Re: loop device broken in 2.4.6-pre5

Rogier Wolff (R.E.Wolff@BitWizard.nl)
Mon, 25 Jun 2001 18:31:07 +0200 (MEST)


Andries.Brouwer@cwi.nl wrote:
> From: Jari Ruusu <jari.ruusu@pp.inet.fi>
>
> File backed loop device on 4k block size ext2 filesystem:
>
> # dd if=/dev/zero of=file1 bs=1024 count=10
> 10+0 records in
> 10+0 records out
> # losetup /dev/loop0 file1
> # dd if=/dev/zero of=/dev/loop0 bs=1024 count=10 conv=notrunc
> dd: /dev/loop0: No space left on device
> 9+0 records in
> 8+0 records out
> # tune2fs -l /dev/hda1 2>&1| grep "Block size"
> Block size: 4096
> # uname -a
> Linux debian 2.4.6-pre5 #1 Thu Jun 21 14:27:25 EEST 2001 i686 unknown
>
> Stock 2.4.5 and 2.4.5-ac15 don't have this problem.
>
> I am not sure there is an error here.

How about:

dd if=/dev/hda1 of=disk.img bs=1k
mount disk.img /mnt/d1 -o loop

If the filesystem on hda1 happens to use the last 2k of the partition,
and the partition size is 2k mod 4k, then I get a non-working disk.img
if I don't pad the disk.img file with another 2k. And then I might
trip up the "how big is this partition" code in the fs-driver....

Roger.

-- 
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 **
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