X-Git-Url: https://git.whamcloud.com/?a=blobdiff_plain;f=lustre%2Fldlm%2Fldlm_inodebits.c;h=1723db40cf09f9044d74fbeb0ce2f5671c8887f8;hb=b2e73f26c73f32db81458253ac319d60d4e3a4bf;hp=90e34a612d7c8ee95188923ae3355060e43c2946;hpb=2ae4276ed35c0d89bde8029982e089b916620ae3;p=fs%2Flustre-release.git

diff --git a/lustre/ldlm/ldlm_inodebits.c b/lustre/ldlm/ldlm_inodebits.c
index 90e34a6..1723db4 100644
--- a/lustre/ldlm/ldlm_inodebits.c
+++ b/lustre/ldlm/ldlm_inodebits.c
@@ -23,7 +23,7 @@
  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
  * Use is subject to license terms.
  *
- * Copyright (c) 2011, 2016, Intel Corporation.
+ * Copyright (c) 2011, 2017, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
@@ -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;
+	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 & BIT(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.
  *
@@ -79,12 +162,18 @@ ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req,
 	struct list_head *tmp;
 	struct ldlm_lock *lock;
 	__u64 req_bits = req->l_policy_data.l_inodebits.bits;
+	__u64 *try_bits = &req->l_policy_data.l_inodebits.try_bits;
 	int compat = 1;
+
 	ENTRY;
 
-	/* There is no sense in lock with no bits set, I think.
-	 * Also, such a lock would be compatible with any other bit lock */
-	LASSERT(req_bits != 0);
+	/* There is no sense in lock with no bits set. Also such a lock
+	 * would be compatible with any other bit lock.
+	 * Meanwhile that can be true if there were just try_bits and all
+	 * are failed, so just exit gracefully and let the caller to care.
+	 */
+	if ((req_bits | *try_bits) == 0)
+		RETURN(0);
 
 	list_for_each(tmp, queue) {
 		struct list_head *mode_tail;
@@ -99,11 +188,10 @@ ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req,
 
 		/* last lock in mode group */
 		LASSERT(lock->l_sl_mode.prev != NULL);
-		mode_tail = &list_entry(lock->l_sl_mode.prev,
-					struct ldlm_lock,
+		mode_tail = &list_entry(lock->l_sl_mode.prev, struct ldlm_lock,
 					l_sl_mode)->l_res_link;
 
-		/* if reqest lock is not COS_INCOMPAT and COS is disabled,
+		/* if request lock is not COS_INCOMPAT and COS is disabled,
 		 * they are compatible, IOW this request is from a local
 		 * transaction on a DNE system. */
 		if (lock->l_req_mode == LCK_COS && !ldlm_is_cos_incompat(req) &&
@@ -125,8 +213,24 @@ ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req,
 
 			/* Advance loop cursor to last lock in policy group. */
 			tmp = &list_entry(lock->l_sl_policy.prev,
-					      struct ldlm_lock,
-					      l_sl_policy)->l_res_link;
+					  struct ldlm_lock,
+					  l_sl_policy)->l_res_link;
+
+			/* New lock's try_bits are filtered out by ibits
+			 * of all locks in both granted and waiting queues.
+			 */
+			*try_bits &= ~(lock->l_policy_data.l_inodebits.bits |
+				lock->l_policy_data.l_inodebits.try_bits);
+
+			if ((req_bits | *try_bits) == 0)
+				RETURN(0);
+
+			/* The new lock ibits is more preferable than try_bits
+			 * of waiting locks so drop conflicting try_bits in
+			 * the waiting queue.
+			 * Notice that try_bits of granted locks must be zero.
+			 */
+			lock->l_policy_data.l_inodebits.try_bits &= ~req_bits;
 
 			/* Locks with overlapping bits conflict. */
 			if (lock->l_policy_data.l_inodebits.bits & req_bits) {
@@ -138,6 +242,7 @@ ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req,
 				    ldlm_is_cos_enabled(req) &&
 				    lock->l_client_cookie == req->l_client_cookie)
 					goto not_conflicting;
+
 				/* Found a conflicting policy group. */
 				if (!work_list)
 					RETURN(0);
@@ -146,22 +251,21 @@ ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req,
 
