pnfs: encode_layoutcommit

Add a layout driver method to encode the layout type specific
opaque part of layout commit in-line in the xdr stream.

Currently, the pnfs-objects layout driver uses it to encode metadata hints
to the MDS and the blocks layout driver to commit provisionally allocated
extents to the file.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>

2 files changed, 17 insertions, 3 deletions

diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index d464badc0067..d869a5e5464b 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1875,6 +1875,7 @@ encode_layoutget(struct xdr_stream *xdr,
 
 static int
 encode_layoutcommit(struct xdr_stream *xdr,
+                    struct inode *inode,
                     const struct nfs4_layoutcommit_args *args,
                     struct compound_hdr *hdr)
 {
@@ -1883,7 +1884,7 @@ encode_layoutcommit(struct xdr_stream *xdr,
         dprintk("%s: lbw: %llu type: %d\n", __func__, args->lastbytewritten,
                 NFS_SERVER(args->inode)->pnfs_curr_ld->id);
 
-        p = reserve_space(xdr, 48 + NFS4_STATEID_SIZE);
+        p = reserve_space(xdr, 44 + NFS4_STATEID_SIZE);
         *p++ = cpu_to_be32(OP_LAYOUTCOMMIT);
         /* Only whole file layouts */
         p = xdr_encode_hyper(p, 0); /* offset */
@@ -1894,7 +1895,14 @@ encode_layoutcommit(struct xdr_stream *xdr,
         p = xdr_encode_hyper(p, args->lastbytewritten);
         *p++ = cpu_to_be32(0); /* Never send time_modify_changed */
         *p++ = cpu_to_be32(NFS_SERVER(args->inode)->pnfs_curr_ld->id);/* type */
-        *p++ = cpu_to_be32(0); /* no file layout payload */
+
+        if (NFS_SERVER(inode)->pnfs_curr_ld->encode_layoutcommit)
+                NFS_SERVER(inode)->pnfs_curr_ld->encode_layoutcommit(
+                        NFS_I(inode)->layout, xdr, args);
+        else {
+                p = reserve_space(xdr, 4);
+                *p = cpu_to_be32(0); /* no layout-type payload */
+        }
 
         hdr->nops++;
         hdr->replen += decode_layoutcommit_maxsz;
@@ -2751,6 +2759,8 @@ static void nfs4_xdr_enc_layoutcommit(struct rpc_rqst *req,
                                       struct xdr_stream *xdr,
                                       struct nfs4_layoutcommit_args *args)
 {
+        struct nfs4_layoutcommit_data *data =
+                container_of(args, struct nfs4_layoutcommit_data, args);
         struct compound_hdr hdr = {
                 .minorversion = nfs4_xdr_minorversion(&args->seq_args),
         };
@@ -2758,7 +2768,7 @@ static void nfs4_xdr_enc_layoutcommit(struct rpc_rqst *req,
         encode_compound_hdr(xdr, req, &hdr);
         encode_sequence(xdr, &args->seq_args, &hdr);
         encode_putfh(xdr, NFS_FH(args->inode), &hdr);
-        encode_layoutcommit(xdr, args, &hdr);
+        encode_layoutcommit(xdr, data->args.inode, args, &hdr);
         encode_getfattr(xdr, args->bitmask, &hdr);
         encode_nops(&hdr);
 }
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index 1b6b207a8806..3fda97146777 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -108,6 +108,10 @@ struct pnfs_layoutdriver_type {
         void (*encode_layoutreturn) (struct pnfs_layout_hdr *layoutid,
                                      struct xdr_stream *xdr,
                                      const struct nfs4_layoutreturn_args *args);
+
+        void (*encode_layoutcommit) (struct pnfs_layout_hdr *layoutid,
+                                     struct xdr_stream *xdr,
+                                     const struct nfs4_layoutcommit_args *args);
 };
 
 struct pnfs_layout_hdr {