touch-packages team mailing list archive

[Rafael David Tinoco <rafael.tinoco@xxxxxxxxxxxxx>]

I believe that this comment:

https://code.launchpad.net/~noorez-kassam/ubuntu/utopic/initramfs-tools
/fix-for-1317437/+merge/219927/comments/592175

""""
This is the way I understand this is and my testing is shown below:

Mounting and creating the loop device in the same step with the readonly
option, makes it impossible to remount the loop device later as read-
write.

By creating the loop device separately (which defaults to read-write
capable unless the -r option is supplied), the loop device can then be
mounted readonly, and later remounted as read-write.

This change is needed since release 14.04, which - for unknown reasons -
now won't let the loop device be remounted read-write (perhaps it's
passing the -r option to losetup internally and it's losetup which has
started enforcing this?).

The end result is that Wubi installs cannot boot, because the remount
read-write fails.

My tests confirm this:
Setup:
1. Create a file, format as ext4.
bcbc@neptune:~$ dd if=/dev/zero of=new.disk bs=1MB count=100
bcbc@neptune:~$ mkfs.ext4 -F new.disk

2. Old method, mount and create loop device as read only, then try to remount
bcbc@neptune:~$ sudo mount -r -t ext4 -o loop new.disk /mnt
bcbc@neptune:~$ sudo touch /mnt/test
touch: impossible de faire un touch «/mnt/test»: Système de fichiers accessible en lecture seulement
bcbc@neptune:~$ sudo mount -o remount,rw /mnt
mount : impossible de remonter périphérique bloc /dev/loop0 en lecture/écriture, est protégé en écriture
bcbc@neptune:~$ sudo umount /mnt

3. New method, first create loop device (defaults to read-write capable), then mount as read only, then try to remount read-write
bcbc@neptune:~$ sudo losetup /dev/loop0 new.disk
bcbc@neptune:~$ sudo mount -r -t ext4 /dev/loop0 /mnt
bcbc@neptune:~$ sudo touch /mnt/test
touch: impossible de faire un touch «/mnt/test»: Système de fichiers accessible en lecture seulement
bcbc@neptune:~$ sudo mount -o remount,rw /mnt
bcbc@neptune:~$ sudo touch /mnt/test
bcbc@neptune:~$ sudo umount /mnt
bcbc@neptune:~$ sudo losetup -d /dev/loop0

4. To confirm it's probably passing -r to losetup
bcbc@neptune:~$ sudo losetup -r /dev/loop0 new.disk
bcbc@neptune:~$ sudo mount -r -t ext4 /dev/loop0 /mnt
bcbc@neptune:~$ sudo touch /mnt/test
touch: impossible de faire un touch «/mnt/test»: Système de fichiers accessible en lecture seulement
bcbc@neptune:~$ sudo mount -o remount,rw /mnt
mount : impossible de remonter périphérique bloc /dev/loop0 en lecture/écriture, est protégé en écriture
bcbc@neptune:~$ sudo umount /mnt
bcbc@neptune:~$ sudo losetup -d /dev/loop0

Conclusion:
This fix is appropriate and required for loop mounted installs
""""

>From "bcbc" is what this bug is all about.

** Changed in: initramfs-tools (Ubuntu)
     Assignee: (unassigned) => Rafael David Tinoco (inaddy)

** Changed in: initramfs-tools (Ubuntu)
       Status: Confirmed => In Progress

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to initramfs-tools in Ubuntu.
https://bugs.launchpad.net/bugs/1317437

Title:
  wubi kernel option "rw" required

Status in initramfs-tools package in Ubuntu:
  In Progress

Bug description:
  We have installed ubuntu beta-64amd.iso (trusty tahr) as wubi on a
  windows 8.1.

  Since upgrade
   * busybox-initramfs from "1.20.0-8.1ubuntu1" to "1.21.0-1ubuntu1"
   * busybox-static from "1.20.0-8.1ubuntu1" to "1.21.0-1ubuntu1"
  the wubi installation won't work / start and ends with the massage:
  "Bei der Ueberpruefung des Laufwerkes auf / wurden schwere Fehler gefunden"

  "key: »I« zum Ignorieren, »S« ueberspringt das Einhaengen, »M« fuer
  manuelle Wiederherstellung"

  Changing the sequence of "/boot/grub/grub.cfg" inside the line:
   * linux	/boot/vmlinuz-3.13.0-24-generic root=UUID=B65449E05449A449 loop=/ubuntu/disks/root.disk ro   quiet splash $vt_handoff
  into
   * linux	/boot/vmlinuz-3.13.0-24-generic root=UUID=B65449E05449A449 loop=/ubuntu/disks/root.disk rw  quiet splash $vt_handoff
  (kernel option »ro« into »rw«) lets start the wubi installation without any restrictions.

  For further system-information see -> annex

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: lupin-support 0.55
  ProcVersionSignature: Ubuntu 3.13.0-24.47-generic 3.13.9
  Uname: Linux 3.13.0-24-generic x86_64
  ApportVersion: 2.14.1-0ubuntu3
  Architecture: amd64
  Date: Thu May  8 10:53:53 2014
  ProcEnviron:
   LANGUAGE=de_DE
   TERM=xterm
   PATH=(custom, no user)
   LANG=de_DE.UTF-8
   SHELL=/bin/bash
  SourcePackage: lupin
  UpgradeStatus: No upgrade log present (probably fresh install)

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