From owner-freebsd-fs@freebsd.org Tue May 1 06:12:49 2018 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C36CFFC57DE for ; Tue, 1 May 2018 06:12:49 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 3D710835B4 for ; Tue, 1 May 2018 06:12:49 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id EBE46FC57DB; Tue, 1 May 2018 06:12:48 +0000 (UTC) Delivered-To: fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id D9163FC57D9 for ; Tue, 1 May 2018 06:12:48 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 6AD33835A9 for ; Tue, 1 May 2018 06:12:48 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id 737B210E03 for ; Tue, 1 May 2018 06:12:47 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id w416ClxM011932 for ; Tue, 1 May 2018 06:12:47 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id w416Clm8011921 for fs@FreeBSD.org; Tue, 1 May 2018 06:12:47 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: fs@FreeBSD.org Subject: [Bug 210316] panic after trying to r/w mount msdosfs on write protected media Date: Tue, 01 May 2018 06:12:45 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: damjan.jov@gmail.com X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: fs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 May 2018 06:12:50 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D210316 --- Comment #7 from Damjan Jovanovic --- If I add this code snippet (copied from somewhere in the ext2fs driver) so = that vinvalbuf() is called before g_vfs_close(), the r/w mount of a r/o geom fai= ls (EPERM), and the panic doesn't happen: diff --git a/sys/fs/msdosfs/msdosfs_vfsops.c b/sys/fs/msdosfs/msdosfs_vfsop= s.c index 76a238c5ff77..7477d5b03a1f 100644 --- a/sys/fs/msdosfs/msdosfs_vfsops.c +++ b/sys/fs/msdosfs/msdosfs_vfsops.c @@ -717,6 +717,12 @@ mountmsdosfs(struct vnode *devvp, struct mount *mp) error_exit: if (bp) brelse(bp); + + vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY); + if (vinvalbuf(devvp, 0, 0, 0) !=3D 0) + panic("mountmsdosfs: dirty"); + VOP_UNLOCK(devvp, 0); + if (cp !=3D NULL) { g_topology_lock(); g_vfs_close(cp); Apart from not really understanding it, I don't like it, because if every filesystem should be calling vinvalbuf() before g_vfs_close(), then shouldn= 't g_vfs_close() rather be calling vinvalbuf() itself? Also msdosfs_unmount() doesn't call vinvalbuf() before its own g_vfs_close(), but it does call msdosfs_sync() and vflush(). Would those also work, or be even better? Fixing UFS will be a different story, as msdosfs writes to the filesystem during mount [in markvoldirty()], so the panic is almost immediate. I could only crash UFS by trying to write to a file after mounting. --=20 You are receiving this mail because: You are the assignee for the bug.=