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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 26F1AC43466 for ; Fri, 18 Sep 2020 02:44:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECABB214D8 for ; Fri, 18 Sep 2020 02:44:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600397095; bh=kTJohrvFeDf7PAJqiJ0VxYqe6eULk0B1XARyAaTDZFg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mvF7m9k8ZFVcJW31/UJBgW8lDJcC+AAuwjCt9CCvXlO2KE84ZE3GodOival4e4svB W5Kro+J3OrCNOGmMsSnPZnua1EljEtEUXvA7kYiCBG4qmJEWfho+o8GZTx5j6wYIa0 DIz2w1Np/E5b2zD4xidbPlSXu9N+MDn9syWGvZAk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728434AbgIRCKX (ORCPT ); Thu, 17 Sep 2020 22:10:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:34756 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728423AbgIRCKT (ORCPT ); Thu, 17 Sep 2020 22:10:19 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D76392311A; Fri, 18 Sep 2020 02:10:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600395017; bh=kTJohrvFeDf7PAJqiJ0VxYqe6eULk0B1XARyAaTDZFg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=w8ruHLFfCO6MTi0Ljgg695mSjmfZY6d1OftK6ExlKHnZYtGPwUWxfFh88LgSgbdDC PvdNRPWpO9CfT0k4AiP1HyOpWJVO3CiJSjA4+CnQFKphwZff359moG8Rd19fv45I2q GX5nCVgeVIn+4+pkoeCmUqhUhEFfnIkdHinaYwXA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Trond Myklebust , Trond Myklebust , Chuck Lever , Sasha Levin , linux-nfs@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 112/206] nfsd: Don't add locks to closed or closing open stateids Date: Thu, 17 Sep 2020 22:06:28 -0400 Message-Id: <20200918020802.2065198-112-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200918020802.2065198-1-sashal@kernel.org> References: <20200918020802.2065198-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: Trond Myklebust [ Upstream commit a451b12311aa8c96c6f6e01c783a86995dc3ec6b ] In NFSv4, the lock stateids are tied to the lockowner, and the open stateid, so that the action of closing the file also results in either an automatic loss of the locks, or an error of the form NFS4ERR_LOCKS_HELD. In practice this means we must not add new locks to the open stateid after the close process has been invoked. In fact doing so, can result in the following panic: kernel BUG at lib/list_debug.c:51! invalid opcode: 0000 [#1] SMP NOPTI CPU: 2 PID: 1085 Comm: nfsd Not tainted 5.6.0-rc3+ #2 Hardware name: VMware, Inc. VMware7,1/440BX Desktop Reference Platform, BIOS VMW71.00V.14410784.B64.1908150010 08/15/2019 RIP: 0010:__list_del_entry_valid.cold+0x31/0x55 Code: 1a 3d 9b e8 74 10 c2 ff 0f 0b 48 c7 c7 f0 1a 3d 9b e8 66 10 c2 ff 0f 0b 48 89 f2 48 89 fe 48 c7 c7 b0 1a 3d 9b e8 52 10 c2 ff <0f> 0b 48 89 fe 4c 89 c2 48 c7 c7 78 1a 3d 9b e8 3e 10 c2 ff 0f 0b RSP: 0018:ffffb296c1d47d90 EFLAGS: 00010246 RAX: 0000000000000054 RBX: ffff8ba032456ec8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff8ba039e99cc8 RDI: ffff8ba039e99cc8 RBP: ffff8ba032456e60 R08: 0000000000000781 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000000001 R12: ffff8ba009a4abe0 R13: ffff8ba032456e8c R14: 0000000000000000 R15: ffff8ba00adb01d8 FS: 0000000000000000(0000) GS:ffff8ba039e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb213f0b008 CR3: 00000001347de006 CR4: 00000000003606e0 Call Trace: release_lock_stateid+0x2b/0x80 [nfsd] nfsd4_free_stateid+0x1e9/0x210 [nfsd] nfsd4_proc_compound+0x414/0x700 [nfsd] ? nfs4svc_decode_compoundargs+0x407/0x4c0 [nfsd] nfsd_dispatch+0xc1/0x200 [nfsd] svc_process_common+0x476/0x6f0 [sunrpc] ? svc_sock_secure_port+0x12/0x30 [sunrpc] ? svc_recv+0x313/0x9c0 [sunrpc] ? nfsd_svc+0x2d0/0x2d0 [nfsd] svc_process+0xd4/0x110 [sunrpc] nfsd+0xe3/0x140 [nfsd] kthread+0xf9/0x130 ? nfsd_destroy+0x50/0x50 [nfsd] ? kthread_park+0x90/0x90 ret_from_fork+0x1f/0x40 The fix is to ensure that lock creation tests for whether or not the open stateid is unhashed, and to fail if that is the case. Fixes: 659aefb68eca ("nfsd: Ensure we don't recognise lock stateids after freeing them") Signed-off-by: Trond Myklebust Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- fs/nfsd/nfs4state.c | 73 ++++++++++++++++++++++++++------------------- 1 file changed, 43 insertions(+), 30 deletions(-) diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index