NFSD: De-duplicate hash bucket indexing

Clean up: The details of finding the right hash bucket are exactly
the same in both nfsd_cache_lookup() and nfsd_cache_update().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c
index a4a69ab..f79790d 100644 (file)
--- a/fs/nfsd/nfscache.c
+++ b/fs/nfsd/nfscache.c
@@ -84,12 +84,6 @@ 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)
-{
-       return hash_32((__force u32)xid, nn->maskbits);
-}
-
 static struct svc_cacherep *
 nfsd_reply_cache_alloc(struct svc_rqst *rqstp, __wsum csum,
                        struct nfsd_net *nn)
@@ -241,6 +235,14 @@ lru_put_end(struct nfsd_drc_bucket *b, struct svc_cacherep *rp)
        list_move_tail(&rp->c_lru, &b->lru_head);
 }
 
+static noinline struct nfsd_drc_bucket *
+nfsd_cache_bucket_find(__be32 xid, struct nfsd_net *nn)
+{
+       unsigned int hash = hash_32((__force u32)xid, nn->maskbits);
+
+       return &nn->drc_hashtbl[hash];
+}
+
 static long prune_bucket(struct nfsd_drc_bucket *b, struct nfsd_net *nn,
                         unsigned int max)
 {
@@ -421,10 +423,8 @@ 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;
-       __be32                  xid = rqstp->rq_xid;
        __wsum                  csum;
-       u32 hash = nfsd_cache_hash(xid, nn);
-       struct nfsd_drc_bucket *b = &nn->drc_hashtbl[hash];
+       struct nfsd_drc_bucket  *b = nfsd_cache_bucket_find(rqstp->rq_xid, nn);
        int type = rqstp->rq_cachetype;
        int rtn = RC_DOIT;
 
@@ -528,7 +528,6 @@ 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;
        struct kvec     *resv = &rqstp->rq_res.head[0], *cachv;
-       u32             hash;
        struct nfsd_drc_bucket *b;
        int             len;
        size_t          bufsize = 0;
@@ -536,8 +535,7 @@ 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;