Re: [PATCH] nfsd: allow setting SEQ4_STATUS_RECALLABLE_STATE_REVOKED

[Jeff Layton <jlayton@kernel.org>]

On Tue, 2023-08-29 at 12:26 -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.
> 
> Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
> ---
>  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;


Seems like a useful knob.

Reviewed-by: Jeff Layton <jlayton@kernel.org>