#include "ldlm_internal.h"
#ifdef HAVE_SERVER_SUPPORT
+
+/**
+ * It should iterate through all waiting locks on a given resource queue and
+ * attempt to grant them. An optimization is to check only heads waitintg
+ * locks for each inodebit type.
+ *
+ * Must be called with resource lock held.
+ */
+int ldlm_reprocess_inodebits_queue(struct ldlm_resource *res,
+ struct list_head *queue,
+ struct list_head *work_list,
+ enum ldlm_process_intention intention,
+ struct ldlm_lock *hint)
+{
+ __u64 flags;
+ int rc = LDLM_ITER_CONTINUE;
+ enum ldlm_error err;
+ LIST_HEAD(bl_ast_list);
+ struct ldlm_ibits_queues *queues = res->lr_ibits_queues;
+ int i;
+
+ ENTRY;
+
+ check_res_locked(res);
+
+ LASSERT(res->lr_type == LDLM_IBITS);
+ LASSERT(intention == LDLM_PROCESS_RESCAN ||
+ intention == LDLM_PROCESS_RECOVERY);
+
+ if (intention == LDLM_PROCESS_RECOVERY)
+ return ldlm_reprocess_queue(res, queue, work_list, intention,
+ NULL);
+
+restart:
+ CDEBUG(D_DLMTRACE, "--- Reprocess resource "DLDLMRES" (%p)\n",
+ PLDLMRES(res), res);
+
+ for (i = 0; i < MDS_INODELOCK_NUMBITS; i++) {
+ LIST_HEAD(rpc_list);
+ struct list_head *head = &queues->liq_waiting[i];
+ struct ldlm_lock *pending;
+ struct ldlm_ibits_node *node;
+
+ if (list_empty(head))
+ continue;
+ if (hint && !(hint->l_policy_data.l_inodebits.bits & (1 << i)))
+ continue;
+
+ node = list_entry(head->next, struct ldlm_ibits_node,
+ lin_link[i]);
+
+ pending = node->lock;
+ LDLM_DEBUG(pending, "Reprocessing lock from queue %d", i);
+
+ flags = 0;
+ rc = ldlm_process_inodebits_lock(pending, &flags, intention,
+ &err, &rpc_list);
+ if (ldlm_is_granted(pending)) {
+ list_splice(&rpc_list, work_list);
+ /* Try to grant more locks from current queue */
+ i--;
+ } else {
+ list_splice(&rpc_list, &bl_ast_list);
+ }
+ }
+
+ if (!list_empty(&bl_ast_list)) {
+ unlock_res(res);
+
+ rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &bl_ast_list,
+ LDLM_WORK_BL_AST);
+
+ lock_res(res);
+ if (rc == -ERESTART)
+ GOTO(restart, rc);
+ }
+
+ if (!list_empty(&bl_ast_list))
+ ldlm_discard_bl_list(&bl_ast_list);
+
+ RETURN(rc);
+}
+
/**
* Determine if the lock is compatible with all locks on the queue.
*
ENTRY;
- LASSERT(lock->l_granted_mode != lock->l_req_mode);
+ LASSERT(!ldlm_is_granted(lock));
check_res_locked(res);
if (intention == LDLM_PROCESS_RESCAN) {
- *err = ELDLM_LOCK_ABORTED;
+ struct list_head *bl_list;
+
+ if (*flags & LDLM_FL_BLOCK_NOWAIT) {
+ bl_list = NULL;
+ *err = ELDLM_LOCK_WOULDBLOCK;
+ } else {
+ bl_list = work_list;
+ *err = ELDLM_LOCK_ABORTED;
+ }
LASSERT(lock->l_policy_data.l_inodebits.bits != 0);
- rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, NULL);
+ /* It is possible that some of granted locks was not canceled
+ * but converted and is kept in granted queue. So there is
+ * a window where lock with 'ast_sent' might become granted
+ * again. Meanwhile a new lock may appear in that window and
+ * conflicts with the converted lock so the following scenario
+ * is possible:
+ *
+ * 1) lock1 conflicts with lock2
+ * 2) bl_ast was sent for lock2
+ * 3) lock3 comes and conflicts with lock2 too
+ * 4) no bl_ast sent because lock2->l_bl_ast_sent is 1
+ * 5) lock2 was converted for lock1 but not for lock3
+ * 6) lock1 granted, lock3 still is waiting for lock2, but
+ * there will never be another bl_ast for that
+ *
+ * To avoid this scenario the work_list is used below to collect
+ * any blocked locks from granted queue during every reprocess
+ * and bl_ast will be sent if needed.
