On Mon 21-01-13 13:30:26, Sedat Dilek wrote:

On Mon, Jan 21, 2013 at 12:40 PM, Sedat Dilek [off-list ref] wrote:

quoted

On Mon, Jan 21, 2013 at 11:47 AM, Jan Kara [off-list ref] wrote:

quoted

  The traces don't suggest an ext4/jbd2 problem. What is happening is that
jbd2 is waiting for IO to finish and that never happens. Seeing that you
loop device I'd think it's some interaction of the loop device and
freezing. Can you reproduce the issue without the loop device (i.e. with
the filesystem directly on e.g. scsi disk)? I suspect the reason is
something like that the backing filesystem is already frozen so filesystem
on top of it cannot write all the data and hangs waiting for IO -> suspend
doesn't happen. Contents of /proc/mounts and losetup -l would help us
understand what's going on.

As said I am here in a very uncommon WUBI environment means my
Ubuntu/precise rootfs-image lays on the Win7-partition (NTFS).
Your explanation sounds reasonable to me as this line from my attached
testcase causes the troubles.

     echo mem > /sys/power/state && sleep 1

So, /sys/ is not writable immediately after freezer ends

I checked again and again my logs and have seen "starving" lines
reported by rtkit-daemon, but did not really get wiser what they want
to tell me. Stopping rtkit-daemon or resetting all or all-known
threads before running my pm_test/freezer did not help, too.

/usr/sbin/rtkitctl --help
rtkitctl [options]

  -h, --help         Show this help
      --version      Show version

      --reset-known  Reset real-time status of known threads
      --reset-all    Reset real-time status of all threads
      --start        Start RealtimeKit if it is not running already
  -k, --exit         Terminate running RealtimeKit daemon

Here are the outputs you wanted with some more (fstab, grub-config) etc.
I have here no -l option for losetup command.


- Sedat -

P.S.: Outputs for Honza...

$ sudo cat /proc/mounts
rootfs / rootfs rw 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
udev /dev devtmpfs rw,relatime,size=1966948k,nr_inodes=491737,mode=755 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
tmpfs /run tmpfs rw,nosuid,relatime,size=788076k,mode=755 0 0
/dev/sda2 /host fuseblk
rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other,blksize=4096
0 0
/dev/loop0 / ext4 rw,relatime,errors=remount-ro,data=ordered 0 0
none /sys/fs/fuse/connections fusectl rw,relatime 0 0
none /sys/kernel/debug debugfs rw,relatime 0 0
none /sys/kernel/security securityfs rw,relatime 0 0
none /run/lock tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k 0 0
none /run/shm tmpfs rw,nosuid,nodev,relatime 0 0
gvfs-fuse-daemon /home/wearefam/.gvfs fuse.gvfs-fuse-daemon
rw,nosuid,nodev,relatime,user_id=1000,group_id=1000 0 0

$ sudo losetup --all --verbose
/dev/loop0: [0802]:17982 (/host/ubuntu/disks/root.disk)

$ sudo losetup --find --verbose
Loop device is /dev/loop1
/dev/loop1

 [ /etc/fstab ]
# /etc/fstab: static file system information.

# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).

# <file system>                 <mount point>   <type>  <options>
         <dump>  <pass>
proc                            /proc           proc
nodev,noexec,nosuid     0       0
/host/ubuntu/disks/root.disk    /               ext4
loop,errors=remount-ro  0       1
/host/ubuntu/disks/swap.disk    none            swap    loop,sw
         0       0
- EOF -

[ /boot/grub/grub.cfg ]
...
menuentry 'Ubuntu, mit Linux 3.8.0-rc4-next20130121-1-iniza-generic'
--class ubuntu --class gnu-linux --class gnu --class os {
        set gfxpayload=$linux_gfx_mode
        insmod part_msdos
        insmod ntfs
        set root='(hd0,msdos2)'
        search --no-floppy --fs-uuid --set=root 001AADA61AAD9964
        loopback loop0 /ubuntu/disks/root.disk
        set root=(loop0)
        linux   /boot/vmlinuz-3.8.0-rc4-next20130121-1-iniza-generic
root=UUID=001AADA61AAD9964 loop=/ubuntu/disks/root.disk ro
        initrd  /boot/initrd.img-3.8.0-rc4-next20130121-1-iniza-generic
}
...

Here some more useful outputs:

$ LC_ALL=C df -h -T
Filesystem     Type      Size  Used Avail Use% Mounted on
rootfs         rootfs     17G   15G  1.5G  92% /
udev           devtmpfs  1.9G   12K  1.9G   1% /dev
tmpfs          tmpfs     770M  892K  769M   1% /run
/dev/sda2      fuseblk   444G   81G  364G  19% /host
/dev/loop0     ext4       17G   15G  1.5G  92% /
none           tmpfs     5.0M     0  5.0M   0% /run/lock
none           tmpfs     1.9G  260K  1.9G   1% /run/shm

$ sudo LC_ALL=C fdisk -l /dev/sda

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0xcb9885ab

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      206847      102400    7  HPFS/NTFS/exFAT
/dev/sda2          206848   931299327   465546240    7  HPFS/NTFS/exFAT
/dev/sda3       931299328   976773119    22736896   27  Hidden NTFS WinRE

I am still reflecting on any shitty userspace app is causing all the
trouble, but I have zero clue how to dig that...

  Well, I think the outputs make it pretty clear. /dev/loop0 is a mounted
image from fuse filesystem. Fuse daemon making filesystem accessible gets
frozen before /dev/loop0 gets fully written out and so jbd2 journal thread
hangs. Maybe Miklos (added to CC) could fill in some details / ideas but I
think the setup like you have never really worked...

								Honza
-- 
Jan Kara [off-list ref]
SUSE Labs, CR