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?
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
