From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Chmielewski Subject: Re: btrfs hang (deadlock?) when trying to create a ext4 filesystem in KVM guest Date: Thu, 28 Oct 2010 08:29:27 +0200 Message-ID: <4CC91847.6020205@wpkg.org> References: <4CC82942.1020101@wpkg.org> <20101027225541.GT27796@think> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: Chris Mason , linux-btrfs@vger.kernel.org Return-path: In-Reply-To: <20101027225541.GT27796@think> List-ID: On 28.10.2010 00:55, Chris Mason wrote: > On Wed, Oct 27, 2010 at 03:29:38PM +0200, Tomasz Chmielewski wrote: >> There are a couple of problems when running KVM guests with images stored on btrfs filesystem. >> >> One of them is inability to create a filesystem (i.e. ext4) in the guest: >> >> - btrfs filesystem on the host was mounted with noatime,compress-force >> - guest was using a 50 GB sparse file, >> - attempt to create a ext4 filesystem within the guest does not succeed (hangs); host prints below messages in dmesg - some deadlock in btrfs? >> >> kernel: 2.6.36 >> qemu-kvm: 0.13.0 > > Is this the full dmesg output? I think there are other messages hiding > in there. There were indeed "bad ordered accounting left" (see below), I think they are coming from btrfs? > Is this a single disk btrfs? Yes. [ 8072.773053] device fsid 1142843480ad2d13-4bdc742fd9b1f7b0 devid 1 transid 1508 /dev/sdb4 [ 8072.773674] btrfs: forcing compression [ 8122.052221] device tap0 entered promiscuous mode [ 8122.052245] br0: port 2(tap0) entering learning state [ 8122.052248] br0: port 2(tap0) entering learning state [ 8122.451587] br0: port 2(tap0) entering learning state [ 8122.543477] br0: port 2(tap0) entering disabled state [ 8122.609645] device tap0 left promiscuous mode [ 8122.609650] br0: port 2(tap0) entering disabled state [ 8131.325647] EXT4-fs (md4): recovery complete [ 8131.325809] EXT4-fs (md4): mounted filesystem with ordered data mode. Opts: (null) [ 8133.392100] device tap0 entered promiscuous mode [ 8133.392127] br0: port 2(tap0) entering learning state [ 8133.392131] br0: port 2(tap0) entering learning state [ 8134.106594] kvm: 5004: cpu0 unhandled wrmsr: 0x198 data 0 [ 8134.106618] kvm: 5004: cpu1 unhandled wrmsr: 0x198 data 0 [ 8143.460927] tap0: no IPv6 routers present [ 8148.359485] br0: port 2(tap0) entering forwarding state [ 8309.103502] bad ordered accounting left 65536 size 385024 [ 8309.106206] bad ordered accounting left 65536 size 385024 [ 8309.108915] bad ordered accounting left 65536 size 385024 [ 8309.111630] bad ordered accounting left 36864 size 385024 [ 8501.965625] INFO: task qemu-system-x86:5148 blocked for more than 120 seconds. [ 8501.965629] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 8501.965632] qemu-system-x D ffff880001e14cc0 0 5148 4924 0x00000000 [ 8501.965638] ffff880223bc3b38 0000000000000086 ffff880223bc3fd8 0000000000014cc0 [ 8501.965642] 0000000000014cc0 ffff880223bc3fd8 0000000000014cc0 ffff880223bc3fd8 [ 8501.965647] 0000000000014cc0 ffff880221965f18 ffff880221965f20 ffff880221965b80 [ 8501.965651] Call Trace: [ 8501.965678] [] btrfs_start_ordered_extent+0x6c/0xb0 [btrfs] [ 8501.965685] [] ? autoremove_wake_function+0x0/0x40 [ 8501.965701] [] btrfs_wait_ordered_range+0xd2/0x160 [btrfs] [ 8501.965716] [] btrfs_file_aio_write+0x269/0x990 [btrfs] [ 8501.965721] [] ? try_to_wake_up+0xf4/0x3f0 [ 8501.965726] [] ? __pollwake+0x49/0x50 [ 