From patchwork Tue Mar 28 23:26:54 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Germano Percossi X-Patchwork-Id: 9650647 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E15C860349 for ; Tue, 28 Mar 2017 23:27:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D224D205FC for ; Tue, 28 Mar 2017 23:27:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C6EE128334; Tue, 28 Mar 2017 23:27:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6C5C927F90 for ; Tue, 28 Mar 2017 23:27:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932088AbdC1X1F (ORCPT ); Tue, 28 Mar 2017 19:27:05 -0400 Received: from smtp.citrix.com ([66.165.176.89]:7410 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753119AbdC1X1F (ORCPT ); Tue, 28 Mar 2017 19:27:05 -0400 X-IronPort-AV: E=Sophos;i="5.36,238,1486425600"; d="scan'208";a="416365977" From: Germano Percossi To: , , CC: Subject: [PATCH 4/4] CIFS: store results of cifs_reopen_file to avoid infinite wait Date: Wed, 29 Mar 2017 00:26:54 +0100 Message-ID: <1490743614-5439-5-git-send-email-germano.percossi@citrix.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This fixes Continuous Availability when errors during file reopen are encountered. cifs_user_readv and cifs_user_writev would wait for ever if results of cifs_reopen_file are not stored and for later inspection. In fact, results are checked and, in case of errors, a chain of function calls leading to reads and writes to be scheduled in a separate thread is skipped. These threads will wake up the corresponding waiters once reads and writes are done. However, given the return value is not stored, when rc is checked for errors a previous one (always zero) is inspected instead. This leads to pending reads/writes added to the list, making cifs_user_readv and cifs_user_writev wait for ever. Signed-off-by: Germano Percossi --- fs/cifs/file.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index aa3debb..21d4045 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2597,7 +2597,7 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, wdata->credits = credits; if (!wdata->cfile->invalidHandle || - !cifs_reopen_file(wdata->cfile, false)) + !(rc = cifs_reopen_file(wdata->cfile, false))) rc = server->ops->async_writev(wdata, cifs_uncached_writedata_release); if (rc) { @@ -3022,7 +3022,7 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file, rdata->credits = credits; if (!rdata->cfile->invalidHandle || - !cifs_reopen_file(rdata->cfile, true)) + !(rc = cifs_reopen_file(rdata->cfile, true))) rc = server->ops->async_readv(rdata); error: if (rc) { @@ -3617,7 +3617,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping, } if (!rdata->cfile->invalidHandle || - !cifs_reopen_file(rdata->cfile, true)) + !(rc = cifs_reopen_file(rdata->cfile, true))) rc = server->ops->async_readv(rdata); if (rc) { add_credits_and_wake_if(server, rdata->credits, 0);