > err = fill_fscrypt_truncate(inode, req, attr);
> > - if (err)
> > + if (err) {
> > + filemap_invalidate_unlock(inode->i_mapping);
> > goto out;
> > + }
> > }
> >
> > /*
> > @@ -2660,6 +2663,8 @@ int __ceph_setattr(struct inode *inode, struct iattr *attr, struct ceph_iattr *c
> > * it.
> > */
> > err = ceph_mdsc_do_request(mdsc, NULL, req);
> > + if (fill_fscrypt)
> > + filemap_invalidate_unlock(inode->i_mapping);
> > if (err == -EAGAIN && truncate_retry--) {
> > dout("setattr %p result=%d (%s locally, %d remote), retry it!\n",
> > inode, err, ceph_cap_string(dirtied), mask);
>
> Looks reasonable. Is there any reason we shouldn't do this in the non-
> encrypted case too? I suppose it doesn't make as much difference in that
> case.
>
> I'll plan to pull this and the other patch into the wip-fscrypt branch.
> Should I just fold them into your earlier patches?
OTOH...do we really need this? I'm not sure I understand the race you're
trying to prevent. Can you lay it out for me?
Thanks,
--
Jeff Layton <jlayton@xxxxxxxxxx>
