From owner-svn-src-all@freebsd.org Sun Jan 26 00:40:28 2020 Return-Path: Delivered-To: svn-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 17B54229886; Sun, 26 Jan 2020 00:40:28 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 484vDW4yWxz4LMd; Sun, 26 Jan 2020 00:40:27 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id A5A9A18D01; Sun, 26 Jan 2020 00:40:27 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 00Q0eRaR099788; Sun, 26 Jan 2020 00:40:27 GMT (envelope-from mjg@FreeBSD.org) Received: (from mjg@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 00Q0eR2s099787; Sun, 26 Jan 2020 00:40:27 GMT (envelope-from mjg@FreeBSD.org) Message-Id: <202001260040.00Q0eR2s099787@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mjg set sender to mjg@FreeBSD.org using -f From: Mateusz Guzik Date: Sun, 26 Jan 2020 00:40:27 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r357130 - head/sys/kern X-SVN-Group: head X-SVN-Commit-Author: mjg X-SVN-Commit-Paths: head/sys/kern X-SVN-Commit-Revision: 357130 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 26 Jan 2020 00:40:28 -0000 Author: mjg Date: Sun Jan 26 00:40:27 2020 New Revision: 357130 URL: https://svnweb.freebsd.org/changeset/base/357130 Log: vfs: fix freevnodes count update race against preemption vdbatch_process leaves the critical section too early, openign a time window where another thread can get scheduled and modify vd->freevnodes. Once it the preempted thread gets back it overrides the value with 0. Just move critical_exit to the end of the function. Modified: head/sys/kern/vfs_subr.c Modified: head/sys/kern/vfs_subr.c ============================================================================== --- head/sys/kern/vfs_subr.c Sun Jan 26 00:38:06 2020 (r357129) +++ head/sys/kern/vfs_subr.c Sun Jan 26 00:40:27 2020 (r357130) @@ -3324,10 +3324,10 @@ vdbatch_process(struct vdbatch *vd) vp->v_dbatchcpu = NOCPU; } mtx_unlock(&vnode_list_mtx); - critical_exit(); vd->freevnodes = 0; bzero(vd->tab, sizeof(vd->tab)); vd->index = 0; + critical_exit(); } static void