-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
+/*
+ * GPL HEADER START
*
- * Copyright (c) 2002, 2003, 2004 Cluster File Systems, Inc.
- * Author: Peter Braam <braam@clusterfs.com>
- * Author: Phil Schwan <phil@clusterfs.com>
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
- * This file is part of Lustre, http://www.lustre.org.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 only,
+ * as published by the Free Software Foundation.
*
- * Lustre is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License version 2 for more details (a copy is included
+ * in the LICENSE file that accompanied this code).
*
- * Lustre is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; If not, see
+ * http://www.gnu.org/licenses/gpl-2.0.html
*
- * You should have received a copy of the GNU General Public License
- * along with Lustre; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * GPL HEADER END
+ */
+/*
+ * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Use is subject to license terms.
+ *
+ * Copyright (c) 2011, 2017, Intel Corporation.
+ */
+/*
+ * This file is part of Lustre, http://www.lustre.org/
+ * Lustre is a trademark of Sun Microsystems, Inc.
+ *
+ * lustre/ldlm/ldlm_inodebits.c
+ *
+ * Author: Peter Braam <braam@clusterfs.com>
+ * 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 <linux/lustre_dlm.h>
-#include <linux/obd_support.h>
-#include <linux/lustre_lib.h>
+#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(struct list_head *queue, struct ldlm_lock *req,
- struct list_head *work_list)
+ struct list_head *work_list)
+{
+ 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. 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;
+
+ 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 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) &&
+ !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;
+
+ /* 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) {
+ /* 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;
+ 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. */
+
+ RETURN(compat);
+}
+
+/**
+ * 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;
+ struct list_head *grant_work = intention == LDLM_PROCESS_ENQUEUE ?
+ NULL : work_list;
+ int rc;
+
+ ENTRY;
+
+ LASSERT(lock->l_granted_mode != lock->l_req_mode);
+ check_res_locked(res);
+
+ 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;
+ }
+
+ LASSERT(lock->l_policy_data.l_inodebits.bits != 0);
+
+ /* 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);
+ }
+
+ 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) {
+ *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, grant_work);
+ *err = ELDLM_OK;
+ }
+
+ RETURN(LDLM_ITER_CONTINUE);
+}
+#endif /* HAVE_SERVER_SUPPORT */
+
+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;
+ lpolicy->l_inodebits.try_bits = wpolicy->l_inodebits.try_bits;
+}
+
+void ldlm_ibits_policy_local_to_wire(const union ldlm_policy_data *lpolicy,
+ union ldlm_wire_policy_data *wpolicy)
{
- struct list_head *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 sence in lock with no bits set,
- I think. Also such a lock would be compatible
- with any other bit lock */
- list_for_each(tmp, queue) {
- lock = list_entry(tmp, struct ldlm_lock, l_res_link);
-
- if (req == lock)
- RETURN(compat);
-
- /* locks are compatible, bits don't matter */
- if (lockmode_compat(lock->l_req_mode, req_mode))
- continue;
-
- /* if bits don't overlap skip it */
- if (!(lock->l_policy_data.l_inodebits.bits & req_bits))
- continue;
-
- if (!work_list)
- RETURN(0);
-
- compat = 0;
- if (lock->l_blocking_ast)
- ldlm_add_ast_work_item(lock, req, work_list);
- }
-
- RETURN(compat);
+ 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);
-/* If first_enq is 0 (ie, called from ldlm_reprocess_queue):
- * - blocking ASTs have already been sent
- * - the caller has already initialized req->lr_tmp
- * - 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
- * - the caller has NOT initialized req->lr_tmp, so we must
- * - 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,
- struct list_head *work_list)
+/* convert single lock */
+int ldlm_cli_dropbits(struct ldlm_lock *lock, __u64 drop_bits)
{
- struct ldlm_resource *res = lock->l_resource;
- struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
- int rc;
- ENTRY;
-
- LASSERT(list_empty(&res->lr_converting));
- check_res_locked(res);
-
- if (!first_enq) {
- LASSERT(work_list != NULL);
- 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);
-
- ldlm_resource_unlink_lock(lock);
- ldlm_grant_lock(lock, work_list);
- RETURN(LDLM_ITER_CONTINUE);
- }
-
- 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 (list_empty(&lock->l_res_link))
- ldlm_resource_add_lock(res, &res->lr_waiting, lock);
- unlock_res(res);
- rc = ldlm_run_bl_ast_work(&rpc_list);
- 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);
+ 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;
}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff