Re: WAPBL and backwards compatibility

[David Holland <dholland-tech%netbsd.org@localhost>]

On Fri, Aug 01, 2008 at 05:22:09PM +1000, Simon Burge wrote:
 >  - WAPBL has relaxed ordering constraints, since it knows it can replay
 >    the journal if there is a crash.  I'm not sure if in practice this
 >    can cause the filesystem to get into a state where a non-WAPBL-aware
 >    fsck_ffs can get too confused, and am also not too sure how to verify
 >    if this is really an issue.

It is quite likely that such states exist. There are definitely states
that will cause fsck -p to fail.

In general it'll be like trying to fsck after crashing with -o async,
that is, sometimes it will work but more often fsck will get
hopelessly lost.

-- 
David A. Holland
dholland%netbsd.org@localhost