Re: 2.4.19-rc1,2 + ext3 data=journal: data loss on unmount

[Nick Piggin]

Alan Cox wrote:

>On Thu, 2002-07-18 at 07:12, Piggin, Nick wrote:
>
>>mount /mnt/backup
>>tar cvf $FILENAME directory
>>bzip2 $FILENAME
>>umount /mnt/backup
>>
>>Upon remounting and inspection, the resulting bzip2 file is corrupted every
>>time. Adding a sync after bzip2 corrects the problem.
>>
>
>That sounds like a bug in the core code somewhere since the flush should
>have happened automatically on umount. Does 2.4.19 proper show this on
>your box (or 2.4.20-rc) ? [I'd suspect yes but would like to be sure]
>
>
2.4.20 does indeed show this bug. The following script will trigger it:

#!/bin/sh
mount /mnt/backup
dd if=/dev/urandom of=/mnt/backup/test.bin bs=1024 count=512
bzip2 /mnt/backup/test.bin
umount /mnt/backup

After running:
mount /mnt/backup
bunzip2 /mnt/backup/test.bin.bz2
bunzip2: x is not a bzip2 file.

The file is filled mostly with zeros

Nick