MFC r262814

- If we fail to do a non-blocking acquire of a buf lock while doing a
  waiting sync pass we need to do a blocking acquire and restart.
  Another thread, typically the buf daemon, may have this buf locked and
  if we don't wait we can fail to sync the file.  This lead to a great
  variety of softdep panics because we rely on all dependencies being
  flushed before proceeding in several cases.

Submitted by:	jeffr

0 files changed, 0 insertions, 0 deletions