From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5956AC433E0 for ; Thu, 21 May 2020 14:36:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2DDF6206F6 for ; Thu, 21 May 2020 14:36:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="FRP7w+ew" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729799AbgEUOgJ (ORCPT ); Thu, 21 May 2020 10:36:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55890 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728103AbgEUOgJ (ORCPT ); Thu, 21 May 2020 10:36:09 -0400 Received: from mail-il1-x142.google.com (mail-il1-x142.google.com [IPv6:2607:f8b0:4864:20::142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC0A3C061A0E; Thu, 21 May 2020 07:36:07 -0700 (PDT) Received: by mail-il1-x142.google.com with SMTP id j2so7303224ilr.5; Thu, 21 May 2020 07:36:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:subject:from:to:cc:date:message-id:in-reply-to:references :user-agent:mime-version:content-transfer-encoding; bh=lJyCmn+wrw9fOiuFD6p/GmVDOI8LWar9S6pYuPj9wAU=; b=FRP7w+ewFfnuhYFY2mpAwj3U/rXlCTUJuuZIcWQZAJT3ad7SX8qA3dc72JLsnipYio SBOVyZJUWHK+J9rEMLDtZihQW9z/mv398Kx3K2ozRGi/XBdy52VOCZVIdZRaMlzH93kk kvO04Y09K1Np08Edr121IejXHIyg5R7kjh9K+6GPxd3IS7m5xal17yBVgM6wnpmLKaOE lg6CFhfexK9mnK8PAXzA3wnHeitgo97sSl091k+J2LYKMJWZfTE3QcRFfnC1+dNa7PKb ZBd/9D2ZY2YXj2u91h+kZhYy0kVp6H+cqnF3LhgbOfzVOmrKZucS5IJNnnHlJ9hsgaNu +RKg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:subject:from:to:cc:date:message-id :in-reply-to:references:user-agent:mime-version :content-transfer-encoding; bh=lJyCmn+wrw9fOiuFD6p/GmVDOI8LWar9S6pYuPj9wAU=; b=BpFYqcnMZY8vbQ4HMApUHOmeaVqMKwVdA3Cd3aY1dvGk2QBO+9vC2gcF1YYS++aLtf Nfb1BSbnng1donc8i70DhgJt9mQS4ZRkQiDC68NQVoa9O7ojERIo8ssBdGnL0Nr6Eqfz 6KY5+OacIXp3IO/9W9q42fg54NR6NjpnwLRoLQBdNi5v77Qjj+etiJyiQmavMZB9tZoJ DfPzO8sIINA3oJtgFPZB1IqKtaMf9ht3bYILkZpQ3CWtQlrD93VLLu5l/dmSulRM+413 L5YGF/V4Edvqfw9C/Z0g1+4xSiMfGNQYaF0LDCkqn/8tggBJfPtUb3Y5eZF9QDydlLVN t46A== X-Gm-Message-State: AOAM5302vjr0xZ+W5dVgna7oBNkbBKBsXN6tV4o9FA4OhESIPAsj539U NCs0RI3z+H5S9OAzDSRT1ipGbhbK X-Google-Smtp-Source: ABdhPJykbZGB/3x7caD7BJATm389Iwv8VMrG1tZyq+7tak40kc6s0EZmTtDZh2FqCcZl6WSkPVD02g== X-Received: by 2002:a92:984e:: with SMTP id l75mr9014887ili.22.1590071766944; Thu, 21 May 2020 07:36:06 -0700 (PDT) Received: from gateway.1015granger.net (c-68-61-232-219.hsd1.mi.comcast.net. [68.61.232.219]) by smtp.gmail.com with ESMTPSA id h29sm3118668ilf.23.2020.05.21.07.36.06 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 May 2020 07:36:06 -0700 (PDT) Received: from klimt.1015granger.net (klimt.1015granger.net [192.168.1.55]) by gateway.1015granger.net (8.14.7/8.14.7) with ESMTP id 04LEa5Vi000920; Thu, 21 May 2020 14:36:05 GMT Subject: [PATCH v3 27/32] NFSD: Add tracepoints to NFSD's duplicate reply cache From: Chuck Lever To: bfields@fieldses.org Cc: linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org Date: Thu, 21 May 2020 10:36:05 -0400 Message-ID: <20200521143605.3557.32136.stgit@klimt.1015granger.net> In-Reply-To: <20200521141100.3557.17098.stgit@klimt.1015granger.net> References: <20200521141100.3557.17098.stgit@klimt.1015granger.net> User-Agent: StGit/0.22-31-g4b47 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Try to capture DRC failures. Two additional clean-ups: - Introduce Doxygen-style comments for the main entry points - Remove a dprintk that fires for an allocation failure. This was the only dprintk in the REPCACHE class. Reported-by: kbuild test robot [ cel: force typecast for display of checksum values ] Signed-off-by: Chuck Lever --- fs/nfsd/nfscache.c | 57 +++++++++++++++++++++++++++++++------------------- fs/nfsd/trace.h | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 94 insertions(+), 22 deletions(-) diff --git a/fs/nfsd/nfscache.c b/fs/nfsd/nfscache.c index 96352ab7bd81..945d2f5e760e 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 @@ -323,8 +322,10 @@ 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 +378,22 @@ nfsd_cache_insert(struct nfsd_drc_bucket *b, struct svc_cacherep *key, 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 +407,7 @@ 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 +417,8 @@ 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 +437,10 @@ 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 +450,13 @@ nfsd_cache_lookup(struct svc_rqst *rqstp) /* 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) { @@ -460,7 +468,7 @@ nfsd_cache_lookup(struct svc_rqst *rqstp) 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: @@ -468,13 +476,19 @@ nfsd_cache_lookup(struct svc_rqst *rqstp) nfsd_reply_cache_free_locked(b, rp, nn); } - 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 +501,7 @@ nfsd_cache_lookup(struct svc_rqst *rqstp) * 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; diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h index 78c574251c60..371dc198d28e 100644 --- a/fs/nfsd/trace.h +++ b/fs/nfsd/trace.h @@ -432,6 +432,65 @@ TRACE_EVENT(nfsd_file_fsnotify_handle_event, __entry->nlink, __entry->mode, __entry->mask) ); +#include "cache.h" + +TRACE_DEFINE_ENUM(RC_DROPIT); +TRACE_DEFINE_ENUM(RC_REPLY); +TRACE_DEFINE_ENUM(RC_DOIT); + +#define show_drc_retval(x) \ + __print_symbolic(x, \ + { RC_DROPIT, "DROPIT" }, \ + { RC_REPLY, "REPLY" }, \ + { RC_DOIT, "DOIT" }) + +TRACE_EVENT(nfsd_drc_found, + TP_PROTO( + const struct nfsd_net *nn, + const struct svc_rqst *rqstp, + int result + ), + TP_ARGS(nn, rqstp, result), + TP_STRUCT__entry( + __field(unsigned long long, boot_time) + __field(unsigned long, result) + __field(u32, xid) + ), + TP_fast_assign( + __entry->boot_time = nn->boot_time; + __entry->result = result; + __entry->xid = be32_to_cpu(rqstp->rq_xid); + ), + TP_printk("boot_time=%16llx xid=0x%08x result=%s", + __entry->boot_time, __entry->xid, + show_drc_retval(__entry->result)) + +); + +TRACE_EVENT(nfsd_drc_mismatch, + TP_PROTO( + const struct nfsd_net *nn, + const struct svc_cacherep *key, + const struct svc_cacherep *rp + ), + TP_ARGS(nn, key, rp), + TP_STRUCT__entry( + __field(unsigned long long, boot_time) + __field(u32, xid) + __field(u32, cached) + __field(u32, ingress) + ), + TP_fast_assign( + __entry->boot_time = nn->boot_time; + __entry->xid = be32_to_cpu(key->c_key.k_xid); + __entry->cached = (__force u32)key->c_key.k_csum; + __entry->ingress = (__force u32)rp->c_key.k_csum; + ), + TP_printk("boot_time=%16llx xid=0x%08x cached-csum=0x%08x ingress-csum=0x%08x", + __entry->boot_time, __entry->xid, __entry->cached, + __entry->ingress) +); + #endif /* _NFSD_TRACE_H */ #undef TRACE_INCLUDE_PATH