Re: [PATCH v2 0/6] btrfs: qgroup: Delay subtree scan to reduce overhead

From: Filipe Manana <fdmanana@gmail.com>
To: dsterba@suse.cz, Qu Wenruo <wqu@suse.com>,
	linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: [PATCH v2 0/6] btrfs: qgroup: Delay subtree scan to reduce overhead
Date: Tue, 13 Nov 2018 17:58:14 +0000	[thread overview]
Message-ID: <CAL3q7H5H+c6XzwCQP9=bS_TdUam1fFh3HOiWojDkNfdDsKj=yQ@mail.gmail.com> (raw)
In-Reply-To: <20181113170724.GE24115@twin.jikos.cz>

On Tue, Nov 13, 2018 at 5:08 PM David Sterba <dsterba@suse.cz> wrote:
>
> On Mon, Nov 12, 2018 at 10:33:33PM +0100, David Sterba wrote:
> > On Thu, Nov 08, 2018 at 01:49:12PM +0800, Qu Wenruo wrote:
> > > This patchset can be fetched from github:
> > > https://github.com/adam900710/linux/tree/qgroup_delayed_subtree_rebased
> > >
> > > Which is based on v4.20-rc1.
> >
> > Thanks, I'll add it to for-next soon.
>
> During test generic/517, the logs were full of the warning below. The reference
> test on current master, effectively misc-4.20 which was used as base of your
> branch did not get the warning.
>
> [11540.167829] BTRFS: end < start 2519039 2519040
> [11540.170513] WARNING: CPU: 1 PID: 539 at fs/btrfs/extent_io.c:436 insert_state+0xd8/0x100 [btrfs]
> [11540.174411] Modules linked in: dm_thin_pool dm_persistent_data dm_bufio dm_bio_prison btrfs libcrc32c xor zstd_decompress zstd_compress xxhash raid6_pq dm_mod loop [last unloaded: libcrc32c]
> [11540.178279] CPU: 1 PID: 539 Comm: xfs_io Tainted: G      D W         4.20.0-rc1-default+ #329
> [11540.180616] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014
> [11540.183754] RIP: 0010:insert_state+0xd8/0x100 [btrfs]
> [11540.189173] RSP: 0018:ffffa0d245eafb20 EFLAGS: 00010282
> [11540.189885] RAX: 0000000000000000 RBX: ffff9f0bb3267320 RCX: 0000000000000000
> [11540.191646] RDX: 0000000000000002 RSI: 0000000000000001 RDI: ffffffffa40c400d
> [11540.192942] RBP: 0000000000266fff R08: 0000000000000001 R09: 0000000000000000
> [11540.193871] R10: 0000000000000000 R11: ffffffffa629da2d R12: ffff9f0ba0281c60
> [11540.195527] R13: 0000000000267000 R14: ffffa0d245eafb98 R15: ffffa0d245eafb90
> [11540.197026] FS:  00007fa338eb4b80(0000) GS:ffff9f0bbd600000(0000) knlGS:0000000000000000
> [11540.198251] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [11540.199698] CR2: 00007fa33873bfb8 CR3: 000000006fb6e000 CR4: 00000000000006e0
> [11540.201428] Call Trace:
> [11540.202164]  __set_extent_bit+0x43b/0x5b0 [btrfs]
> [11540.203223]  lock_extent_bits+0x5d/0x210 [btrfs]
> [11540.204346]  ? _raw_spin_unlock+0x24/0x40
> [11540.205381]  ? test_range_bit+0xdf/0x130 [btrfs]
> [11540.206573]  lock_extent_range+0xb8/0x150 [btrfs]
> [11540.207696]  btrfs_double_extent_lock+0x78/0xb0 [btrfs]
> [11540.208988]  btrfs_extent_same_range+0x131/0x4e0 [btrfs]
> [11540.210237]  btrfs_remap_file_range+0x337/0x350 [btrfs]
> [11540.211448]  vfs_dedupe_file_range_one+0x141/0x150
> [11540.212622]  vfs_dedupe_file_range+0x146/0x1a0
> [11540.213795]  do_vfs_ioctl+0x520/0x6c0
> [11540.214711]  ? __fget+0x109/0x1e0
> [11540.215616]  ksys_ioctl+0x3a/0x70
> [11540.216233]  __x64_sys_ioctl+0x16/0x20
> [11540.216860]  do_syscall_64+0x54/0x180
> [11540.217409]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
> [11540.218126] RIP: 0033:0x7fa338a4daa7

That's the infinite loop issue fixed by one of the patches submitted
for 4.20-rc2:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v4.20-rc2&id=11023d3f5fdf89bba5e1142127701ca6e6014587

The branch you used for testing doesn't have that fix?

>

-- 
Filipe David Manana,

“Whether you think you can, or you think you can't — you're right.”