[uml-devel] starting an UML image sometimes failed, next (identical) attempt works

[uml-devel] starting an UML image sometimes failed, next (identical) attempt works

[Toralf Förster]

/me wonders, why the same call few seconds later works (current git kernel), but not for the first time :

$ nice start_uml.sh -r trinity 
+ /usr/local/bin/linux-v3.18-rc4 earlyprintk ubda=/home/tfoerste/virtual/uml/trinity ubdb=/mnt/ramdisk/trinity_swap eth0=tuntap,tap0,72:ef:3d:9f:c3:5a mem=2000M con0=fd:0,fd:1 con=pts umid=uml_trinity rootfstype=ext4 softlockup_all_cpu_backtrace=1

Locating the bottom of the address space ... 0x1000
Locating the top of the address space ... 0xc0000000
Core dump limits :
        soft - 0
        hard - NONE
Checking that ptrace can change system call numbers...OK
Checking syscall emulation patch for ptrace...OK
Checking advanced syscall emulation patch for ptrace...OK
Checking environment variables for a tempdir...none found
Checking if /dev/shm is on tmpfs...OK
Checking PROT_EXEC mmap in /dev/shm...OK
Checking for the skas3 patch in the host:
  - /proc/mm...not found: No such file or directory
  - PTRACE_FAULTINFO...not found
  - PTRACE_LDT...not found
UML running in SKAS0 mode
Adding 28835840 bytes to physical memory to account for exec-shield gap
Kernel virtual memory size shrunk to 953155584 bytes
bootconsole [earlycon0] enabled
PID hash table entries: 4096 (order: 2, 16384 bytes)
Dentry cache hash table entries: 262144 (order: 8, 1048576 bytes)
Inode-cache hash table entries: 131072 (order: 7, 524288 bytes)
Memory: 2022804K/2076160K available (4848K kernel code, 310K rwdata, 1784K rodata, 118K init, 240K bss, 53356K reserved)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
NR_IRQS:15
Calibrating delay loop... 2072.57 BogoMIPS (lpj=10362880)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 4096 (order: 2, 16384 bytes)
Mountpoint-cache hash table entries: 4096 (order: 2, 16384 bytes)
Checking for host processor cmov support...Yes
Checking that host ptys support output SIGIO...tty_output : read failed, err = -1
Checking that host ptys support SIGIO on close...No, enabling workaround
devtmpfs: initialized
Using 2.6 host AIO
xor: measuring software checksum speed
   8regs     :  2519.200 MB/sec
   8regs_prefetch:  2843.600 MB/sec
   32regs    :  1999.200 MB/sec
   32regs_prefetch:  1238.400 MB/sec
xor: using function: 8regs_prefetch (2843.600 MB/sec)
prandom: seed boundary self test passed
prandom: 100 self tests passed
NET: Registered protocol family 16
raid6: int32x1    235 MB/s
raid6: int32x2    292 MB/s
raid6: int32x4    188 MB/s
raid6: int32x8    183 MB/s
raid6: using algorithm int32x2 (292 MB/s)
raid6: using intx1 recovery algorithm
Switched to clocksource itimer
NET: Registered protocol family 2
TCP established hash table entries: 16384 (order: 4, 65536 bytes)
TCP bind hash table entries: 16384 (order: 6, 327680 bytes)
TCP: Hash tables configured (established 16384 bind 16384)
TCP: reno registered
UDP hash table entries: 1024 (order: 3, 49152 bytes)
UDP-Lite hash table entries: 1024 (order: 3, 49152 bytes)
NET: Registered protocol family 1
RPC: Registered named UNIX socket transport module.
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
console [stderr0] disabled
mconsole (version 2) initialized on /home/tfoerste/.uml/uml_trinity/mconsole
Checking host MADV_REMOVE support...OK
UML Audio Relay (host dsp = /dev/sound/dsp, host mixer = /dev/sound/mixer)
Host TLS support detected
Detected host type: i386 (GDT indexes 6 to 9)
futex hash table entries: 256 (order: 0, 7168 bytes)
audit: initializing netlink subsys (disabled)
audit: type=2000 audit(1416416597.671:1): initialized
zpool: loaded
zbud: loaded
NFS: Registering the id_resolver key type
Key type id_resolver registered
Key type id_legacy registered
nfs4filelayout_init: NFSv4 File Layout Driver Registering...
Installing knfsd (copyright (C) 1996 okir@monad.swb.de).
msgmni has been set to 3950
alg: No test for stdrng (krng)
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254)
io scheduler noop registered (default)
loop: module loaded
device-mapper: uevent: version 1.0.3
device-mapper: ioctl: 4.28.0-ioctl (2014-09-17) initialised: dm-devel@redhat.com
TCP: cubic registered
NET: Registered protocol family 10
sit: IPv6 over IPv4 tunneling driver
NET: Registered protocol family 17

