nfsd4: support BIND_CONN_TO_SESSION

Basic xdr and processing for BIND_CONN_TO_SESSION.  This adds a
connection to the list of connections associated with a session.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

5 files changed, 99 insertions, 10 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index fd6694b49e1c..db52546143d1 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1004,8 +1004,8 @@ static const char *nfsd4_op_name(unsigned opnum);
  * Also note, enforced elsewhere:
  *      - SEQUENCE other than as first op results in
  *        NFS4ERR_SEQUENCE_POS. (Enforced in nfsd4_sequence().)
- *      - BIND_CONN_TO_SESSION must be the only op in its compound
- *        (Will be enforced in nfsd4_bind_conn_to_session().)
+ *      - BIND_CONN_TO_SESSION must be the only op in its compound.
+ *        (Enforced in nfsd4_bind_conn_to_session().)
  *      - DESTROY_SESSION must be the final operation in a compound, if
  *        sessionid's in SEQUENCE and DESTROY_SESSION are the same.
  *        (Enforced in nfsd4_destroy_session().)
@@ -1326,6 +1326,11 @@ static struct nfsd4_operation nfsd4_ops[] = {
                 .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
                 .op_name = "OP_EXCHANGE_ID",
         },
+        [OP_BIND_CONN_TO_SESSION] = {
+                .op_func = (nfsd4op_func)nfsd4_bind_conn_to_session,
+                .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
+                .op_name = "OP_BIND_CONN_TO_SESSION",
+        },
         [OP_CREATE_SESSION] = {
                 .op_func = (nfsd4op_func)nfsd4_create_session,
                 .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 3cf9900d5f32..956174f488a7 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -679,15 +679,12 @@ static int nfsd4_register_conn(struct nfsd4_conn *conn)
         return register_xpt_user(conn->cn_xprt, &conn->cn_xpt_user);
 }
 
-static __be32 nfsd4_new_conn(struct svc_rqst *rqstp, struct nfsd4_session *ses)
+static __be32 nfsd4_new_conn(struct svc_rqst *rqstp, struct nfsd4_session *ses, u32 dir)
 {
         struct nfsd4_conn *conn;
-        u32 flags = NFS4_CDFC4_FORE;
         int ret;
 
-        if (ses->se_flags & SESSION4_BACK_CHAN)
-                flags |= NFS4_CDFC4_BACK;
-        conn = alloc_conn(rqstp, flags);
+        conn = alloc_conn(rqstp, dir);
         if (!conn)
                 return nfserr_jukebox;
         nfsd4_hash_conn(conn, ses);
@@ -698,6 +695,17 @@ static __be32 nfsd4_new_conn(struct svc_rqst *rqstp, struct nfsd4_session *ses)
         return nfs_ok;
 }
 
+static __be32 nfsd4_new_conn_from_crses(struct svc_rqst *rqstp, struct nfsd4_session *ses)
+{
+        u32 dir = NFS4_CDFC4_FORE;
+
+        if (ses->se_flags & SESSION4_BACK_CHAN)
+                dir |= NFS4_CDFC4_BACK;
+
+        return nfsd4_new_conn(rqstp, ses, dir);
+}
+
+/* must be called under client_lock */
 static void nfsd4_del_conns(struct nfsd4_session *s)
 {
         struct nfs4_client *clp = s->se_client;
@@ -776,7 +784,7 @@ static struct nfsd4_session *alloc_init_session(struct svc_rqst *rqstp, struct n
         spin_unlock(&clp->cl_lock);
         spin_unlock(&client_lock);
 
-        status = nfsd4_new_conn(rqstp, new);
+        status = nfsd4_new_conn_from_crses(rqstp, new);
         /* whoops: benny points out, status is ignored! (err, or bogus) */
         if (status) {
                 free_session(&new->se_ref);
@@ -1597,6 +1605,45 @@ static bool nfsd4_last_compound_op(struct svc_rqst *rqstp)
         return argp->opcnt == resp->opcnt;
 }
 
+static __be32 nfsd4_map_bcts_dir(u32 *dir)
+{
+        switch (*dir) {
+        case NFS4_CDFC4_FORE:
+        case NFS4_CDFC4_BACK:
+                return nfs_ok;
+        case NFS4_CDFC4_FORE_OR_BOTH:
+        case NFS4_CDFC4_BACK_OR_BOTH:
+                *dir = NFS4_CDFC4_BOTH;
+                return nfs_ok;
+        };
+        return nfserr_inval;
+}
+
+__be32 nfsd4_bind_conn_to_session(struct svc_rqst *rqstp,
+                     struct nfsd4_compound_state *cstate,
+                     struct nfsd4_bind_conn_to_session *bcts)
+{
+        __be32 status;
+
+        if (!nfsd4_last_compound_op(rqstp))
+                return nfserr_not_only_op;
+        spin_lock(&client_lock);
+        cstate->session = find_in_sessionid_hashtbl(&bcts->sessionid);
+        /* Sorta weird: we only need the refcnt'ing because new_conn acquires
+         * client_lock iself: */
+        if (cstate->session) {
+                nfsd4_get_session(cstate->session);
+                atomic_inc(&cstate->session->se_client->cl_refcount);
+        }
+        spin_unlock(&client_lock);
+        if (!cstate->session)
+                return nfserr_badsession;
+
+        status = nfsd4_map_bcts_dir(&bcts->dir);
+        nfsd4_new_conn(rqstp, cstate->session, bcts->dir);
+        return nfs_ok;
+}
+
 static bool nfsd4_compound_in_session(struct nfsd4_session *session, struct nfs4_sessionid *sid)
 {
         if (!session)
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index ca3786905dec..4ff2c9e0b276 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -421,6 +421,21 @@ nfsd4_decode_access(struct nfsd4_compoundargs *argp, struct nfsd4_access *access
         DECODE_TAIL;
 }
 
