Re: xen/blkfront: Ubuntu 14.04 crashes when it is booting

[Ken]

On 2016/7/12 15:30, uvptools wrote:
> Please give us some suggests to deal with this problem.
>
> Thanks & best wishes.
>
> On 2016/7/12 14:58, Ouyangzhaowei (Charles) wrote:
> > Hi all,
> >
> > Recently we found that a VM which runs Ubuntu 14.04 went to crash when
> > it was booting, and the VM was run on xen-4.1.2, seems like the
> > xen-blkfront was stuck when add_disk() was called, and the core dump
> > shows the stack log like below:
> >
> > [    5.514140] usb 2-1: SerialNumber: 42
> > [    5.436081] xenbus_probe_frontend: Waiting for devices to
> > initialise: 25s...20s...15s...10s...5s...0s...
> > [   61.164383] random: nonblocking pool is initialized
> > [  240.188145] INFO: task xenwatch:275 blocked for more than 120 seconds.
> > [  240.190214]       Not tainted 3.13.0-24-generic #46-Ubuntu
> > [  240.191211] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
> > disables this message.
> > [   35.436090]
> > 235s...230s...225s...220s...215s...210s...205s...200s...195s...190s...185s...180s...175s...170s...165s...160s...155s...150s...145s...140s...135s...130s...125s...120s...1
> >
> > 15s...110s...105s...100s...95s...90s...85s...80s...75s...70s...65s...60s...55s...50s...45s...40s...35s...
> >
> > [  240.192231] xenwatch        D
> > [  240.193211]  ffff88003ce34440     0   275      2 0x00000000
> > [  240.194269]  ffff88003b4dd9b8 0000000000000002 ffff88003b4a17f0
> > ffff88003b4ddfd8
> > [  240.195315]  0000000000014440 0000000000014440 ffff88003b4a17f0
> > ffff88003ce34cd8
> > [  240.196392]  ffff88003f7d28e8 ffff88003b4dda40 0000000000000002
> > ffffffff8114df10
> > [  240.197453] Call Trace:
> > [  240.198483]  [<ffffffff8114df10>] ? wait_on_page_read+0x60/0x60
> > [  240.199522]  [<ffffffff8171a1ad>] io_schedule+0x9d/0x140
> > [  240.200537]  [<ffffffff8114df1e>] sleep_on_page+0xe/0x20
> > [  240.201537]  [<ffffffff8171a738>] __wait_on_bit_lock+0x48/0xb0
> > [  240.202540]  [<ffffffff811f23a0>] ? blkdev_write_begin+0x30/0x30
> > [  240.203624]  [<ffffffff8114e02a>] __lock_page+0x6a/0x70
> > [  240.204644]  [<ffffffff810aaed0>] ? autoremove_wake_function+0x40/0x40
> > [  240.205650]  [<ffffffff811f23b8>] ? blkdev_readpage+0x18/0x20
> > [  240.206648]  [<ffffffff8114ee40>] do_read_cache_page+0x100/0x1a0
> > [  240.207649]  [<ffffffff8114ef19>] read_cache_page+0x19/0x30
> > [  240.208692]  [<ffffffff8134386d>] read_dev_sector+0x2d/0x90
> > [  240.209672]  [<ffffffff813445f0>] ? check_partition+0x240/0x240
> > [  240.210642]  [<ffffffff81344660>] adfspart_check_ICS+0x70/0x280
> > [  240.211596]  [<ffffffff81368bd9>] ? snprintf+0x39/0x40
> > [  240.212591]  [<ffffffff813445f0>] ? check_partition+0x240/0x240
> > [  240.213520]  [<ffffffff813444b8>] check_partition+0x108/0x240
> > [  240.214424]  [<ffffffff813440e4>] rescan_partitions+0xb4/0x2c0
> > [  240.215305]  [<ffffffff811f3714>] __blkdev_get+0x384/0x4c0
> > [  240.216174]  [<ffffffff811f3a15>] blkdev_get+0x1c5/0x340
> > [  240.217271]  [<ffffffff811d34f0>] ? unlock_new_inode+0x50/0x70
> > [  240.218126]  [<ffffffff811f2263>] ? bdget+0x133/0x150
> > [  240.218984]  [<ffffffff81341981>] add_disk+0x3a1/0x4b0
> > [  240.219841]  [<ffffffff814b40e1>] blkback_changed+0xd71/0x10b0
> > [  240.220697]  [<ffffffff8142f79d>] xenbus_otherend_changed+0xad/0x110
> > [  240.221533]  [<ffffffff8142eae0>] ?
