1 files changed, 233 insertions, 180 deletions

diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 0a0cf1fd77d3..ab13ee9c7fd8 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -27,7 +27,7 @@
  * cache size, the idea being that when the cache is at its maximum number
  * of entries, then this should be the average number of entries per bucket.
  */
-#define TARGET_BUCKET_SIZE	64
+#define TARGET_BUCKET_SIZE	8
 
 struct nfsd_drc_bucket {
 	struct rb_root rb_head;
@@ -84,17 +84,11 @@ nfsd_hashsize(unsigned int limit)
 	return roundup_pow_of_two(limit / TARGET_BUCKET_SIZE);
 }
 
-static u32
-nfsd_cache_hash(__be32 xid, struct nfsd_net *nn)
+static struct nfsd_cacherep *
+nfsd_cacherep_alloc(struct svc_rqst *rqstp, __wsum csum,
+		    struct nfsd_net *nn)
 {
-	return hash_32(be32_to_cpu(xid), nn->maskbits);
-}
-
-static struct svc_cacherep *
-nfsd_reply_cache_alloc(struct svc_rqst *rqstp, __wsum csum,
-			struct nfsd_net *nn)
-{
-	struct svc_cacherep	*rp;
+	struct nfsd_cacherep *rp;
 
 	rp = kmem_cache_alloc(drc_slab, GFP_KERNEL);
 	if (rp) {
@@ -116,36 +110,63 @@ nfsd_reply_cache_alloc(struct svc_rqst *rqstp, __wsum csum,
 	return rp;
 }
 
-static void
-nfsd_reply_cache_free_locked(struct nfsd_drc_bucket *b, struct svc_cacherep *rp,
-				struct nfsd_net *nn)
+static void nfsd_cacherep_free(struct nfsd_cacherep *rp)
 {
-	if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base) {
-		nn->drc_mem_usage -= rp->c_replvec.iov_len;
+	if (rp->c_type == RC_REPLBUFF)
 		kfree(rp->c_replvec.iov_base);
+	kmem_cache_free(drc_slab, rp);
+}
+
+static unsigned long
+nfsd_cacherep_dispose(struct list_head *dispose)
+{
+	struct nfsd_cacherep *rp;
+	unsigned long freed = 0;
+
+	while (!list_empty(dispose)) {
+		rp = list_first_entry(dispose, struct nfsd_cacherep, c_lru);
+		list_del(&rp->c_lru);
+		nfsd_cacherep_free(rp);
+		freed++;
 	}
+	return freed;
+}
+
+static void
+nfsd_cacherep_unlink_locked(struct nfsd_net *nn, struct nfsd_drc_bucket *b,
+			    struct nfsd_cacherep *rp)
+{
+	if (rp->c_type == RC_REPLBUFF && rp->c_replvec.iov_base)
+		nfsd_stats_drc_mem_usage_sub(nn, rp->c_replvec.iov_len);
 	if (rp->c_state != RC_UNUSED) {
 		rb_erase(&rp->c_node, &b->rb_head);
 		list_del(&rp->c_lru);
 		atomic_dec(&nn->num_drc_entries);
-		nn->drc_mem_usage -= sizeof(*rp);
+		nfsd_stats_drc_mem_usage_sub(nn, sizeof(*rp));
 	}
-	kmem_cache_free(drc_slab, rp);
 }
 
 static void
-nfsd_reply_cache_free(struct nfsd_drc_bucket *b, struct svc_cacherep *rp,
+nfsd_reply_cache_free_locked(struct nfsd_drc_bucket *b, struct nfsd_cacherep *rp,
+				struct nfsd_net *nn)
+{
+	nfsd_cacherep_unlink_locked(nn, b, rp);
+	nfsd_cacherep_free(rp);
+}
+
+static void
+nfsd_reply_cache_free(struct nfsd_drc_bucket *b, struct nfsd_cacherep *rp,
 			struct nfsd_net *nn)
 {
 	spin_lock(&b->cache_lock);
-	nfsd_reply_cache_free_locked(b, rp, nn);
+	nfsd_cacherep_unlink_locked(nn, b, rp);
 	spin_unlock(&b->cache_lock);
+	nfsd_cacherep_free(rp);
 }
 
 int nfsd_drc_slab_create(void)
 {
-	drc_slab = kmem_cache_create("nfsd_drc",
-				sizeof(struct svc_cacherep), 0, 0, NULL);
+	drc_slab = KMEM_CACHE(nfsd_cacherep, 0);
 	return drc_slab ? 0: -ENOMEM;
 }
 