c24306af9758f..655079ae1dd1f 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -471,6 +471,8 @@ find_any_file(struct nfs4_file *f) { struct file *ret; + if (!f) + return NULL; spin_lock(&f->fi_lock); ret = __nfs4_get_fd(f, O_RDWR); if (!ret) { @@ -1207,6 +1209,12 @@ static void nfs4_put_stateowner(struct nfs4_stateowner *sop) nfs4_free_stateowner(sop); } +static bool +nfs4_ol_stateid_unhashed(const struct nfs4_ol_stateid *stp) +{ + return list_empty(&stp->st_perfile); +} + static bool unhash_ol_stateid(struct nfs4_ol_stateid *stp) { struct nfs4_file *fp = stp->st_stid.sc_file; @@ -1274,9 +1282,11 @@ static bool unhash_lock_stateid(struct nfs4_ol_stateid *stp) { lockdep_assert_held(&stp->st_stid.sc_client->cl_lock); + if (!unhash_ol_stateid(stp)) + return false; list_del_init(&stp->st_locks); nfs4_unhash_stid(&stp->st_stid); - return unhash_ol_stateid(stp); + return true; } static void release_lock_stateid(struct nfs4_ol_stateid *stp) @@ -1341,13 +1351,12 @@ static void release_open_stateid_locks(struct nfs4_ol_stateid *open_stp, static bool unhash_open_stateid(struct nfs4_ol_stateid *stp, struct list_head *reaplist) { - bool unhashed; - lockdep_assert_held(&stp->st_stid.sc_client->cl_lock); - unhashed = unhash_ol_stateid(stp); + if (!unhash_ol_stateid(stp)) + return false; release_open_stateid_locks(stp, reaplist); - return unhashed; + return true; } static void release_open_stateid(struct nfs4_ol_stateid *stp) @@ -5774,21 +5783,21 @@ alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp, } static struct nfs4_ol_stateid * -find_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fp) +find_lock_stateid(const struct nfs4_lockowner *lo, + const struct nfs4_ol_stateid *ost) { struct nfs4_ol_stateid *lst; - struct nfs4_client *clp = lo->lo_owner.so_client; - lockdep_assert_held(&clp->cl_lock); + lockdep_assert_held(&ost->st_stid.sc_client->cl_lock); - list_for_each_entry(lst, &lo->lo_owner.so_stateids, st_perstateowner) { - if (lst->st_stid.sc_type != NFS4_LOCK_STID) - continue; - if (lst->st_stid.sc_file == fp) { - refcount_inc(&lst->st_stid.sc_count); - return lst; + /* If ost is not hashed, ost->st_locks will not be valid */ + if (!nfs4_ol_stateid_unhashed(ost)) + list_for_each_entry(lst, &ost->st_locks, st_locks) { + if (lst->st_stateowner == &lo->lo_owner) { + refcount_inc(&lst->st_stid.sc_count); + return lst; + } } - } return NULL; } @@ -5804,11 +5813,11 @@ init_lock_stateid(struct nfs4_ol_stateid *stp, struct nfs4_lockowner *lo, mutex_lock_nested(&stp->st_mutex, OPEN_STATEID_MUTEX); retry: spin_lock(&clp->cl_lock); - spin_lock(&fp->fi_lock); - retstp = find_lock_stateid(lo, fp); + if (nfs4_ol_stateid_unhashed(open_stp)) + goto out_close; + retstp = find_lock_stateid(lo, open_stp); if (retstp) - goto out_unlock; - + goto out_found; refcount_inc(&stp->st_stid.sc_count); stp->st_stid.sc_type = NFS4_LOCK_STID; stp->st_stateowner = nfs4_get_stateowner(&lo->lo_owner); @@ -5817,22 +5826,26 @@ retry: stp->st_access_bmap = 0; stp->st_deny_bmap = open_stp->st_deny_bmap; stp->st_openstp = open_stp; + spin_lock(&fp->fi_lock); list_add(&stp->st_locks, &open_stp->st_locks); list_add(&stp->st_perstateowner, &lo->lo_owner.so_stateids); list_add(&stp->st_perfile, &fp->fi_stateids); -out_unlock: spin_unlock(&fp->fi_lock); spin_unlock(&clp->cl_lock); - if (retstp) { - if (nfsd4_lock_ol_stateid(retstp) != nfs_ok) { - nfs4_put_stid(&retstp->st_stid); - goto retry; - } - /* To keep mutex tracking happy */ - mutex_unlock(&stp->st_mutex); - stp = retstp; - } return stp; +out_found: + spin_unlock(&clp->cl_lock); + if (nfsd4_lock_ol_stateid(retstp) != nfs_ok) { + nfs4_put_stid(&retstp->st_stid); + goto retry; + } + /* To keep mutex tracking happy */ + mutex_unlock(&stp->st_mutex); + return retstp; +out_close: + spin_unlock(&clp->cl_lock); + mutex_unlock(&stp->st_mutex); + return NULL; } static struct nfs4_ol_stateid * @@ -5847,7 +5860,7 @@ find_or_create_lock_stateid(struct nfs4_lockowner *lo, struct nfs4_file *fi, *new = false; spin_lock(&clp->cl_lock); - lst = find_lock_stateid(lo, fi); + lst = find_lock_stateid(lo, ost); spin_unlock(&clp->cl_lock); if (lst != NULL) { if (nfsd4_lock_ol_stateid(lst) == nfs_ok) -- 2.25.1