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10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
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18 * http://www.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2011, 2016, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
32 * lustre/ldlm/ldlm_inodebits.c
34 * Author: Peter Braam <braam@clusterfs.com>
35 * Author: Phil Schwan <phil@clusterfs.com>
39 * This file contains implementation of IBITS lock type
41 * IBITS lock type contains a bit mask determining various properties of an
42 * object. The meanings of specific bits are specific to the caller and are
43 * opaque to LDLM code.
45 * Locks with intersecting bitmasks and conflicting lock modes (e.g. LCK_PW)
46 * are considered conflicting. See the lock mode compatibility matrix
50 #define DEBUG_SUBSYSTEM S_LDLM
52 #include <lustre_dlm.h>
53 #include <obd_support.h>
54 #include <lustre_lib.h>
55 #include <obd_class.h>
57 #include "ldlm_internal.h"
59 #ifdef HAVE_SERVER_SUPPORT
61 * Determine if the lock is compatible with all locks on the queue.
63 * If \a work_list is provided, conflicting locks are linked there.
64 * If \a work_list is not provided, we exit this function on first conflict.
66 * \retval 0 if there are conflicting locks in the \a queue
67 * \retval 1 if the lock is compatible to all locks in \a queue
69 * IBITS locks in granted queue are organized in bunches of
70 * same-mode/same-bits locks called "skip lists". The First lock in the
71 * bunch contains a pointer to the end of the bunch. This allows us to
72 * skip an entire bunch when iterating the list in search for conflicting
73 * locks if first lock of the bunch is not conflicting with us.
76 ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req,
77 struct list_head *work_list)
79 struct list_head *tmp;
80 struct ldlm_lock *lock;
81 __u64 req_bits = req->l_policy_data.l_inodebits.bits;
85 /* There is no sense in lock with no bits set, I think.
86 * Also, such a lock would be compatible with any other bit lock */
87 LASSERT(req_bits != 0);
89 list_for_each(tmp, queue) {
90 struct list_head *mode_tail;
92 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
94 /* We stop walking the queue if we hit ourselves so we don't
95 * take conflicting locks enqueued after us into account,
96 * or we'd wait forever. */
100 /* last lock in mode group */
101 LASSERT(lock->l_sl_mode.prev != NULL);
102 mode_tail = &list_entry(lock->l_sl_mode.prev,
104 l_sl_mode)->l_res_link;
106 /* if reqest lock is not COS_INCOMPAT and COS is disabled,
107 * they are compatible, IOW this request is from a local
108 * transaction on a DNE system. */
109 if (lock->l_req_mode == LCK_COS && !ldlm_is_cos_incompat(req) &&
110 !ldlm_is_cos_enabled(req)) {
111 /* jump to last lock in mode group */
116 /* locks' mode are compatible, bits don't matter */
117 if (lockmode_compat(lock->l_req_mode, req->l_req_mode)) {
118 /* jump to last lock in mode group */
124 struct list_head *head;
126 /* Advance loop cursor to last lock in policy group. */
127 tmp = &list_entry(lock->l_sl_policy.prev,
129 l_sl_policy)->l_res_link;
131 /* Locks with overlapping bits conflict. */
132 if (lock->l_policy_data.l_inodebits.bits & req_bits) {
133 /* COS lock mode has a special compatibility
134 * requirement: it is only compatible with
135 * locks from the same client. */
136 if (lock->l_req_mode == LCK_COS &&
137 !ldlm_is_cos_incompat(req) &&
138 ldlm_is_cos_enabled(req) &&
139 lock->l_client_cookie == req->l_client_cookie)
140 goto not_conflicting;
141 /* Found a conflicting policy group. */
147 /* Add locks of the policy group to @work_list
148 * as blocking locks for @req */
149 if (lock->l_blocking_ast)
150 ldlm_add_ast_work_item(lock, req,
152 head = &lock->l_sl_policy;
153 list_for_each_entry(lock, head, l_sl_policy)
154 if (lock->l_blocking_ast)
155 ldlm_add_ast_work_item(lock, req,
159 if (tmp == mode_tail)
163 lock = list_entry(tmp, struct ldlm_lock,
165 } /* Loop over policy groups within one mode group. */
166 } /* Loop over mode groups within @queue. */
172 * Process a granting attempt for IBITS lock.
173 * Must be called with ns lock held
175 * This function looks for any conflicts for \a lock in the granted or
176 * waiting queues. The lock is granted if no conflicts are found in
179 int ldlm_process_inodebits_lock(struct ldlm_lock *lock, __u64 *flags,
180 enum ldlm_process_intention intention,
181 enum ldlm_error *err,
182 struct list_head *work_list)
184 struct ldlm_resource *res = lock->l_resource;
185 struct list_head rpc_list;
189 LASSERT(lock->l_granted_mode != lock->l_req_mode);
190 LASSERT(list_empty(&res->lr_converting));
191 INIT_LIST_HEAD(&rpc_list);
192 check_res_locked(res);
194 /* (*flags & LDLM_FL_BLOCK_NOWAIT) is for layout lock right now. */
195 if (intention == LDLM_PROCESS_RESCAN ||
196 (*flags & LDLM_FL_BLOCK_NOWAIT)) {
197 *err = ELDLM_LOCK_ABORTED;
198 if (*flags & LDLM_FL_BLOCK_NOWAIT)
199 *err = ELDLM_LOCK_WOULDBLOCK;
201 rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, NULL);
203 RETURN(LDLM_ITER_STOP);
204 rc = ldlm_inodebits_compat_queue(&res->lr_waiting, lock, NULL);
206 RETURN(LDLM_ITER_STOP);
208 ldlm_resource_unlink_lock(lock);
209 ldlm_grant_lock(lock, work_list);
212 RETURN(LDLM_ITER_CONTINUE);
215 LASSERT((intention == LDLM_PROCESS_ENQUEUE && work_list == NULL) ||
216 (intention == LDLM_PROCESS_RECOVERY && work_list != NULL));
218 rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, &rpc_list);
219 rc += ldlm_inodebits_compat_queue(&res->lr_waiting, lock, &rpc_list);
222 rc = ldlm_handle_conflict_lock(lock, flags, &rpc_list, 0);
227 ldlm_resource_unlink_lock(lock);
228 ldlm_grant_lock(lock, work_list);
232 if (!list_empty(&rpc_list))
233 ldlm_discard_bl_list(&rpc_list);
237 #endif /* HAVE_SERVER_SUPPORT */
239 void ldlm_ibits_policy_wire_to_local(const union ldlm_wire_policy_data *wpolicy,
240 union ldlm_policy_data *lpolicy)
242 lpolicy->l_inodebits.bits = wpolicy->l_inodebits.bits;
245 void ldlm_ibits_policy_local_to_wire(const union ldlm_policy_data *lpolicy,
246 union ldlm_wire_policy_data *wpolicy)
248 memset(wpolicy, 0, sizeof(*wpolicy));
249 wpolicy->l_inodebits.bits = lpolicy->l_inodebits.bits;