@@ -158,28 +179,28 @@ int nfsd_reply_cache_init(struct nfsd_net *nn)
 {
 	unsigned int hashsize;
 	unsigned int i;
-	int status = 0;
 
 	nn->max_drc_entries = nfsd_cache_size_limit();
 	atomic_set(&nn->num_drc_entries, 0);
 	hashsize = nfsd_hashsize(nn->max_drc_entries);
 	nn->maskbits = ilog2(hashsize);
 
-	nn->nfsd_reply_cache_shrinker.scan_objects = nfsd_reply_cache_scan;
-	nn->nfsd_reply_cache_shrinker.count_objects = nfsd_reply_cache_count;
-	nn->nfsd_reply_cache_shrinker.seeks = 1;
-	status = register_shrinker(&nn->nfsd_reply_cache_shrinker);
-	if (status)
-		goto out_nomem;
-
-	nn->drc_hashtbl = kcalloc(hashsize,
-				sizeof(*nn->drc_hashtbl), GFP_KERNEL);
-	if (!nn->drc_hashtbl) {
-		nn->drc_hashtbl = vzalloc(array_size(hashsize,
-						 sizeof(*nn->drc_hashtbl)));
-		if (!nn->drc_hashtbl)
-			goto out_shrinker;
-	}
+	nn->drc_hashtbl = kvzalloc(array_size(hashsize,
+				sizeof(*nn->drc_hashtbl)), GFP_KERNEL);
+	if (!nn->drc_hashtbl)
+		return -ENOMEM;
+
+	nn->nfsd_reply_cache_shrinker = shrinker_alloc(0, "nfsd-reply:%s",
+						       nn->nfsd_name);
+	if (!nn->nfsd_reply_cache_shrinker)
+		goto out_shrinker;
+
+	nn->nfsd_reply_cache_shrinker->scan_objects = nfsd_reply_cache_scan;
+	nn->nfsd_reply_cache_shrinker->count_objects = nfsd_reply_cache_count;
+	nn->nfsd_reply_cache_shrinker->seeks = 1;
+	nn->nfsd_reply_cache_shrinker->private_data = nn;
+
+	shrinker_register(nn->nfsd_reply_cache_shrinker);
 
 	for (i = 0; i < hashsize; i++) {
 		INIT_LIST_HEAD(&nn->drc_hashtbl[i].lru_head);
@@ -189,23 +210,22 @@ int nfsd_reply_cache_init(struct nfsd_net *nn)
 
 	return 0;
 out_shrinker:
-	unregister_shrinker(&nn->nfsd_reply_cache_shrinker);
-out_nomem:
+	kvfree(nn->drc_hashtbl);
 	printk(KERN_ERR "nfsd: failed to allocate reply cache\n");
 	return -ENOMEM;
 }
 
 void nfsd_reply_cache_shutdown(struct nfsd_net *nn)
 {
-	struct svc_cacherep	*rp;
+	struct nfsd_cacherep *rp;
 	unsigned int i;
 
-	unregister_shrinker(&nn->nfsd_reply_cache_shrinker);
+	shrinker_free(nn->nfsd_reply_cache_shrinker);
 
 	for (i = 0; i < nn->drc_hashsize; i++) {
 		struct list_head *head = &nn->drc_hashtbl[i].lru_head;
 		while (!list_empty(head)) {
-			rp = list_first_entry(head, struct svc_cacherep, c_lru);
+			rp = list_first_entry(head, struct nfsd_cacherep, c_lru);
 			nfsd_reply_cache_free_locked(&nn->drc_hashtbl[i],
 									rp, nn);
 		}
@@ -217,105 +237,149 @@ void nfsd_reply_cache_shutdown(struct nfsd_net *nn)
 
