int
osd_register(u_int type, osd_destructor_t destructor, osd_method_t *methods)
{
void *newptr;
u_int i, m;
KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
/*
* If no destructor is given, use default one. We need to use some
* destructor, because NULL destructor means unused slot.
*/
if (destructor == NULL)
destructor = osd_default_destructor;
sx_xlock(&osd_module_lock[type]);
/*
* First, we try to find unused slot.
*/
for (i = 0; i < osd_nslots[type]; i++) {
if (osd_destructors[type][i] == NULL) {
OSD_DEBUG("Unused slot found (type=%u, slot=%u).",
type, i);
break;
}
}
/*
* If no unused slot was found, allocate one.
*/
if (i == osd_nslots[type]) {
osd_nslots[type]++;
if (osd_nmethods[type] != 0)
osd_methods[type] = realloc(osd_methods[type],
sizeof(osd_method_t) * osd_nslots[type] *
osd_nmethods[type], M_OSD, M_WAITOK);
newptr = malloc(sizeof(osd_destructor_t) * osd_nslots[type],
M_OSD, M_WAITOK);
rm_wlock(&osd_object_lock[type]);
bcopy(osd_destructors[type], newptr,
sizeof(osd_destructor_t) * i);
free(osd_destructors[type], M_OSD);
osd_destructors[type] = newptr;
rm_wunlock(&osd_object_lock[type]);
OSD_DEBUG("New slot allocated (type=%u, slot=%u).",
type, i + 1);
}
osd_destructors[type][i] = destructor;
if (osd_nmethods[type] != 0) {
for (m = 0; m < osd_nmethods[type]; m++)
osd_methods[type][i * osd_nmethods[type] + m] =
methods != NULL ? methods[m] : NULL;
}
sx_xunlock(&osd_module_lock[type]);
return (i + 1);
}
void
osd_deregister(u_int type, u_int slot)
{
struct osd *osd, *tosd;
KASSERT(type >= OSD_FIRST && type <= OSD_LAST, ("Invalid type."));
KASSERT(slot > 0, ("Invalid slot."));
KASSERT(osd_destructors[type][slot - 1] != NULL, ("Unused slot."));
sx_xlock(&osd_module_lock[type]);
rm_wlock(&osd_object_lock[type]);
/*
* Free all OSD for the given slot.
*/
mtx_lock(&osd_list_lock[type]);
LIST_FOREACH_SAFE(osd, &osd_list[type], osd_next, tosd)
do_osd_del(type, osd, slot, 1);
mtx_unlock(&osd_list_lock[type]);
/*
* Set destructor to NULL to free the slot.
*/
osd_destructors[type][slot - 1] = NULL;
if (slot == osd_nslots[type]) {
osd_nslots[type]--;
osd_destructors[type] = realloc(osd_destructors[type],
sizeof(osd_destructor_t) * osd_nslots[type], M_OSD,
M_NOWAIT | M_ZERO);
if (osd_nmethods[type] != 0)
osd_methods[type] = realloc(osd_methods[type],
sizeof(osd_method_t) * osd_nslots[type] *
osd_nmethods[type], M_OSD, M_NOWAIT | M_ZERO);
/*
* We always reallocate to smaller size, so we assume it will
* always succeed.
*/
KASSERT(osd_destructors[type] != NULL &&
(osd_nmethods[type] == 0 || osd_methods[type] != NULL),
("realloc() failed"));
OSD_DEBUG("Deregistration of the last slot (type=%u, slot=%u).",
type, slot);
} else {
OSD_DEBUG("Slot deregistration (type=%u, slot=%u).",
type, slot);
}
rm_wunlock(&osd_object_lock[type]);
sx_xunlock(&osd_module_lock[type]);
}
static uintptr_t
unlock_rm(struct lock_object *lock)
{
struct thread *td;
struct pcpu *pc;
struct rmlock *rm;
struct rm_queue *queue;
struct rm_priotracker *tracker;
uintptr_t how;
rm = (struct rmlock *)lock;
tracker = NULL;
how = 0;
rm_assert(rm, RA_LOCKED | RA_NOTRECURSED);
if (rm_wowned(rm))
rm_wunlock(rm);
else {
/*
* Find the right rm_priotracker structure for curthread.
* The guarantee about its uniqueness is given by the fact
* we already asserted the lock wasn't recursively acquired.
*/
critical_enter();
td = curthread;
pc = pcpu_find(curcpu);
for (queue = pc->pc_rm_queue.rmq_next;
queue != &pc->pc_rm_queue; queue = queue->rmq_next) {
tracker = (struct rm_priotracker *)queue;
if ((tracker->rmp_rmlock == rm) &&
(tracker->rmp_thread == td)) {
how = (uintptr_t)tracker;
break;
}
}
KASSERT(tracker != NULL,
("rm_priotracker is non-NULL when lock held in read mode"));
critical_exit();
rm_runlock(rm, tracker);
}
return (how);
}
