problems checking a partition from Android (but not mounting!)

[Ivan Zakharyaschev]

I've installed Ubuntu 12.04 for Toshiba AC100, following the instructions at https://wiki.ubuntu.com/ARM/TEGRA/AC100 .

Originally, there was Android on the computer. So, besides the partitions used for Ubuntu now, there are some partitions left untouched from Android.

In the freshly installed system, they were mounted with a helper into /media/*, but then I wanted have permanent mountpoints for them (for saving stuff there), so I added them to /etc/fstab as ext3 (My names for the mountpoints may be not sensible and may not correspond to their actual purpose in Android, as for example listed in http://android.stackexchange.com/a/27852/13117; I haven't tried hard to determine the purpise of these partitions):

# mount
/dev/mmcblk0p12 on / type ext4 (rw,noatime,nodiratime,discard)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
/dev/mmcblk0p7 on /mnt/toshiba/recovery type ext3 (rw,nosuid,nodev,noatime,nodiratime)
/dev/mmcblk0p10 on /mnt/toshiba/android type ext3 (rw,nosuid,nodev,noatime,nodiratime)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
gvfs-fuse-daemon on /home/imz/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=imz)
/dev/mmcblk0p6 on /media/system type ext2 (rw,nosuid,nodev,uhelper=udisks)
#

If I added "discard" option in fstab for them, they wouldn't mount. (But this way they are mounted fine.)

There appeared an error during boot: the check of these partitions fails.

Let's have a look: what's wrong with the check?

root@potka:~# umount /dev/mmcblk0p7
root@potka:~# fsck.ext3 /dev/mmcblk0p7
e2fsck 1.42 (29-Nov-2011)
fsck.ext3: Superblock invalid, trying backup blocks...
fsck.ext3: The ext2 superblock is corrupt при попытке открыть /dev/mmcblk0p7

The superблок could not be read or does not describe a correct ext2
ФС. If the устройство is valid and it really contains an ext2
ФС (and not swap or ufs or something else), then the superблок
is corrupt, and you might try running e2fsck with an alternate superблок:
    e2fsck -b 8193 <устройство>

root@potka:~# mount /dev/mmcblk0p7
root@potka:~# dmesg | tail
[12523.855878] tegra_dvfs: rate 216000000 too high for dvfs on disp1
[14798.460340] tegra_dvfs: rate 216000000 too high for dvfs on disp1
[25522.814250] ec system event c5 04 01 00 02 00 ......
[27051.782313] ec system event c5 04 01 00 00 00 ......
[27052.067613] tegra_dvfs: rate 216000000 too high for dvfs on disp1
[28435.236168] EXT3-fs: barriers not enabled
[28435.238916] kjournald starting. Commit interval 5 seconds
[28435.239018] EXT3-fs (mmcblk0p7): warning: maximal mount count reached, running e2fsck is recommended
[28435.244047] EXT3-fs (mmcblk0p7): using internal journal
[28435.244144] EXT3-fs (mmcblk0p7): mounted filesystem with writeback data mode
root@potka:~#

Mounting is OK, but the check fails. Strange. A bug in e2fsck?

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: e2fsprogs 1.42-1ubuntu2
Uname: Linux 3.0.27-1-ac100 armv7l
ApportVersion: 2.0.1-0ubuntu13
Architecture: armhf
Date: Thu Sep 6 04:26:06 2012
SourcePackage: e2fsprogs
UpgradeStatus: No upgrade log present (probably fresh install)

[Ivan Zakharyaschev (imz)]

(Asked about it the Android community, too -- http://android.stackexchange.com/q/28855/13117 ).

For, I'll just put zeros as the last field in /etc/fstab for these partitions, so that their check is skipped during the boot.

[Andrey Danin (danindrey)]

Ivan, could you please post output from
tune2fs -l /dev/mmcblk0p7
?