Key type dns_resolver registered
Initialized stdio console driver
Console initialized on /dev/tty0
                                console [tty0] enabled
console [tty0] enabled
                      bootconsole [earlycon0] disabled
bootconsole [earlycon0] disabled
                                Initializing software serial port version 1
console [mc-1] enabled
Failed to initialize ubd device 0 :Couldn't determine size of device's file
 ubdb: unknown partition table
Netdevice 0 (72:ef:3d:9f:c3:5a) : 
TUN/TAP backend - 
Btrfs loaded
winch_thread : TIOCSCTTY failed on fd 1 err = 1
VFS: Cannot open root device "98:0" or unknown-block(98,0): error -6
Please append a correct "root=" boot option; here are the available partitions:
6210          262144 ubdb  driver: uml-blkdev
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(98,0)
CPU: 0 PID: 1 Comm: swapper Not tainted 3.18.0-rc4 #12
Stack:
 085c8b17 085c8b17 086f8547 085068c1 fffffffa 864aff40 864afef8 08509f65
 00000000 864afed0 864aff20 085060bd 085d4920 08739180 085c5be0 864aff30
 00000000 fffffffa 864aff40 00008001 864aff6c 08048f9d 085c5be0 864aff40
Call Trace:
 [<085068c1>] ? printk+0x38/0x3a
 [<08060ae9>] show_stack+0x119/0x180
 [<085068c1>] ? printk+0x38/0x3a
 [<08509f65>] dump_stack+0x26/0x28
 [<085060bd>] panic+0x8f/0x1a9
 [<08048f9d>] mount_block_root+0x1e0/0x261
 [<0811bea8>] ? SyS_mknod+0x28/0x30
 [<0804907e>] mount_root+0x60/0x66
 [<080491c3>] prepare_namespace+0x13f/0x185
 [<08048cb2>] kernel_init_freeable+0x190/0x19d
 [<0804821f>] ? repair_env_string+0x0/0x91
 [<0850493b>] kernel_init+0xb/0xe0
 [<0805f69b>] new_thread_handler+0x6b/0x90



-- 
Toralf
pgp key: 0076 E94E


------------------------------------------------------------------------------
Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server
from Actuate! Instantly Supercharge Your Business Reports and Dashboards
with Interactivity, Sharing, Native Excel Exports, App Integration & more
Get technology previously reserved for billion-dollar corporations, FREE
http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] starting an UML image sometimes failed, next (identical) attempt works

[Anton Ivanov]

I have seen this a couple of times as well.

I am a bit snowed under at the moment, when I have some spare time I
will try to dig through my trees to see exactly what did I come up with
as a root cause.

A.

