nfsd41: destroy_session operation

Implement the destory_session operation confoming to
http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-26

[use sessionid_lock spin lock]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/nfs4state.c

@@ -1422,7 +1422,34 @@ nfsd4_destroy_session(struct svc_rqst *r,
 		      struct nfsd4_compound_state *cstate,
 		      struct nfsd4_destroy_session *sessionid)
 {
-	return -1;	/* stub */
+	struct nfsd4_session *ses;
+	u32 status = nfserr_badsession;
+
+	/* Notes:
+	 * - The confirmed nfs4_client->cl_sessionid holds destroyed sessinid
+	 * - Should we return nfserr_back_chan_busy if waiting for
+	 *   callbacks on to-be-destroyed session?
+	 * - Do we need to clear any callback info from previous session?
+	 */
+
+	dump_sessionid(__func__, &sessionid->sessionid);
+	spin_lock(&sessionid_lock);
+	ses = find_in_sessionid_hashtbl(&sessionid->sessionid);
+	if (!ses) {
+		spin_unlock(&sessionid_lock);
+		goto out;
+	}
+
+	unhash_session(ses);
+	spin_unlock(&sessionid_lock);
+
+	/* wait for callbacks */
+	shutdown_callback_client(ses->se_client);
+	nfsd4_put_session(ses);
+	status = nfs_ok;
+out:
+	dprintk("%s returns %d\n", __func__, ntohl(status));
+	return status;
 }
 
 __be32

fs/nfsd/nfs4xdr.c

@@ -1207,7 +1207,11 @@ static __be32
 nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
 			     struct nfsd4_destroy_session *destroy_session)
 {
-	return nfserr_opnotsupp;	/* stub */
+	DECODE_HEAD;
+	READ_BUF(NFS4_MAX_SESSIONID_LEN);
+	COPYMEM(destroy_session->sessionid.data, NFS4_MAX_SESSIONID_LEN);
+
+	DECODE_TAIL;
 }
 
 static __be32
@@ -2971,7 +2975,6 @@ static __be32
 nfsd4_encode_destroy_session(struct nfsd4_compoundres *resp, int nfserr,
 			     struct nfsd4_destroy_session *destroy_session)
 {
-	/* stub */
 	return nfserr;
 }
 

include/linux/nfsd/xdr4.h

@@ -395,7 +395,7 @@ struct nfsd4_sequence {
 };
 
 struct nfsd4_destroy_session {
-	int	foo;	/* stub */
+	struct nfs4_sessionid	sessionid;
 };
 
 struct nfsd4_op {