Re: netbsd-5: panic: ureadc: non-positive resid

[Matthew Mondor <mm_lists%pulsar-zone.net@localhost>]

On Sun, 11 Oct 2009 18:24:24 +0100
David Laight <david%l8s.co.uk@localhost> wrote:

> Fixed in rev 1.234 of kern/tty.c
> I'll request a pullup for 5.1.

Thanks a lot :)

As a side note, since this panic occurred a few times unexpectedly
before I could investigate and isolate it to readv related tests (and
stop running the application causing it), several file corruption
problems occurred, using WAPBL.

Any very recently written file would have some unrelated data (which
seems to also be related to the application or another block recently
written by another application).  For instance, claws-mail's
folderlist.xml was filled with binary data (some packed message summary
block unrelated to that file), and had to be restored from a backup,
causing for instance loss of the state of recently read/tagged messages
(or possibly this state loss might even be related to other similar
corrupted files).

In another instance panic.c (my test code) was also corrupted with some
binary data originating from another unrelated write.

This suggests that after WAPBL replay a metadata reference might exist
for a block which shouldn't be kept, or that it referenced to a wrong
block...  I'm not familiar with FFS or WAPBL enough to really know
what's going on without further investigation.

Thanks again,
-- 
Matt