On 19/11/14 17:06, Toralf Förster wrote:
> /me wonders, why the same call few seconds later works (current git kernel), but not for the first time :
>
> $ nice start_uml.sh -r trinity 
> + /usr/local/bin/linux-v3.18-rc4 earlyprintk ubda=/home/tfoerste/virtual/uml/trinity ubdb=/mnt/ramdisk/trinity_swap eth0=tuntap,tap0,72:ef:3d:9f:c3:5a mem=2000M con0=fd:0,fd:1 con=pts umid=uml_trinity rootfstype=ext4 softlockup_all_cpu_backtrace=1
>
> Locating the bottom of the address space ... 0x1000
> Locating the top of the address space ... 0xc0000000
> Core dump limits :
>         soft - 0
>         hard - NONE
> Checking that ptrace can change system call numbers...OK
> Checking syscall emulation patch for ptrace...OK
> Checking advanced syscall emulation patch for ptrace...OK
> Checking environment variables for a tempdir...none found
> Checking if /dev/shm is on tmpfs...OK
> Checking PROT_EXEC mmap in /dev/shm...OK
> Checking for the skas3 patch in the host:
>   - /proc/mm...not found: No such file or directory
>   - PTRACE_FAULTINFO...not found
>   - PTRACE_LDT...not found
> UML running in SKAS0 mode
> Adding 28835840 bytes to physical memory to account for exec-shield gap
> Kernel virtual memory size shrunk to 953155584 bytes
> bootconsole [earlycon0] enabled
> PID hash table entries: 4096 (order: 2, 16384 bytes)
> Dentry cache hash table entries: 262144 (order: 8, 1048576 bytes)
> Inode-cache hash table entries: 131072 (order: 7, 524288 bytes)
> Memory: 2022804K/2076160K available (4848K kernel code, 310K rwdata, 1784K rodata, 118K init, 240K bss, 53356K reserved)
> SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
> NR_IRQS:15
> Calibrating delay loop... 2072.57 BogoMIPS (lpj=10362880)
> pid_max: default: 32768 minimum: 301
> Mount-cache hash table entries: 4096 (order: 2, 16384 bytes)
> Mountpoint-cache hash table entries: 4096 (order: 2, 16384 bytes)
> Checking for host processor cmov support...Yes
> Checking that host ptys support output SIGIO...tty_output : read failed, err = -1
> Checking that host ptys support SIGIO on close...No, enabling workaround
> devtmpfs: initialized
> Using 2.6 host AIO
> xor: measuring software checksum speed
>    8regs     :  2519.200 MB/sec
>    8regs_prefetch:  2843.600 MB/sec
>    32regs    :  1999.200 MB/sec
>    32regs_prefetch:  1238.400 MB/sec
> xor: using function: 8regs_prefetch (2843.600 MB/sec)
> prandom: seed boundary self test passed
> prandom: 100 self tests passed
> NET: Registered protocol family 16
> raid6: int32x1    235 MB/s
> raid6: int32x2    292 MB/s
> raid6: int32x4    188 MB/s
> raid6: int32x8    183 MB/s
> raid6: using algorithm int32x2 (292 MB/s)
> raid6: using intx1 recovery algorithm
> Switched to clocksource itimer
> NET: Registered protocol family 2
> TCP established hash table entries: 16384 (order: 4, 65536 bytes)
> TCP bind hash table entries: 16384 (order: 6, 327680 bytes)
> TCP: Hash tables configured (established 16384 bind 16384)
> TCP: reno registered
> UDP hash table entries: 1024 (order: 3, 49152 bytes)
> UDP-Lite hash table entries: 1024 (order: 3, 49152 bytes)
> NET: Registered protocol family 1
> RPC: Registered named UNIX socket transport module.
> RPC: Registered udp transport module.
> RPC: Registered tcp transport module.
> RPC: Registered tcp NFSv4.1 backchannel transport module.
> console [stderr0] disabled
> mconsole (version 2) initialized on /home/tfoerste/.uml/uml_trinity/mconsole
> Checking host MADV_REMOVE support...OK
> UML Audio Relay (host dsp = /dev/sound/dsp, host mixer = /dev/sound/mixer)
> Host TLS support detected
> Detected host type: i386 (GDT indexes 6 to 9)
> futex hash table entries: 256 (order: 0, 7168 bytes)
> audit: initializing netlink subsys (disabled)
> audit: type=2000 audit(1416416597.671:1): initialized
> zpool: loaded
> zbud: loaded
> NFS: Registering the id_resolver key type
> Key type id_resolver registered
> Key type id_legacy registered
> nfs4filelayout_init: NFSv4 File Layout Driver Registering...
> Installing knfsd (copyright (C) 1996 okir@monad.swb.de).
> msgmni has been set to 3950
> alg: No test for stdrng (krng)
> Block layer SCSI generic (bsg) driver version 0.4 loaded (major 254)
> io scheduler noop registered (default)
> loop: module loaded
> device-mapper: uevent: version 1.0.3
> device-mapper: ioctl: 4.28.0-ioctl (2014-09-17) initialised: dm-devel@redhat.com
> TCP: cubic registered
> NET: Registered protocol family 10
> sit: IPv6 over IPv4 tunneling driver
> NET: Registered protocol family 17
>
> Key type dns_resolver registered
> Initialized stdio console driver
> Console initialized on /dev/tty0
>                                 console [tty0] enabled
> console [tty0] enabled
>                       bootconsole [earlycon0] disabled
> bootconsole [earlycon0] disabled
>                                 Initializing software serial port version 1
> console [mc-1] enabled
> Failed to initialize ubd device 0 :Couldn't determine size of device's file
>  ubdb: unknown partition table
> Netdevice 0 (72:ef:3d:9f:c3:5a) : 
> TUN/TAP backend - 
> Btrfs loaded
> winch_thread : TIOCSCTTY failed on fd 1 err = 1
> VFS: Cannot open root device "98:0" or unknown-block(98,0): error -6
> Please append a correct "root=" boot option; here are the available partitions:
> 6210          262144 ubdb  driver: uml-blkdev
> Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(98,0)
> CPU: 0 PID: 1 Comm: swapper Not tainted 3.18.0-rc4 #12
> Stack:
>  085c8b17 085c8b17 086f8547 085068c1 fffffffa 864aff40 864afef8 08509f65
>  00000000 864afed0 864aff20 085060bd 085d4920 08739180 085c5be0 864aff30
>  00000000 fffffffa 864aff40 00008001 864aff6c 08048f9d 085c5be0 864aff40
> Call Trace:
>  [<085068c1>] ? printk+0x38/0x3a
>  [<08060ae9>] show_stack+0x119/0x180
>  [<085068c1>] ? printk+0x38/0x3a
>  [<08509f65>] dump_stack+0x26/0x28
>  [<085060bd>] panic+0x8f/0x1a9
>  [<08048f9d>] mount_block_root+0x1e0/0x261
>  [<0811bea8>] ? SyS_mknod+0x28/0x30
>  [<0804907e>] mount_root+0x60/0x66
>  [<080491c3>] prepare_namespace+0x13f/0x185
>  [<08048cb2>] kernel_init_freeable+0x190/0x19d
>  [<0804821f>] ? repair_env_string+0x0/0x91
>  [<0850493b>] kernel_init+0xb/0xe0
>  [<0805f69b>] new_thread_handler+0x6b/0x90
>
>
>


