Commit 03339696 authored Dec 08, 2008 by David Teigland

dlm: remove extra blocking callback check



Just before delivering a blocking callback (bast), the dlm_astd
thread checks again that the granted mode of the lkb actually
blocks the mode requested by the bast.  The idea behind this was
originally that the granted mode may have changed since the bast
was queued, making the callback now unnecessary.  Reasons for
removing this extra check are:
- dlm_astd doesn't lock the rsb before reading the lkb grmode, so
  it's not technically safe (this removes the long standing FIXME)
- after running some tests, it doesn't appear the check ever actually
  eliminates a bast
- delivering an unnecessary blocking callback isn't a bad thing and
  can happen anyway

Signed-off-by: David Teigland <teigland@redhat.com>

parent d61e9aac

fs/dlm/ast.c

+1 −6

Original line number	Diff line number	Diff line
		@@ -89,12 +89,7 @@ static void process_asts(void)
		if ((type & AST_COMP) && cast)
		cast(lkb->lkb_astparam);

		/* FIXME: Is it safe to look at lkb_grmode here
		without doing a lock_rsb() ?
		Look at other checks in v1 to avoid basts. */

		if ((type & AST_BAST) && bast)
		if (!dlm_modes_compat(lkb->lkb_grmode, bmode))
		bast(lkb->lkb_astparam, bmode);

		/* this removes the reference added by dlm_add_ast

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