On Thu, Oct 14, 2010 at 12:22:50PM -0500, Alex Elder wrote: > On Mon, 2010-10-04 at 21:13 +1100, Dave Chinner wrote: > > diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c > > index b7bdc43..0c8eeba 100644 > > --- a/fs/xfs/xfs_vnodeops.c > > +++ b/fs/xfs/xfs_vnodeops.c > > OK, this comment is unrelated to your exact change. But just above > the next hunk there's a big nasty condition, which appears to > be *almost* duplicated in xfs_inactive() (twice!). It would be > very nice if, while you're at modifying this nearby code, you > could encapsulate that condition in a macro that has a meaningful > name. I've looked at doing this factoring before, but the conditions are subtly different and hence cannot be factored into a single macro. The xfs_inactive case can be cleaned up (i've got old patches around that do half the job, IIRC), but the tests in the two functions are not the same. > > @@ -979,14 +979,27 @@ xfs_release( > > * chance to drop them once the last reference to > > * the inode is dropped, so we'll never leak blocks > > * permanently. > > I'm curious what the effect is if we simply don't do the truncate > *except* when the inode becomes inactive. It means we hang onto > the stuff for a while longer, and maybe it makes things messier > in the event of a crash. It doesn't change a thing in the event of a crash - speculative preallocation is entirely in-memory state. > Can you tell me why we do the truncate > here as well as in xfs_inactive() (or what the problem is of > *not* doing it here)? the truncation in ->release is not guaranteed to succeed - it uses trylock semantics to avoid blocking unnecessarily. It can do this because we know that when xfs_inactive() is called, the truncation will happen for real. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