+static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp, struct nfsd4_bind_conn_to_session *bcts)
+{
+        DECODE_HEAD;
+        u32 dummy;
+
+        READ_BUF(NFS4_MAX_SESSIONID_LEN + 8);
+        COPYMEM(bcts->sessionid.data, NFS4_MAX_SESSIONID_LEN);
+        READ32(bcts->dir);
+        /* XXX: Perhaps Tom Tucker could help us figure out how we
+         * should be using ctsa_use_conn_in_rdma_mode: */
+        READ32(dummy);
+
+        DECODE_TAIL;
+}
+
 static __be32
 nfsd4_decode_close(struct nfsd4_compoundargs *argp, struct nfsd4_close *close)
 {
@@ -1359,7 +1374,7 @@ static nfsd4_dec nfsd41_dec_ops[] = {
 
         /* new operations for NFSv4.1 */
         [OP_BACKCHANNEL_CTL]    = (nfsd4_dec)nfsd4_decode_notsupp,
-        [OP_BIND_CONN_TO_SESSION]= (nfsd4_dec)nfsd4_decode_notsupp,
+        [OP_BIND_CONN_TO_SESSION]= (nfsd4_dec)nfsd4_decode_bind_conn_to_session,
         [OP_EXCHANGE_ID]        = (nfsd4_dec)nfsd4_decode_exchange_id,
         [OP_CREATE_SESSION]     = (nfsd4_dec)nfsd4_decode_create_session,
         [OP_DESTROY_SESSION]    = (nfsd4_dec)nfsd4_decode_destroy_session,
@@ -2383,6 +2398,21 @@ nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_
         return nfserr;
 }
 
+static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_bind_conn_to_session *bcts)
+{
+        __be32 *p;
+
+        if (!nfserr) {
+                RESERVE_SPACE(NFS4_MAX_SESSIONID_LEN + 8);
+                WRITEMEM(bcts->sessionid.data, NFS4_MAX_SESSIONID_LEN);
+                WRITE32(bcts->dir);
+                /* XXX: ? */
+                WRITE32(0);
+                ADJUST_ARGS();
+        }
+        return nfserr;
+}
+
 static __be32
 nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_close *close)
 {
@@ -3174,7 +3204,7 @@ static nfsd4_enc nfsd4_enc_ops[] = {
 
         /* NFSv4.1 operations */
         [OP_BACKCHANNEL_CTL]    = (nfsd4_enc)nfsd4_encode_noop,
-        [OP_BIND_CONN_TO_SESSION] = (nfsd4_enc)nfsd4_encode_noop,
+        [OP_BIND_CONN_TO_SESSION] = (nfsd4_enc)nfsd4_encode_bind_conn_to_session,
         [OP_EXCHANGE_ID]        = (nfsd4_enc)nfsd4_encode_exchange_id,
         [OP_CREATE_SESSION]     = (nfsd4_enc)nfsd4_encode_create_session,
         [OP_DESTROY_SESSION]    = (nfsd4_enc)nfsd4_encode_destroy_session,
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index cf6dc83fd545..442f6d8e024c 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -148,6 +148,11 @@ struct nfsd4_create_session {
         u32                             gid;
 };
 
+struct nfsd4_bind_conn_to_session {
+        struct nfs4_sessionid           sessionid;
+        u32                             dir;
+};
+
 /* The single slot clientid cache structure */
 struct nfsd4_clid_slot {
         u32                             sl_seqid;
diff --git a/fs/nfsd/xdr4.h b/fs/nfsd/xdr4.h
index 799c30c3b495..3a7aa4d98c1f 100644
--- a/fs/nfsd/xdr4.h
+++ b/fs/nfsd/xdr4.h
@@ -427,6 +427,7 @@ struct nfsd4_op {
 
                 /* NFSv4.1 */
                 struct nfsd4_exchange_id        exchange_id;
+                struct nfsd4_bind_conn_to_session bind_conn_to_session;
                 struct nfsd4_create_session     create_session;
                 struct nfsd4_destroy_session    destroy_session;
                 struct nfsd4_sequence           sequence;
@@ -523,6 +524,7 @@ extern __be32 nfsd4_replay_cache_entry(struct nfsd4_compoundres *resp,
                 struct nfsd4_sequence *seq);
 extern __be32 nfsd4_exchange_id(struct svc_rqst *rqstp,
                 struct nfsd4_compound_state *, struct nfsd4_exchange_id *);
+extern __be32 nfsd4_bind_conn_to_session(struct svc_rqst *, struct nfsd4_compound_state *, struct nfsd4_bind_conn_to_session *);
 extern __be32 nfsd4_create_session(struct svc_rqst *,
                 struct nfsd4_compound_state *,
                 struct nfsd4_create_session *);