static int osc_lock_unuse(const struct lu_env *env,
const struct cl_lock_slice *slice)
{
struct osc_lock *ols = cl2osc_lock(slice);
LINVRNT(osc_lock_invariant(ols));
switch (ols->ols_state) {
case OLS_NEW:
LASSERT(!ols->ols_hold);
LASSERT(ols->ols_agl);
return 0;
case OLS_UPCALL_RECEIVED:
osc_lock_unhold(ols);
case OLS_ENQUEUED:
LASSERT(!ols->ols_hold);
osc_lock_detach(env, ols);
ols->ols_state = OLS_NEW;
return 0;
case OLS_GRANTED:
LASSERT(!ols->ols_glimpse);
LASSERT(ols->ols_hold);
/*
* Move lock into OLS_RELEASED state before calling
* osc_cancel_base() so that possible synchronous cancellation
* (that always happens e.g., for liblustre) sees that lock is
* released.
*/
ols->ols_state = OLS_RELEASED;
return osc_lock_unhold(ols);
default:
CERROR("Impossible state: %d\n", ols->ols_state);
LBUG();
}
}
void osc_lock_fini(const struct lu_env *env, struct cl_lock_slice *slice)
{
struct osc_lock *ols = cl2osc_lock(slice);
LINVRNT(osc_lock_invariant(ols));
LASSERT(ols->ols_dlmlock == NULL);
OBD_SLAB_FREE_PTR(ols, osc_lock_kmem);
}
static void osc_lock_granted(const struct lu_env *env, struct osc_lock *oscl,
struct lustre_handle *lockh, bool lvb_update)
{
struct ldlm_lock *dlmlock;
dlmlock = ldlm_handle2lock_long(lockh, 0);
LASSERT(dlmlock);
/* lock reference taken by ldlm_handle2lock_long() is
* owned by osc_lock and released in osc_lock_detach()
*/
lu_ref_add(&dlmlock->l_reference, "osc_lock", oscl);
oscl->ols_has_ref = 1;
LASSERT(!oscl->ols_dlmlock);
oscl->ols_dlmlock = dlmlock;
/* This may be a matched lock for glimpse request, do not hold
* lock reference in that case.
*/
if (!oscl->ols_glimpse) {
/* hold a refc for non glimpse lock which will
* be released in osc_lock_cancel()
*/
lustre_handle_copy(&oscl->ols_handle, lockh);
ldlm_lock_addref(lockh, oscl->ols_einfo.ei_mode);
oscl->ols_hold = 1;
}
/* Lock must have been granted. */
lock_res_and_lock(dlmlock);
if (dlmlock->l_granted_mode == dlmlock->l_req_mode) {
struct ldlm_extent *ext = &dlmlock->l_policy_data.l_extent;
struct cl_lock_descr *descr = &oscl->ols_cl.cls_lock->cll_descr;
/* extend the lock extent, otherwise it will have problem when
* we decide whether to grant a lockless lock.
*/
descr->cld_mode = osc_ldlm2cl_lock(dlmlock->l_granted_mode);
descr->cld_start = cl_index(descr->cld_obj, ext->start);
descr->cld_end = cl_index(descr->cld_obj, ext->end);
descr->cld_gid = ext->gid;
/* no lvb update for matched lock */
if (lvb_update) {
LASSERT(oscl->ols_flags & LDLM_FL_LVB_READY);
osc_lock_lvb_update(env, cl2osc(oscl->ols_cl.cls_obj),
dlmlock, NULL);
}
LINVRNT(osc_lock_invariant(oscl));
}
unlock_res_and_lock(dlmlock);
LASSERT(oscl->ols_state != OLS_GRANTED);
oscl->ols_state = OLS_GRANTED;
}
static void osc_lock_fini(const struct lu_env *env,
struct cl_lock_slice *slice)
{
struct osc_lock *ols = cl2osc_lock(slice);
LINVRNT(osc_lock_invariant(ols));
LASSERT(!ols->ols_dlmlock);
kmem_cache_free(osc_lock_kmem, ols);
}
static void osc_lock_fini(const struct lu_env *env,
struct cl_lock_slice *slice)
{
struct osc_lock *ols = cl2osc_lock(slice);
LINVRNT(osc_lock_invariant(ols));
/*
* ->ols_hold can still be true at this point if, for example, a
* thread that requested a lock was killed (and released a reference
* to the lock), before reply from a server was received. In this case
* lock is destroyed immediately after upcall.
