ext3 partition unmountable

ext3 partition unmountable

[Dewet Diener]

Hi all

After umounting a removable ext3 partition from my work PC, and 
trying to remount it at home, I've run into the following error
trying to mount it as both ext2 and ext3:

EXT2-fs: ide1(22,65): couldn't mount because of unsupported optional features (10000).
EXT3-fs: ide1(22,65): couldn't mount because of unsupported optional features (10000).

e2fsck is similarly unhelpful:
e2fsck: Filesystem has unsupported feature(s) while trying to open /dev/hdd1

The kernels on both machines have the same ext3 options enabled, and 
they're both 2.4.8-ac6.

This is the first time I've tried moving the drive like this - I 
assumed it would work flawlessly.  However, ext3 doco seems a bit
sparse under Documentation/, so I'm not quite sure about the recovery
steps needed.

I'd appreciate your help on this one :)  Please CC me in...

Regards,
Dewet

--
Dewet Diener     dewet@itouchlabs.com     -o)
Systems Administrator     iTouch Labs     / \
Self-confessed geek and Linux fanatic    _\_v

SYN! ..... SYN! ACK! ..... ACK!
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Re: ext3 partition unmountable

[Mike Black]

If I'm reading the files right it looks like:
#define EXT3_FEATURE_INCOMPAT_COMPRESSION  0x0001

Did you compress the file system?

Do a "tune2fs -l /dev/hdc" and see what features are set.

----- Original Message -----
From: "Dewet Diener" <linux-kernel@dewet.org>
To: <linux-kernel@vger.kernel.org>
Sent: Friday, August 17, 2001 9:03 PM
Subject: ext3 partition unmountable


> Hi all
>
> After umounting a removable ext3 partition from my work PC, and
> trying to remount it at home, I've run into the following error
> trying to mount it as both ext2 and ext3:
>
> EXT2-fs: ide1(22,65): couldn't mount because of unsupported optional
features (10000).
> EXT3-fs: ide1(22,65): couldn't mount because of unsupported optional
features (10000).
>
> e2fsck is similarly unhelpful:
> e2fsck: Filesystem has unsupported feature(s) while trying to open
/dev/hdd1
>
> The kernels on both machines have the same ext3 options enabled, and
> they're both 2.4.8-ac6.
>
> This is the first time I've tried moving the drive like this - I
> assumed it would work flawlessly.  However, ext3 doco seems a bit
> sparse under Documentation/, so I'm not quite sure about the recovery
> steps needed.
>
> I'd appreciate your help on this one :)  Please CC me in...
>
> Regards,
> Dewet
>
> --
> Dewet Diener     dewet@itouchlabs.com     -o)
> Systems Administrator     iTouch Labs     / \
> Self-confessed geek and Linux fanatic    _\_v
>
> SYN! ..... SYN! ACK! ..... ACK!
> The mating call of the internet
>
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Re: ext3 partition unmountable

[Dewet Diener]

On Sat, Aug 18, 2001 at 07:07:32AM -0400, Mike Black wrote:
> If I'm reading the files right it looks like:
> #define EXT3_FEATURE_INCOMPAT_COMPRESSION  0x0001
> 
> Did you compress the file system?
Not knowingly, no.  Is that a mount option?  I'm mounting them the 
same on both sides, so its rather strange...

> Do a "tune2fs -l /dev/hdc" and see what features are set.
Heh, not much more useful:

# tune2fs -l /dev/hdd1
tune2fs 1.22, 22-Jun-2001 for EXT2 FS 0.5b, 95/08/09
tune2fs: Filesystem has unsupported feature(s) while trying to open /dev/hdd1
Couldn't find valid filesystem superblock.

I'll probably have to take the drive back, and see if it now mounts
in the original system :-/

Dewet

-- 
Dewet Diener   linux-kernel@dewet.org     -o)
Systems Administrator     iTouch Labs     / \
Self-confessed geek and Linux fanatic    _\_v

SYN! ..... SYN! ACK! ..... ACK!
The mating call of the internet

Re: ext3 partition unmountable

[Riley Williams]

Hi Dewet.

 >> If I'm reading the files right it looks like:
 >> #define EXT3_FEATURE_INCOMPAT_COMPRESSION 0x0001

 >> Did you compress the file system?

 > Not knowingly, no. Is that a mount option?

The relevant mount option is to specify the ext3 rather than the ext2
file system, and the flag you refer to gets set if ANYBODY sets the
"COMPRESS THIS FILE" flag on ANY file on that file system. As far as I
can tell, nothing ever resets that flag, even if the last file that
was compressed gets uncompressed.

I suggested a while back that fsck should check whether there are any
compressed files on the filesystem, and reset that flag if not, but as
far as I can tell, nothing was ever done to implement that suggestion.

 > I'm mounting them the same on both sides, so its rather
 > strange...

 >> Do a "tune2fs -l /dev/hdc" and see what features are set.

 > Heh, not much more useful:

 > # tune2fs -l /dev/hdd1
 > tune2fs 1.22, 22-Jun-2001 for EXT2 FS 0.5b, 95/08/09
 > tune2fs: Filesystem has unsupported feature(s) while trying to open /dev/hdd1
 > Couldn't find valid filesystem superblock.

