3 files changed, 32 insertions, 2 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 128519769ea8..db4188ce9b00 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -43,6 +43,7 @@
 #include <linux/sunrpc/xdr.h>
 #include <linux/sunrpc/svc.h>
 #include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/svcsock.h>
 #include <linux/nfsd/nfsd.h>
 #include <linux/nfsd/state.h>
 #include <linux/sunrpc/sched.h>
@@ -52,16 +53,19 @@
 
 #define NFSPROC4_CB_NULL 0
 #define NFSPROC4_CB_COMPOUND 1
+#define NFS4_STATEID_SIZE 16
 
 /* Index of predefined Linux callback client operations */
 
 enum {
         NFSPROC4_CLNT_CB_NULL = 0,
         NFSPROC4_CLNT_CB_RECALL,
+        NFSPROC4_CLNT_CB_SEQUENCE,
 };
 
 enum nfs_cb_opnum4 {
         OP_CB_RECALL            = 4,
+        OP_CB_SEQUENCE          = 11,
 };
 
 #define NFS4_MAXTAGLEN          20
@@ -70,15 +74,22 @@ enum nfs_cb_opnum4 {
 #define NFS4_dec_cb_null_sz             0
 #define cb_compound_enc_hdr_sz          4
 #define cb_compound_dec_hdr_sz          (3 + (NFS4_MAXTAGLEN >> 2))
+#define sessionid_sz                    (NFS4_MAX_SESSIONID_LEN >> 2)
+#define cb_sequence_enc_sz              (sessionid_sz + 4 +             \
+                                        1 /* no referring calls list yet */)
+#define cb_sequence_dec_sz              (op_dec_sz + sessionid_sz + 4)
+
 #define op_enc_sz                       1
 #define op_dec_sz                       2
 #define enc_nfs4_fh_sz                  (1 + (NFS4_FHSIZE >> 2))
 #define enc_stateid_sz                  (NFS4_STATEID_SIZE >> 2)
 #define NFS4_enc_cb_recall_sz           (cb_compound_enc_hdr_sz +       \
+                                        cb_sequence_enc_sz +            \
                                         1 + enc_stateid_sz +            \
                                         enc_nfs4_fh_sz)
 
 #define NFS4_dec_cb_recall_sz           (cb_compound_dec_hdr_sz  +      \
+                                        cb_sequence_dec_sz +            \
                                         op_dec_sz)
 
 /*
@@ -137,11 +148,13 @@ xdr_error:                                      \
 } while (0)
 
 struct nfs4_cb_compound_hdr {
-        int             status;
-        u32             ident;
+        /* args */
+        u32             ident;  /* minorversion 0 only */
         u32             nops;
         __be32          *nops_p;
         u32             minorversion;
+        /* res */
+        int             status;
         u32             taglen;
         char            *tag;
 };
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 0445192d660d..d8196b453f61 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -702,6 +702,8 @@ static inline void
 free_client(struct nfs4_client *clp)
 {
         shutdown_callback_client(clp);
+        if (clp->cl_cb_xprt)
+                svc_xprt_put(clp->cl_cb_xprt);
         if (clp->cl_cred.cr_group_info)
                 put_group_info(clp->cl_cred.cr_group_info);
         kfree(clp->cl_principal);
@@ -1317,6 +1319,18 @@ nfsd4_create_session(struct svc_rqst *rqstp,
                 cr_ses->flags &= ~SESSION4_PERSIST;
                 cr_ses->flags &= ~SESSION4_RDMA;
 
+                if (cr_ses->flags & SESSION4_BACK_CHAN) {
+                        unconf->cl_cb_xprt = rqstp->rq_xprt;
+                        svc_xprt_get(unconf->cl_cb_xprt);
+                        rpc_copy_addr(
+                                (struct sockaddr *)&unconf->cl_cb_conn.cb_addr,
+                                sa);
+                        unconf->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
+                        unconf->cl_cb_conn.cb_minorversion =
+                                cstate->minorversion;
+                        unconf->cl_cb_conn.cb_prog = cr_ses->callback_prog;
+                        nfsd4_probe_callback(unconf);
+                }
                 conf = unconf;
         } else {
                 status = nfserr_stale_clientid;
diff --git a/include/linux/nfsd/state.h b/include/linux/nfsd/state.h
index 9bf3aa8c5aea..c916032570c4 100644
--- a/include/linux/nfsd/state.h
+++ b/include/linux/nfsd/state.h
@@ -211,6 +211,9 @@ struct nfs4_client {
         struct nfsd4_clid_slot  cl_cs_slot;     /* create_session slot */
         u32                     cl_exchange_flags;
         struct nfs4_sessionid   cl_sessionid;
+
+        /* for nfs41 callbacks */
+        struct svc_xprt         *cl_cb_xprt;    /* 4.1 callback transport */
 };
 
 /* struct nfs4_client_reset