1 files changed, 64 insertions, 9 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 3cef6bfa09d4..fc13236d1be1 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1472,8 +1472,10 @@ free_session_slots(struct nfsd4_session *ses)
 {
 	int i;
 
-	for (i = 0; i < ses->se_fchannel.maxreqs; i++)
+	for (i = 0; i < ses->se_fchannel.maxreqs; i++) {
+		free_svc_cred(&ses->se_slots[i]->sl_cred);
 		kfree(ses->se_slots[i]);
+	}
 }
 
 /*
@@ -1500,11 +1502,16 @@ static u32 nfsd4_get_drc_mem(struct nfsd4_channel_attrs *ca)
 {
 	u32 slotsize = slot_bytes(ca);
 	u32 num = ca->maxreqs;
-	int avail;
+	unsigned long avail, total_avail;
 
 	spin_lock(&nfsd_drc_lock);
-	avail = min((unsigned long)NFSD_MAX_MEM_PER_SESSION,
-		    nfsd_drc_max_mem - nfsd_drc_mem_used);
+	total_avail = nfsd_drc_max_mem - nfsd_drc_mem_used;
+	avail = min((unsigned long)NFSD_MAX_MEM_PER_SESSION, total_avail);
+	/*
+	 * Never use more than a third of the remaining memory,
+	 * unless it's the only way to give this client a slot:
+	 */
+	avail = clamp_t(unsigned long, avail, slotsize, total_avail/3);
 	num = min_t(int, num, avail / slotsize);
 	nfsd_drc_mem_used += num * slotsize;
 	spin_unlock(&nfsd_drc_lock);
@@ -2331,14 +2338,18 @@ nfsd4_store_cache_entry(struct nfsd4_compoundres *resp)
 
 	dprintk("--> %s slot %p\n", __func__, slot);
 
+	slot->sl_flags |= NFSD4_SLOT_INITIALIZED;
 	slot->sl_opcnt = resp->opcnt;
 	slot->sl_status = resp->cstate.status;
+	free_svc_cred(&slot->sl_cred);
+	copy_cred(&slot->sl_cred, &resp->rqstp->rq_cred);
 
-	slot->sl_flags |= NFSD4_SLOT_INITIALIZED;
-	if (nfsd4_not_cached(resp)) {
-		slot->sl_datalen = 0;
+	if (!nfsd4_cache_this(resp)) {
+		slot->sl_flags &= ~NFSD4_SLOT_CACHED;
 		return;
 	}
+	slot->sl_flags |= NFSD4_SLOT_CACHED;
+
 	base = resp->cstate.data_offset;
 	slot->sl_datalen = buf->len - base;
 	if (read_bytes_from_xdr_buf(buf, base, slot->sl_data, slot->sl_datalen))
@@ -2365,8 +2376,16 @@ nfsd4_enc_sequence_replay(struct nfsd4_compoundargs *args,
 	op = &args->ops[resp->opcnt - 1];
 	nfsd4_encode_operation(resp, op);
 
-	/* Return nfserr_retry_uncached_rep in next operation. */
-	if (args->opcnt > 1 && !(slot->sl_flags & NFSD4_SLOT_CACHETHIS)) {
+	if (slot->sl_flags & NFSD4_SLOT_CACHED)
+		return op->status;
+	if (args->opcnt == 1) {
+		/*
+		 * The original operation wasn't a solo sequence--we
+		 * always cache those--so this retry must not match the
+		 * original:
+		 */
+		op->status = nfserr_seq_false_retry;
+	} else {
 		op = &args->ops[resp->opcnt++];
 		op->status = nfserr_retry_uncached_rep;
 		nfsd4_encode_operation(resp, op);
@@ -3030,6 +3049,39 @@ static bool nfsd4_request_too_big(struct svc_rqst *rqstp,
 	return xb->len > session->se_fchannel.maxreq_sz;
 }
 
+static bool replay_matches_cache(struct svc_rqst *rqstp,
+		 struct nfsd4_sequence *seq, struct nfsd4_slot *slot)
+{
+	struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+
+	if ((bool)(slot->sl_flags & NFSD4_SLOT_CACHETHIS) !=
+	    (bool)seq->cachethis)
+		return false;
+	/*
+	 * If there's an error then the reply can have fewer ops than
+	 * the call.
+	 */
+	if (slot->sl_opcnt < argp->opcnt && !slot->sl_status)
+		return false;
+	/*
+	 * But if we cached a reply with *more* ops than the call you're
+	 * sending us now, then this new call is clearly not really a
+	 * replay of the old one:
+	 */
+	if (slot->sl_opcnt > argp->opcnt)
+		return false;
+	/* This is the only check explicitly called by spec: */
+	if (!same_creds(&rqstp->rq_cred, &slot->sl_cred))
+		return false;
+	/*
+	 * There may be more comparisons we could actually do, but the
+	 * spec doesn't require us to catch every case where the calls
+	 * don't match (that would require caching the call as well as
+	 * the reply), so we don't bother.
+	 */
+	return true;
+}
+
 __be32
 nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		union nfsd4_op_u *u)
@@ -3089,6 +3141,9 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		status = nfserr_seq_misordered;
 		if (!(slot->sl_flags & NFSD4_SLOT_INITIALIZED))
 			goto out_put_session;
+		status = nfserr_seq_false_retry;
+		if (!replay_matches_cache(rqstp, seq, slot))
+			goto out_put_session;
 		cstate->slot = slot;
 		cstate->session = session;
 		cstate->clp = clp;