NFS: added FREE_STATEID call

FREE_STATEID is used to tell the server that we want to free a stateid
that no longer has any locks associated with it.  This allows the client
to reclaim locks without encountering edge conditions documented in
section 8.4.3 of RFC 5661.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 80 insertions, 0 deletions

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 7d914d9e7584..c191a9baa422 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -348,6 +348,9 @@ static int nfs4_stat_to_errno(int);
 #define encode_test_stateid_maxsz       (op_encode_hdr_maxsz + 2 + \
                                          XDR_QUADLEN(NFS4_STATEID_SIZE))
 #define decode_test_stateid_maxsz       (op_decode_hdr_maxsz + 2 + 1)
+#define encode_free_stateid_maxsz       (op_encode_hdr_maxsz + 1 + \
+                                         XDR_QUADLEN(NFS4_STATEID_SIZE))
+#define decode_free_stateid_maxsz       (op_decode_hdr_maxsz + 1)
 #else /* CONFIG_NFS_V4_1 */
 #define encode_sequence_maxsz   0
 #define decode_sequence_maxsz   0
@@ -791,6 +794,12 @@ static int nfs4_stat_to_errno(int);
 #define NFS4_dec_test_stateid_sz        (compound_decode_hdr_maxsz + \
                                          decode_sequence_maxsz + \
                                          decode_test_stateid_maxsz)
+#define NFS4_enc_free_stateid_sz        (compound_encode_hdr_maxsz + \
+                                         encode_sequence_maxsz + \
+                                         encode_free_stateid_maxsz)
+#define NFS4_dec_free_stateid_sz        (compound_decode_hdr_maxsz + \
+                                         decode_sequence_maxsz + \
+                                         decode_free_stateid_maxsz)
 
 const u32 nfs41_maxwrite_overhead = ((RPC_MAX_HEADER_WITH_AUTH +
                                       compound_encode_hdr_maxsz +
@@ -1985,6 +1994,18 @@ static void encode_test_stateid(struct xdr_stream *xdr,
         hdr->nops++;
         hdr->replen += decode_test_stateid_maxsz;
 }
+
+static void encode_free_stateid(struct xdr_stream *xdr,
+                                struct nfs41_free_stateid_args *args,
+                                struct compound_hdr *hdr)
+{
+        __be32 *p;
+        p = reserve_space(xdr, 4 + NFS4_STATEID_SIZE);
+        *p++ = cpu_to_be32(OP_FREE_STATEID);
+        xdr_encode_opaque_fixed(p, args->stateid->data, NFS4_STATEID_SIZE);
+        hdr->nops++;
+        hdr->replen += decode_free_stateid_maxsz;
+}
 #endif /* CONFIG_NFS_V4_1 */
 
 /*
@@ -2873,6 +2894,23 @@ static void nfs4_xdr_enc_test_stateid(struct rpc_rqst *req,
         encode_test_stateid(xdr, args, &hdr);
         encode_nops(&hdr);
 }
+
+/*
+ *  Encode FREE_STATEID request
+ */
+static void nfs4_xdr_enc_free_stateid(struct rpc_rqst *req,
+                                     struct xdr_stream *xdr,
+                                     struct nfs41_free_stateid_args *args)
+{
+        struct compound_hdr hdr = {
+                .minorversion = nfs4_xdr_minorversion(&args->seq_args),
+        };
+
+        encode_compound_hdr(xdr, req, &hdr);
+        encode_sequence(xdr, &args->seq_args, &hdr);
+        encode_free_stateid(xdr, args, &hdr);
+        encode_nops(&hdr);
+}
 #endif /* CONFIG_NFS_V4_1 */
 
 static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
@@ -5440,6 +5478,26 @@ out_overflow:
 out:
         return -EIO;
 }
+
+static int decode_free_stateid(struct xdr_stream *xdr,
+                               struct nfs41_free_stateid_res *res)
+{
+        __be32 *p;
+        int status;
+
+        status = decode_op_hdr(xdr, OP_FREE_STATEID);
+        if (status)
+                return status;
+
+        p = xdr_inline_decode(xdr, 4);
+        if (unlikely(!p))
+                goto out_overflow;
+        res->status = be32_to_cpup(p++);
+        return res->status;
+out_overflow:
+        print_overflow_msg(__func__, xdr);
+        return -EIO;
+}
 #endif /* CONFIG_NFS_V4_1 */
 
 /*
@@ -6624,6 +6682,27 @@ static int nfs4_xdr_dec_test_stateid(struct rpc_rqst *rqstp,
 out:
         return status;
 }
+
+/*
+ * Decode FREE_STATEID response
+ */
+static int nfs4_xdr_dec_free_stateid(struct rpc_rqst *rqstp,
+                                     struct xdr_stream *xdr,
+                                     struct nfs41_free_stateid_res *res)
+{
+        struct compound_hdr hdr;
+        int status;
+
+        status = decode_compound_hdr(xdr, &hdr);
+        if (status)
+                goto out;
+        status = decode_sequence(xdr, &res->seq_res, rqstp);
+        if (status)
+                goto out;
+        status = decode_free_stateid(xdr, res);
+out:
+        return status;
+}
 #endif /* CONFIG_NFS_V4_1 */
 
 /**
@@ -6828,6 +6907,7 @@ struct rpc_procinfo	nfs4_procedures[] = {
         PROC(LAYOUTRETURN,      enc_layoutreturn,       dec_layoutreturn),
         PROC(SECINFO_NO_NAME,   enc_secinfo_no_name,    dec_secinfo_no_name),
         PROC(TEST_STATEID,      enc_test_stateid,       dec_test_stateid),
+        PROC(FREE_STATEID,      enc_free_stateid,       dec_free_stateid),
 #endif /* CONFIG_NFS_V4_1 */
 };