nfs: Add DEALLOCATE support

This patch adds support for using the NFS v4.2 operation DEALLOCATE to
punch holes in a file.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 64 insertions, 0 deletions

diff --git a/fs/nfs/nfs42xdr.c b/fs/nfs/nfs42xdr.c
index 4248d034479c..038a7e1521fa 100644
--- a/fs/nfs/nfs42xdr.c
+++ b/fs/nfs/nfs42xdr.c
@@ -10,6 +10,9 @@
 #define encode_allocate_maxsz           (op_encode_hdr_maxsz + \
                                          encode_fallocate_maxsz)
 #define decode_allocate_maxsz           (op_decode_hdr_maxsz)
+#define encode_deallocate_maxsz         (op_encode_hdr_maxsz + \
+                                         encode_fallocate_maxsz)
+#define decode_deallocate_maxsz         (op_decode_hdr_maxsz)
 #define encode_seek_maxsz               (op_encode_hdr_maxsz + \
                                          encode_stateid_maxsz + \
                                          2 /* offset */ + \
@@ -26,6 +29,12 @@
 #define NFS4_dec_allocate_sz            (compound_decode_hdr_maxsz + \
                                          decode_putfh_maxsz + \
                                          decode_allocate_maxsz)
+#define NFS4_enc_deallocate_sz          (compound_encode_hdr_maxsz + \
+                                         encode_putfh_maxsz + \
+                                         encode_deallocate_maxsz)
+#define NFS4_dec_deallocate_sz          (compound_decode_hdr_maxsz + \
+                                         decode_putfh_maxsz + \
+                                         decode_deallocate_maxsz)
 #define NFS4_enc_seek_sz                (compound_encode_hdr_maxsz + \
                                          encode_putfh_maxsz + \
                                          encode_seek_maxsz)
@@ -50,6 +59,14 @@ static void encode_allocate(struct xdr_stream *xdr,
         encode_fallocate(xdr, args);
 }
 
+static void encode_deallocate(struct xdr_stream *xdr,
+                              struct nfs42_falloc_args *args,
+                              struct compound_hdr *hdr)
+{
+        encode_op_hdr(xdr, OP_DEALLOCATE, decode_deallocate_maxsz, hdr);
+        encode_fallocate(xdr, args);
+}
+
 static void encode_seek(struct xdr_stream *xdr,
                         struct nfs42_seek_args *args,
                         struct compound_hdr *hdr)
@@ -79,6 +96,24 @@ static void nfs4_xdr_enc_allocate(struct rpc_rqst *req,
 }
 
 /*
+ * Encode DEALLOCATE request
+ */
+static void nfs4_xdr_enc_deallocate(struct rpc_rqst *req,
+                                    struct xdr_stream *xdr,
+                                    struct nfs42_falloc_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_putfh(xdr, args->falloc_fh, &hdr);
+        encode_deallocate(xdr, args, &hdr);
+        encode_nops(&hdr);
+}
+
+/*
  * Encode SEEK request
  */
 static void nfs4_xdr_enc_seek(struct rpc_rqst *req,
@@ -101,6 +136,11 @@ static int decode_allocate(struct xdr_stream *xdr, struct nfs42_falloc_res *res)
         return decode_op_hdr(xdr, OP_ALLOCATE);
 }
 
+static int decode_deallocate(struct xdr_stream *xdr, struct nfs42_falloc_res *res)
+{
+        return decode_op_hdr(xdr, OP_DEALLOCATE);
+}
+
 static int decode_seek(struct xdr_stream *xdr, struct nfs42_seek_res *res)
 {
         int status;
@@ -148,6 +188,30 @@ out:
 }
 
 /*
+ * Decode DEALLOCATE request
+ */
+static int nfs4_xdr_dec_deallocate(struct rpc_rqst *rqstp,
+                                   struct xdr_stream *xdr,
+                                   struct nfs42_falloc_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_putfh(xdr);
+        if (status)
+                goto out;
+        status = decode_deallocate(xdr, res);
+out:
+        return status;
+}
+
+/*
  * Decode SEEK request
  */
 static int nfs4_xdr_dec_seek(struct rpc_rqst *rqstp,