/*
* Low level device-layer operations.
*/
static struct dm_task *_setup_task(const char *name, const char *uuid,
uint32_t *event_nr, int task,
uint32_t major, uint32_t minor)
{
struct dm_task *dmt;
if (!(dmt = dm_task_create(task)))
return_NULL;
if (name)
dm_task_set_name(dmt, name);
if (uuid && *uuid)
dm_task_set_uuid(dmt, uuid);
if (event_nr)
dm_task_set_event_nr(dmt, *event_nr);
if (major)
dm_task_set_major_minor(dmt, major, minor, 1);
return dmt;
}
/*
* returns the reschedule delay
* negative means *stop*
*/
int waiteventloop (struct event_thread *waiter)
{
sigset_t set;
int event_nr;
int r;
if (!waiter->event_nr)
waiter->event_nr = dm_geteventnr(waiter->mapname);
if (!(waiter->dmt = dm_task_create(DM_DEVICE_WAITEVENT))) {
condlog(0, "%s: devmap event #%i dm_task_create error",
waiter->mapname, waiter->event_nr);
return 1;
}
if (!dm_task_set_name(waiter->dmt, waiter->mapname)) {
condlog(0, "%s: devmap event #%i dm_task_set_name error",
waiter->mapname, waiter->event_nr);
dm_task_destroy(waiter->dmt);
return 1;
}
if (waiter->event_nr && !dm_task_set_event_nr(waiter->dmt,
waiter->event_nr)) {
condlog(0, "%s: devmap event #%i dm_task_set_event_nr error",
waiter->mapname, waiter->event_nr);
dm_task_destroy(waiter->dmt);
return 1;
}
dm_task_no_open_count(waiter->dmt);
/* accept wait interruption */
set = unblock_signals();
/* wait */
r = dm_task_run(waiter->dmt);
/* wait is over : event or interrupt */
pthread_sigmask(SIG_SETMASK, &set, NULL);
if (!r) /* wait interrupted by signal */
return -1;
dm_task_destroy(waiter->dmt);
waiter->dmt = NULL;
waiter->event_nr++;
/*
* upon event ...
*/
while (1) {
condlog(3, "%s: devmap event #%i",
waiter->mapname, waiter->event_nr);
/*
* event might be :
*
* 1) a table reload, which means our mpp structure is
* obsolete : refresh it through update_multipath()
* 2) a path failed by DM : mark as such through
* update_multipath()
* 3) map has gone away : stop the thread.
* 4) a path reinstate : nothing to do
* 5) a switch group : nothing to do
*/
pthread_cleanup_push(cleanup_lock, &waiter->vecs->lock);
lock(waiter->vecs->lock);
r = update_multipath(waiter->vecs, waiter->mapname);
lock_cleanup_pop(waiter->vecs->lock);
if (r) {
condlog(2, "%s: event checker exit",
waiter->mapname);
return -1; /* stop the thread */
}
event_nr = dm_geteventnr(waiter->mapname);
if (waiter->event_nr == event_nr)
return 1; /* upon problem reschedule 1s later */
waiter->event_nr = event_nr;
}
return -1; /* never reach there */
}