 }
 
-/*
- * Move cache entry to end of LRU list, and queue the cleaner to run if it's
- * not already scheduled.
- */
 static void
-lru_put_end(struct nfsd_drc_bucket *b, struct svc_cacherep *rp)
+lru_put_end(struct nfsd_drc_bucket *b, struct nfsd_cacherep *rp)
 {
 	rp->c_timestamp = jiffies;
 	list_move_tail(&rp->c_lru, &b->lru_head);
 }
 
-static long
-prune_bucket(struct nfsd_drc_bucket *b, struct nfsd_net *nn)
+static noinline struct nfsd_drc_bucket *
+nfsd_cache_bucket_find(__be32 xid, struct nfsd_net *nn)
 {
-	struct svc_cacherep *rp, *tmp;
-	long freed = 0;
+	unsigned int hash = hash_32((__force u32)xid, nn->maskbits);
 
-	list_for_each_entry_safe(rp, tmp, &b->lru_head, c_lru) {
-		/*
-		 * Don't free entries attached to calls that are still
-		 * in-progress, but do keep scanning the list.
-		 */
-		if (rp->c_state == RC_INPROG)
-			continue;
-		if (atomic_read(&nn->num_drc_entries) <= nn->max_drc_entries &&
-		    time_before(jiffies, rp->c_timestamp + RC_EXPIRE))
-			break;
-		nfsd_reply_cache_free_locked(b, rp, nn);
-		freed++;
-	}
-	return freed;
+	return &nn->drc_hashtbl[hash];
 }
 
 /*
- * Walk the LRU list and prune off entries that are older than RC_EXPIRE.
- * Also prune the oldest ones when the total exceeds the max number of entries.
+ * Remove and return no more than @max expired entries in bucket @b.
+ * If @max is zero, do not limit the number of removed entries.
  */
-static long
-prune_cache_entries(struct nfsd_net *nn)
+static void
+nfsd_prune_bucket_locked(struct nfsd_net *nn, struct nfsd_drc_bucket *b,
+			 unsigned int max, struct list_head *dispose)
 {
-	unsigned int i;
-	long freed = 0;
+	unsigned long expiry = jiffies - RC_EXPIRE;
+	struct nfsd_cacherep *rp, *tmp;
+	unsigned int freed = 0;
 
-	for (i = 0; i < nn->drc_hashsize; i++) {
-		struct nfsd_drc_bucket *b = &nn->drc_hashtbl[i];
+	lockdep_assert_held(&b->cache_lock);
 
-		if (list_empty(&b->lru_head))
-			continue;
-		spin_lock(&b->cache_lock);
-		freed += prune_bucket(b, nn);
-		spin_unlock(&b->cache_lock);
+	/* The bucket LRU is ordered oldest-first. */
+	list_for_each_entry_safe(rp, tmp, &b->lru_head, c_lru) {
+		if (atomic_read(&nn->num_drc_entries) <= nn->max_drc_entries &&
+		    time_before(expiry, rp->c_timestamp))
+			break;
+
+		nfsd_cacherep_unlink_locked(nn, b, rp);
+		list_add(&rp->c_lru, dispose);
+
+		if (max && ++freed > max)
+			break;
 	}
-	return freed;
 }
 
+/**
+ * nfsd_reply_cache_count - count_objects method for the DRC shrinker
+ * @shrink: our registered shrinker context
+ * @sc: garbage collection parameters
+ *
+ * Returns the total number of entries in the duplicate reply cache. To
+ * keep things simple and quick, this is not the number of expired entries
+ * in the cache (ie, the number that would be removed by a call to
+ * nfsd_reply_cache_scan).
+ */
 static unsigned long
 nfsd_reply_cache_count(struct shrinker *shrink, struct shrink_control *sc)
 {
-	struct nfsd_net *nn = container_of(shrink,
-				struct nfsd_net, nfsd_reply_cache_shrinker);
+	struct nfsd_net *nn = shrink->private_data;
 
