dlm: fix unlock balance warnings

The in_recovery rw_semaphore has always been acquired and
released by different threads by design.  To work around
the "BUG: bad unlock balance detected!" messages, adjust
things so the dlm_recoverd thread always does both down_write
and up_write.

Signed-off-by: David Teigland <teigland@redhat.com>
This commit is contained in:
David Teigland 2012-08-02 11:08:21 -05:00
Родитель 6ad2291624
Коммит 475f230c60
6 изменённых файлов: 78 добавлений и 30 удалений

Просмотреть файл

@ -604,6 +604,7 @@ struct dlm_ls {
struct idr ls_recover_idr;
spinlock_t ls_recover_idr_lock;
wait_queue_head_t ls_wait_general;
wait_queue_head_t ls_recover_lock_wait;
struct mutex ls_clear_proc_locks;
struct list_head ls_root_list; /* root resources */
@ -616,15 +617,40 @@ struct dlm_ls {
char ls_name[1];
};
#define LSFL_WORK 0
#define LSFL_RUNNING 1
#define LSFL_RECOVERY_STOP 2
#define LSFL_RCOM_READY 3
#define LSFL_RCOM_WAIT 4
#define LSFL_UEVENT_WAIT 5
#define LSFL_TIMEWARN 6
#define LSFL_CB_DELAY 7
#define LSFL_NODIR 8
/*
* LSFL_RECOVER_STOP - dlm_ls_stop() sets this to tell dlm recovery routines
* that they should abort what they're doing so new recovery can be started.
*
* LSFL_RECOVER_DOWN - dlm_ls_stop() sets this to tell dlm_recoverd that it
* should do down_write() on the in_recovery rw_semaphore. (doing down_write
* within dlm_ls_stop causes complaints about the lock acquired/released
* in different contexts.)
*
* LSFL_RECOVER_LOCK - dlm_recoverd holds the in_recovery rw_semaphore.
* It sets this after it is done with down_write() on the in_recovery
* rw_semaphore and clears it after it has released the rw_semaphore.
*
* LSFL_RECOVER_WORK - dlm_ls_start() sets this to tell dlm_recoverd that it
* should begin recovery of the lockspace.
*
* LSFL_RUNNING - set when normal locking activity is enabled.
* dlm_ls_stop() clears this to tell dlm locking routines that they should
* quit what they are doing so recovery can run. dlm_recoverd sets
* this after recovery is finished.
*/
#define LSFL_RECOVER_STOP 0
#define LSFL_RECOVER_DOWN 1
#define LSFL_RECOVER_LOCK 2
#define LSFL_RECOVER_WORK 3
#define LSFL_RUNNING 4
#define LSFL_RCOM_READY 5
#define LSFL_RCOM_WAIT 6
#define LSFL_UEVENT_WAIT 7
#define LSFL_TIMEWARN 8
#define LSFL_CB_DELAY 9
#define LSFL_NODIR 10
/* much of this is just saving user space pointers associated with the
lock that we pass back to the user lib with an ast */
@ -667,7 +693,7 @@ static inline int dlm_locking_stopped(struct dlm_ls *ls)
static inline int dlm_recovery_stopped(struct dlm_ls *ls)
{
return test_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
return test_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
}
static inline int dlm_no_directory(struct dlm_ls *ls)

Просмотреть файл

@ -582,8 +582,6 @@ static int new_lockspace(const char *name, const char *cluster,
INIT_LIST_HEAD(&ls->ls_root_list);
init_rwsem(&ls->ls_root_sem);
down_write(&ls->ls_in_recovery);
spin_lock(&lslist_lock);
ls->ls_create_count = 1;
list_add(&ls->ls_list, &lslist);
@ -597,13 +595,24 @@ static int new_lockspace(const char *name, const char *cluster,
}
}
/* needs to find ls in lslist */
init_waitqueue_head(&ls->ls_recover_lock_wait);
/*
* Once started, dlm_recoverd first looks for ls in lslist, then
* initializes ls_in_recovery as locked in "down" mode. We need
* to wait for the wakeup from dlm_recoverd because in_recovery
* has to start out in down mode.
*/
error = dlm_recoverd_start(ls);
if (error) {
log_error(ls, "can't start dlm_recoverd %d", error);
goto out_callback;
}
wait_event(ls->ls_recover_lock_wait,
test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags));
ls->ls_kobj.kset = dlm_kset;
error = kobject_init_and_add(&ls->ls_kobj, &dlm_ktype, NULL,
"%s", ls->ls_name);

