Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933401AbaLJWrx (ORCPT ); Wed, 10 Dec 2014 17:47:53 -0500 Received: from ec2-54-183-128-9.us-west-1.compute.amazonaws.com ([54.183.128.9]:52598 "EHLO ip-172-31-29-154.us-west-1.compute.internal" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S933041AbaLJWru (ORCPT ); Wed, 10 Dec 2014 17:47:50 -0500 X-Greylist: delayed 333 seconds by postgrey-1.27 at vger.kernel.org; Wed, 10 Dec 2014 17:47:50 EST MIME-Version: 1.0 In-Reply-To: <20141208114813.GA2724@gmail.com> References: <20141124041629.GA17907@kmo-pixel> <20141204110027.GA28552@gmail.com> <20141206030205.GA22669@kmo-pixel> <20141208114813.GA2724@gmail.com> Date: Wed, 10 Dec 2014 14:42:14 -0800 Message-ID: Subject: Re: Block layer projects that I haven't had time for From: Ming Lin To: Dongsu Park Cc: Kent Overstreet , linux-fsdevel@vger.kernel.org, lkml , Jens Axboe , Christoph Hellwig Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 8, 2014 at 3:48 AM, Dongsu Park wrote: > Thanks for the reply. > > On 05.12.2014 19:02, Kent Overstreet wrote: >> On Thu, Dec 04, 2014 at 12:00:27PM +0100, Dongsu Park wrote: >> > Playing a little with your block_stuff tree based on 3.15, however, >> > I think there still seems to be a couple of issues. >> > First of all, it doesn't work with virtio-blk. A testing Qemu VM panics >> > at the very early stage of booting. This issue should be addressed as >> > the first step, so that other parts can be tested. >> >> Really? I was testing with virtio-blk, that's odd.. > > The culprit seems to be the plugging commit. > Before that change, it works well also with virtio-blk. > Though that's not the only issue... > >> > Moreover, I've already tried to rebase these patches on top of current >> > mainline, 3.18-rc7. It's now compilable, but it seems to introduce >> > more bugs about direct-IO. I didn't manage to find out the reason. >> > I'd need to also look at the previous review comments in [1], [2]. >> > >> > Don't you have other trees based on top of 3.17 or higher? >> > If not, can I create my own tree based on 3.18-rc7 to publish? >> >> Yeah, I'd post what you have now and I'll try and take a look. > > I've created a git tree to include what I have right now. > Please see . > > To be able to handle different issues one by one, > I got the entire tree separated out into 4 branches based on 3.18. > > * block-generic-req-for-next : the most stable branch you can test with. > With this branch, you can test most of block drivers as well as file > systems with less critical bugs. Though it's not 100% perfect yet, > e.g. btrfs doesn't seem to work quite well. Thus more tests are needed. > > * block-mpage-bvecs-for-next : block-generic-req-for-next + multipage bvecs. > This branch shows a critical issue that writing blocks to ext4 rootfs > causes the whole system to crash. Need-to-investigate. I tried block-mpage-bvecs-for-next branch on qemu-kvm with ext4 rootfs. Run "sync" will stuck in kernel. [ 480.751901] INFO: task sync:4424 blocked for more than 120 seconds. [ 480.753064] Not tainted 3.18.0-00025-g46c8231 #39 [ 480.753720] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 480.754737] sync D ffff88001fc11180 0 4424 4338 0x00000000 [ 480.755719] ffff88001cdfbc98 0000000000000086 ffff88001cdfbba8 ffff880014adefc0 [ 480.756810] 0000000000011180 0000000000004000 ffffffff81813460 ffff880014adefc0 [ 480.758102] ffff88001cdfbbc8 ffffffff812f08be ffff88001cdfbc18 ffff880014adf028 [ 480.759454] Call Trace: [ 480.759852] [] ? debug_smp_processor_id+0x17/0x19 [ 480.760609] [] ? __enqueue_entity+0x69/0x6b [ 480.761318] [] ? __dequeue_entity+0x33/0x38 [ 480.762026] [] ? set_next_entity+0x28/0x7d [ 480.762739] [] ? get_parent_ip+0xf/0x3f [ 480.763425] [] ? ktime_get+0x50/0x8f [ 480.763848] [] ? bit_wait_timeout+0x60/0x60 [ 480.764555] [] schedule+0x6a/0x6c [ 480.765186] [] io_schedule+0x8f/0xcd [ 480.765841] [] bit_wait_io+0x3e/0x42 [ 480.766493] [] __wait_on_bit+0x4d/0x86 [ 480.767183] [] ? find_get_pages_tag+0x106/0x133 [ 480.767847] [] wait_on_page_bit+0x76/0x78 [ 480.768532] [] ? wake_atomic_t_function+0x2d/0x2d [ 480.769262] [] filemap_fdatawait_range+0x7e/0x11d [ 480.769992] [] ? preempt_schedule+0x36/0x51 [ 480.770677] [] ? get_parent_ip+0xf/0x3f [ 480.771848] [] filemap_fdatawait+0x21/0x23 [ 480.772530] [] sync_inodes_sb+0x158/0x1aa [ 480.773201] [] ? br_mdb_dump+0x225/0x495 [ 480.773885] [] ? fdatawrite_one_bdev+0x18/0x18 [ 480.774592] [] sync_inodes_one_sb+0x14/0x16 [ 480.775278] [] iterate_supers+0x6f/0xc4 [ 480.775847] [] sys_sync+0x35/0x83 [ 480.776460] [] system_call_fastpath+0x12/0x17 Here is a quick hack. diff --git a/block/bio.c b/block/bio.c index 4020ccc..fbc7108 100644 --- a/block/bio.c +++ b/block/bio.c @@ -829,6 +829,11 @@ int bio_add_page(struct bio *bio, struct page *page, if (bvec_to_phys(bv) + bv->bv_len == page_to_phys(page) + offset) { bv->bv_len += len; + /* + * Page is not added to bio vec. + * Clear PG_writeback so filemap_fdatawait_range() won't wait for it. + */ + TestClearPageWriteback(page); goto done; } } Thanks, Ming -- 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/