 	return atomic_read(&nn->num_drc_entries);
 }
 
+/**
+ * nfsd_reply_cache_scan - scan_objects method for the DRC shrinker
+ * @shrink: our registered shrinker context
+ * @sc: garbage collection parameters
+ *
+ * Free expired entries on each bucket's LRU list until we've released
+ * nr_to_scan freed objects. Nothing will be released if the cache
+ * has not exceeded it's max_drc_entries limit.
+ *
+ * Returns the number of entries released by this call.
+ */
 static unsigned long
 nfsd_reply_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
 {
-	struct nfsd_net *nn = container_of(shrink,
-				struct nfsd_net, nfsd_reply_cache_shrinker);
+	struct nfsd_net *nn = shrink->private_data;
+	unsigned long freed = 0;
+	LIST_HEAD(dispose);
+	unsigned int i;
 
-	return prune_cache_entries(nn);
+	for (i = 0; i < nn->drc_hashsize; i++) {
+		struct nfsd_drc_bucket *b = &nn->drc_hashtbl[i];
+
+		if (list_empty(&b->lru_head))
+			continue;
+
+		spin_lock(&b->cache_lock);
+		nfsd_prune_bucket_locked(nn, b, 0, &dispose);
+		spin_unlock(&b->cache_lock);
+
+		freed += nfsd_cacherep_dispose(&dispose);
+		if (freed > sc->nr_to_scan)
+			break;
+	}
+	return freed;
 }
-/*
- * Walk an xdr_buf and get a CRC for at most the first RC_CSUMLEN bytes
+
+/**
+ * nfsd_cache_csum - Checksum incoming NFS Call arguments
+ * @buf: buffer containing a whole RPC Call message
+ * @start: starting byte of the NFS Call header
+ * @remaining: size of the NFS Call header, in bytes
+ *
+ * Compute a weak checksum of the leading bytes of an NFS procedure
+ * call header to help verify that a retransmitted Call matches an
+ * entry in the duplicate reply cache.
+ *
+ * To avoid assumptions about how the RPC message is laid out in
+ * @buf and what else it might contain (eg, a GSS MIC suffix), the
+ * caller passes us the exact location and length of the NFS Call
+ * header.
+ *
+ * Returns a 32-bit checksum value, as defined in RFC 793.
  */
-static __wsum
-nfsd_cache_csum(struct svc_rqst *rqstp)
+static __wsum nfsd_cache_csum(struct xdr_buf *buf, unsigned int start,
+			      unsigned int remaining)
 {
+	unsigned int base, len;
+	struct xdr_buf subbuf;
+	__wsum csum = 0;
+	void *p;
 	int idx;
-	unsigned int base;
-	__wsum csum;
-	struct xdr_buf *buf = &rqstp->rq_arg;
-	const unsigned char *p = buf->head[0].iov_base;
-	size_t csum_len = min_t(size_t, buf->head[0].iov_len + buf->page_len,
-				RC_CSUMLEN);
-	size_t len = min(buf->head[0].iov_len, csum_len);
+
+	if (remaining > RC_CSUMLEN)
+		remaining = RC_CSUMLEN;
+	if (xdr_buf_subsegment(buf, &subbuf, start, remaining))
+		return csum;
 
 	/* rq_arg.head first */
-	csum = csum_partial(p, len, 0);
-	csum_len -= len;
+	if (subbuf.head[0].iov_len) {
+		len = min_t(unsigned int, subbuf.head[0].iov_len, remaining);
+		csum = csum_partial(subbuf.head[0].iov_base, len, csum);
+		remaining -= len;
+	}
 
