knfsd: reply cache cleanups

Make REQHASH() an inline function.  Rename hash_list to cache_hash.
Fix an obsolete comment.

Signed-off-by: Greg Banks <gnb@sgi.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

2 files changed, 20 insertions, 12 deletions

diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index 5bfc2ac60d54..6f0aa4989c61 100644
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -29,15 +29,24 @@
  */
 #define CACHESIZE               1024
 #define HASHSIZE                64
-#define REQHASH(xid)            (((((__force __u32)xid) >> 24) ^ ((__force __u32)xid)) & (HASHSIZE-1))
 
-static struct hlist_head *      hash_list;
+static struct hlist_head *      cache_hash;
 static struct list_head         lru_head;
 static int                      cache_disabled = 1;
 
+/*
+ * Calculate the hash index from an XID.
+ */
+static inline u32 request_hash(u32 xid)
+{
+        u32 h = xid;
+        h ^= (xid >> 24);
+        return h & (HASHSIZE-1);
+}
+
 static int      nfsd_cache_append(struct svc_rqst *rqstp, struct kvec *vec);
 
-/* 
+/*
  * locking for the reply cache:
  * A cache entry is "single use" if c_state == RC_INPROG
  * Otherwise, it when accessing _prev or _next, the lock must be held.
@@ -62,8 +71,8 @@ int nfsd_reply_cache_init(void)
                 i--;
         }
 
-        hash_list = kcalloc (HASHSIZE, sizeof(struct hlist_head), GFP_KERNEL);
-        if (!hash_list)
+        cache_hash = kcalloc (HASHSIZE, sizeof(struct hlist_head), GFP_KERNEL);
+        if (!cache_hash)
                 goto out_nomem;
 
         cache_disabled = 0;
@@ -88,8 +97,8 @@ void nfsd_reply_cache_shutdown(void)
 
         cache_disabled = 1;
 
-        kfree (hash_list);
-        hash_list = NULL;
+        kfree (cache_hash);
+        cache_hash = NULL;
 }
 
 /*
@@ -108,7 +117,7 @@ static void
 hash_refile(struct svc_cacherep *rp)
 {
         hlist_del_init(&rp->c_hash);
-        hlist_add_head(&rp->c_hash, hash_list + REQHASH(rp->c_xid));
+        hlist_add_head(&rp->c_hash, cache_hash + request_hash(rp->c_xid));
 }
 
 /*
@@ -138,7 +147,7 @@ nfsd_cache_lookup(struct svc_rqst *rqstp, int type)
         spin_lock(&cache_lock);
         rtn = RC_DOIT;
 
-        rh = &hash_list[REQHASH(xid)];
+        rh = &cache_hash[request_hash(xid)];
         hlist_for_each_entry(rp, hn, rh, c_hash) {
                 if (rp->c_state != RC_UNUSED &&
                     xid == rp->c_xid && proc == rp->c_proc &&
@@ -264,7 +273,7 @@ nfsd_cache_update(struct svc_rqst *rqstp, int cachetype, __be32 *statp)
 
         len = resv->iov_len - ((char*)statp - (char*)resv->iov_base);
         len >>= 2;
-        
+
         /* Don't cache excessive amounts of data and XDR failures */
         if (!statp || len > (256 >> 2)) {
                 rp->c_state = RC_UNUSED;
diff --git a/include/linux/nfsd/cache.h b/include/linux/nfsd/cache.h
index 5bccaab81056..3a3f58934f5e 100644
--- a/include/linux/nfsd/cache.h
+++ b/include/linux/nfsd/cache.h
@@ -14,8 +14,7 @@
 #include <linux/uio.h>
 
 /*
- * Representation of a reply cache entry. The first two members *must*
- * be hash_next and hash_prev.
+ * Representation of a reply cache entry.
  */
 struct svc_cacherep {
         struct hlist_node       c_hash;