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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 012B1C4332F for ; Mon, 18 Apr 2022 12:20:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238585AbiDRMX1 (ORCPT ); Mon, 18 Apr 2022 08:23:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238573AbiDRMWh (ORCPT ); Mon, 18 Apr 2022 08:22:37 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 548251E3E3; Mon, 18 Apr 2022 05:17:52 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id A4195CE1077; Mon, 18 Apr 2022 12:17:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90880C385A7; Mon, 18 Apr 2022 12:17:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650284269; bh=8knLZoPJk4a53zkhcmAmTdECi6kU/0EGUcp5Zlk78SE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vXnwJoaeDGMn+1uZ/f7kDg3xFOec8iOjzfst893O6W3e1Jpr7pdsNr2B6TDaOzlAx xe8EeiAjCAwgmySGy4Vi9I+GquCP6Is143AjqRXIZQtOR8bQoCPwTpJBri/8xrTHa8 NEQgKv8iRfLzBblP97ty4q4aZvcuHbGatUW9uC80= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Kara , Trond Myklebust , Chuck Lever , Sasha Levin Subject: [PATCH 5.17 059/219] nfsd: Fix a write performance regression Date: Mon, 18 Apr 2022 14:10:28 +0200 Message-Id: <20220418121207.048407777@linuxfoundation.org> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220418121203.462784814@linuxfoundation.org> References: <20220418121203.462784814@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Trond Myklebust [ Upstream commit 6b8a94332ee4f7d9a8ae0cbac7609f79c212f06c ] The call to filemap_flush() in nfsd_file_put() is there to ensure that we clear out any writes belonging to a NFSv3 client relatively quickly and avoid situations where the file can't be evicted by the garbage collector. It also ensures that we detect write errors quickly. The problem is this causes a regression in performance for some workloads. So try to improve matters by deferring writeback until we're ready to close the file, and need to detect errors so that we can force the client to resend. Tested-by: Jan Kara Fixes: b6669305d35a ("nfsd: Reduce the number of calls to nfsd_file_gc()") Signed-off-by: Trond Myklebust Link: https://lore.kernel.org/all/20220330103457.r4xrhy2d6nhtouzk@quack3.lan Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- fs/nfsd/filecache.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index cc2831cec669..496f7b3f7523 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -235,6 +235,13 @@ nfsd_file_check_write_error(struct nfsd_file *nf) return filemap_check_wb_err(file->f_mapping, READ_ONCE(file->f_wb_err)); } +static void +nfsd_file_flush(struct nfsd_file *nf) +{ + if (nf->nf_file && vfs_fsync(nf->nf_file, 1) != 0) + nfsd_reset_write_verifier(net_generic(nf->nf_net, nfsd_net_id)); +} + static void nfsd_file_do_unhash(struct nfsd_file *nf) { @@ -302,11 +309,14 @@ nfsd_file_put(struct nfsd_file *nf) return; } - filemap_flush(nf->nf_file->f_mapping); is_hashed = test_bit(NFSD_FILE_HASHED, &nf->nf_flags) != 0; - nfsd_file_put_noref(nf); - if (is_hashed) + if (!is_hashed) { + nfsd_file_flush(nf); + nfsd_file_put_noref(nf); + } else { + nfsd_file_put_noref(nf); nfsd_file_schedule_laundrette(); + } if (atomic_long_read(&nfsd_filecache_count) >= NFSD_FILE_LRU_LIMIT) nfsd_file_gc(); } @@ -327,6 +337,7 @@ nfsd_file_dispose_list(struct list_head *dispose) while(!list_empty(dispose)) { nf = list_first_entry(dispose, struct nfsd_file, nf_lru); list_del(&nf->nf_lru); + nfsd_file_flush(nf); nfsd_file_put_noref(nf); } } @@ -340,6 +351,7 @@ nfsd_file_dispose_list_sync(struct list_head *dispose) while(!list_empty(dispose)) { nf = list_first_entry(dispose, struct nfsd_file, nf_lru); list_del(&nf->nf_lru); + nfsd_file_flush(nf); if (!refcount_dec_and_test(&nf->nf_ref)) continue; if (nfsd_file_free(nf)) -- 2.35.1