 	/* Continue into page array */
-	idx = buf->page_base / PAGE_SIZE;
-	base = buf->page_base & ~PAGE_MASK;
-	while (csum_len) {
-		p = page_address(buf->pages[idx]) + base;
-		len = min_t(size_t, PAGE_SIZE - base, csum_len);
+	idx = subbuf.page_base / PAGE_SIZE;
+	base = subbuf.page_base & ~PAGE_MASK;
+	while (remaining) {
+		p = page_address(subbuf.pages[idx]) + base;
+		len = min_t(unsigned int, PAGE_SIZE - base, remaining);
 		csum = csum_partial(p, len, csum);
-		csum_len -= len;
+		remaining -= len;
 		base = 0;
 		++idx;
 	}
@@ -323,12 +387,12 @@ nfsd_cache_csum(struct svc_rqst *rqstp)
 }
 
 static int
-nfsd_cache_key_cmp(const struct svc_cacherep *key,
-			const struct svc_cacherep *rp, struct nfsd_net *nn)
+nfsd_cache_key_cmp(const struct nfsd_cacherep *key,
+		   const struct nfsd_cacherep *rp, struct nfsd_net *nn)
 {
 	if (key->c_key.k_xid == rp->c_key.k_xid &&
 	    key->c_key.k_csum != rp->c_key.k_csum) {
-		++nn->payload_misses;
+		nfsd_stats_payload_misses_inc(nn);
 		trace_nfsd_drc_mismatch(nn, key, rp);
 	}
 
@@ -340,11 +404,11 @@ nfsd_cache_key_cmp(const struct svc_cacherep *key,
  * Must be called with cache_lock held. Returns the found entry or
  * inserts an empty key on failure.
  */
-static struct svc_cacherep *
-nfsd_cache_insert(struct nfsd_drc_bucket *b, struct svc_cacherep *key,
+static struct nfsd_cacherep *
+nfsd_cache_insert(struct nfsd_drc_bucket *b, struct nfsd_cacherep *key,
 			struct nfsd_net *nn)
 {
-	struct svc_cacherep	*rp, *ret = key;
+	struct nfsd_cacherep	*rp, *ret = key;
 	struct rb_node		**p = &b->rb_head.rb_node,
 				*parent = NULL;
 	unsigned int		entries = 0;
@@ -353,7 +417,7 @@ nfsd_cache_insert(struct nfsd_drc_bucket *b, struct svc_cacherep *key,
 	while (*p != NULL) {
 		++entries;
 		parent = *p;
-		rp = rb_entry(parent, struct svc_cacherep, c_node);
+		rp = rb_entry(parent, struct nfsd_cacherep, c_node);
 
 		cmp = nfsd_cache_key_cmp(key, rp, nn);
 		if (cmp < 0)
@@ -378,14 +442,15 @@ out:
 				nn->longest_chain_cachesize,
 				atomic_read(&nn->num_drc_entries));
 	}
-
-	lru_put_end(b, ret);
 	return ret;
 }
 
 /**
  * nfsd_cache_lookup - Find an entry in the duplicate reply cache
  * @rqstp: Incoming Call to find
+ * @start: starting byte in @rqstp->rq_arg of the NFS Call header
+ * @len: size of the NFS Call header, in bytes
+ * @cacherep: OUT: DRC entry for this request
  *
  * Try to find an entry matching the current call in the cache. When none
  * is found, we try to grab the oldest expired entry off the LRU list. If
@@ -398,60 +463,55 @@ out:
  *   %RC_REPLY: Reply from cache
  *   %RC_DROPIT: Do not process the request further
  */
-int nfsd_cache_lookup(struct svc_rqst *rqstp)
+int nfsd_cache_lookup(struct svc_rqst *rqstp, unsigned int start,
+		      unsigned int len, struct nfsd_cacherep **cacherep)
 {
-	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
-	struct svc_cacherep	*rp, *found;
-	__be32			xid = rqstp->rq_xid;
+	struct nfsd_net		*nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+	struct nfsd_cacherep	*rp, *found;
 	__wsum			csum;
-	u32 hash = nfsd_cache_hash(xid, nn);
-	struct nfsd_drc_bucket *b = &nn->drc_hashtbl[hash];
+	struct nfsd_drc_bucket	*b;
 	int type = rqstp->rq_cachetype;
+	LIST_HEAD(dispose);
 	int rtn = RC_DOIT;
 
-	rqstp->rq_cacherep = NULL;
 	if (type == RC_NOCACHE) {
-		nfsdstats.rcnocache++;
+		nfsd_stats_rc_nocache_inc(nn);
 		goto out;
 	}
 
