From nobody Tue Oct 26 23:46:59 2021 X-Original-To: bugs@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id D82311821CE8 for ; Tue, 26 Oct 2021 23:46:59 +0000 (UTC) (envelope-from bugzilla-noreply@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 "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Hf7lR5L8rz3Dgn for ; Tue, 26 Oct 2021 23:46:59 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (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 did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 9080125C2E for ; Tue, 26 Oct 2021 23:46:59 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 19QNkx4t095903 for ; Tue, 26 Oct 2021 23:46:59 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 19QNkxK2095902 for bugs@FreeBSD.org; Tue, 26 Oct 2021 23:46:59 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: bugs@FreeBSD.org Subject: [Bug 259071] Read past EoF in NFS client and fusefs Date: Tue, 26 Oct 2021 23:46:59 +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 Some People X-Bugzilla-Who: rmacklem@FreeBSD.org X-Bugzilla-Status: Open X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: attachments.created 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 List-Id: Bug reports List-Archive: https://lists.freebsd.org/archives/freebsd-bugs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-bugs@freebsd.org MIME-Version: 1.0 X-ThisMailContainsUnwantedMimeParts: N https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D259071 --- Comment #7 from Rick Macklem --- Created attachment 229053 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D229053&action= =3Dedit timestamp file mods so Lookup can discard stale attributes against Writing Similar to attachment #228973, I believe there could be a race between the = NFS client VOP_LOOKUP() and file Writing that could result in stale file attributes being loaded into the NFS vnode by VOP_LOOKUP(). I have not been able to reproduce a failure due to this race, but I believe that there are two possibilities: The Lookup RPC happens while VOP_WRITE() is being executed and loads stale = file attributes after VOP_WRITE() returns when it has already completed the Write/Commit RPC(s).=20 --> For this case, setting the local modify timestamp at the end of VOP_WRI= TE()=20 should ensure that stale file attributes are not loaded. The Lookup RPC occurs after VOP_WRITE() has returned, while asynchronous=20 Write/Commit RPCs are in progress and then is blocked by the vnode held by VOP_OPEN/VOP_CLOSE/VOP_FSYNC which will flush writes via ncl_flush() or ncl_vinvalbuf(), clearing the NMODIFIED flag (which indicates Writes-in-progress). The VOP_LOOKUP() then acquires the NFS vnode lock and fills in stale file attributes.=20 --> Setting the local modify timestamp in ncl_flsuh() and ncl_vinvalbuf() w= hen=20 they clear NMODIFIED should ensure that stale file attributes are not=20 loaded. This patch does the above. --=20 You are receiving this mail because: You are the assignee for the bug.=