+ */
+ rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock,
+ bl_list);
if (!rc)
RETURN(LDLM_ITER_STOP);
rc = ldlm_inodebits_compat_queue(&res->lr_waiting, lock, NULL);
union ldlm_policy_data *lpolicy)
{
lpolicy->l_inodebits.bits = wpolicy->l_inodebits.bits;
- lpolicy->l_inodebits.try_bits = wpolicy->l_inodebits.try_bits;
+ /**
+ * try_bits are to be handled outside of generic write_to_local due
+ * to different behavior on a server and client.
+ */
}
void ldlm_ibits_policy_local_to_wire(const union ldlm_policy_data *lpolicy,
wpolicy->l_inodebits.try_bits = lpolicy->l_inodebits.try_bits;
}
-int ldlm_inodebits_drop(struct ldlm_lock *lock, __u64 to_drop)
+/**
+ * Attempt to convert already granted IBITS lock with several bits set to
+ * a lock with less bits (downgrade).
+ *
+ * Such lock conversion is used to keep lock with non-blocking bits instead of
+ * cancelling it, introduced for better support of DoM files.
+ */
+int ldlm_inodebits_drop(struct ldlm_lock *lock, __u64 to_drop)
{
ENTRY;
/* Just return if there are no conflicting bits */
if ((lock->l_policy_data.l_inodebits.bits & to_drop) == 0) {
- LDLM_WARN(lock, "try to drop unset bits %#llx/%#llx\n",
+ LDLM_WARN(lock, "try to drop unset bits %#llx/%#llx",
lock->l_policy_data.l_inodebits.bits, to_drop);
/* nothing to do */
RETURN(0);
RETURN(0);
}
EXPORT_SYMBOL(ldlm_inodebits_drop);
+
+/* convert single lock */
+int ldlm_cli_inodebits_convert(struct ldlm_lock *lock,
+ enum ldlm_cancel_flags cancel_flags)
+{
+ struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
+ struct ldlm_lock_desc ld = { { 0 } };
+ __u64 drop_bits, new_bits;
+ __u32 flags = 0;
+ int rc;
+
+ ENTRY;
+
+ check_res_locked(lock->l_resource);
+
+ /* Lock is being converted already */
+ if (ldlm_is_converting(lock)) {
+ if (!(cancel_flags & LCF_ASYNC)) {
+ unlock_res_and_lock(lock);
+ wait_event_idle(lock->l_waitq,
+ is_lock_converted(lock));
+ lock_res_and_lock(lock);
+ }
+ RETURN(0);
+ }
+
+ /* lru_cancel may happen in parallel and call ldlm_cli_cancel_list()
+ * independently.
+ */
+ if (ldlm_is_canceling(lock))
+ RETURN(-EINVAL);
+
+ /* no need in only local convert */
+ if (lock->l_flags & (LDLM_FL_LOCAL_ONLY | LDLM_FL_CANCEL_ON_BLOCK))
+ RETURN(-EINVAL);
+
+ drop_bits = lock->l_policy_data.l_inodebits.cancel_bits;
+ /* no cancel bits - means that caller needs full cancel */
+ if (drop_bits == 0)
+ RETURN(-EINVAL);
+
+ new_bits = lock->l_policy_data.l_inodebits.bits & ~drop_bits;
+ /* check if all lock bits are dropped, proceed with cancel */
+ if (!new_bits)
+ RETURN(-EINVAL);
+
+ /* check if no dropped bits, consider this as successful convert */
+ if (lock->l_policy_data.l_inodebits.bits == new_bits)
+ RETURN(0);
+
+ ldlm_set_converting(lock);
+ /* Finally call cancel callback for remaining bits only.
+ * It is important to have converting flag during that
+ * so blocking_ast callback can distinguish convert from
+ * cancels.
+ */
+ ld.l_policy_data.l_inodebits.cancel_bits = drop_bits;
+ unlock_res_and_lock(lock);
+ lock->l_blocking_ast(lock, &ld, lock->l_ast_data, LDLM_CB_CANCELING);
+ /* now notify server about convert */
+ rc = ldlm_cli_convert_req(lock, &flags, new_bits);
+ lock_res_and_lock(lock);
+ if (rc)
+ GOTO(full_cancel, rc);
+
+ /* Finally clear these bits in lock ibits */
+ ldlm_inodebits_drop(lock, drop_bits);
+
+ /* Being locked again check if lock was canceled, it is important
+ * to do and don't drop cbpending below
+ */
+ if (ldlm_is_canceling(lock))
+ GOTO(full_cancel, rc = -EINVAL);
+
+ /* also check again if more bits to be cancelled appeared */
+ if (drop_bits != lock->l_policy_data.l_inodebits.cancel_bits)
+ GOTO(clear_converting, rc = -EAGAIN);
+
+ /* clear cbpending flag early, it is safe to match lock right after
+ * client convert because it is downgrade always.
+ */
+ ldlm_clear_cbpending(lock);
+ ldlm_clear_bl_ast(lock);
+ spin_lock(&ns->ns_lock);
+ if (list_empty(&lock->l_lru))
+ ldlm_lock_add_to_lru_nolock(lock);
+ spin_unlock(&ns->ns_lock);
+
+ /* the job is done, zero the cancel_bits. If more conflicts appear,
+ * it will result in another cycle of ldlm_cli_inodebits_convert().
+ */
+full_cancel:
+ lock->l_policy_data.l_inodebits.cancel_bits = 0;
+clear_converting:
+ ldlm_clear_converting(lock);
+ RETURN(rc);
+}
+
+int ldlm_inodebits_alloc_lock(struct ldlm_lock *lock)
+{
+ if (ldlm_is_ns_srv(lock)) {
+ int i;
+
+ OBD_SLAB_ALLOC_PTR(lock->l_ibits_node, ldlm_inodebits_slab);
+ if (lock->l_ibits_node == NULL)
+ return -ENOMEM;
+ for (i = 0; i < MDS_INODELOCK_NUMBITS; i++)
+ INIT_LIST_HEAD(&lock->l_ibits_node->lin_link[i]);
+ lock->l_ibits_node->lock = lock;
+ } else {
+ lock->l_ibits_node = NULL;
+ }
+ return 0;
+}
+
+void ldlm_inodebits_add_lock(struct ldlm_resource *res, struct list_head *head,
+ struct ldlm_lock *lock)
+{
+ int i;
+
+ if (!ldlm_is_ns_srv(lock))
+ return;
+
+ if (head == &res->lr_waiting) {
+ for (i = 0; i < MDS_INODELOCK_NUMBITS; i++) {
+ if (lock->l_policy_data.l_inodebits.bits & (1 << i))
+ list_add_tail(&lock->l_ibits_node->lin_link[i],
+ &res->lr_ibits_queues->liq_waiting[i]);
+ }
+ } else if (head == &res->lr_granted && lock->l_ibits_node != NULL) {
+ for (i = 0; i < MDS_INODELOCK_NUMBITS; i++)
+ LASSERT(list_empty(&lock->l_ibits_node->lin_link[i]));
+ OBD_SLAB_FREE_PTR(lock->l_ibits_node, ldlm_inodebits_slab);
+ lock->l_ibits_node = NULL;
+ }
+}
+
+void ldlm_inodebits_unlink_lock(struct ldlm_lock *lock)
+{
+ int i;
+
+ ldlm_unlink_lock_skiplist(lock);
+ if (!ldlm_is_ns_srv(lock))
+ return;
+
+ for (i = 0; i < MDS_INODELOCK_NUMBITS; i++)
+ list_del_init(&lock->l_ibits_node->lin_link[i]);
+}