1 files changed, 44 insertions, 50 deletions

diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index cef4686f87ef..527ce4c65765 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -121,7 +121,7 @@ nfsd_cache_hash(__be32 xid)
 }
 
 static struct svc_cacherep *
-nfsd_reply_cache_alloc(void)
+nfsd_reply_cache_alloc(struct svc_rqst *rqstp, __wsum csum)
 {
         struct svc_cacherep     *rp;
 
@@ -130,6 +130,16 @@ nfsd_reply_cache_alloc(void)
                 rp->c_state = RC_UNUSED;
                 rp->c_type = RC_NOCACHE;
                 INIT_LIST_HEAD(&rp->c_lru);
+
+                rp->c_xid = rqstp->rq_xid;
+                rp->c_proc = rqstp->rq_proc;
+                memset(&rp->c_addr, 0, sizeof(rp->c_addr));
+                rpc_copy_addr((struct sockaddr *)&rp->c_addr, svc_addr(rqstp));
+                rpc_set_port((struct sockaddr *)&rp->c_addr, rpc_get_port(svc_addr(rqstp)));
+                rp->c_prot = rqstp->rq_prot;
+                rp->c_vers = rqstp->rq_vers;
+                rp->c_len = rqstp->rq_arg.len;
+                rp->c_csum = csum;
         }
         return rp;
 }
@@ -141,9 +151,11 @@ nfsd_reply_cache_free_locked(struct svc_cacherep *rp)
                 drc_mem_usage -= rp->c_replvec.iov_len;
                 kfree(rp->c_replvec.iov_base);
         }
-        list_del(&rp->c_lru);
-        atomic_dec(&num_drc_entries);
-        drc_mem_usage -= sizeof(*rp);
+        if (rp->c_state != RC_UNUSED) {
+                list_del(&rp->c_lru);
+                atomic_dec(&num_drc_entries);
+                drc_mem_usage -= sizeof(*rp);
+        }
         kmem_cache_free(drc_slab, rp);
 }
 
@@ -319,24 +331,23 @@ nfsd_cache_csum(struct svc_rqst *rqstp)
 }
 
 static bool
-nfsd_cache_match(struct svc_rqst *rqstp, __wsum csum, struct svc_cacherep *rp)
+nfsd_cache_match(const struct svc_cacherep *key, const struct svc_cacherep *rp)
 {
         /* Check RPC XID first */
-        if (rqstp->rq_xid != rp->c_xid)
+        if (key->c_xid != rp->c_xid)
                 return false;
         /* compare checksum of NFS data */
-        if (csum != rp->c_csum) {
+        if (key->c_csum != rp->c_csum) {
                 ++payload_misses;
                 return false;
         }
 
         /* Other discriminators */
-        if (rqstp->rq_proc != rp->c_proc ||
-            rqstp->rq_prot != rp->c_prot ||
-            rqstp->rq_vers != rp->c_vers ||
-            rqstp->rq_arg.len != rp->c_len ||
-            !rpc_cmp_addr(svc_addr(rqstp), (struct sockaddr *)&rp->c_addr) ||
-            rpc_get_port(svc_addr(rqstp)) != rpc_get_port((struct sockaddr *)&rp->c_addr))
+        if (key->c_proc != rp->c_proc ||
+            key->c_prot != rp->c_prot ||
+            key->c_vers != rp->c_vers ||
+            key->c_len != rp->c_len ||
+            memcmp(&key->c_addr, &rp->c_addr, sizeof(key->c_addr)) != 0)
                 return false;
 
         return true;
@@ -345,19 +356,18 @@ nfsd_cache_match(struct svc_rqst *rqstp, __wsum csum, struct svc_cacherep *rp)
 /*
  * Search the request hash for an entry that matches the given rqstp.
  * Must be called with cache_lock held. Returns the found entry or
- * NULL on failure.
+ * inserts an empty key on failure.
  */
 static struct svc_cacherep *
-nfsd_cache_search(struct nfsd_drc_bucket *b, struct svc_rqst *rqstp,
-                __wsum csum)
+nfsd_cache_insert(struct nfsd_drc_bucket *b, struct svc_cacherep *key)
 {
-        struct svc_cacherep     *rp, *ret = NULL;
+        struct svc_cacherep     *rp, *ret = key;
         struct list_head        *rh = &b->lru_head;
         unsigned int            entries = 0;
 
         list_for_each_entry(rp, rh, c_lru) {
                 ++entries;
-                if (nfsd_cache_match(rqstp, csum, rp)) {
+                if (nfsd_cache_match(key, rp)) {
                         ret = rp;
                         break;
                 }
@@ -374,6 +384,7 @@ nfsd_cache_search(struct nfsd_drc_bucket *b, struct svc_rqst *rqstp,
                                 atomic_read(&num_drc_entries));
         }
 
+        lru_put_end(b, ret);
         return ret;
 }
 
@@ -389,9 +400,6 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
 {
         struct svc_cacherep     *rp, *found;
         __be32                  xid = rqstp->rq_xid;
-        u32                     proto =  rqstp->rq_prot,
-                                vers = rqstp->rq_vers,
-                                proc = rqstp->rq_proc;
         __wsum                  csum;
         u32 hash = nfsd_cache_hash(xid);
         struct nfsd_drc_bucket *b = &drc_hashtbl[hash];
@@ -410,52 +418,38 @@ nfsd_cache_lookup(struct svc_rqst *rqstp)
          * Since the common case is a cache miss followed by an insert,
          * preallocate an entry.
          */
-        rp = nfsd_reply_cache_alloc();
-        spin_lock(&b->cache_lock);
-        if (likely(rp)) {
-                atomic_inc(&num_drc_entries);
-                drc_mem_usage += sizeof(*rp);
+        rp = nfsd_reply_cache_alloc(rqstp, csum);
+        if (!rp) {
+                dprintk("nfsd: unable to allocate DRC entry!\n");
+                return rtn;
         }
 
-        /* go ahead and prune the cache */
-        prune_bucket(b);
-
-        found = nfsd_cache_search(b, rqstp, csum);
-        if (found) {
-                if (likely(rp))
-                        nfsd_reply_cache_free_locked(rp);
+        spin_lock(&b->cache_lock);
+        found = nfsd_cache_insert(b, rp);
+        if (found != rp) {
+                nfsd_reply_cache_free_locked(rp);
                 rp = found;
                 goto found_entry;
         }
 
-        if (!rp) {
-                dprintk("nfsd: unable to allocate DRC entry!\n");
-                goto out;
-        }
-
         nfsdstats.rcmisses++;
         rqstp->rq_cacherep = rp;
         rp->c_state = RC_INPROG;
-        rp->c_xid = xid;
-        rp->c_proc = proc;
-        rpc_copy_addr((struct sockaddr *)&rp->c_addr, svc_addr(rqstp));
-        rpc_set_port((struct sockaddr *)&rp->c_addr, rpc_get_port(svc_addr(rqstp)));
-        rp->c_prot = proto;
-        rp->c_vers = vers;
-        rp->c_len = rqstp->rq_arg.len;
-        rp->c_csum = csum;
 
-        lru_put_end(b, rp);
+        atomic_inc(&num_drc_entries);
+        drc_mem_usage += sizeof(*rp);
+
+        /* go ahead and prune the cache */
+        prune_bucket(b);
  out:
         spin_unlock(&b->cache_lock);
         return rtn;
 
 found_entry:
-        nfsdstats.rchits++;
         /* We found a matching entry which is either in progress or done. */
-        lru_put_end(b, rp);
-
+        nfsdstats.rchits++;
         rtn = RC_DROPIT;
+
         /* Request being processed */
         if (rp->c_state == RC_INPROG)
                 goto out;