-	csum = nfsd_cache_csum(rqstp);
+	csum = nfsd_cache_csum(&rqstp->rq_arg, start, len);
 
 	/*
 	 * Since the common case is a cache miss followed by an insert,
 	 * preallocate an entry.
 	 */
-	rp = nfsd_reply_cache_alloc(rqstp, csum, nn);
+	rp = nfsd_cacherep_alloc(rqstp, csum, nn);
 	if (!rp)
 		goto out;
 
+	b = nfsd_cache_bucket_find(rqstp->rq_xid, nn);
 	spin_lock(&b->cache_lock);
 	found = nfsd_cache_insert(b, rp, nn);
-	if (found != rp) {
-		nfsd_reply_cache_free_locked(NULL, rp, nn);
-		rp = found;
+	if (found != rp)
 		goto found_entry;
-	}
-
-	nfsdstats.rcmisses++;
-	rqstp->rq_cacherep = rp;
+	*cacherep = rp;
 	rp->c_state = RC_INPROG;
+	nfsd_prune_bucket_locked(nn, b, 3, &dispose);
+	spin_unlock(&b->cache_lock);
 
-	atomic_inc(&nn->num_drc_entries);
-	nn->drc_mem_usage += sizeof(*rp);
-
-	/* go ahead and prune the cache */
-	prune_bucket(b, nn);
+	nfsd_cacherep_dispose(&dispose);
 
-out_unlock:
-	spin_unlock(&b->cache_lock);
-out:
-	return rtn;
+	nfsd_stats_rc_misses_inc(nn);
+	atomic_inc(&nn->num_drc_entries);
+	nfsd_stats_drc_mem_usage_add(nn, sizeof(*rp));
+	goto out;
 
 found_entry:
 	/* We found a matching entry which is either in progress or done. */
-	nfsdstats.rchits++;
+	nfsd_reply_cache_free_locked(NULL, rp, nn);
+	nfsd_stats_rc_hits_inc(nn);
 	rtn = RC_DROPIT;
+	rp = found;
 
 	/* Request being processed */
 	if (rp->c_state == RC_INPROG)
@@ -468,7 +528,7 @@ found_entry:
 	case RC_NOCACHE:
 		break;
 	case RC_REPLSTAT:
-		svc_putu32(&rqstp->rq_res.head[0], rp->c_replstat);
+		xdr_stream_encode_be32(&rqstp->rq_res_stream, rp->c_replstat);
 		rtn = RC_REPLY;
 		break;
 	case RC_REPLBUFF:
@@ -482,14 +542,18 @@ found_entry:
 
 out_trace:
 	trace_nfsd_drc_found(nn, rqstp, rtn);
-	goto out_unlock;
+out_unlock:
+	spin_unlock(&b->cache_lock);
+out:
+	return rtn;
 }
 
 /**
  * nfsd_cache_update - Update an entry in the duplicate reply cache.
  * @rqstp: svc_rqst with a finished Reply
+ * @rp: IN: DRC entry for this request
  * @cachetype: which cache to update
- * @statp: Reply's status code
+ * @statp: pointer to Reply's NFS status code, or NULL
  *
  * This is called from nfsd_dispatch when the procedure has been
  * executed and the complete reply is in rqstp->rq_res.
@@ -505,12 +569,11 @@ out_trace:
  * nfsd failed to encode a reply that otherwise would have been cached.
  * In this case, nfsd_cache_update is called with statp == NULL.
  */
-void nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
+void nfsd_cache_update(struct svc_rqst *rqstp, struct nfsd_cacherep *rp,
+		       int cachetype, __be32 *statp)
 {
 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
-	struct svc_cacherep *rp = rqstp->rq_cacherep;
 	struct kvec	*resv = &rqstp->rq_res.head[0], *cachv;
-	u32		hash;
 	struct nfsd_drc_bucket *b;
 	int		len;
 	size_t		bufsize = 0;
@@ -518,8 +581,7 @@ void nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
 	if (!rp)
 		return;
 
