Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932259AbcC2Qmi (ORCPT ); Tue, 29 Mar 2016 12:42:38 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:49190 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757553AbcC2Qmh (ORCPT ); Tue, 29 Mar 2016 12:42:37 -0400 From: Shaohua Li To: , CC: , , "4.2+" , Ming Lei Subject: [PATCH] block: don't make BLK_DEF_MAX_SECTORS too big Date: Tue, 29 Mar 2016 09:42:33 -0700 Message-ID: <21cf85d32278bbe5acbc3def0a6db75db98a2670.1459269590.git.shli@fb.com> X-Mailer: git-send-email 2.8.0.rc2 X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-03-29_06:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1377 Lines: 38 bio_alloc_bioset() allocates bvecs from bvec_slabs which can only allocate maximum 256 bvec (eg, 1M for 4k pages). We can't bump BLK_DEF_MAX_SECTORS to exceed this value otherwise bio_alloc_bioset will fail. In the future, we can extend the size either bvec_slabs array is expanded or the upcoming multipage bvec is added if pages are contiguous. This one is suitable for stable. Fixes: d2be537c3ba (block: bump BLK_DEF_MAX_SECTORS to 2560) Reported-by: Sebastian Roesner Cc: stable@vger.kernel.org (4.2+) Cc: Ming Lei Reviewed-by: Jeff Moyer Signed-off-by: Shaohua Li --- include/linux/blkdev.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 7e5d7e0..da64325 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1153,7 +1153,11 @@ extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); enum blk_default_limits { BLK_MAX_SEGMENTS = 128, BLK_SAFE_MAX_SECTORS = 255, - BLK_DEF_MAX_SECTORS = 2560, + /* + * if you change this, please also change bvec_alloc and BIO_MAX_PAGES. + * Otherwise bio_alloc_bioset will break. + */ + BLK_DEF_MAX_SECTORS = BIO_MAX_SECTORS, BLK_MAX_SEGMENT_SIZE = 65536, BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, }; -- 2.8.0.rc2