4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
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).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
27 * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
30 * Copyright (c) 2011, 2013, Intel Corporation.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
36 * lustre/ldlm/ldlm_inodebits.c
38 * Author: Peter Braam <braam@clusterfs.com>
39 * Author: Phil Schwan <phil@clusterfs.com>
43 * This file contains implementation of IBITS lock type
45 * IBITS lock type contains a bit mask determining various properties of an
46 * object. The meanings of specific bits are specific to the caller and are
47 * opaque to LDLM code.
49 * Locks with intersecting bitmasks and conflicting lock modes (e.g. LCK_PW)
50 * are considered conflicting. See the lock mode compatibility matrix
54 #define DEBUG_SUBSYSTEM S_LDLM
56 # include <liblustre.h>
59 #include <lustre_dlm.h>
60 #include <obd_support.h>
61 #include <lustre_lib.h>
63 #include "ldlm_internal.h"
65 #ifdef HAVE_SERVER_SUPPORT
67 * Determine if the lock is compatible with all locks on the queue.
69 * If \a work_list is provided, conflicting locks are linked there.
70 * If \a work_list is not provided, we exit this function on first conflict.
72 * \retval 0 if there are conflicting locks in the \a queue
73 * \retval 1 if the lock is compatible to all locks in \a queue
75 * IBITS locks in granted queue are organized in bunches of
76 * same-mode/same-bits locks called "skip lists". The First lock in the
77 * bunch contains a pointer to the end of the bunch. This allows us to
78 * skip an entire bunch when iterating the list in search for conflicting
79 * locks if first lock of the bunch is not conflicting with us.
82 ldlm_inodebits_compat_queue(cfs_list_t *queue, struct ldlm_lock *req,
83 cfs_list_t *work_list)
86 struct ldlm_lock *lock;
87 ldlm_mode_t req_mode = req->l_req_mode;
88 __u64 req_bits = req->l_policy_data.l_inodebits.bits;
92 LASSERT(req_bits); /* There is no sense in lock with no bits set,
93 I think. Also such a lock would be compatible
94 with any other bit lock */
96 cfs_list_for_each(tmp, queue) {
97 cfs_list_t *mode_tail;
99 lock = cfs_list_entry(tmp, struct ldlm_lock, l_res_link);
101 /* We stop walking the queue if we hit ourselves so we don't
102 * take conflicting locks enqueued after us into account,
103 * or we'd wait forever. */
107 /* last lock in mode group */
108 LASSERT(lock->l_sl_mode.prev != NULL);
109 mode_tail = &cfs_list_entry(lock->l_sl_mode.prev,
111 l_sl_mode)->l_res_link;
113 /* locks are compatible, bits don't matter */
114 if (lockmode_compat(lock->l_req_mode, req_mode)) {
115 /* jump to last lock in mode group */
123 /* Advance loop cursor to last lock in policy group. */
124 tmp = &cfs_list_entry(lock->l_sl_policy.prev,
126 l_sl_policy)->l_res_link;
128 /* Locks with overlapping bits conflict. */
129 if (lock->l_policy_data.l_inodebits.bits & req_bits) {
130 /* COS lock mode has a special compatibility
131 * requirement: it is only compatible with
132 * locks from the same client. */
133 if (lock->l_req_mode == LCK_COS &&
134 lock->l_client_cookie == req->l_client_cookie)
135 goto not_conflicting;
136 /* Found a conflicting policy group. */
142 /* Add locks of the policy group to @work_list
143 * as blocking locks for @req */
144 if (lock->l_blocking_ast)
145 ldlm_add_ast_work_item(lock, req,
147 head = &lock->l_sl_policy;
148 cfs_list_for_each_entry(lock, head, l_sl_policy)
149 if (lock->l_blocking_ast)
150 ldlm_add_ast_work_item(lock, req,
154 if (tmp == mode_tail)
158 lock = cfs_list_entry(tmp, struct ldlm_lock,
160 } /* Loop over policy groups within one mode group. */
161 } /* Loop over mode groups within @queue. */
167 * Process a granting attempt for IBITS lock.
168 * Must be called with ns lock held
170 * This function looks for any conflicts for \a lock in the granted or
171 * waiting queues. The lock is granted if no conflicts are found in
174 * If \a first_enq is 0 (ie, called from ldlm_reprocess_queue):
175 * - blocking ASTs have already been sent
177 * If \a first_enq is 1 (ie, called from ldlm_lock_enqueue):
178 * - blocking ASTs have not been sent yet, so list of conflicting locks
179 * would be collected and ASTs sent.
181 int ldlm_process_inodebits_lock(struct ldlm_lock *lock, __u64 *flags,
182 int first_enq, ldlm_error_t *err,
183 cfs_list_t *work_list)
185 struct ldlm_resource *res = lock->l_resource;
186 CFS_LIST_HEAD(rpc_list);
190 LASSERT(cfs_list_empty(&res->lr_converting));
191 check_res_locked(res);
193 /* (*flags & LDLM_FL_BLOCK_NOWAIT) is for layout lock right now. */
194 if (!first_enq || (*flags & LDLM_FL_BLOCK_NOWAIT)) {
195 *err = ELDLM_LOCK_ABORTED;
196 if (*flags & LDLM_FL_BLOCK_NOWAIT)
197 *err = ELDLM_LOCK_WOULDBLOCK;
199 rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, NULL);
201 RETURN(LDLM_ITER_STOP);
202 rc = ldlm_inodebits_compat_queue(&res->lr_waiting, lock, NULL);
204 RETURN(LDLM_ITER_STOP);
206 ldlm_resource_unlink_lock(lock);
207 ldlm_grant_lock(lock, work_list);
210 RETURN(LDLM_ITER_CONTINUE);
214 rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, &rpc_list);
215 rc += ldlm_inodebits_compat_queue(&res->lr_waiting, lock, &rpc_list);
218 /* If either of the compat_queue()s returned 0, then we
219 * have ASTs to send and must go onto the waiting list.
221 * bug 2322: we used to unlink and re-add here, which was a
222 * terrible folly -- if we goto restart, we could get
223 * re-ordered! Causes deadlock, because ASTs aren't sent! */
224 if (cfs_list_empty(&lock->l_res_link))
225 ldlm_resource_add_lock(res, &res->lr_waiting, lock);
227 rc = ldlm_run_ast_work(ldlm_res_to_ns(res), &rpc_list,
231 GOTO(restart, -ERESTART);
232 *flags |= LDLM_FL_BLOCK_GRANTED;
234 ldlm_resource_unlink_lock(lock);
235 ldlm_grant_lock(lock, NULL);
239 #endif /* HAVE_SERVER_SUPPORT */
241 void ldlm_ibits_policy_wire_to_local(const ldlm_wire_policy_data_t *wpolicy,
242 ldlm_policy_data_t *lpolicy)
244 memset(lpolicy, 0, sizeof(*lpolicy));
245 lpolicy->l_inodebits.bits = wpolicy->l_inodebits.bits;
248 void ldlm_ibits_policy_local_to_wire(const ldlm_policy_data_t *lpolicy,
249 ldlm_wire_policy_data_t *wpolicy)
251 memset(wpolicy, 0, sizeof(*wpolicy));
252 wpolicy->l_inodebits.bits = lpolicy->l_inodebits.bits;