-	hash = nfsd_cache_hash(rp->c_key.k_xid, nn);
-	b = &nn->drc_hashtbl[hash];
+	b = nfsd_cache_bucket_find(rp->c_key.k_xid, nn);
 
 	len = resv->iov_len - ((char*)statp - (char*)resv->iov_base);
 	len >>= 2;
@@ -552,7 +614,7 @@ void nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
 		return;
 	}
 	spin_lock(&b->cache_lock);
-	nn->drc_mem_usage += bufsize;
+	nfsd_stats_drc_mem_usage_add(nn, bufsize);
 	lru_put_end(b, rp);
 	rp->c_secure = test_bit(RQ_SECURE, &rqstp->rq_flags);
 	rp->c_type = cachetype;
@@ -561,24 +623,17 @@ void nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
 	return;
 }
 
-/*
- * Copy cached reply to current reply buffer. Should always fit.
- * FIXME as reply is in a page, we should just attach the page, and
- * keep a refcount....
- */
 static int
 nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *data)
 {
-	struct kvec	*vec = &rqstp->rq_res.head[0];
-
-	if (vec->iov_len + data->iov_len > PAGE_SIZE) {
-		printk(KERN_WARNING "nfsd: cached reply too large (%zd).\n",
-				data->iov_len);
-		return 0;
-	}
-	memcpy((char*)vec->iov_base + vec->iov_len, data->iov_base, data->iov_len);
-	vec->iov_len += data->iov_len;
-	return 1;
+	__be32 *p;
+
+	p = xdr_reserve_space(&rqstp->rq_res_stream, data->iov_len);
+	if (unlikely(!p))
+		return false;
+	memcpy(p, data->iov_base, data->iov_len);
+	xdr_commit_encode(&rqstp->rq_res_stream);
+	return true;
 }
 
 /*
@@ -586,28 +641,26 @@ nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *data)
  * scraping this file for info should test the labels to ensure they're
  * getting the correct field.
  */
-static int nfsd_reply_cache_stats_show(struct seq_file *m, void *v)
+int nfsd_reply_cache_stats_show(struct seq_file *m, void *v)
 {
-	struct nfsd_net *nn = m->private;
+	struct nfsd_net *nn = net_generic(file_inode(m->file)->i_sb->s_fs_info,
+					  nfsd_net_id);
 
 	seq_printf(m, "max entries:           %u\n", nn->max_drc_entries);
 	seq_printf(m, "num entries:           %u\n",
-			atomic_read(&nn->num_drc_entries));
+		   atomic_read(&nn->num_drc_entries));
 	seq_printf(m, "hash buckets:          %u\n", 1 << nn->maskbits);
-	seq_printf(m, "mem usage:             %u\n", nn->drc_mem_usage);
-	seq_printf(m, "cache hits:            %u\n", nfsdstats.rchits);
-	seq_printf(m, "cache misses:          %u\n", nfsdstats.rcmisses);
-	seq_printf(m, "not cached:            %u\n", nfsdstats.rcnocache);
-	seq_printf(m, "payload misses:        %u\n", nn->payload_misses);
+	seq_printf(m, "mem usage:             %lld\n",
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_DRC_MEM_USAGE]));
+	seq_printf(m, "cache hits:            %lld\n",
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_HITS]));
+	seq_printf(m, "cache misses:          %lld\n",
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_MISSES]));
+	seq_printf(m, "not cached:            %lld\n",
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_NOCACHE]));
+	seq_printf(m, "payload misses:        %lld\n",
+		   percpu_counter_sum_positive(&nn->counter[NFSD_STATS_PAYLOAD_MISSES]));
 	seq_printf(m, "longest chain len:     %u\n", nn->longest_chain);
 	seq_printf(m, "cachesize at longest:  %u\n", nn->longest_chain_cachesize);
 	return 0;
 }
-
-int nfsd_reply_cache_stats_open(struct inode *inode, struct file *file)
-{
-	struct nfsd_net *nn = net_generic(file_inode(file)->i_sb->s_fs_info,
-								nfsd_net_id);
-
-	return single_open(file, nfsd_reply_cache_stats_show, nn);
-}