 				/* Add locks of the policy group to @work_list
 				 * as blocking locks for @req */
-                                if (lock->l_blocking_ast)
-                                        ldlm_add_ast_work_item(lock, req,
-                                                               work_list);
-                                head = &lock->l_sl_policy;
+				if (lock->l_blocking_ast)
+					ldlm_add_ast_work_item(lock, req,
+							       work_list);
+				head = &lock->l_sl_policy;
 				list_for_each_entry(lock, head, l_sl_policy)
-                                        if (lock->l_blocking_ast)
-                                                ldlm_add_ast_work_item(lock, req,
-                                                                       work_list);
-                        }
-                not_conflicting:
-                        if (tmp == mode_tail)
-                                break;
-
-                        tmp = tmp->next;
-			lock = list_entry(tmp, struct ldlm_lock,
-                                              l_res_link);
+					if (lock->l_blocking_ast)
+						ldlm_add_ast_work_item(lock,
+								req, work_list);
+			}
+not_conflicting:
+			if (tmp == mode_tail)
+				break;
+
+			tmp = tmp->next;
+			lock = list_entry(tmp, struct ldlm_lock, l_res_link);
 		} /* Loop over policy groups within one mode group. */
 	} /* Loop over mode groups within @queue. */
 
@@ -182,57 +286,95 @@ 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);
 
-	/* (*flags & LDLM_FL_BLOCK_NOWAIT) is for layout lock right now. */
-	if (intention == LDLM_PROCESS_RESCAN ||
-	    (*flags & LDLM_FL_BLOCK_NOWAIT)) {
-		*err = ELDLM_LOCK_ABORTED;
-		if (*flags & LDLM_FL_BLOCK_NOWAIT)
+	if (intention == LDLM_PROCESS_RESCAN) {
+		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;
+		}
 
-                rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, NULL);
-                if (!rc)
-                        RETURN(LDLM_ITER_STOP);
-                rc = ldlm_inodebits_compat_queue(&res->lr_waiting, lock, NULL);
-                if (!rc)
-                        RETURN(LDLM_ITER_STOP);
+		LASSERT(lock->l_policy_data.l_inodebits.bits != 0);
 
-                ldlm_resource_unlink_lock(lock);
-                ldlm_grant_lock(lock, work_list);
+		/* 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);
+		if (!rc)
+			RETURN(LDLM_ITER_STOP);
+
+		/* grant also try_bits if any */
+		if (lock->l_policy_data.l_inodebits.try_bits != 0) {
+			lock->l_policy_data.l_inodebits.bits |=
+				lock->l_policy_data.l_inodebits.try_bits;
+			lock->l_policy_data.l_inodebits.try_bits = 0;
+			*flags |= LDLM_FL_LOCK_CHANGED;
+		}
+		ldlm_resource_unlink_lock(lock);
+		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) {
-		rc = ldlm_handle_conflict_lock(lock, flags, &rpc_list, 0);
-		if (rc == -ERESTART)
-			GOTO(restart, rc);
-		*err = rc;
+	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) {
+			*err = ELDLM_LOCK_WOULDBLOCK;
+		} else {
+			*err = ELDLM_OK;
+		}
 	} else {
+		/* grant also all remaining try_bits */
+		if (lock->l_policy_data.l_inodebits.try_bits != 0) {
+			lock->l_policy_data.l_inodebits.bits |=
+				lock->l_policy_data.l_inodebits.try_bits;
+			lock->l_policy_data.l_inodebits.try_bits = 0;
+			*flags |= LDLM_FL_LOCK_CHANGED;
+		}
+		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 */
 
@@ -240,6 +382,10 @@ void ldlm_ibits_policy_wire_to_local(const union ldlm_wire_policy_data *wpolicy,
 				     union ldlm_policy_data *lpolicy)
 {
 	lpolicy->l_inodebits.bits = wpolicy->l_inodebits.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,
@@ -247,4 +393,183 @@ void ldlm_ibits_policy_local_to_wire(const union ldlm_policy_data *lpolicy,
 {
 	memset(wpolicy, 0, sizeof(*wpolicy));
 	wpolicy->l_inodebits.bits = lpolicy->l_inodebits.bits;
+	wpolicy->l_inodebits.try_bits = lpolicy->l_inodebits.try_bits;
+}
+
+/**
+ * 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;
+
+	check_res_locked(lock->l_resource);
+
+	/* 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",
+			  lock->l_policy_data.l_inodebits.bits, to_drop);
+		/* nothing to do */
+		RETURN(0);
+	}
+
+	/* remove lock from a skiplist and put in the new place
+	 * according with new inodebits */
+	ldlm_resource_unlink_lock(lock);
+	lock->l_policy_data.l_inodebits.bits &= ~to_drop;
+	ldlm_grant_lock_with_skiplist(lock);
+	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 & BIT(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]);
 }