> > unregister_xenbus_watch+0x230/0x230
> > [  240.222330]  [<ffffffff81431a73>] backend_changed+0x13/0x20
> > [  240.223101]  [<ffffffff8142eb7f>] xenwatch_thread+0x9f/0x160
> > [  240.223852]  [<ffffffff810aae90>] ? prepare_to_wait_event+0x100/0x100
> > [  240.224593]  [<ffffffff8108b312>] kthread+0xd2/0xf0
> > [  240.225309]  [<ffffffff8108b240>] ? kthread_create_on_node+0x1d0/0x1d0
> > [  240.226138]  [<ffffffff8172637c>] ret_from_fork+0x7c/0xb0
> > [  240.226830]  [<ffffffff8108b240>] ? kthread_create_on_node+0x1d0/0x1d0
> > [  240.340091] 30s...25s...20s...15s...10s...5s...0s...
> > [  270.340821]
> > [  270.341507] xenbus_probe_frontend: Device with no driver:
> > device/vbd/51760
> > [  270.342469] xenbus_probe_frontend: Timeout connecting to device:
> > device/vif/0 (local state 1, remote state 2)
> > [  270.344062] xenbus_probe_frontend: Timeout connecting to device:
> > device/vif/1 (local state 1, remote state 2)
> > [  270.345798] xenbus_probe_frontend: Timeout connecting to device:
> > device/vif/2 (local state 1, remote state 2)
> > [  270.347381] regulator-dummy: disabling
> > [  270.348274]   Magic number: 4:767:195
> > [  270.349178] rtc_cmos 00:03: setting system clock to 2016-06-27
> > 20:16:13 UTC (1467058573)
> > [  270.350133] BIOS EDD facility v0.16 2004-Jun-25, 0 devices found
> > [  270.350966] EDD information not available.
> > [  270.351845] PM: Hibernation image not present or could not be loaded.
> > [  270.351903] md: Waiting for all devices to be available before
> > autodetect
> > [  270.352778] md: If you don't use raid, use raid=noautodetect
> > [  270.353913] md: Autodetecting RAID arrays.
> > [  270.354784] md: Scanned 0 and added 0 devices.
> > [  270.355645] md: autorun ...
> > [  270.356512] md: ... autorun DONE.
> > [  270.357446] VFS: Cannot open root device "mapper/ubuntu--vg-root"
> > or unknown-block(0,0): error -6
> > [  270.358403] Please append a correct "root=" boot option; here are
> > the available partitions:
> > [  270.359323] ca00        10485760 xvda  driver: vbd
> > [  270.360263] 0b00         1048575 sr0  driver: sr
> > [  270.361183] Kernel panic - not syncing: VFS: Unable to mount root
> > fs on unknown-block(0,0)
> > [  270.362136] CPU: 1 PID: 1 Comm: swapper/0 Not tainted
> > 3.13.0-24-generic #46-Ubuntu
> > [  270.363107] Hardware name: Xen HVM domU, BIOS Unknown 06/25/2016
> > [  270.364085]  0000000000008001 ffff88003bc3bdf0 ffffffff81715a64
> > ffffffff81a3a0f0
> > [  270.364252]  ffff88003bc3be68 ffffffff8170ec65 3030623000000010
> > ffff88003bc3be78
> > [  270.364252]  ffff88003bc3be18 ffffff0000307273 ffff88003bc3be88
> > 00000000000000a4
> > [  270.364252] Call Trace:
> > [  270.364252]  [<ffffffff81715a64>] dump_stack+0x45/0x56
> > [  270.364252]  [<ffffffff8170ec65>] panic+0xc8/0x1d7
> > [  270.364252]  [<ffffffff81d3546a>] mount_block_root+0x225/0x2b0
> > [  270.364252]  [<ffffffff81d35692>] mount_root+0x53/0x56
> > [  270.364252]  [<ffffffff81d35801>] prepare_namespace+0x16c/0x1a4
> > [  270.364252]  [<ffffffff81d3516e>] kernel_init_freeable+0x1f3/0x200
> > [  270.364252]  [<ffffffff81d348e5>] ? do_early_param+0x88/0x88
> > [  270.364252]  [<ffffffff81703f40>] ? rest_init+0x80/0x80
> > [  270.364252]  [<ffffffff81703f4e>] kernel_init+0xe/0x130
> > [  270.364252]  [<ffffffff8172637c>] ret_from_fork+0x7c/0xb0
> > [  270.364252]  [<ffffffff81703f40>] ? rest_init+0x80/0x80
> >
> > Any ideas? Thanks
> >
> >
> > .