Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750947Ab3DXEJb (ORCPT ); Wed, 24 Apr 2013 00:09:31 -0400 Received: from mail-pd0-f174.google.com ([209.85.192.174]:57324 "EHLO mail-pd0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750750Ab3DXEJ3 (ORCPT ); Wed, 24 Apr 2013 00:09:29 -0400 MIME-Version: 1.0 In-Reply-To: <1366724561.1930.3.camel@dabdike> References: <1366722406-2899-1-git-send-email-linkinjeon@gmail.com> <1366724561.1930.3.camel@dabdike> Date: Wed, 24 Apr 2013 13:09:28 +0900 Message-ID: Subject: Re: [PATCH] block: fix max discard sectors limit From: Namjae Jeon To: James Bottomley Cc: "axboe@kernel.dk" , "linux-kernel@vger.kernel.org" , Namjae Jeon , Vivek Trivedi , Shaohua Li , Kent Overstreet , Tejun Heo , "stable@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3355 Lines: 86 2013/4/23, James Bottomley : > On Tue, 2013-04-23 at 22:06 +0900, Namjae Jeon wrote: >> From: Namjae Jeon > > Hey, it's very impolite to send a patch I just gave you as a suggestion > to fix the issue under your own authorship. > > What we need to know is has this been tested ... there's no tested-by > tags (and there also should really be a reported by). Sorry James, as I do not have the exact MMC on which the issue is reproduce. So I just checked for sanity on my MMC - there was no issue. But for exact issue fix it was mistake to not request for testing. I will take care of this in future, for pushing such patches. Thanks. > > James > >> 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: Vivek Trivedi >> Signed-off-by: James Bottomley >> Cc: Shaohua Li >> Cc: Kent Overstreet >> Cc: Tejun Heo >> Cc: Jens Axboe >> 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; > > -- 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/