Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-qa0-f53.google.com ([209.85.216.53]:49953 "EHLO mail-qa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756449Ab3BUS2p (ORCPT ); Thu, 21 Feb 2013 13:28:45 -0500 Received: by mail-qa0-f53.google.com with SMTP id z4so3168166qan.19 for ; Thu, 21 Feb 2013 10:28:45 -0800 (PST) From: Jeff Layton To: bfields@fieldses.org Cc: linux-nfs@vger.kernel.org Subject: [PATCH v2 1/5] nfsd: break out comparator into separate function Date: Thu, 21 Feb 2013 13:28:34 -0500 Message-Id: <1361471318-17971-2-git-send-email-jlayton@redhat.com> In-Reply-To: <1361471318-17971-1-git-send-email-jlayton@redhat.com> References: <1361471318-17971-1-git-send-email-jlayton@redhat.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Break out the function that compares the rqstp and checksum against a reply cache entry. While we're at it, track the efficacy of the checksum over the NFS data by tracking the cases where we would have incorrectly matched a DRC entry if we had not tracked it or the length. Signed-off-by: Jeff Layton --- fs/nfsd/nfscache.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c index ca43664..8986568 100644 --- a/fs/nfsd/nfscache.c +++ b/fs/nfsd/nfscache.c @@ -25,6 +25,7 @@ static struct list_head lru_head; static struct kmem_cache *drc_slab; static unsigned int num_drc_entries; static unsigned int max_drc_entries; +static unsigned int csum_misses; /* * Calculate the hash index from an XID. @@ -272,6 +273,26 @@ nfsd_cache_csum(struct svc_rqst *rqstp) return csum; } +static bool +nfsd_cache_match(struct svc_rqst *rqstp, __wsum csum, struct svc_cacherep *rp) +{ + /* Check RPC header info first */ + if (rqstp->rq_xid != rp->c_xid || 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)) + return false; + + /* compare checksum of NFS data */ + if (csum != rp->c_csum) { + ++csum_misses; + return false; + } + + return true; +} + /* * Search the request hash for an entry that matches the given rqstp. * Must be called with cache_lock held. Returns the found entry or @@ -283,18 +304,10 @@ nfsd_cache_search(struct svc_rqst *rqstp, __wsum csum) struct svc_cacherep *rp; struct hlist_node *hn; struct hlist_head *rh; - __be32 xid = rqstp->rq_xid; - u32 proto = rqstp->rq_prot, - vers = rqstp->rq_vers, - proc = rqstp->rq_proc; - rh = &cache_hash[request_hash(xid)]; + rh = &cache_hash[request_hash(rqstp->rq_xid)]; hlist_for_each_entry(rp, hn, rh, c_hash) { - if (xid == rp->c_xid && proc == rp->c_proc && - proto == rp->c_prot && vers == rp->c_vers && - rqstp->rq_arg.len == rp->c_len && csum == rp->c_csum && - 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 (nfsd_cache_match(rqstp, csum, rp)) return rp; } return NULL; -- 1.7.11.7