Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161144Ab3DEBxh (ORCPT ); Thu, 4 Apr 2013 21:53:37 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:36934 "EHLO mail-pb0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161131Ab3DEBxf (ORCPT ); Thu, 4 Apr 2013 21:53:35 -0400 Date: Fri, 5 Apr 2013 09:53:27 +0800 From: Shaohua Li To: Max Filippov Cc: LKML , Jens Axboe , Jaegeuk Kim , linux-f2fs-devel@lists.sourceforge.net, slava@dubeyko.com Subject: Re: mkfs.f2fs gets stuck with "blk_update_request: bio idx 0 >= vcnt 0" on 3.8 Message-ID: <20130405015327.GA319@kernel.org> References: <254789F5-7950-4239-AB7B-2DB9DC73565F@dubeyko.com> <5159EC3D.2020501@gmail.com> <1364884045.3301.18.camel@slavad-ubuntu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2714 Lines: 59 On Thu, Apr 04, 2013 at 06:00:18AM +0400, Max Filippov wrote: > Hi, > > On Tue, Apr 2, 2013 at 7:41 PM, Max Filippov wrote: > > I'm trying to create f2fs filesystem on SD card on pandaboard using > > f2fs-tools v1.0.0. > > It works fine on Linus' v3.6, but fails on both v3.8 and stable v3.8.5: > > > > # mkfs.f2fs /dev/mmcblk0p3 > > 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 > > [...] > > >> So, I think that it needs to investigate issue in the direction of > >> BLKDISCARD code on the kernel side. It makes sense to debug > >> f2fs_trim_device() method of mkfs.f2fs utility too. But I can't see > >> anything strange in this function at a glance. > > > > Ok, I'll try to find what has changed in that ioctl handler since 3.6. > > the commit 0cfbcafcae8b7364b5fa96c2b26ccde7a3a296a9 'block: add plug > for blkdev_issue_discard' > have added merge opportunity for DISCARD requests. When I do > mkfs.f2fs on a 5G partition (0xad8000 sectors) it submits two bios, > one for 0x7fe000 sectors (0xffc00000 bytes) and another for > 0x2da000 sectors (0x5b400000 bytes). Prior to that commit these > bios weren't merged into one request. Now the second bio gets > merged with the first, but the request's __data_len field is unsigned int > and it gets wrapped to 0x5b000000 bytes instead of 0x15b000000 > in the bio_attempt_back_merge. Later this reduced size is passed to > the blk_update_request causing KERN_ERR and not completed > request. Reverting this commit fixes mkfs.f2fs for me. A workaround is setting limits.max_discard_sectors to a smaller value. So the question is why __data_len isn't sector based? Since disk is sector based, is there any disk finishing IO in byte granularity? Maybe Jens can answer. Thanks, Shaohua -- 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/