X-Git-Url: https://git.whamcloud.com/?a=blobdiff_plain;f=lustre%2Fldlm%2Fldlm_inodebits.c;h=22daed502957d19618be467edafd321d74179497;hb=2250e072c3785;hp=a0814dda94b08473613f71a434d0fd13619963b3;hpb=ccabce23bd9e366c345c852f565766a799f61238;p=fs%2Flustre-release.git

diff --git a/lustre/ldlm/ldlm_inodebits.c b/lustre/ldlm/ldlm_inodebits.c
index a0814dd..22daed5 100644
--- a/lustre/ldlm/ldlm_inodebits.c
+++ b/lustre/ldlm/ldlm_inodebits.c
@@ -57,6 +57,89 @@
 #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;
+	struct list_head bl_ast_list = LIST_HEAD_INIT(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++) {
+		struct list_head rpc_list = LIST_HEAD_INIT(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.
  *
@@ -203,22 +286,49 @@ int ldlm_process_inodebits_lock(struct ldlm_lock *lock, __u64 *flags,
 				struct list_head *work_list)
 {
 	struct ldlm_resource *res = lock->l_resource;
-	struct list_head rpc_list;
+	struct list_head *grant_work = intention == LDLM_PROCESS_ENQUEUE ?
+							NULL : work_list;
 	int rc;
 
 	ENTRY;
 
-	LASSERT(lock->l_granted_mode != lock->l_req_mode);
-	LASSERT(list_empty(&res->lr_converting));
-	INIT_LIST_HEAD(&rpc_list);
+	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);
@@ -233,30 +343,23 @@ int ldlm_process_inodebits_lock(struct ldlm_lock *lock, __u64 *flags,
 			*flags |= LDLM_FL_LOCK_CHANGED;
 		}
 		ldlm_resource_unlink_lock(lock);
-		ldlm_grant_lock(lock, work_list);
+		ldlm_grant_lock(lock, grant_work);
 
 		*err = ELDLM_OK;
 		RETURN(LDLM_ITER_CONTINUE);
 	}
 
-	LASSERT((intention == LDLM_PROCESS_ENQUEUE && work_list == NULL) ||
-		(intention == LDLM_PROCESS_RECOVERY && work_list != NULL));
-restart:
-	rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, &rpc_list);
-	rc += ldlm_inodebits_compat_queue(&res->lr_waiting, lock, &rpc_list);
+	rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, work_list);
+	rc += ldlm_inodebits_compat_queue(&res->lr_waiting, lock, work_list);
 
 	if (rc != 2) {
 		/* if there were only bits to try and all are conflicting */
 		if ((lock->l_policy_data.l_inodebits.bits |
 		     lock->l_policy_data.l_inodebits.try_bits) == 0) {
-			rc = ELDLM_LOCK_WOULDBLOCK;
+			*err = ELDLM_LOCK_WOULDBLOCK;
 		} else {
-			rc = ldlm_handle_conflict_lock(lock, flags,
-						       &rpc_list, 0);
-			if (rc == -ERESTART)
-				GOTO(restart, rc);
+			*err = ELDLM_OK;
 		}
-		*err = rc;
 	} else {
 		/* grant also all remaining try_bits */
 		if (lock->l_policy_data.l_inodebits.try_bits != 0) {
@@ -267,14 +370,11 @@ restart:
 		}
 		LASSERT(lock->l_policy_data.l_inodebits.bits);
 		ldlm_resource_unlink_lock(lock);
-		ldlm_grant_lock(lock, work_list);
-		rc = 0;
+		ldlm_grant_lock(lock, grant_work);
+		*err = ELDLM_OK;
 	}
 
-	if (!list_empty(&rpc_list))
-		ldlm_discard_bl_list(&rpc_list);
-
-	RETURN(rc);
+	RETURN(LDLM_ITER_CONTINUE);
 }
 #endif /* HAVE_SERVER_SUPPORT */
 
@@ -293,7 +393,14 @@ 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;
 
@@ -301,7 +408,7 @@ int ldlm_inodebits_drop(struct ldlm_lock *lock,  __u64 to_drop)
 
 	/* 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);
@@ -315,3 +422,143 @@ int ldlm_inodebits_drop(struct ldlm_lock *lock,  __u64 to_drop)
 	RETURN(0);
 }
 EXPORT_SYMBOL(ldlm_inodebits_drop);
+
+/* convert single lock */
+int ldlm_cli_dropbits(struct ldlm_lock *lock, __u64 drop_bits)
+{
+	struct lustre_handle lockh;
+	__u32 flags = 0;
+	int rc;
+
+	ENTRY;
+
+	LASSERT(drop_bits);
+	LASSERT(!lock->l_readers && !lock->l_writers);
+
+	LDLM_DEBUG(lock, "client lock convert START");
+
+	ldlm_lock2handle(lock, &lockh);
+	lock_res_and_lock(lock);
+	/* check if all bits are blocked */
+	if (!(lock->l_policy_data.l_inodebits.bits & ~drop_bits)) {
+		unlock_res_and_lock(lock);
+		/* return error to continue with cancel */
+		GOTO(exit, rc = -EINVAL);
+	}
+
+	/* check if no common bits, consider this as successful convert */
+	if (!(lock->l_policy_data.l_inodebits.bits & drop_bits)) {
+		unlock_res_and_lock(lock);
+		GOTO(exit, rc = 0);
+	}
+
+	/* check if there is race with cancel */
+	if (ldlm_is_canceling(lock) || ldlm_is_cancel(lock)) {
+		unlock_res_and_lock(lock);
+		GOTO(exit, rc = -EINVAL);
+	}
+
+	/* 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);
+
+	/* If lock is being converted already, check drop bits first */
+	if (ldlm_is_converting(lock)) {
+		/* raced lock convert, lock inodebits are remaining bits
+		 * so check if they are conflicting with new convert or not.
+		 */
+		if (!(lock->l_policy_data.l_inodebits.bits & drop_bits)) {
+			unlock_res_and_lock(lock);
+			GOTO(exit, rc = 0);
+		}
+		/* Otherwise drop new conflicting bits in new convert */
+	}
+	ldlm_set_converting(lock);
+	/* from all bits of blocking lock leave only conflicting */
+	drop_bits &= lock->l_policy_data.l_inodebits.bits;
+	/* save them in cancel_bits, so l_blocking_ast will know
+	 * which bits from the current lock were dropped. */
+	lock->l_policy_data.l_inodebits.cancel_bits = drop_bits;
+	/* Finally clear these bits in lock ibits */
+	ldlm_inodebits_drop(lock, drop_bits);
+	unlock_res_and_lock(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.
+	 */
+	if (lock->l_blocking_ast)
+		lock->l_blocking_ast(lock, NULL, lock->l_ast_data,
+				     LDLM_CB_CANCELING);
+
+	/* now notify server about convert */
+	rc = ldlm_cli_convert(lock, &flags);
+	if (rc) {
+		lock_res_and_lock(lock);
+		if (ldlm_is_converting(lock)) {
+			ldlm_clear_converting(lock);
+			ldlm_set_cbpending(lock);
+			ldlm_set_bl_ast(lock);
+		}
+		unlock_res_and_lock(lock);
+		GOTO(exit, rc);
+	}
+	EXIT;
+exit:
+	LDLM_DEBUG(lock, "client lock convert END");
+	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]);
+}