*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
-** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
+** Copyright (C) 2004-2010 Red Hat, Inc. All rights reserved.
**
** This copyrighted material is made available to anyone wishing to use,
** modify, copy, or redistribute it subject to the terms and conditions
spin_unlock(&ast_queue_lock);
}
-void dlm_add_ast(struct dlm_lkb *lkb, int type)
+void dlm_add_ast(struct dlm_lkb *lkb, int type, int mode)
{
if (lkb->lkb_flags & DLM_IFL_USER) {
- dlm_user_add_ast(lkb, type);
+ dlm_user_add_ast(lkb, type, mode);
return;
}
if (!(lkb->lkb_ast_type & (AST_COMP | AST_BAST))) {
kref_get(&lkb->lkb_ref);
list_add_tail(&lkb->lkb_astqueue, &ast_queue);
+ lkb->lkb_ast_first = type;
}
+
+ /* sanity check, this should not happen */
+
+ if ((type == AST_COMP) && (lkb->lkb_ast_type & AST_COMP))
+ log_print("repeat cast %d castmode %d lock %x %s",
+ mode, lkb->lkb_castmode,
+ lkb->lkb_id, lkb->lkb_resource->res_name);
+
lkb->lkb_ast_type |= type;
+ if (type == AST_BAST)
+ lkb->lkb_bastmode = mode;
+ else
+ lkb->lkb_castmode = mode;
spin_unlock(&ast_queue_lock);
set_bit(WAKE_ASTS, &astd_wakeflags);
struct dlm_ls *ls = NULL;
struct dlm_rsb *r = NULL;
struct dlm_lkb *lkb;
- void (*cast) (void *astparam);
- void (*bast) (void *astparam, int mode);
- int type = 0, found, bmode;
-
- for (;;) {
- found = 0;
- spin_lock(&ast_queue_lock);
- list_for_each_entry(lkb, &ast_queue, lkb_astqueue) {
- r = lkb->lkb_resource;
- ls = r->res_ls;
-
- if (dlm_locking_stopped(ls))
- continue;
-
- list_del(&lkb->lkb_astqueue);
- type = lkb->lkb_ast_type;
- lkb->lkb_ast_type = 0;
- found = 1;
- break;
- }
+ void (*castfn) (void *astparam);
+ void (*bastfn) (void *astparam, int mode);
+ int type, first, bastmode, castmode, do_bast, do_cast, last_castmode;
+
+repeat:
+ spin_lock(&ast_queue_lock);
+ list_for_each_entry(lkb, &ast_queue, lkb_astqueue) {
+ r = lkb->lkb_resource;
+ ls = r->res_ls;
+
+ if (dlm_locking_stopped(ls))
+ continue;
+
+ list_del(&lkb->lkb_astqueue);
+ type = lkb->lkb_ast_type;
+ lkb->lkb_ast_type = 0;
+ first = lkb->lkb_ast_first;
+ lkb->lkb_ast_first = 0;
+ bastmode = lkb->lkb_bastmode;
+ castmode = lkb->lkb_castmode;
+ castfn = lkb->lkb_astfn;
+ bastfn = lkb->lkb_bastfn;
spin_unlock(&ast_queue_lock);
- if (!found)
- break;
+ do_cast = (type & AST_COMP) && castfn;
+ do_bast = (type & AST_BAST) && bastfn;
- cast = lkb->lkb_astfn;
- bast = lkb->lkb_bastfn;
- bmode = lkb->lkb_bastmode;
+ /* Skip a bast if its blocking mode is compatible with the
+ granted mode of the preceding cast. */
- if ((type & AST_COMP) && cast)
- cast(lkb->lkb_astparam);
+ if (do_bast) {
+ if (first == AST_COMP)
+ last_castmode = castmode;
+ else
+ last_castmode = lkb->lkb_castmode_done;
+ if (dlm_modes_compat(bastmode, last_castmode))
+ do_bast = 0;
+ }
- /* 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 (first == AST_COMP) {
+ if (do_cast)
+ castfn(lkb->lkb_astparam);
+ if (do_bast)
+ bastfn(lkb->lkb_astparam, bastmode);
+ } else if (first == AST_BAST) {
+ if (do_bast)
+ bastfn(lkb->lkb_astparam, bastmode);
+ if (do_cast)
+ castfn(lkb->lkb_astparam);
+ } else {
+ log_error(ls, "bad ast_first %d ast_type %d",
+ first, type);
+ }
- if ((type & AST_BAST) && bast)
- if (!dlm_modes_compat(lkb->lkb_grmode, bmode))
- bast(lkb->lkb_astparam, bmode);
+ if (do_cast)
+ lkb->lkb_castmode_done = castmode;
+ if (do_bast)
+ lkb->lkb_bastmode_done = bastmode;
/* this removes the reference added by dlm_add_ast
and may result in the lkb being freed */
dlm_put_lkb(lkb);
- schedule();
+ cond_resched();
+ goto repeat;
}
+ spin_unlock(&ast_queue_lock);
}
static inline int no_asts(void)