ok guenther@ and deraadt@ missed in the commit msg. oops.
On Sat, Nov 17, 2012 at 4:08 PM, Bob Beck <b...@cvs.openbsd.org> wrote: > CVSROOT: /cvs > Module name: src > Changes by: b...@cvs.openbsd.org 2012/11/17 16:08:22 > > Modified files: > sys/sys : buf.h > sys/kern : vfs_subr.c vfs_biomem.c > > Log message: > Don't map a buffer (and potentially sleep) when invalidating it in vinvalbuf. > This fixes a problem where we could sleep for kva and then our pointers > would not be valid on the next pass through the loop. We do this > by adding buf_acquire_nomap() - which can be used to busy up the buffer > without changing its mapped or unmapped state. We do not need to have > the buffer mapped to invalidate it, so it is sufficient to acquire it > for that. In the case where we write the buffer, we do map the buffer, and > potentially sleep.
