Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755842Ab3DXNzd (ORCPT ); Wed, 24 Apr 2013 09:55:33 -0400 Received: from mail-pa0-f49.google.com ([209.85.220.49]:45903 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755781Ab3DXNzc (ORCPT ); Wed, 24 Apr 2013 09:55:32 -0400 From: Namjae Jeon To: axboe@kernel.dk Cc: linux-kernel@vger.kernel.org, Namjae Jeon , James Bottomley , Namjae Jeon , Subject: [PATCH] block: fix max discard sectors limit Date: Wed, 24 Apr 2013 22:55:20 +0900 Message-Id: <1366811721-2478-1-git-send-email-linkinjeon@gmail.com> X-Mailer: git-send-email 1.7.9.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2396 Lines: 67 From: James Bottomley linux-v3.8-rc1 and later support for plug for blkdev_issue_discard with commit 0cfbcafcae8b7364b5fa96c2b26ccde7a3a296a9 (block: add plug for blkdev_issue_discard ) For example, 1) DISCARD rq-1 with size size 4GB 2) DISCARD rq-2 with size size 1GB If these 2 discard requests get merged, final request size will be 5GB. In this case, request's __data_len field may overflow as it can store max 4GB(unsigned int). This issue was observed while doing mkfs.f2fs on 5GB SD card: https://lkml.org/lkml/2013/4/1/292 Info: sector size = 512 Info: total sectors = 11370496 (in 512bytes) Info: zone aligned segment0 blkaddr: 512 [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0 mkfs process gets stuck in D state and I see the following in the dmesg: [ 257.789733] __end_that: dev mmcblk0: type=1, flags=122c8081 [ 257.789764] sector 4194304, nr/cnr 2981888/4294959104 [ 257.789764] bio df3840c0, biotail df3848c0, buffer (null), len 1526726656 [ 257.789764] blk_update_request: bio idx 0 >= vcnt 0 [ 257.794921] request botched: dev mmcblk0: type=1, flags=122c8081 [ 257.794921] sector 4194304, nr/cnr 2981888/4294959104 [ 257.794921] bio df3840c0, biotail df3848c0, buffer (null), len 1526726656 This patch fixes this issue. Reported-by: Max Filippov Signed-off-by: Namjae Jeon Signed-off-by: James Bottomley Tested-by: Max Filippov Cc: --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 07aa5f6..ff636bd 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -844,7 +844,7 @@ static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, unsigned int cmd_flags) { if (unlikely(cmd_flags & REQ_DISCARD)) - return q->limits.max_discard_sectors; + return min(q->limits.max_discard_sectors, UINT_MAX >> 9); if (unlikely(cmd_flags & REQ_WRITE_SAME)) return q->limits.max_write_same_sectors; -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/