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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 2F65DCA9ECB for ; Thu, 31 Oct 2019 16:59:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1081620873 for ; Thu, 31 Oct 2019 16:59:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728826AbfJaQ7J (ORCPT ); Thu, 31 Oct 2019 12:59:09 -0400 Received: from mx2.suse.de ([195.135.220.15]:36280 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728597AbfJaQ7I (ORCPT ); Thu, 31 Oct 2019 12:59:08 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id A3B4AB355; Thu, 31 Oct 2019 16:59:06 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id CC7811E482D; Thu, 31 Oct 2019 17:59:05 +0100 (CET) Date: Thu, 31 Oct 2019 17:59:05 +0100 From: Jan Kara To: Dmitry Monakhov Cc: linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, jack@suse.cz, tytso@mit.edu, lixi@ddn.com, Dmitry Monakhov , Konstantin Khlebnikov Subject: Re: [PATCH] fs/ext4: get project quota from inode for mangling statfs results Message-ID: <20191031165905.GE13321@quack2.suse.cz> References: <20191031110348.6991-1-dmonakhov@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191031110348.6991-1-dmonakhov@openvz.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 31-10-19 11:03:48, Dmitry Monakhov wrote: > From: Dmitry Monakhov > > Right now ext4_statfs_project() does quota lookup by id every time. > This is costly operation, especially if there is no inode who hold > reference to this dquot. This means that each statfs performs useless > ext4_acquire_dquot()/ext4_release_dquot() which serialized on __jbd2_log_wait_for_space() > dqget() > ->ext4_acquire_dquot > -> ext4_journal_start > -> __jbd2_log_wait_for_space > dqput() > -> ext4_release_dquot > ->ext4_journal_start > ->__jbd2_log_wait_for_space > > > Function ext4_statfs_project() could be moved into generic quota code, > it is required for every filesystem which uses generic project quota. > > Reported-by: Dmitry Monakhov > Signed-off-by: Konstantin Khlebnikov Thanks! The patch looks good to me. You can add: Reviewed-by: Jan Kara Honza > --- > fs/ext4/super.c | 25 ++++++++++++++++--------- > 1 file changed, 16 insertions(+), 9 deletions(-) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 2318e5f..4e8f97d68 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -5532,18 +5532,23 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data) > } > > #ifdef CONFIG_QUOTA > -static int ext4_statfs_project(struct super_block *sb, > - kprojid_t projid, struct kstatfs *buf) > +static int ext4_statfs_project(struct inode *inode, struct kstatfs *buf) > { > - struct kqid qid; > + struct super_block *sb = inode->i_sb; > struct dquot *dquot; > u64 limit; > u64 curblock; > + int err; > + > + err = dquot_initialize(inode); > + if (err) > + return err; > + > + spin_lock(&inode->i_lock); > + dquot = ext4_get_dquots(inode)[PRJQUOTA]; > + if (!dquot) > + goto out_unlock; > > - qid = make_kqid_projid(projid); > - dquot = dqget(sb, qid); > - if (IS_ERR(dquot)) > - return PTR_ERR(dquot); > spin_lock(&dquot->dq_dqb_lock); > > limit = (dquot->dq_dqb.dqb_bsoftlimit ? > @@ -5569,7 +5574,9 @@ static int ext4_statfs_project(struct super_block *sb, > } > > spin_unlock(&dquot->dq_dqb_lock); > - dqput(dquot); > +out_unlock: > + spin_unlock(&inode->i_lock); > + > return 0; > } > #endif > @@ -5609,7 +5616,7 @@ static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf) > #ifdef CONFIG_QUOTA > if (ext4_test_inode_flag(dentry->d_inode, EXT4_INODE_PROJINHERIT) && > sb_has_quota_limits_enabled(sb, PRJQUOTA)) > - ext4_statfs_project(sb, EXT4_I(dentry->d_inode)->i_projid, buf); > + ext4_statfs_project(dentry->d_inode, buf); > #endif > return 0; > } > -- > 2.7.4 > -- Jan Kara SUSE Labs, CR