kern/77234: [udf] [patch] corrupted data is read from UDF filesystem if read starts at non-aligned offset

[Bruce Evans]

On Sun, 11 Mar 2007, Kris Kennaway wrote:

> FYI I dunno about this particular problem but UDF is indeed full of
> bugs.  I tried to get Scott (original author) to look at some problems
> last year but he didnt get back to it.

I tried the same (with patches similar to the ones in this PR) the
year before last.  Then I lost interest in udf since it works worse
than cd9660 for my only application of backing up ffs file systems a
file at a time, and I don't have time to fix this.  (Sequential media
like DVDs needs large non-vnode-based read-ahead unless the drive does
it, but FreeBSD only does vnode-based read ahead.  This loses especially
for metadata.  cd9660 metadata is smaller and more packed than udf
metadata, so cd9660 loses less than udf from this.)

Bruce