NTFS-3G silenty mount devices Readonly, even while setting -o rw

[Valentin Quequet]

Hi dear co-linuxiens,

That might strike you that I aim this bug report towards FUSE instead of towards NTFS-3G, but here follows my explanation :

    I roughly estimate there exist a dozen bugs related to the FUSE technology in Ubuntu/Natty-Beta (and maybe in Debian sid too), amongst those the half were already present in Ubuntu/Maverick-Stable (not LTS either, though).

    This will take me huge (astronomical, I'm not a developer) time to investigate that matter, so be patient, please.

    I encourage U to ask me for more information, and to instruct me debugging material & practices, for the sake of Godness OSS.

    I cannot do more right now, which I'm very sorry about.

PS1 : /etc/mtab says the ntfs-3g-mounted filesystem is mounted read/write.
PS2 : ls -ld OR ls -l, followed by <mount_point> clearly shows the tree hierarchy is readonly for anybody, root included.

{
  PS3: In order to help diagnose such kind of troubles, I would like some would to tell me how to do the thing here depicted :
  Most people know how QEmu provides COW devices and allow the user either to commit or abort the changes made to a block device.
  I would like someone to tell me whether it exists a (linux-2.6.38+) driver which allows experiments on a block device so that the modifications made to the storage contents never get written to the underlying block device without explicit instruction from the user to flush and commit those actual modifications.
}

Franco de Porc,
Valentin.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: libfuse2 2.8.4-1.1ubuntu4
ProcVersionSignature: Ubuntu 2.6.38-8.40-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
Architecture: amd64
Date: Tue Apr 5 19:12:04 2011
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429)
ProcEnviron:
 LANGUAGE=fr_FR:en
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: fuse
UpgradeStatus: Upgraded to natty on 2010-11-23 (133 days ago)

[Valentin Quequet (valentin-quequet)]

Hello,

In fact, NTFS-3G doesn't function at all, and the kernel NTFS driver takes over if I'm not clear about the driver to use (ntfs-3g/ntfs-fuse).

Here follows a few attempts to mount my NTFS partition :
(I used NBD client/server in order to preserve my data, but I would have got the same result on the real partition.)

root@valentin-laptop:~# ntfsmount /dev/nbd1 /mnt/nbd1 -o nosilent,debug
fuse_mount failed.
Unmounting /dev/nbd1 (DATA_EXCHANGE)

root@valentin-laptop:~# ntfsmount /dev/nbd1 /mnt/nbd1 -o nosilent,debug,force
fuse_mount failed.
Unmounting /dev/nbd1 (DATA_EXCHANGE)

root@valentin-laptop:~# ntfsmount /dev/nbd1 /mnt/nbd1 -o nosilent,debug,hello
fuse_mount failed.
Unmounting /dev/nbd1 (DATA_EXCHANGE)

root@valentin-laptop:~# ntfsmount /dev/nbd1 /mnt/nbd1 -o debug
fuse_mount failed.
Unmounting /dev/nbd1 (DATA_EXCHANGE)

root@valentin-laptop:~# ntfsmount /dev/nbd1 /mnt/nbd1 -odebug
fuse_mount failed.
Unmounting /dev/nbd1 (DATA_EXCHANGE)

root@valentin-laptop:~# ntfsmount /dev/nbd1 /mnt/nbd1
fuse_mount failed.
Unmounting /dev/nbd1 (DATA_EXCHANGE)

root@valentin-laptop:~# mount -t ntfs-fuse /dev/nbd1 /mnt/nbd1 ; echo RESULT=$?
fuse_mount failed.
Unmounting /dev/nbd1 (DATA_EXCHANGE)
RESULT=1

root@valentin-laptop:~# ntfsresize --info /dev/nbd1
ntfsresize v2.0.0 (libntfs 10:0:0)
Device name : /dev/nbd1
NTFS volume version: 3.1
Cluster size : 4096 bytes
Current volume size: 9536999936 bytes (9537 MB)
Current device size: 9536999424 bytes (9537 MB)
Checking filesystem consistency ...
100.00 percent completed
Accounting clusters ...
Space in use : 6283 MB (65.9%)
Collecting resizing constraints ...
You might resize at 6282199040 bytes or 6283 MB (freeing 3254 MB).
Please make a test run using both the -n and -s options before real resizing!
root@valentin-laptop:~#

root@valentin-laptop:~# ntfsresize --verbose --info /dev/nbd1
ntfsresize v2.0.0 (libntfs 10:0:0)
Device name : /dev/nbd1
NTFS volume version: 3.1
Cluster size : 4096 bytes
Current volume size: 9536999936 bytes (9537 MB)
Current device size: 9536999424 bytes (9537 MB)
Checking for bad sectors ...
Checking filesystem consistency ...
100.00 percent completed
Accounting clusters ...
Space in use : 6283 MB (65.9%)
Collecting resizing constraints ...
Estimating smallest shrunken size supported ...
File feature Last used at By inode
$MFT : 1 MB 0
Multi-Record : 1193 MB 360
$MFTMirr : 4769 MB 1
Sparse : 1042 MB 40
Ordinary : 7223 MB 448
You might resize at 6282199040 bytes or 6283 MB (freeing 3254 MB).
Please make a test run using both the -n and -s options before real resizing!
root@valentin-laptop:~#

root@valentin-laptop:~# ntfslabel --verbose /dev/nbd1
DATA_EXCHANGE
root@valentin-laptop:~#

root@valentin-laptop:~# ntfsls --verbose /dev/nbd1
$RECYCLE.BIN
apt_conf_d.tar.gz
Compte_E-Bay_MAJ-01.7z
Compte_PayPal.7z
Dossier_Pratiques_Modernes
Dossier_Pratiques_Modernes_2
Dossier_Pratiques_Modernes_4
DVB-T.txt
DVD
ECHANGE
Emploi_All
FIND-_.err
FIND-_.err.bak
FIND-_.out
FIND-_.ou...

[Valentin Quequet (valentin-quequet)]

Hello, I'm here again, but with more explanations:

It seams that FUSE is completely broken on Maverink : whichever FUSE-based filesystem I tried (sshfs, zfs-fuse, ...) that failed miserably with not a single message.

Just zfs-fuse asked me whether I had the FUSE module loaded, which is compiled in indeed!

Moreover, I put 'root' and an ordinary user in the 'fuse' group, but to check whether that would improve the situation, but that failed too.

I am continuing investigations ...

Valentin.

[Valentin Quequet (valentin-quequet)]

Sorry, I meant FUSE is broken on Natty Narval beta.

Valentin.

[Valentin Quequet (valentin-quequet)]

Hello,

The problem seem to have disappeared.

Bye,
Valentin