From owner-svn-src-head@freebsd.org Wed Aug 26 21:49:43 2020 Return-Path: Delivered-To: svn-src-head@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 ADEC13BDDC5; Wed, 26 Aug 2020 21:49:43 +0000 (UTC) (envelope-from rmacklem@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) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 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 4BcKJl4Brcz3TSq; Wed, 26 Aug 2020 21:49:43 +0000 (UTC) (envelope-from rmacklem@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 73C0819A9B; Wed, 26 Aug 2020 21:49:43 +0000 (UTC) (envelope-from rmacklem@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 07QLnhj6097230; Wed, 26 Aug 2020 21:49:43 GMT (envelope-from rmacklem@FreeBSD.org) Received: (from rmacklem@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 07QLnhMI097229; Wed, 26 Aug 2020 21:49:43 GMT (envelope-from rmacklem@FreeBSD.org) Message-Id: <202008262149.07QLnhMI097229@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: rmacklem set sender to rmacklem@FreeBSD.org using -f From: Rick Macklem Date: Wed, 26 Aug 2020 21:49:43 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r364844 - head/sys/kern X-SVN-Group: head X-SVN-Commit-Author: rmacklem X-SVN-Commit-Paths: head/sys/kern X-SVN-Commit-Revision: 364844 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Aug 2020 21:49:43 -0000 Author: rmacklem Date: Wed Aug 26 21:49:43 2020 New Revision: 364844 URL: https://svnweb.freebsd.org/changeset/base/364844 Log: Fix a "v_seqc_users == 0 not met" panic when VFS_STATFS() fails during mount. r363210 introduced v_seqc_users to the vnodes. This change requires a vn_seqc_write_end() to match the vn_seqc_write_begin() in vfs_cache_root_clear(). mjg@ provided this patch which seems to fix the panic. Tested for an NFS mount where the VFS_STATFS() call will fail. Submitted by: mjg Reviewed by: mjg Differential Revision: https://reviews.freebsd.org/D26160 Modified: head/sys/kern/vfs_mount.c Modified: head/sys/kern/vfs_mount.c ============================================================================== --- head/sys/kern/vfs_mount.c Wed Aug 26 21:41:14 2020 (r364843) +++ head/sys/kern/vfs_mount.c Wed Aug 26 21:49:43 2020 (r364844) @@ -969,11 +969,14 @@ vfs_domount_first( if ((error = VFS_MOUNT(mp)) != 0 || (error1 = VFS_STATFS(mp, &mp->mnt_stat)) != 0 || (error1 = VFS_ROOT(mp, LK_EXCLUSIVE, &newdp)) != 0) { + rootvp = NULL; if (error1 != 0) { error = error1; rootvp = vfs_cache_root_clear(mp); - if (rootvp != NULL) + if (rootvp != NULL) { + vhold(rootvp); vrele(rootvp); + } if ((error1 = VFS_UNMOUNT(mp, 0)) != 0) printf("VFS_UNMOUNT returned %d\n", error1); } @@ -983,6 +986,10 @@ vfs_domount_first( VI_LOCK(vp); vp->v_iflag &= ~VI_MOUNT; VI_UNLOCK(vp); + if (rootvp != NULL) { + vn_seqc_write_end(rootvp); + vdrop(rootvp); + } vn_seqc_write_end(vp); vrele(vp); return (error);