------------------------------------------------------------------------------
Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server
from Actuate! Instantly Supercharge Your Business Reports and Dashboards
with Interactivity, Sharing, Native Excel Exports, App Integration & more
Get technology previously reserved for billion-dollar corporations, FREE
http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] starting an UML image sometimes failed, next (identical) attempt works

[Richard Weinberger]

On Wed, Nov 19, 2014 at 6:06 PM, Toralf Förster <toralf.foerster@gmx.de> wrote:
> console [mc-1] enabled
> Failed to initialize ubd device 0 :Couldn't determine size of device's file

This is ubd_file_size(). Can you find out where exactly it is failing?
Just add a few printk()s into it.

-- 
Thanks,
//richard

------------------------------------------------------------------------------
Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server
from Actuate! Instantly Supercharge Your Business Reports and Dashboards
with Interactivity, Sharing, Native Excel Exports, App Integration & more
Get technology previously reserved for billion-dollar corporations, FREE
http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] starting an UML image sometimes failed, next (identical) attempt works

[Toralf Förster]

On 11/19/2014 10:13 PM, Richard Weinberger wrote:
>> console [mc-1] enabled
>> > Failed to initialize ubd device 0 :Couldn't determine size of device's file
> This is ubd_file_size(). Can you find out where exactly it is failing?
> Just add a few printk()s into it.

Did it:

diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index e8ab93c..22390f9 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -508,19 +508,25 @@ static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out)
        int sector_size;
        int bitmap_offset;

+printk(KERN_INFO "ubd_file_size 0");
        if (ubd_dev->file && ubd_dev->cow.file) {
                file = ubd_dev->cow.file;
+printk(KERN_INFO "ubd_file_size 1");

                goto out;
        }

        fd = os_open_file(ubd_dev->file, of_read(OPENFLAGS()), 0);
+printk(KERN_INFO "ubd_file_size 2");
        if (fd < 0)
                return fd;
+printk(KERN_INFO "ubd_file_size 3");

        err = read_cow_header(file_reader, &fd, &version, &backing_file, \
                &mtime, &size, &sector_size, &align, &bitmap_offset);
        os_close_file(fd);
+printk(KERN_INFO "ubd_file_size 4, err=%i", err);

        if(err == -EINVAL)
                file = ubd_dev->file;




but no result so far (did the issue knows that I do observe him ???). I might test if this happens at the first time the UML image file is mounted using a loop device (after reboot of the host).

-- 
Toralf
pgp key: 0076 E94E


------------------------------------------------------------------------------
Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server
from Actuate! Instantly Supercharge Your Business Reports and Dashboards
with Interactivity, Sharing, Native Excel Exports, App Integration & more
Get technology previously reserved for billion-dollar corporations, FREE
http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk
_______________________________________________
User-mode-linux-devel mailing list
User-mode-linux-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel

Re: [uml-devel] starting an UML image sometimes failed, next (identical) attempt works

[Geert Uytterhoeven]

On Fri, Nov 21, 2014 at 2:32 PM, Toralf Förster <toralf.foerster@gmx.de> wrote:
> diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
> index e8ab93c..22390f9 100644
> --- a/arch/um/drivers/ubd_kern.c
> +++ b/arch/um/drivers/ubd_kern.c
> @@ -508,19 +508,25 @@ static inline int ubd_file_size(struct ubd *ubd_dev, __u64 *size_out)
>         int sector_size;
>         int bitmap_offset;
>
> +printk(KERN_INFO "ubd_file_size 0");
>         if (ubd_dev->file && ubd_dev->cow.file) {
>                 file = ubd_dev->cow.file;
> +printk(KERN_INFO "ubd_file_size 1");
>
>                 goto out;
>         }
>
>         fd = os_open_file(ubd_dev->file, of_read(OPENFLAGS()), 0);
> +printk(KERN_INFO "ubd_file_size 2");
>         if (fd < 0)
>                 return fd;
> +printk(KERN_INFO "ubd_file_size 3");

Not really on-topic, but it's faster to add lines like

    pr_info("%s:%u\n", __func__, __LINE__);

They're identical (i.e. copy-'n-paste), but give unique output depending
on context.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds