On Wed, 30 Aug 2023, Chuck Lever wrote:
> On Tue, Aug 29, 2023 at 12:26:56PM -0400, Benjamin Coddington wrote:
> > This patch sets the SEQ4_STATUS_RECALLABLE_STATE_REVOKED bit for a single
> > SEQUENCE response after writing "revoke" to the client's ctl file in procfs.
> > It has been generally useful to test various NFS client implementations, so
> > I'm sending it along for others to find and use.
>
> Intriguing!
>
> It looks to me like the client would probe its state and
> find nothing missing... fair enough.
>
> Would it be even more useful if the server administrator could
> actually revoke some state, rather than just pretending to?
> How difficult do you think that might be?
I have patches for revoking state. I sent them some time ago and we
discussed them, but you wanted to wait for the courteous client code to
land (which was fair enough) and then I forgot to come back with them.
I'll try to make time to repost them.
NeilBrown
>
> Or, conversely, what exactly can you test with this mechanism?
>
>
> > Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx>
> > ---
> > fs/nfsd/nfs4state.c | 19 +++++++++++++++----
> > fs/nfsd/state.h | 1 +
> > 2 files changed, 16 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> > index daf305daa751..f91e2857df65 100644
> > --- a/fs/nfsd/nfs4state.c
> > +++ b/fs/nfsd/nfs4state.c
> > @@ -2830,18 +2830,28 @@ static ssize_t client_ctl_write(struct file *file, const char __user *buf,
> > {
> > char *data;
> > struct nfs4_client *clp;
> > + ssize_t rc = size;
> >
> > data = simple_transaction_get(file, buf, size);
> > if (IS_ERR(data))
> > return PTR_ERR(data);
> > - if (size != 7 || 0 != memcmp(data, "expire\n", 7))
> > +
> > + if (size != 7)
> > return -EINVAL;
> > +
> > clp = get_nfsdfs_clp(file_inode(file));
> > if (!clp)
> > return -ENXIO;
> > - force_expire_client(clp);
> > +
> > + if (!memcmp(data, "revoke\n", 7))
> > + set_bit(NFSD4_CLIENT_CL_REVOKED, &clp->cl_flags);
> > + else if (!memcmp(data, "expire\n", 7))
> > + force_expire_client(clp);
> > + else
> > + rc = -EINVAL;
> > +
> > drop_client(clp);
> > - return 7;
> > + return rc;
> > }
> >
> > static const struct file_operations client_ctl_fops = {
> > @@ -4042,7 +4052,8 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> > default:
> > seq->status_flags = 0;
> > }
> > - if (!list_empty(&clp->cl_revoked))
> > + if (!list_empty(&clp->cl_revoked) ||
> > + test_and_clear_bit(NFSD4_CLIENT_CL_REVOKED, &clp->cl_flags))
> > seq->status_flags |= SEQ4_STATUS_RECALLABLE_STATE_REVOKED;
> > out_no_session:
> > if (conn)
> > diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
> > index d49d3060ed4f..a9154b7da022 100644
> > --- a/fs/nfsd/state.h
> > +++ b/fs/nfsd/state.h
> > @@ -369,6 +369,7 @@ struct nfs4_client {
> > #define NFSD4_CLIENT_CB_FLAG_MASK (1 << NFSD4_CLIENT_CB_UPDATE | \
> > 1 << NFSD4_CLIENT_CB_KILL)
> > #define NFSD4_CLIENT_CB_RECALL_ANY (6)
> > +#define NFSD4_CLIENT_CL_REVOKED (7)
> > unsigned long cl_flags;
> > const struct cred *cl_cb_cred;
> > struct rpc_clnt *cl_cb_client;
> > --
> > 2.40.1
> >
>
> --
> Chuck Lever
>
