On Fri, Oct 26, 2012 at 09:37:08PM +0100, Nix wrote: > > I can reproduce this on a small filesystem and stick the image somewhere > if that would be of any use to anyone. (If I'm very lucky, merely making > this offer will make the problem go away. :} ) I'm not sure the image is going to be that useful. What we really need to do is to get a reliable reproduction of what _you_ are seeing. It's clear from Eric's experiments that journal_checksum is dangerous. In fact, I will likely put it under an #ifdef EXT4_EXPERIMENTAL to try to discourage people from using it in the future. There are things I've been planning on doing to make it be safer, but there's a very good *reason* that both journal_checksum and journal_async_commit are not on by default. That's why one of the things I asked you to do when you had time was to see if you could reproduce the problem you are seeing w/o nobarrier,journal_checksum,journal_async_commit. The other experiment that would be really useful if you could do is to try to apply these two patches which I sent earlier this week: [PATCH 1/2] ext4: revert "jbd2: don't write superblock when if its empty [PATCH 2/2] ext4: fix I/O error when unmounting an ro file system ... and see if they make a difference. If they don't make a difference, I don't want to apply patches just for placebo/PR reasons. And for Eric at least, he can reproduce the journal checksum error followed by fairly significant corruption reported by e2fsck with journal_checksum, and the presence or absense of these patches make no difference for him. So I really don't want to push these patches to Linus until I get confirmation that they make a difference to *somebody*. Regards, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html