1 files changed, 53 insertions, 36 deletions

diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 96352ab7bd81..0a0cf1fd77d3 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -20,8 +20,7 @@
 
 #include "nfsd.h"
 #include "cache.h"
-
-#define NFSDDBG_FACILITY	NFSDDBG_REPCACHE
+#include "trace.h"
 
 /*
  * We use this value to determine the number of hash buckets from the max
@@ -36,6 +35,8 @@ struct nfsd_drc_bucket {
 	spinlock_t cache_lock;
 };
 
+static struct kmem_cache	*drc_slab;
+
 static int	nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec);
 static unsigned long nfsd_reply_cache_count(struct shrinker *shrink,
 					    struct shrink_control *sc);
@@ -95,7 +96,7 @@ nfsd_reply_cache_alloc(struct svc_rqst *rqstp, __wsum csum,
 {
 	struct svc_cacherep	*rp;
 
-	rp = kmem_cache_alloc(nn->drc_slab, GFP_KERNEL);
+	rp = kmem_cache_alloc(drc_slab, GFP_KERNEL);
 	if (rp) {
 		rp->c_state = RC_UNUSED;
 		rp->c_type = RC_NOCACHE;
@@ -129,7 +130,7 @@ nfsd_reply_cache_free_locked(struct nfsd_drc_bucket *b, struct svc_cacherep *rp,
 		atomic_dec(&nn->num_drc_entries);
 		nn->drc_mem_usage -= sizeof(*rp);
 	}
-	kmem_cache_free(nn->drc_slab, rp);
+	kmem_cache_free(drc_slab, rp);
 }
 
 static void
@@ -141,6 +142,18 @@ nfsd_reply_cache_free(struct nfsd_drc_bucket *b, struct svc_cacherep *rp,
 	spin_unlock(&b->cache_lock);
 }
 
+int nfsd_drc_slab_create(void)
+{
+	drc_slab = kmem_cache_create("nfsd_drc",
+				sizeof(struct svc_cacherep), 0, 0, NULL);
+	return drc_slab ? 0: -ENOMEM;
+}
+
+void nfsd_drc_slab_free(void)
+{
+	kmem_cache_destroy(drc_slab);
+}
+
 int nfsd_reply_cache_init(struct nfsd_net *nn)
 {
 	unsigned int hashsize;
@@ -159,18 +172,13 @@ int nfsd_reply_cache_init(struct nfsd_net *nn)
 	if (status)
 		goto out_nomem;
 
-	nn->drc_slab = kmem_cache_create("nfsd_drc",
-				sizeof(struct svc_cacherep), 0, 0, NULL);
-	if (!nn->drc_slab)
-		goto out_shrinker;
-
 	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_slab;
+			goto out_shrinker;
 	}
 
 	for (i = 0; i < hashsize; i++) {
@@ -180,8 +188,6 @@ int nfsd_reply_cache_init(struct nfsd_net *nn)
 	nn->drc_hashsize = hashsize;
 
 	return 0;
-out_slab:
-	kmem_cache_destroy(nn->drc_slab);
 out_shrinker:
 	unregister_shrinker(&nn->nfsd_reply_cache_shrinker);
 out_nomem:
@@ -209,8 +215,6 @@ void nfsd_reply_cache_shutdown(struct nfsd_net *nn)
 	nn->drc_hashtbl = NULL;
 	nn->drc_hashsize = 0;
 
-	kmem_cache_destroy(nn->drc_slab);
-	nn->drc_slab = NULL;
 }
 
 /*
@@ -323,8 +327,10 @@ nfsd_cache_key_cmp(const struct svc_cacherep *key,
 			const struct svc_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)
+	    key->c_key.k_csum != rp->c_key.k_csum) {
 		++nn->payload_misses;
+		trace_nfsd_drc_mismatch(nn, key, rp);
+	}
 
 	return memcmp(&key->c_key, &rp->c_key, sizeof(key->c_key));
 }
@@ -377,15 +383,22 @@ out:
 	return ret;
 }
 
-/*
+/**
+ * nfsd_cache_lookup - Find an entry in the duplicate reply cache
+ * @rqstp: Incoming Call to find
+ *
  * 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
  * a suitable one isn't there, then drop the cache_lock and allocate a
  * new one, then search again in case one got inserted while this thread
  * didn't hold the lock.
+ *
+ * Return values:
+ *   %RC_DOIT: Process the request normally
+ *   %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)
 {
 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 	struct svc_cacherep	*rp, *found;
@@ -399,7 +412,7 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
 	rqstp->rq_cacherep = NULL;
 	if (type == RC_NOCACHE) {
 		nfsdstats.rcnocache++;
-		return rtn;
+		goto out;
 	}
 
 	csum = nfsd_cache_csum(rqstp);
@@ -409,10 +422,8 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
 	 * preallocate an entry.
 	 */
 	rp = nfsd_reply_cache_alloc(rqstp, csum, nn);
-	if (!rp) {
-		dprintk("nfsd: unable to allocate DRC entry!\n");
-		return rtn;
-	}
+	if (!rp)
+		goto out;
 
 	spin_lock(&b->cache_lock);
 	found = nfsd_cache_insert(b, rp, nn);
@@ -431,8 +442,10 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
 
 	/* go ahead and prune the cache */
 	prune_bucket(b, nn);
- out:
+
+out_unlock:
 	spin_unlock(&b->cache_lock);
+out:
 	return rtn;
 
 found_entry:
@@ -442,13 +455,13 @@ found_entry:
 
 	/* Request being processed */
 	if (rp->c_state == RC_INPROG)
-		goto out;
+		goto out_trace;
 
 	/* From the hall of fame of impractical attacks:
 	 * Is this a user who tries to snoop on the cache? */
 	rtn = RC_DOIT;
 	if (!test_bit(RQ_SECURE, &rqstp->rq_flags) && rp->c_secure)
-		goto out;
+		goto out_trace;
 
 	/* Compose RPC reply header */
 	switch (rp->c_type) {
@@ -460,21 +473,26 @@ found_entry:
 		break;
 	case RC_REPLBUFF:
 		if (!nfsd_cache_append(rqstp, &rp->c_replvec))
-			goto out;	/* should not happen */
+			goto out_unlock; /* should not happen */
 		rtn = RC_REPLY;
 		break;
 	default:
-		printk(KERN_WARNING "nfsd: bad repcache type %d\n", rp->c_type);
-		nfsd_reply_cache_free_locked(b, rp, nn);
+		WARN_ONCE(1, "nfsd: bad repcache type %d\n", rp->c_type);
 	}
 
-	goto out;
+out_trace:
+	trace_nfsd_drc_found(nn, rqstp, rtn);
+	goto out_unlock;
 }
 
-/*
- * Update a cache entry. This is called from nfsd_dispatch when
- * the procedure has been executed and the complete reply is in
- * rqstp->rq_res.
+/**
+ * nfsd_cache_update - Update an entry in the duplicate reply cache.
+ * @rqstp: svc_rqst with a finished Reply
+ * @cachetype: which cache to update
+ * @statp: Reply's status code
+ *
+ * This is called from nfsd_dispatch when the procedure has been
+ * executed and the complete reply is in rqstp->rq_res.
  *
  * We're copying around data here rather than swapping buffers because
  * the toplevel loop requires max-sized buffers, which would be a waste
@@ -487,8 +505,7 @@ found_entry:
  * 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, int cachetype, __be32 *statp)
 {
 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
 	struct svc_cacherep *rp = rqstp->rq_cacherep;