1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
4 * Copyright (c) 2002, 2003, 2004 Cluster File Systems, Inc.
5 * Author: Peter Braam <braam@clusterfs.com>
6 * Author: Phil Schwan <phil@clusterfs.com>
8 * This file is part of Lustre, http://www.lustre.org.
10 * Lustre is free software; you can redistribute it and/or
11 * modify it under the terms of version 2 of the GNU General Public
12 * License as published by the Free Software Foundation.
14 * Lustre is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with Lustre; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #define DEBUG_SUBSYSTEM S_LDLM
26 # include <liblustre.h>
29 #include <linux/lustre_dlm.h>
30 #include <linux/obd_support.h>
31 #include <linux/lustre_lib.h>
33 #include "ldlm_internal.h"
35 /* Determine if the lock is compatible with all locks on the queue. */
37 ldlm_inodebits_compat_queue(struct list_head *queue, struct ldlm_lock *req,
40 struct list_head *tmp;
41 struct ldlm_lock *lock;
42 ldlm_mode_t req_mode = req->l_req_mode;
43 __u64 req_bits = req->l_policy_data.l_inodebits.bits;
47 LASSERT(req_bits); /* There is no sence in lock with no bits set,
48 I think. Also such a lock would be compatible
49 with any other bit lock */
50 list_for_each(tmp, queue) {
51 lock = list_entry(tmp, struct ldlm_lock, l_res_link);
56 /* locks are compatible, bits don't matter */
57 if (lockmode_compat(lock->l_req_mode, req_mode))
60 /* if bits don't overlap skip it */
61 if (!(lock->l_policy_data.l_inodebits.bits & req_bits))
68 if (lock->l_blocking_ast)
69 ldlm_add_ast_work_item(lock, req, NULL, 0);
75 /* If first_enq is 0 (ie, called from ldlm_reprocess_queue):
76 * - blocking ASTs have already been sent
77 * - the caller has already initialized req->lr_tmp
78 * - must call this function with the ns lock held
80 * If first_enq is 1 (ie, called from ldlm_lock_enqueue):
81 * - blocking ASTs have not been sent
82 * - the caller has NOT initialized req->lr_tmp, so we must
83 * - must call this function with the ns lock held once */
84 int ldlm_process_inodebits_lock(struct ldlm_lock *lock, int *flags,
85 int first_enq, ldlm_error_t *err)
87 struct ldlm_resource *res = lock->l_resource;
88 struct list_head rpc_list = LIST_HEAD_INIT(rpc_list);
92 LASSERT(list_empty(&res->lr_converting));
95 LASSERT(res->lr_tmp != NULL);
96 rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, 0);
98 RETURN(LDLM_ITER_STOP);
99 rc = ldlm_inodebits_compat_queue(&res->lr_waiting, lock, 0);
101 RETURN(LDLM_ITER_STOP);
103 ldlm_resource_unlink_lock(lock);
104 ldlm_grant_lock(lock, NULL, 0, 1);
105 RETURN(LDLM_ITER_CONTINUE);
109 LASSERT(res->lr_tmp == NULL);
110 res->lr_tmp = &rpc_list;
111 rc = ldlm_inodebits_compat_queue(&res->lr_granted, lock, 1);
112 rc += ldlm_inodebits_compat_queue(&res->lr_waiting, lock, 1);
116 /* If either of the compat_queue()s returned 0, then we
117 * have ASTs to send and must go onto the waiting list.
119 * bug 2322: we used to unlink and re-add here, which was a
120 * terrible folly -- if we goto restart, we could get
121 * re-ordered! Causes deadlock, because ASTs aren't sent! */
122 if (list_empty(&lock->l_res_link))
123 ldlm_resource_add_lock(res, &res->lr_waiting, lock);
124 l_unlock(&res->lr_namespace->ns_lock);
125 rc = ldlm_run_ast_work(res->lr_namespace, &rpc_list);
126 l_lock(&res->lr_namespace->ns_lock);
128 GOTO(restart, -ERESTART);
129 *flags |= LDLM_FL_BLOCK_GRANTED;
131 ldlm_resource_unlink_lock(lock);
132 ldlm_grant_lock(lock, NULL, 0, 0);