Просмотреть файл

@ -616,13 +616,13 @@ int dlm_ls_stop(struct dlm_ls *ls)
down_write(&ls->ls_recv_active);
/*
* Abort any recovery that's in progress (see RECOVERY_STOP,
* Abort any recovery that's in progress (see RECOVER_STOP,
* dlm_recovery_stopped()) and tell any other threads running in the
* dlm to quit any processing (see RUNNING, dlm_locking_stopped()).
*/
spin_lock(&ls->ls_recover_lock);
set_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
set_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
new = test_and_clear_bit(LSFL_RUNNING, &ls->ls_flags);
ls->ls_recover_seq++;
spin_unlock(&ls->ls_recover_lock);
@ -642,12 +642,16 @@ int dlm_ls_stop(struct dlm_ls *ls)
* when recovery is complete.
*/
if (new)
down_write(&ls->ls_in_recovery);
if (new) {
set_bit(LSFL_RECOVER_DOWN, &ls->ls_flags);
wake_up_process(ls->ls_recoverd_task);
wait_event(ls->ls_recover_lock_wait,
test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags));
}
/*
* The recoverd suspend/resume makes sure that dlm_recoverd (if
* running) has noticed RECOVERY_STOP above and quit processing the
* running) has noticed RECOVER_STOP above and quit processing the
* previous recovery.
*/
@ -709,7 +713,8 @@ int dlm_ls_start(struct dlm_ls *ls)
kfree(rv_old);
}
dlm_recoverd_kick(ls);
set_bit(LSFL_RECOVER_WORK, &ls->ls_flags);
wake_up_process(ls->ls_recoverd_task);
return 0;
fail:

Просмотреть файл

@ -581,7 +581,7 @@ void dlm_receive_rcom(struct dlm_ls *ls, struct dlm_rcom *rc, int nodeid)
spin_lock(&ls->ls_recover_lock);
status = ls->ls_recover_status;
stop = test_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
stop = test_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
seq = ls->ls_recover_seq;
spin_unlock(&ls->ls_recover_lock);

Просмотреть файл

@ -41,6 +41,7 @@ static int enable_locking(struct dlm_ls *ls, uint64_t seq)
set_bit(LSFL_RUNNING, &ls->ls_flags);
/* unblocks processes waiting to enter the dlm */
up_write(&ls->ls_in_recovery);
clear_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
error = 0;
}
spin_unlock(&ls->ls_recover_lock);
@ -262,7 +263,7 @@ static void do_ls_recovery(struct dlm_ls *ls)
rv = ls->ls_recover_args;
ls->ls_recover_args = NULL;
if (rv && ls->ls_recover_seq == rv->seq)
clear_bit(LSFL_RECOVERY_STOP, &ls->ls_flags);
clear_bit(LSFL_RECOVER_STOP, &ls->ls_flags);
spin_unlock(&ls->ls_recover_lock);
if (rv) {
@ -282,26 +283,34 @@ static int dlm_recoverd(void *arg)
return -1;
}
down_write(&ls->ls_in_recovery);
set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
wake_up(&ls->ls_recover_lock_wait);
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
if (!test_bit(LSFL_WORK, &ls->ls_flags))
if (!test_bit(LSFL_RECOVER_WORK, &ls->ls_flags) &&
!test_bit(LSFL_RECOVER_DOWN, &ls->ls_flags))
schedule();
set_current_state(TASK_RUNNING);
if (test_and_clear_bit(LSFL_WORK, &ls->ls_flags))
if (test_and_clear_bit(LSFL_RECOVER_DOWN, &ls->ls_flags)) {
down_write(&ls->ls_in_recovery);
set_bit(LSFL_RECOVER_LOCK, &ls->ls_flags);
wake_up(&ls->ls_recover_lock_wait);
}
if (test_and_clear_bit(LSFL_RECOVER_WORK, &ls->ls_flags))
do_ls_recovery(ls);
}
if (test_bit(LSFL_RECOVER_LOCK, &ls->ls_flags))
up_write(&ls->ls_in_recovery);
dlm_put_lockspace(ls);
return 0;
}
void dlm_recoverd_kick(struct dlm_ls *ls)
{
set_bit(LSFL_WORK, &ls->ls_flags);
wake_up_process(ls->ls_recoverd_task);
}
int dlm_recoverd_start(struct dlm_ls *ls)
{
struct task_struct *p;

Просмотреть файл

@ -14,7 +14,6 @@
#ifndef __RECOVERD_DOT_H__
#define __RECOVERD_DOT_H__
void dlm_recoverd_kick(struct dlm_ls *ls);
void dlm_recoverd_stop(struct dlm_ls *ls);
int dlm_recoverd_start(struct dlm_ls *ls);
void dlm_recoverd_suspend(struct dlm_ls *ls);