nfsd4: more precise nfsd4_max_reply
It will turn out to be useful to have a more accurate estimate of reply
size; so, piggyback on the existing op reply-size estimators.
Also move nfsd4_max_reply to nfs4proc.c to get easier access to struct
nfsd4_operation and friends. (Thanks to Christoph Hellwig for pointing
out that simplification.)
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 2f0ea20..8b3d24d 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1605,40 +1605,13 @@
return true;
}
-/*
- * Return a rough estimate of the maximum possible reply size. Note the
- * estimate includes rpc headers so is meant to be passed to
- * svc_reserve, not svc_reserve_auth.
- *
- * Also note the current compound encoding permits only one operation to
- * use pages beyond the first one, so the maximum possible length is the
- * maximum over these values, not the sum.
- */
-static int nfsd4_max_reply(u32 opnum)
-{
- switch (opnum) {
- case OP_READLINK:
- case OP_READDIR:
- /*
- * Both of these ops take a single page for data and put
- * the head and tail in another page:
- */
- return 2 * PAGE_SIZE;
- case OP_GETATTR:
- case OP_READ:
- return INT_MAX;
- default:
- return PAGE_SIZE;
- }
-}
-
static __be32
nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
{
DECODE_HEAD;
struct nfsd4_op *op;
bool cachethis = false;
- int max_reply = PAGE_SIZE;
+ int max_reply = 2 * RPC_MAX_AUTH_SIZE + 8; /* opcnt, status */
int i;
READ_BUF(4);
@@ -1647,6 +1620,7 @@
SAVEMEM(argp->tag, argp->taglen);
READ32(argp->minorversion);
READ32(argp->opcnt);
+ max_reply += 4 + (XDR_QUADLEN(argp->taglen) << 2);
if (argp->taglen > NFSD4_MAX_TAGLEN)
goto xdr_error;
@@ -1684,7 +1658,7 @@
*/
cachethis |= nfsd4_cache_this_op(op);
- max_reply = max(max_reply, nfsd4_max_reply(op->opnum));
+ max_reply += nfsd4_max_reply(argp->rqstp, op);
if (op->status) {
argp->opcnt = i+1;
@@ -1694,8 +1668,7 @@
/* Sessions make the DRC unnecessary: */
if (argp->minorversion)
cachethis = false;
- if (max_reply != INT_MAX)
- svc_reserve(argp->rqstp, max_reply);
+ svc_reserve(argp->rqstp, max_reply);
argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
DECODE_TAIL;
