-/* -*- 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.
* in the LICENSE file that accompanied this code).
*
* You should have received a copy of the GNU General Public License
- * version 2 along with this program; If not, see [sun.com URL with a
- * copy of GPLv2].
+ * 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
* GPL HEADER END
*/
/*
- * Copyright 2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2013, 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>
#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(struct list_head *queue, struct ldlm_lock *req,
- struct list_head *work_list)
+ldlm_inodebits_compat_queue(cfs_list_t *queue, struct ldlm_lock *req,
+ cfs_list_t *work_list)
{
- struct list_head *tmp;
+ 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;
I think. Also such a lock would be compatible
with any other bit lock */
- list_for_each(tmp, queue) {
- struct list_head *mode_tail;
+ cfs_list_for_each(tmp, queue) {
+ cfs_list_t *mode_tail;
- lock = list_entry(tmp, struct ldlm_lock, l_res_link);
+ lock = cfs_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;
+ 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)) {
tmp = mode_tail;
continue;
}
-
- for (;;) {
- struct list_head *head;
-
- /* last lock in policy group */
- tmp = &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) {
- /* conflicting policy */
- if (!work_list)
- RETURN(0);
- compat = 0;
-
- /* add locks of the policy group to
- * @work_list as blocking locks for
- * @req */
+ for (;;) {
+ cfs_list_t *head;
+
+ /* Advance loop cursor to 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 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 &&
+ 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;
- list_for_each_entry(lock, head, l_sl_policy)
+ cfs_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);
- } /* loop over policy groups within one mode group */
- } /* loop over mode groups within @queue */
+ lock = cfs_list_entry(tmp, struct ldlm_lock,
+ l_res_link);
+ } /* 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,
+/**
+ * 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.
+ *
+ * If \a first_enq is 0 (ie, called from ldlm_reprocess_queue):
+ * - blocking ASTs have already been sent
+ *
+ * If \a first_enq is 1 (ie, called from ldlm_lock_enqueue):
+ * - blocking ASTs have not been sent yet, so list of conflicting locks
+ * would be collected and ASTs sent.
+ */
+int ldlm_process_inodebits_lock(struct ldlm_lock *lock, __u64 *flags,
int first_enq, ldlm_error_t *err,
- struct list_head *work_list)
+ cfs_list_t *work_list)
{
struct ldlm_resource *res = lock->l_resource;
CFS_LIST_HEAD(rpc_list);
int rc;
ENTRY;
- LASSERT(list_empty(&res->lr_converting));
+ LASSERT(cfs_list_empty(&res->lr_converting));
check_res_locked(res);
- if (!first_enq) {
- LASSERT(work_list != NULL);
+ /* (*flags & LDLM_FL_BLOCK_NOWAIT) is for layout lock right now. */
+ if (!first_enq || (*flags & LDLM_FL_BLOCK_NOWAIT)) {
+ *err = ELDLM_LOCK_ABORTED;
+ if (*flags & LDLM_FL_BLOCK_NOWAIT)
+ *err = ELDLM_LOCK_WOULDBLOCK;
+
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);
+
+ *err = ELDLM_OK;
RETURN(LDLM_ITER_CONTINUE);
}
* 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 (list_empty(&lock->l_res_link))
+ 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);
+ rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
+ LDLM_WORK_BL_AST);
lock_res(res);
if (rc == -ERESTART)
GOTO(restart, -ERESTART);
}
RETURN(0);
}
+#endif /* HAVE_SERVER_SUPPORT */
+
+void ldlm_ibits_policy_wire_to_local(const ldlm_wire_policy_data_t *wpolicy,
+ ldlm_policy_data_t *lpolicy)
+{
+ memset(lpolicy, 0, sizeof(*lpolicy));
+ 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)
+{
+ memset(wpolicy, 0, sizeof(*wpolicy));
+ wpolicy->l_inodebits.bits = lpolicy->l_inodebits.bits;
+}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff