Re: 1352 NUL bytes at the end of a page? (was Re: Assertion `s && s->tree' failed: The saga continues.)

Steven Cole
2004-05-17T15:49:59Z

On May 17, 2004, at 9:23 AM, Chris Mason wrote:

> On Mon, 2004-05-17 at 11:02, Linus Torvalds wrote:
>> Of course, my theory also depended on a page unlock happening in a
>> place
>> where it didn't actually happen, so the exact details of my theory are
>> crap. I'll need to re-think that part.
>
> You've described it correctly for reiserfs though, we unlock the page
> too soon. I'll fix the page locking for reiserfs_file_write. Steven,
> we need to figure out why you're seeing this on ext3.

I'll have to wait until tonight since I've only been able to trigger
this
using dialup, and I don't have that here at work. The failures were
only
seen with PREEMPT of course, and very early in the testing I ran the
test on ext3 too, to exonerate reiserfs as a primary cause. However, I
did not examine or preserve the RESYNC/SCCS/s.ChangeSet file on ext3
since I didn't know what the issues were at that early stage of testing.
So, I don't really know any details of the failure on ext3, apart from
the most superficial symptoms.

>
> The two filesystems don't share much code for the normal write path,
> and
> I don't see how you can trigger this on ext3 without truncate jumping
> into the fun.
>
> -chris

The "Assertion `s && s->tree' failed" happened fairly quickly (on the
3rd bk pull) on reiserfs with PREEMPT enabled. I'll let you know
how ext3 behaves later tonight.

Steven