On Mon, Dec 8, 2014 at 3:48 AM, Dongsu Park <dongsu.park@xxxxxxxxxxxxxxxx> 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 <https://github.com/dongsupark/linux>. > > 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] [<ffffffff812f08be>] ? debug_smp_processor_id+0x17/0x19 [ 480.760609] [<ffffffff8106093e>] ? __enqueue_entity+0x69/0x6b [ 480.761318] [<ffffffff8106017e>] ? __dequeue_entity+0x33/0x38 [ 480.762026] [<ffffffff810601ab>] ? set_next_entity+0x28/0x7d [ 480.762739] [<ffffffff8105a4fb>] ? get_parent_ip+0xf/0x3f [ 480.763425] [<ffffffff8108562b>] ? ktime_get+0x50/0x8f [ 480.763848] [<ffffffff8148abdb>] ? bit_wait_timeout+0x60/0x60 [ 480.764555] [<ffffffff8148a6be>] schedule+0x6a/0x6c [ 480.765186] [<ffffffff8148a74f>] io_schedule+0x8f/0xcd [ 480.765841] [<ffffffff8148ac19>] bit_wait_io+0x3e/0x42 [ 480.766493] [<ffffffff8148ae80>] __wait_on_bit+0x4d/0x86 [ 480.767183] [<ffffffff810d4302>] ? find_get_pages_tag+0x106/0x133 [ 480.767847] [<ffffffff810d4a63>] wait_on_page_bit+0x76/0x78 [ 480.768532] [<ffffffff8106ab59>] ? wake_atomic_t_function+0x2d/0x2d [ 480.769262] [<ffffffff810d511f>] filemap_fdatawait_range+0x7e/0x11d [ 480.769992] [<ffffffff8148a639>] ? preempt_schedule+0x36/0x51 [ 480.770677] [<ffffffff8105a4fb>] ? get_parent_ip+0xf/0x3f [ 480.771848] [<ffffffff810d51df>] filemap_fdatawait+0x21/0x23 [ 480.772530] [<ffffffff811458ce>] sync_inodes_sb+0x158/0x1aa [ 480.773201] [<ffffffff81480303>] ? br_mdb_dump+0x225/0x495 [ 480.773885] [<ffffffff81149ad8>] ? fdatawrite_one_bdev+0x18/0x18 [ 480.774592] [<ffffffff81149aec>] sync_inodes_one_sb+0x14/0x16 [ 480.775278] [<ffffffff81125937>] iterate_supers+0x6f/0xc4 [ 480.775847] [<ffffffff81149bf4>] sys_sync+0x35/0x83 [ 480.776460] [<ffffffff8148da52>] 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-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
