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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 EB222C433E1 for ; Sat, 15 Aug 2020 22:00:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1AA823358 for ; Sat, 15 Aug 2020 22:00:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729634AbgHOWAQ (ORCPT ); Sat, 15 Aug 2020 18:00:16 -0400 Received: from mailex.mailcore.me ([94.136.40.62]:44384 "EHLO mailex.mailcore.me" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729445AbgHOWAN (ORCPT ); Sat, 15 Aug 2020 18:00:13 -0400 Received: from 82-69-79-175.dsl.in-addr.zen.co.uk ([82.69.79.175] helo=phoenix.fritz.box) by smtp04.mailcore.me with esmtpa (Exim 4.92.3) (envelope-from ) id 1k6nJo-0006KR-8t; Sat, 15 Aug 2020 04:57:20 +0100 From: Phillip Lougher To: linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, pliard@google.com, hch@lst.de, adrien+dev@schischi.me, groeck@chromium.org, drosen@google.com, Phillip Lougher , Nicolas Prochazka , Tomoatsu Shimada Subject: [PATCH] squashfs: avoid bio_alloc() failure with 1Mbyte blocks Date: Sat, 15 Aug 2020 04:56:37 +0100 Message-Id: <20200815035637.15319-1-phillip@squashfs.org.uk> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Mailcore-Auth: 439913985 X-Mailcore-Domain: 1686784 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a regression introduced by the "migrate from ll_rw_block usage to BIO" patch. Bio_alloc() is limited to 256 pages (1 Mbyte). This can cause a failure when reading 1 Mbyte block filesystems. The problem is a datablock can be fully (or almost uncompressed), requiring 256 pages, but, because blocks are not aligned to page boundaries, it may require 257 pages to read. Bio_kmalloc() can handle 1024 pages, and so use this for the edge condition. Reported-by: Nicolas Prochazka Reported-by: Tomoatsu Shimada Signed-off-by: Phillip Lougher --- fs/squashfs/block.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c index 76bb1c846845..8a19773b5a0b 100644 --- a/fs/squashfs/block.c +++ b/fs/squashfs/block.c @@ -87,7 +87,11 @@ static int squashfs_bio_read(struct super_block *sb, u64 index, int length, int error, i; struct bio *bio; - bio = bio_alloc(GFP_NOIO, page_count); + if (page_count <= BIO_MAX_PAGES) + bio = bio_alloc(GFP_NOIO, page_count); + else + bio = bio_kmalloc(GFP_NOIO, page_count); + if (!bio) return -ENOMEM; -- 2.20.1