*/
osc_lock_unhold(ols);
LASSERT(ols->ols_lock == NULL);
LASSERT(atomic_read(&ols->ols_pageref) == 0 ||
atomic_read(&ols->ols_pageref) == _PAGEREF_MAGIC);
OBD_SLAB_FREE_PTR(ols, osc_lock_kmem);
}
/**
* Called when a lock is granted, from an upcall (when server returned a
* granted lock), or from completion AST, when server returned a blocked lock.
*
* Called under lock and resource spin-locks, that are released temporarily
* here.
*/
static void osc_lock_granted(const struct lu_env *env, struct osc_lock *olck,
struct ldlm_lock *dlmlock, int rc)
{
struct ldlm_extent *ext;
struct cl_lock *lock;
struct cl_lock_descr *descr;
LASSERT(dlmlock->l_granted_mode == dlmlock->l_req_mode);
ENTRY;
if (olck->ols_state < OLS_GRANTED) {
lock = olck->ols_cl.cls_lock;
ext = &dlmlock->l_policy_data.l_extent;
descr = &osc_env_info(env)->oti_descr;
descr->cld_obj = lock->cll_descr.cld_obj;
/* XXX check that ->l_granted_mode is valid. */
descr->cld_mode = osc_ldlm2cl_lock(dlmlock->l_granted_mode);
descr->cld_start = cl_index(descr->cld_obj, ext->start);
descr->cld_end = cl_index(descr->cld_obj, ext->end);
descr->cld_gid = ext->gid;
/*
* tell upper layers the extent of the lock that was actually
* granted
*/
olck->ols_state = OLS_GRANTED;
osc_lock_lvb_update(env, olck, rc);
/* release DLM spin-locks to allow cl_lock_{modify,signal}()
* to take a semaphore on a parent lock. This is safe, because
* spin-locks are needed to protect consistency of
* dlmlock->l_*_mode and LVB, and we have finished processing
* them. */
unlock_res_and_lock(dlmlock);
cl_lock_modify(env, lock, descr);
cl_lock_signal(env, lock);
LINVRNT(osc_lock_invariant(olck));
lock_res_and_lock(dlmlock);
}
EXIT;
}
/**
* Helper for osc_dlm_blocking_ast() handling discrepancies between cl_lock
* and ldlm_lock caches.
*/
static int osc_dlm_blocking_ast0(const struct lu_env *env,
struct ldlm_lock *dlmlock,
void *data, int flag)
{
struct osc_lock *olck;
struct cl_lock *lock;
int result;
int cancel;
LASSERT(flag == LDLM_CB_BLOCKING || flag == LDLM_CB_CANCELING);
cancel = 0;
olck = osc_ast_data_get(dlmlock);
if (olck != NULL) {
lock = olck->ols_cl.cls_lock;
cl_lock_mutex_get(env, lock);
LINVRNT(osc_lock_invariant(olck));
if (olck->ols_ast_wait) {
/* wake up osc_lock_use() */
cl_lock_signal(env, lock);
olck->ols_ast_wait = 0;
}
/*
* Lock might have been canceled while this thread was
* sleeping for lock mutex, but olck is pinned in memory.
*/
if (olck == dlmlock->l_ast_data) {
/*
* NOTE: DLM sends blocking AST's for failed locks
* (that are still in pre-OLS_GRANTED state)
* too, and they have to be canceled otherwise
* DLM lock is never destroyed and stuck in
* the memory.
*
* Alternatively, ldlm_cli_cancel() can be
* called here directly for osc_locks with
* ols_state < OLS_GRANTED to maintain an
* invariant that ->clo_cancel() is only called
* for locks that were granted.
*/
LASSERT(data == olck);
osc_lock_blocking(env, dlmlock,
olck, flag == LDLM_CB_BLOCKING);
} else
cancel = 1;
cl_lock_mutex_put(env, lock);
osc_ast_data_put(env, olck);
} else
/*
* DLM lock exists, but there is no cl_lock attached to it.
* This is a `normal' race. cl_object and its cl_lock's can be
* removed by memory pressure, together with all pages.
*/
cancel = (flag == LDLM_CB_BLOCKING);
if (cancel) {
struct lustre_handle *lockh;
lockh = &osc_env_info(env)->oti_handle;
ldlm_lock2handle(dlmlock, lockh);
result = ldlm_cli_cancel(lockh, LCF_ASYNC);
} else
result = 0;
return result;
}
