From patchwork Thu Feb 27 21:14:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Simmons X-Patchwork-Id: 11410395 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4A01517E0 for ; Thu, 27 Feb 2020 21:37:12 +0000 (UTC) Received: from pdx1-mailman02.dreamhost.com (pdx1-mailman02.dreamhost.com [64.90.62.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 306DF24690 for ; Thu, 27 Feb 2020 21:37:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 306DF24690 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lustre-devel-bounces@lists.lustre.org Received: from pdx1-mailman02.dreamhost.com (localhost [IPv6:::1]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id 1DC9334A1F9; Thu, 27 Feb 2020 13:30:41 -0800 (PST) X-Original-To: lustre-devel@lists.lustre.org Delivered-To: lustre-devel-lustre.org@pdx1-mailman02.dreamhost.com Received: from smtp3.ccs.ornl.gov (smtp3.ccs.ornl.gov [160.91.203.39]) by pdx1-mailman02.dreamhost.com (Postfix) with ESMTP id 8D22821FE7B for ; Thu, 27 Feb 2020 13:20:29 -0800 (PST) Received: from star.ccs.ornl.gov (star.ccs.ornl.gov [160.91.202.134]) by smtp3.ccs.ornl.gov (Postfix) with ESMTP id 41E598F1D; Thu, 27 Feb 2020 16:18:18 -0500 (EST) Received: by star.ccs.ornl.gov (Postfix, from userid 2004) id 4066646A; Thu, 27 Feb 2020 16:18:18 -0500 (EST) From: James Simmons To: Andreas Dilger , Oleg Drokin , NeilBrown Date: Thu, 27 Feb 2020 16:14:50 -0500 Message-Id: <1582838290-17243-423-git-send-email-jsimmons@infradead.org> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1582838290-17243-1-git-send-email-jsimmons@infradead.org> References: <1582838290-17243-1-git-send-email-jsimmons@infradead.org> Subject: [lustre-devel] [PATCH 422/622] lustre: lov: Correct write_intent end for trunc X-BeenThere: lustre-devel@lists.lustre.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "For discussing Lustre software development." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Lustre Development List MIME-Version: 1.0 Errors-To: lustre-devel-bounces@lists.lustre.org Sender: "lustre-devel" From: Patrick Farrell When instantiating a layout, the server interprets the write intent from the client as the range [start, end), not including the last byte. This is correct for writes because the last byte given for a write is actually 'endpos', the resulting file pointer position, and so is not included. However, truncate is specifying a size, not an endpos, so truncate is [start, size]. To make this work with the [start, end) processing for write_intents, we have to add 1 to the size when sending a write intent. Without this, a truncate operation to the first byte of a new layout component fails silently because the component is not instantiated. WC-bug-id: https://jira.whamcloud.com/browse/LU-12586 Lustre-commit: c32c7401426d ("LU-12586 lov: Correct write_intent end for trunc") Signed-off-by: Patrick Farrell Reviewed-on: https://review.whamcloud.com/35607 Reviewed-by: Andreas Dilger Reviewed-by: Mike Pershin Reviewed-by: Oleg Drokin Signed-off-by: James Simmons --- fs/lustre/lov/lov_io.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/lustre/lov/lov_io.c b/fs/lustre/lov/lov_io.c index 9328240..6e86efa 100644 --- a/fs/lustre/lov/lov_io.c +++ b/fs/lustre/lov/lov_io.c @@ -555,7 +555,15 @@ static int lov_io_slice_init(struct lov_io *lio, struct lov_object *obj, */ if (cl_io_is_trunc(io)) { io->ci_write_intent.e_start = 0; - io->ci_write_intent.e_end = io->u.ci_setattr.sa_attr.lvb_size; + /* for writes, e_end is endpos, the location of the file + * pointer after the write is completed, so it is not accessed. + * For truncate, 'end' is the size, and *is* acccessed. + * In other words, writes are [start, end), but truncate is + * [start, size], where both are included. So add 1 to the + * size when creating the write intent to account for this. + */ + io->ci_write_intent.e_end = + io->u.ci_setattr.sa_attr.lvb_size + 1; } else { io->ci_write_intent.e_start = lio->lis_pos; io->ci_write_intent.e_end = lio->lis_endpos;