8501.965730] [] ? default_wake_function+0x0/0x20 [ 8501.965733] [] ? try_to_wake_up+0xf4/0x3f0 [ 8501.965737] [] ? pollwake+0x1b/0x20 [ 8501.965752] [] ? btrfs_file_aio_write+0x0/0x990 [btrfs] [ 8501.965761] [] do_sync_readv_writev+0xcb/0x110 [ 8501.965769] [] ? apparmor_file_permission+0x18/0x20 [ 8501.965776] [] ? security_file_permission+0x1e/0x80 [ 8501.965781] [] do_readv_writev+0xd0/0x1d0 [ 8501.965787] [] ? kill_something_info+0x42/0x130 [ 8501.965793] [] ? sys_kill+0x80/0x90 [ 8501.965798] [] vfs_writev+0x3e/0x60 [ 8501.965802] [] sys_pwritev+0xa7/0xc0 [ 8501.965806] [] system_call_fastpath+0x16/0x1b [ 8501.965810] INFO: task qemu-system-x86:5150 blocked for more than 120 seconds. [ 8501.965812] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 8501.965814] qemu-system-x D ffff880001e94cc0 0 5150 4924 0x00000000 [ 8501.965819] ffff8801aba4bb38 0000000000000086 ffff8801aba4bfd8 0000000000014cc0 [ 8501.965823] 0000000000014cc0 ffff8801aba4bfd8 0000000000014cc0 ffff8801aba4bfd8 [ 8501.965827] 0000000000014cc0 ffff880226d14838 ffff880226d14840 ffff880226d144a0 [ 8501.965832] Call Trace: [ 8501.965847] [] btrfs_start_ordered_extent+0x6c/0xb0 [btrfs] [ 8501.965852] [] ? autoremove_wake_function+0x0/0x40 [ 8501.965867] [] btrfs_wait_ordered_range+0xd2/0x160 [btrfs] [ 8501.965883] [] btrfs_file_aio_write+0x269/0x990 [btrfs] [ 8501.965887] [] ? try_to_wake_up+0xf4/0x3f0 [ 8501.965891] [] ? __pollwake+0x49/0x50 [ 8501.965894] [] ? default_wake_function+0x0/0x20 [ 8501.965897] [] ? try_to_wake_up+0xf4/0x3f0 [ 8501.965901] [] ? pollwake+0x1b/0x20 [ 8501.965916] [] ? btrfs_file_aio_write+0x0/0x990 [btrfs] [ 8501.965920] [] do_sync_readv_writev+0xcb/0x110 [ 8501.965924] [] ? send_signal+0x56/0xa0 [ 8501.965928] [] ? apparmor_file_permission+0x18/0x20 [ 8501.965932] [] ? security_file_permission+0x1e/0x80 [ 8501.965936] [] do_readv_writev+0xd0/0x1d0 [ 8501.965940] [] vfs_writev+0x3e/0x60 [ 8501.965943] [] sys_pwritev+0xa7/0xc0 [ 8501.965946] [] system_call_fastpath+0x16/0x1b [ 8501.965950] INFO: task qemu-system-x86:5151 blocked for more than 120 seconds. [ 8501.965952] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 8501.965954] qemu-system-x D ffff880001e94cc0 0 5151 4924 0x00000000 [ 8501.965958] ffff88021923fb38 0000000000000086 ffff88021923ffd8 0000000000014cc0 [ 8501.965963] 0000000000014cc0 ffff88021923ffd8 0000000000014cc0 ffff88021923ffd8 [ 8501.965967] 0000000000014cc0 ffff880226d13158 ffff880226d13160 ffff880226d12dc0 [ 8501.965971] Call Trace: [ 8501.965986] [] btrfs_start_ordered_extent+0x6c/0xb0 [btrfs] [ 8501.965990] [] ? autoremove_wake_function+0x0/0x40 [ 8501.966005] [] btrfs_wait_ordered_range+0xd2/0x160 [btrfs] [ 8501.966021] [] btrfs_file_aio_write+0x269/0x990 [btrfs] [ 8501.966025] [] ? try_to_wake_up+0xf4/0x3f0 [ 8501.966029] [] ? __pollwake+0x49/0x50 [ 8501.966032] [] ? default_wake_function+0x0/0x20 [ 8501.966036] [] ? try_to_wake_up+0xf4/0x3f0 [ 8501.966039] [] ? pollwake+0x1b/0x20 [ 8501.966054] [] ? btrfs_file_aio_write+0x0/0x990 [btrfs] [ 8501.966058] [] do_sync_readv_writev+0xcb/0x110 [ 8501.966062] [] ? send_signal+0x56/0xa0 [ 8501.966066] [] ? apparmor_file_permission+0x18/0x20 [ 8501.966070] [] ? security_file_permission+0x1e/0x80 [ 8501.966074] [] do_readv_writev+0xd0/0x1d0 [ 8501.966078] [] vfs_writev+0x3e/0x60 [ 8501.966081] [] sys_pwritev+0xa7/0xc0 [ 8501.966084] [] system_call_fastpath+0x16/0x1b -- Tomasz Chmielewski http://wpkg.org