You have an old version of tune2fs, and need to get the one that knows
about ext3 or alternatively apply the patch that was distributed some
time ago and recompile - I'm not sure which.

Stephen: What's the current status regarding tune2fs and ext3, I'm a
tad out of date in this respect?

 > I'll probably have to take the drive back, and see if it now mounts
 > in the original system :-/

That might help...

Best wishes from Riley.

Re: ext3 partition unmountable

[Dewet Diener]

On Sat, Aug 18, 2001 at 11:04:41PM +0100, Riley Williams wrote:
> The relevant mount option is to specify the ext3 rather than the ext2
> file system, and the flag you refer to gets set if ANYBODY sets the
> "COMPRESS THIS FILE" flag on ANY file on that file system. As far as I
> can tell, nothing ever resets that flag, even if the last file that
> was compressed gets uncompressed.

I doubt that ever happened - its pretty much a single-user system,
and I can't say that I quite know *how* to set that flag in the first
place :)

> You have an old version of tune2fs, and need to get the one that knows
> about ext3 or alternatively apply the patch that was distributed some
> time ago and recompile - I'm not sure which.
> 
> Stephen: What's the current status regarding tune2fs and ext3, I'm a
> tad out of date in this respect?

I'm running e2fsprogs-1.22 (which is later than the one specified from
Documentation/Changes), so I kinda assumed everything was fine...

Dewet

Re: ext3 partition unmountable

[Stephen C. Tweedie]

Hi,

On Sat, Aug 18, 2001 at 11:04:41PM +0100, Riley Williams wrote:

>  > # tune2fs -l /dev/hdd1
>  > tune2fs 1.22, 22-Jun-2001 for EXT2 FS 0.5b, 95/08/09
>  > tune2fs: Filesystem has unsupported feature(s) while trying to open /dev/hdd1
>  > Couldn't find valid filesystem superblock.
> 
> You have an old version of tune2fs, and need to get the one that knows
> about ext3 or alternatively apply the patch that was distributed some
> time ago and recompile - I'm not sure which.

No, 1.22 tune2fs knows about the journaling flags.

> Stephen: What's the current status regarding tune2fs and ext3, I'm a
> tad out of date in this respect?

As of 1.22, ext3 is fully supported by tune2fs.

>  > I'll probably have to take the drive back, and see if it now mounts
>  > in the original system :-/
> 
> That might help...

Indeed, I'd like to see what that gives you.

One quick question: are either of the machines big-endian (HPPA, PPC
etc)?

Cheers, 
 Stephen

Re: ext3 partition unmountable

[Dewet Diener]

On Mon, Aug 20, 2001 at 07:10:46PM +0100, Stephen C. Tweedie wrote:
> >  > I'll probably have to take the drive back, and see if it now mounts
> >  > in the original system :-/
> > 
> > That might help...
> 
> Indeed, I'd like to see what that gives you.

Well, haven't had a chance to stick it in again, but after I repaired 
it with e2fsck off a backup superblock, I'm assuming it will work fine...

> One quick question: are either of the machines big-endian (HPPA, PPC
> etc)?

Nope, just plain PIII and AMD :)

> Cheers, 
>  Stephen

Regards,
Dewet

Re: ext3 partition unmountable

[Andrew Morton]

Dewet Diener wrote:
> 
> Hi all
> 
> After umounting a removable ext3 partition from my work PC, and
> trying to remount it at home, I've run into the following error
> trying to mount it as both ext2 and ext3:
> 
> EXT2-fs: ide1(22,65): couldn't mount because of unsupported optional features (10000).
> EXT3-fs: ide1(22,65): couldn't mount because of unsupported optional features (10000).
> 

Could you please run

	 od -A x -t x1 /dev/hdd1

and send the output?

For the superblock I get:

000400 c0 74 07 00 e2 e8 0e 00 d8 be 00 00 e1 8c 0e 00
000410 b5 74 07 00 00 00 00 00 02 00 00 00 02 00 00 00
000420 00 80 00 00 00 80 00 00 a0 3f 00 00 2f e9 7e 3b
000430 2f e9 7e 3b 01 00 16 00 53 ef 01 00 01 00 00 00
000440 1f e9 7e 3b 00 4e ed 00 00 00 00 00 01 00 00 00
000450 00 00 00 00 0b 00 00 00 80 00 00 00 04 00 00 00
000460 06 00 00 00 01 00 00 00 b9 d3 6c 59 2d cc 42 13
000470 91 84 d4 7b 60 d2 d9 50 00 00 00 00 00 00 00 00
000480 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

The incompat features are at superblock offset 0x60.
So here it's 0x00000006 - EXT3_FEATURE_INCOMPAT_FILETYPE
and EXT3_FEATURE_INCOMPAT_RECOVER.

Somehow you seem to have set bit 16, which isn't defined.  Not sure how
to fix this without simply running a binary editor against /dev/hdd1 and
clearing the byte at offset 0x462.

