-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
- *
+/*
* GPL HEADER START
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; If not, see
- * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
- *
- * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
+ * http://www.gnu.org/licenses/gpl-2.0.html
*
* GPL HEADER END
*/
* Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
- * Copyright (c) 2011 Whamcloud, Inc.
- *
+ * Copyright (c) 2011, 2016, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
* Author: Phil Schwan <phil@clusterfs.com>
*/
+/**
+ * This file contains implementation of IBITS lock type
+ *
+ * IBITS lock type contains a bit mask determining various properties of an
+ * object. The meanings of specific bits are specific to the caller and are
+ * opaque to LDLM code.
+ *
+ * Locks with intersecting bitmasks and conflicting lock modes (e.g. LCK_PW)
+ * are considered conflicting. See the lock mode compatibility matrix
+ * in lustre_dlm.h.
+ */
+
#define DEBUG_SUBSYSTEM S_LDLM
-#ifndef __KERNEL__
-# include <liblustre.h>
-#endif
#include <lustre_dlm.h>
#include <obd_support.h>
#include <lustre_lib.h>
+#include <obd_class.h>
#include "ldlm_internal.h"
-/* Determine if the lock is compatible with all locks on the queue. */
+#ifdef HAVE_SERVER_SUPPORT
+/**
+ * Determine if the lock is compatible with all locks on the queue.
+ *
+ * If \a work_list is provided, conflicting locks are linked there.
+ * If \a work_list is not provided, we exit this function on first conflict.
+ *
+ * \retval 0 if there are conflicting locks in the \a queue
+ * \retval 1 if the lock is compatible to all locks in \a queue
+ *
+ * IBITS locks in granted queue are organized in bunches of
+ * same-mode/same-bits locks called "skip lists". The First lock in the
+ * bunch contains a pointer to the end of the bunch. This allows us to
+ * skip an entire bunch when iterating the list in search for conflicting
+ * locks if first lock of the bunch is not conflicting with us.
+ */
static int
-ldlm_inodebits_compat_queue(cfs_list_t *queue, struct ldlm_lock *req,
- cfs_list_t *work_list)
+ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req,
+ struct list_head *work_list)
{
- cfs_list_t *tmp;
- struct ldlm_lock *lock;
- ldlm_mode_t req_mode = req->l_req_mode;
- __u64 req_bits = req->l_policy_data.l_inodebits.bits;
- int compat = 1;
- ENTRY;
-
- LASSERT(req_bits); /* There is no sense in lock with no bits set,
- I think. Also such a lock would be compatible
- with any other bit lock */
-
- cfs_list_for_each(tmp, queue) {
- cfs_list_t *mode_tail;
-
- lock = cfs_list_entry(tmp, struct ldlm_lock, l_res_link);
-
- if (req == lock)
- RETURN(compat);
-
- /* last lock in mode group */
- LASSERT(lock->l_sl_mode.prev != NULL);
- mode_tail = &cfs_list_entry(lock->l_sl_mode.prev,
- struct ldlm_lock,
- l_sl_mode)->l_res_link;
-
- /* locks are compatible, bits don't matter */
- if (lockmode_compat(lock->l_req_mode, req_mode)) {
- /* jump to last lock in mode group */
- tmp = mode_tail;
- continue;
- }
-
- for (;;) {
- cfs_list_t *head;
-
- /* last lock in policy group */
- tmp = &cfs_list_entry(lock->l_sl_policy.prev,
- struct ldlm_lock,
- l_sl_policy)->l_res_link;
-
- /* locks with bits overlapped are conflicting locks */
- if (lock->l_policy_data.l_inodebits.bits & req_bits) {
- /* COS lock from the same client is
- not conflicting */
- if (lock->l_req_mode == LCK_COS &&
- lock->l_client_cookie == req->l_client_cookie)
- goto not_conflicting;
- /* conflicting policy */
- if (!work_list)
- RETURN(0);
-
- compat = 0;
-
- /* add locks of the policy group to
- * @work_list as blocking locks for
- * @req */
+ struct list_head *tmp;
+ struct ldlm_lock *lock;
+ __u64 req_bits = req->l_policy_data.l_inodebits.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);
+
+ list_for_each(tmp, queue) {
+ struct list_head *mode_tail;
+
+ lock = list_entry(tmp, struct ldlm_lock, l_res_link);
+
+ /* We stop walking the queue if we hit ourselves so we don't
+ * take conflicting locks enqueued after us into account,
+ * or we'd wait forever. */
+ if (req == lock)
+ RETURN(compat);
+
+ /* last lock in mode group */
+ LASSERT(lock->l_sl_mode.prev != NULL);
+ 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,
+ * 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) &&
+ !ldlm_is_cos_enabled(req)) {
+ /* jump to last lock in mode group */
+ tmp = mode_tail;
+ continue;
+ }
+
+ /* locks' mode are compatible, bits don't matter */
+ if (lockmode_compat(lock->l_req_mode, req->l_req_mode)) {
+ /* jump to last lock in mode group */
+ tmp = mode_tail;
+ continue;
+ }
+
+ for (;;) {
+ struct list_head *head;
+
+ /* 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;
+
+ /* Locks with overlapping bits conflict. */
+ if (lock->l_policy_data.l_inodebits.bits & req_bits) {
+ /* COS lock mode has a special compatibility
+ * requirement: it is only compatible with
+ * locks from the same client. */
+ if (lock->l_req_mode == LCK_COS &&
+ !ldlm_is_cos_incompat(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);
+
+ compat = 0;
+
+ /* 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;
- cfs_list_for_each_entry(lock, head, 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);
break;
tmp = tmp->next;
- lock = cfs_list_entry(tmp, struct ldlm_lock,
+ lock = list_entry(tmp, struct ldlm_lock,
l_res_link);
- } /* loop over policy groups within one mode group */
- } /* loop over mode groups within @queue */
+ } /* Loop over policy groups within one mode group. */
+ } /* Loop over mode groups within @queue. */
- RETURN(compat);
+ RETURN(compat);
}
-/* If first_enq is 0 (ie, called from ldlm_reprocess_queue):
- * - blocking ASTs have already been sent
- * - must call this function with the ns lock held
- *
- * If first_enq is 1 (ie, called from ldlm_lock_enqueue):
- * - blocking ASTs have not been sent
- * - must call this function with the ns lock held once */
-int ldlm_process_inodebits_lock(struct ldlm_lock *lock, int *flags,
- int first_enq, ldlm_error_t *err,
- cfs_list_t *work_list)
+/**
+ * Process a granting attempt for IBITS lock.
