From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1883814-1518711130-2-10692059492045818293 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1518711129; b=Sqdo0jd8AoYHuIes0ENZs8MGI/o/CcHNpoHmTEJ4i9A+UMN 86hFSJ+UA0Add272gq112RdhBAVcNnn0R98ynjGuVAgM0k0WXQ5KI7QEHOrvnCtN A8kZynZlCjGt6FlboN6mvujT/rfRIVimgOo5YdL4UETxA56IsJtgkDa2GMj8UEFU JS7HkMcazd9qyIuFOzhJNlfghhWJdO9yO8Bvd+zMqfAJcuGUU4lDRnJrUZf46+AN EWCRxBK5rLdHb24D2qUCgEM+6FhudGkdiL8d7rMzHtWm2u1KPtYn9tb5Mr/Y6k9y lVg0evMK/nYlZV15XOZc+rE/QxU4j+4D7GH2j0w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1518711129; bh=kAcDUXlyj5uFqXnL/uYxEt3ZKb 14YH4KiSGRQehKIGo=; b=d252zPlt0QO6mjeB+fJ51U2cnTqNPD5MaTrmd0w9FM PBRh/uIiru7OxfKij6s7Hm1Kb5530MaEX2z5KYGedGS9VMdqpkgjILjTIT0Q0sUB 4oAGzD24SwR/WbL/M/sLKfZIIs/QEyXy2AtsrkvuhB7pBzqVCNftHjTqFVA0JIk4 D4dwpGs4kVhj5JWoa4PYEqtEIUYPPJ0GuJ9afJ4gi8gd9KJI/dtt1RQsdWV+U/kV Ue9mIpK9Ehee9bsbMNCs8bz1sNcTjoYpsZTyscGa4wQW14aMvMb/yCdMH7Ob1rJa TEDlY0PPBzcAWpvbvl9wAQKvWCgWI/dzncK3m22DhzDg== ARC-Authentication-Results: i=1; mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Authentication-Results: mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1424432AbeBOPpS (ORCPT ); Thu, 15 Feb 2018 10:45:18 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:34862 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1424417AbeBOPpM (ORCPT ); Thu, 15 Feb 2018 10:45:12 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marc Dionne , David Howells Subject: [PATCH 4.15 144/202] afs: Fix missing cursor clearance Date: Thu, 15 Feb 2018 16:17:24 +0100 Message-Id: <20180215151720.588481731@linuxfoundation.org> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180215151712.768794354@linuxfoundation.org> References: <20180215151712.768794354@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Howells commit fe4d774c847398c2a45c10a780ccfde069840793 upstream. afs_select_fileserver() ends the address cursor it is using in the case in which we get some sort of network error and run out of addresses to iterate through, before it jumps to try the next server. This also needs to be done when the server aborts with some sort of error that means we should try the next server. Fix this by: (1) Move the iterate_address afs_end_cursor() call to the next_server case. (2) End the cursor in the failed case. (3) Make afs_end_cursor() clear the ->begun flag and ->addr pointer in the address cursor. (4) Make afs_end_cursor() able to be called on an already cleared cursor. Without this, something like the following oops may occur: AFS: Assertion failed 18446612134397189888 == 0 is false 0xffff88007c279f00 == 0x0 is false ------------[ cut here ]------------ kernel BUG at fs/afs/rotate.c:360! RIP: 0010:afs_select_fileserver+0x79b/0xa30 [kafs] Call Trace: afs_statfs+0xcc/0x180 [kafs] ? p9_client_statfs+0x9e/0x110 [9pnet] ? _cond_resched+0x19/0x40 statfs_by_dentry+0x6d/0x90 vfs_statfs+0x1b/0xc0 user_statfs+0x4b/0x80 SYSC_statfs+0x15/0x30 SyS_statfs+0xe/0x10 entry_SYSCALL_64_fastpath+0x20/0x83 Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Reported-by: Marc Dionne Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman --- fs/afs/addr_list.c | 13 ++++++++++--- fs/afs/rotate.c | 12 ++++++------ 2 files changed, 16 insertions(+), 9 deletions(-) --- a/fs/afs/addr_list.c +++ b/fs/afs/addr_list.c @@ -332,11 +332,18 @@ bool afs_iterate_addresses(struct afs_ad */ int afs_end_cursor(struct afs_addr_cursor *ac) { - if (ac->responded && ac->index != ac->start) - WRITE_ONCE(ac->alist->index, ac->index); + struct afs_addr_list *alist; - afs_put_addrlist(ac->alist); + alist = ac->alist; + if (alist) { + if (ac->responded && ac->index != ac->start) + WRITE_ONCE(alist->index, ac->index); + afs_put_addrlist(alist); + } + + ac->addr = NULL; ac->alist = NULL; + ac->begun = false; return ac->error; } --- a/fs/afs/rotate.c +++ b/fs/afs/rotate.c @@ -334,6 +334,7 @@ start: next_server: _debug("next"); + afs_end_cursor(&fc->ac); afs_put_cb_interest(afs_v2net(vnode), fc->cbi); fc->cbi = NULL; fc->index++; @@ -408,16 +409,15 @@ iterate_address: /* Iterate over the current server's address list to try and find an * address on which it will respond to us. */ - if (afs_iterate_addresses(&fc->ac)) { - _leave(" = t"); - return true; - } + if (!afs_iterate_addresses(&fc->ac)) + goto next_server; - afs_end_cursor(&fc->ac); - goto next_server; + _leave(" = t"); + return true; failed: fc->flags |= AFS_FS_CURSOR_STOP; + afs_end_cursor(&fc->ac); _leave(" = f [failed %d]", fc->ac.error); return false; }