-

Re: ext3 partition unmountable

[Dewet Diener]

On Sat, Aug 18, 2001 at 03:29:32PM -0700, Andrew Morton wrote:
> Could you please run
> 
> 	 od -A x -t x1 /dev/hdd1
> 
> and send the output?
Here's mine:

000400 c0 5b 0e 81 de ab 1c 00 fe 6e 01 00 2c fa 13 00
000410 1d 36 0e 00 00 00 02 00 02 00 02 00 02 00 00 80
000420 00 80 00 80 00 80 00 20 60 3f 00 00 a3 56 7f 7f
000430 b6 56 7d 3b 0c 00 15 80 53 ef 00 00 01 00 01 81
000440 53 99 48 7b 00 4e ed 00 00 00 01 00 01 00 00 00
000450 00 00 08 00 0b 00 00 00 80 00 00 00 00 00 02 00
000460 02 00 01 00 01 00 e8 00 e8 00 3c 8f 15 e9 42 00
000470 a9 5c fe bf ec a6 84 ef 00 00 00 00 00 00 00 00
000480 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

> For the superblock I get:
> 
> 000400 c0 74 07 00 e2 e8 0e 00 d8 be 00 00 e1 8c 0e 00
> 000410 b5 74 07 00 00 00 00 00 02 00 00 00 02 00 00 00
> 000420 00 80 00 00 00 80 00 00 a0 3f 00 00 2f e9 7e 3b
> 000430 2f e9 7e 3b 01 00 16 00 53 ef 01 00 01 00 00 00
> 000440 1f e9 7e 3b 00 4e ed 00 00 00 00 00 01 00 00 00
> 000450 00 00 00 00 0b 00 00 00 80 00 00 00 04 00 00 00
> 000460 06 00 00 00 01 00 00 00 b9 d3 6c 59 2d cc 42 13
> 000470 91 84 d4 7b 60 d2 d9 50 00 00 00 00 00 00 00 00
> 000480 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 
> The incompat features are at superblock offset 0x60.
> So here it's 0x00000006 - EXT3_FEATURE_INCOMPAT_FILETYPE
> and EXT3_FEATURE_INCOMPAT_RECOVER.

So, mine's 0x00010002 - EXT3_FEATURE_INCOMPAT_FILETYPE, as well as
the undefined bit?

> Somehow you seem to have set bit 16, which isn't defined.  Not sure how
> to fix this without simply running a binary editor against /dev/hdd1 and
> clearing the byte at offset 0x462.

I will certainly give that a try...

Dewet

Re: ext3 partition unmountable

[Dewet Diener]

On Sat, Aug 18, 2001 at 03:29:32PM -0700, Andrew Morton wrote:
> Somehow you seem to have set bit 16, which isn't defined.  Not sure how
> to fix this without simply running a binary editor against /dev/hdd1 and
> clearing the byte at offset 0x462.

Hi Andrew

I managed to fix it by running e2fsck off one of the backup 
superblocks - that seems to have repaired the broken bits:

000400 cc 5b 0e 00 de ab 1c 00 ff 6e 01 00 35 da 13 00
000410 1f 36 0e 00 00 00 00 00 02 00 00 00 02 00 00 00
000420 00 80 00 00 00 80 00 00 60 3f 00 00 df 05 7f 3b
000430 df 05 7f 3b 16 00 14 00 53 ef 01 00 01 00 00 00
000440 60 05 7f 3b ed 4e ed 00 00 00 00 00 01 00 00 00
000450 00 00 00 00 0b 00 00 00 80 00 00 00 04 00 00 00
000460 06 00 00 00 01 00 00 00 e8 08 28 0e 57 e9 42 00
000470 ff 7d fe 3d ec af 84 ef 00 00 00 00 00 00 00 00
000480 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Then I just reran "tune2fs -j", and mounted it as ext3.  I hope that
was the correct approach, but its working in any case :)  Don't quite
know why/how the superblock got corrupted like that in the first
place :-/

Regards,
Dewet

Re: ext3 partition unmountable

[Theodore Tso]

Andrew, for future reference, a much simpler way of debugging this
sort of problem (which doesn't require interpreting od -x dumps) is to
ask the user to use the command:

dumpe2fs -f -h /dev/hdd1

To clear the feature flag, you can use the debugfs program:

% debugfs
debugfs:  open -w -f /tmp/testfs
debugfs:  features   
Filesystem features: filetype FEATURE_I16 sparse_super
debugfs:  feature ^feature_i16
debugfs:  features
Filesystem features: filetype sparse_super
debugfs:  quit

> I managed to fix it by running e2fsck off one of the backup 
> superblocks - that seems to have repaired the broken bits:

> Then I just reran "tune2fs -j", and mounted it as ext3.  I hope that
> was the correct approach, but its working in any case :)  Don't quite
> know why/how the superblock got corrupted like that in the first
> place :-/

Well, sounds like the in-core copy of the superblock got corrupted
somehow, or perhaps a passing bit of cosmic radiation flipped the bit
as it was getting written back to disk.  If you can get it to do it
repeatably it, or if it even happens once or twice more, we'd
definitely want to know more about it.

							- Ted