+ * Must be called with ns lock held
+ *
+ * This function looks for any conflicts for \a lock in the granted or
+ * waiting queues. The lock is granted if no conflicts are found in
+ * either queue.
+ */
+int ldlm_process_inodebits_lock(struct ldlm_lock *lock, __u64 *flags,
+ enum ldlm_process_intention intention,
+ enum ldlm_error *err,
+ struct list_head *work_list)
{
- struct ldlm_resource *res = lock->l_resource;
- CFS_LIST_HEAD(rpc_list);
- int rc;
- ENTRY;
-
- LASSERT(cfs_list_empty(&res->lr_converting));
- check_res_locked(res);
+ struct ldlm_resource *res = lock->l_resource;
+ struct list_head rpc_list;
+ int rc;
+ ENTRY;
+
+ LASSERT(lock->l_granted_mode != lock->l_req_mode);
+ LASSERT(list_empty(&res->lr_converting));
+ INIT_LIST_HEAD(&rpc_list);
+ 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)
+ *err = ELDLM_LOCK_WOULDBLOCK;
- if (!first_enq) {
- LASSERT(work_list != NULL);
rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, NULL);
if (!rc)
RETURN(LDLM_ITER_STOP);
ldlm_resource_unlink_lock(lock);
ldlm_grant_lock(lock, work_list);
- RETURN(LDLM_ITER_CONTINUE);
- }
+ *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);
if (rc != 2) {
- /* If either of the compat_queue()s returned 0, then we
- * have ASTs to send and must go onto the waiting list.
- *
- * bug 2322: we used to unlink and re-add here, which was a
- * terrible folly -- if we goto restart, we could get
- * re-ordered! Causes deadlock, because ASTs aren't sent! */
- if (cfs_list_empty(&lock->l_res_link))
- ldlm_resource_add_lock(res, &res->lr_waiting, lock);
- unlock_res(res);
- rc = ldlm_run_ast_work(&rpc_list, LDLM_WORK_BL_AST);
- lock_res(res);
- if (rc == -ERESTART)
- GOTO(restart, -ERESTART);
- *flags |= LDLM_FL_BLOCK_GRANTED;
- } else {
- ldlm_resource_unlink_lock(lock);
- ldlm_grant_lock(lock, NULL);
- }
- RETURN(0);
+ rc = ldlm_handle_conflict_lock(lock, flags, &rpc_list, 0);
+ if (rc == -ERESTART)
+ GOTO(restart, rc);
+ *err = rc;
+ } else {
+ ldlm_resource_unlink_lock(lock);
+ ldlm_grant_lock(lock, work_list);
+ rc = 0;
+ }
+
+ if (!list_empty(&rpc_list))
+ ldlm_discard_bl_list(&rpc_list);
+
+ RETURN(rc);
}
+#endif /* HAVE_SERVER_SUPPORT */
-void ldlm_ibits_policy_wire_to_local(const ldlm_wire_policy_data_t *wpolicy,
- ldlm_policy_data_t *lpolicy)
+void ldlm_ibits_policy_wire_to_local(const union ldlm_wire_policy_data *wpolicy,
+ union ldlm_policy_data *lpolicy)
{
- memset(lpolicy, 0, sizeof(*lpolicy));
- lpolicy->l_inodebits.bits = wpolicy->l_inodebits.bits;
+ lpolicy->l_inodebits.bits = wpolicy->l_inodebits.bits;
}
-void ldlm_ibits_policy_local_to_wire(const ldlm_policy_data_t *lpolicy,
- ldlm_wire_policy_data_t *wpolicy)
+void ldlm_ibits_policy_local_to_wire(const union ldlm_policy_data *lpolicy,
+ union ldlm_wire_policy_data *wpolicy)
{
- memset(wpolicy, 0, sizeof(*wpolicy));
- wpolicy->l_inodebits.bits = lpolicy->l_inodebits.bits;
+ memset(wpolicy, 0, sizeof(*wpolicy));
+ wpolicy->l_inodebits.bits = lpolicy->l_inodebits.bits;
}