diff options
Diffstat (limited to 'fs/dlm/ast.c')
| -rw-r--r-- | fs/dlm/ast.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c new file mode 100644 index 000000000000..f91d39cb1e0b --- /dev/null +++ b/fs/dlm/ast.c @@ -0,0 +1,173 @@ +/****************************************************************************** +******************************************************************************* +** +** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. +** Copyright (C) 2004-2005 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 +** of the GNU General Public License v.2. +** +******************************************************************************* +******************************************************************************/ + +#include "dlm_internal.h" +#include "lock.h" +#include "user.h" + +#define WAKE_ASTS 0 + +static struct list_head ast_queue; +static spinlock_t ast_queue_lock; +static struct task_struct * astd_task; +static unsigned long astd_wakeflags; +static struct mutex astd_running; + + +void dlm_del_ast(struct dlm_lkb *lkb) +{ + spin_lock(&ast_queue_lock); + if (lkb->lkb_ast_type & (AST_COMP | AST_BAST)) + list_del(&lkb->lkb_astqueue); + spin_unlock(&ast_queue_lock); +} + +void dlm_add_ast(struct dlm_lkb *lkb, int type) +{ + if (lkb->lkb_flags & DLM_IFL_USER) { + dlm_user_add_ast(lkb, type); + return; + } + DLM_ASSERT(lkb->lkb_astaddr != DLM_FAKE_USER_AST, dlm_print_lkb(lkb);); + + spin_lock(&ast_queue_lock); + 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_type |= type; + spin_unlock(&ast_queue_lock); + + set_bit(WAKE_ASTS, &astd_wakeflags); + wake_up_process(astd_task); +} + +static void process_asts(void) +{ + struct dlm_ls *ls = NULL; + struct dlm_rsb *r = NULL; + struct dlm_lkb *lkb; + void (*cast) (long param); + void (*bast) (long param, 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; + } + spin_unlock(&ast_queue_lock); + + if (!found) + break; + + cast = lkb->lkb_astaddr; + bast = lkb->lkb_bastaddr; + bmode = lkb->lkb_bastmode; + + 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 + and may result in the lkb being freed */ + dlm_put_lkb(lkb); + + schedule(); + } +} + +static inline int no_asts(void) +{ + int ret; + + spin_lock(&ast_queue_lock); + ret = list_empty(&ast_queue); + spin_unlock(&ast_queue_lock); + return ret; +} + +static int dlm_astd(void *data) +{ + while (!kthread_should_stop()) { + set_current_state(TASK_INTERRUPTIBLE); + if (!test_bit(WAKE_ASTS, &astd_wakeflags)) + schedule(); + set_current_state(TASK_RUNNING); + + mutex_lock(&astd_running); + if (test_and_clear_bit(WAKE_ASTS, &astd_wakeflags)) + process_asts(); + mutex_unlock(&astd_running); + } + return 0; +} + +void dlm_astd_wake(void) +{ + if (!no_asts()) { + set_bit(WAKE_ASTS, &astd_wakeflags); + wake_up_process(astd_task); + } +} + +int dlm_astd_start(void) +{ + struct task_struct *p; + int error = 0; + + INIT_LIST_HEAD(&ast_queue); + spin_lock_init(&ast_queue_lock); + mutex_init(&astd_running); + + p = kthread_run(dlm_astd, NULL, "dlm_astd"); + if (IS_ERR(p)) + error = PTR_ERR(p); + else + astd_task = p; + return error; +} + +void dlm_astd_stop(void) +{ + kthread_stop(astd_task); +} + +void dlm_astd_suspend(void) +{ + mutex_lock(&astd_running); +} + +void dlm_astd_resume(void) +{ + mutex_unlock(&astd_running); +} + |