nfsd4: use xdr_stream throughout compound encoding

Note this makes ADJUST_ARGS useless; we'll remove it in the following
patch.

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

2 files changed, 16 insertions, 9 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 41c7c0a3ddd0..109b5a84b548 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1284,7 +1284,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
         svcxdr_init_encode(rqstp, resp);
         resp->tagp = resp->xdr.p;
         /* reserve space for: taglen, tag, and opcnt */
-        resp->xdr.p += 2 + XDR_QUADLEN(args->taglen);
+        xdr_reserve_space(&resp->xdr, 8 + args->taglen);
         resp->taglen = args->taglen;
         resp->tag = args->tag;
         resp->opcnt = 0;
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 27d1e94f12fb..5064cb5a0b8e 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1747,10 +1747,10 @@ static void write_cinfo(__be32 **p, struct nfsd4_change_info *c)
 }
 
 #define RESERVE_SPACE(nbytes)   do {                            \
-        p = resp->xdr.p;                                                \
-        BUG_ON(p + XDR_QUADLEN(nbytes) > resp->xdr.end);                \
+        p = xdr_reserve_space(&resp->xdr, nbytes);              \
+        BUG_ON(!p);                                             \
 } while (0)
-#define ADJUST_ARGS()           resp->xdr.p = p
+#define ADJUST_ARGS()           WARN_ON_ONCE(p != resp->xdr.p)  \
 
 /* Encode as an array of strings the string given with components
  * separated @sep, escaped with esc_enter and esc_exit.
@@ -3056,8 +3056,11 @@ nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
                         read->rd_offset, resp->rqstp->rq_vec, read->rd_vlen,
                         &maxcount);
 
-        if (nfserr)
+        if (nfserr) {
+                xdr->p -= 2;
+                xdr->iov->iov_len -= 8;
                 return nfserr;
+        }
         eof = (read->rd_offset + maxcount >=
                read->rd_fhp->fh_dentry->d_inode->i_size);
 
@@ -3110,9 +3113,12 @@ nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd
          */
         nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp, page, &maxcount);
         if (nfserr == nfserr_isdir)
-                return nfserr_inval;
-        if (nfserr)
+                nfserr = nfserr_inval;
+        if (nfserr) {
+                xdr->p--;
+                xdr->iov->iov_len -= 4;
                 return nfserr;
+        }
 
         WRITE32(maxcount);
         ADJUST_ARGS();
@@ -3213,8 +3219,9 @@ nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4
 
         return 0;
 err_no_verf:
-        p = savep;
-        ADJUST_ARGS();
+        xdr->p = savep;
+        xdr->iov->iov_len = ((char *)resp->xdr.p)
+                                - (char *)resp->xdr.buf->head[0].iov_base;
         return nfserr;
 }