On Mon, 2019-12-09 at 19:54 +0800, Xiubo Li wrote:
> On 2019/12/9 19:38, Jeff Layton wrote:
> > On Mon, 2019-12-09 at 04:28 -0500, xiubli@xxxxxxxxxx wrote:
> > > From: Xiubo Li <xiubli@xxxxxxxxxx>
> > >
> > > Try to queue writeback and invalidate the dirty pages when sessions
> > > are closed, rejected or reconnect denied.
> > >
> > > Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
> > > ---
> > > fs/ceph/mds_client.c | 13 +++++++++++++
> > > 1 file changed, 13 insertions(+)
> > >
> > Can you explain a bit more about the problem you're fixing? In what
> > situation is this currently broken, and what are the effects of that
> > breakage?
> >
> > > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> > > index be1ac9f8e0e6..68f3b5ed6ac8 100644
> > > --- a/fs/ceph/mds_client.c
> > > +++ b/fs/ceph/mds_client.c
> > > @@ -1385,9 +1385,11 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
> > > {
> > > struct ceph_fs_client *fsc = (struct ceph_fs_client *)arg;
> > > struct ceph_inode_info *ci = ceph_inode(inode);
> > > + struct ceph_mds_session *session = cap->session;
> > > LIST_HEAD(to_remove);
> > > bool dirty_dropped = false;
> > > bool invalidate = false;
> > > + bool writeback = false;
> > >
> > > dout("removing cap %p, ci is %p, inode is %p\n",
> > > cap, ci, &ci->vfs_inode);
> > > @@ -1398,12 +1400,21 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
> > > if (!ci->i_auth_cap) {
> > > struct ceph_cap_flush *cf;
> > > struct ceph_mds_client *mdsc = fsc->mdsc;
> > > + int s_state = session->s_state;
> > >
> > > if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
> > > if (inode->i_data.nrpages > 0)
> > > invalidate = true;
> > > if (ci->i_wrbuffer_ref > 0)
> > > mapping_set_error(&inode->i_data, -EIO);
> > > + } else if (s_state == CEPH_MDS_SESSION_CLOSED ||
> > > + s_state == CEPH_MDS_SESSION_REJECTED) {
> > > + /* reconnect denied or rejected */
> > > + if (!__ceph_is_any_real_caps(ci) &&
> > > + inode->i_data.nrpages > 0)
> > > + invalidate = true;
> > > + if (ci->i_wrbuffer_ref > 0)
> > > + writeback = true;
> > I don't know here. If the session is CLOSED/REJECTED, is kicking off
> > writeback the right thing to do? In principle, this means that the
> > client may have been blacklisted and none of the writes will succeed.
>
> If the client was blacklisted, it will be not safe to still buffer the
> data and flush it after the related sessions are reconnected without
> remounting.
>
> Maybe we need to throw it directly.
>
>
It depends. We have tunable behavior for this now.
I think you may want to look over the recover_session= patches that
were merged v5.4 ((131d7eb4faa1fc, and previous patches). That mount
option governs what happens if the client is blacklisted, and then the
blacklisting is later removed.
Will this patch change either recover_session= behavior? If so, then you
should explain how and why.
> > > }
> > >
> > > while (!list_empty(&ci->i_cap_flush_list)) {
> > > @@ -1472,6 +1483,8 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap,
> > > }
> > >
> > > wake_up_all(&ci->i_cap_wq);
> > > + if (writeback)
> > > + ceph_queue_writeback(inode);
> > > if (invalidate)
> > > ceph_queue_invalidate(inode);
> > > if (dirty_dropped)
> > Thanks,
>
>
--
Jeff Layton <jlayton@xxxxxxxxxx>
