1 /*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
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.
9 *
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).
15 *
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
19 *
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
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26 /*
27 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 */
30 /*
31 * Copyright (c) 2011, 2012, Intel Corporation.
32 */
33 /*
34 * This file is part of Lustre, http://www.lustre.org/
35 * Lustre is a trademark of Sun Microsystems, Inc.
36 *
37 * lustre/include/lustre_mdc.h
38 *
39 * MDS data structures.
40 * See also lustre_idl.h for wire formats of requests.
41 */
42
43 #ifndef _LUSTRE_MDC_H
44 #define _LUSTRE_MDC_H
45
46 /** \defgroup mdc mdc
47 *
48 * @{
49 */
50
51 #include <linux/fs.h>
52 #include <linux/dcache.h>
53 #include "lustre_intent.h"
54 #include "lustre_handles.h"
55 #include "../../include/linux/libcfs/libcfs.h"
56 #include "obd_class.h"
57 #include "lustre/lustre_idl.h"
58 #include "lustre_lib.h"
59 #include "lustre_dlm.h"
60 #include "lustre_export.h"
61
62 struct ptlrpc_client;
63 struct obd_export;
64 struct ptlrpc_request;
65 struct obd_device;
66
67 struct mdc_rpc_lock {
68 struct mutex rpcl_mutex;
69 struct lookup_intent *rpcl_it;
70 int rpcl_fakes;
71 };
72
73 #define MDC_FAKE_RPCL_IT ((void *)0x2c0012bfUL)
74
mdc_init_rpc_lock(struct mdc_rpc_lock * lck)75 static inline void mdc_init_rpc_lock(struct mdc_rpc_lock *lck)
76 {
77 mutex_init(&lck->rpcl_mutex);
78 lck->rpcl_it = NULL;
79 }
80
mdc_get_rpc_lock(struct mdc_rpc_lock * lck,struct lookup_intent * it)81 static inline void mdc_get_rpc_lock(struct mdc_rpc_lock *lck,
82 struct lookup_intent *it)
83 {
84 if (it != NULL && (it->it_op == IT_GETATTR || it->it_op == IT_LOOKUP ||
85 it->it_op == IT_LAYOUT))
86 return;
87
88 /* This would normally block until the existing request finishes.
89 * If fail_loc is set it will block until the regular request is
90 * done, then set rpcl_it to MDC_FAKE_RPCL_IT. Once that is set
91 * it will only be cleared when all fake requests are finished.
92 * Only when all fake requests are finished can normal requests
93 * be sent, to ensure they are recoverable again. */
94 again:
95 mutex_lock(&lck->rpcl_mutex);
96
97 if (CFS_FAIL_CHECK_QUIET(OBD_FAIL_MDC_RPCS_SEM)) {
98 lck->rpcl_it = MDC_FAKE_RPCL_IT;
99 lck->rpcl_fakes++;
100 mutex_unlock(&lck->rpcl_mutex);
101 return;
102 }
103
104 /* This will only happen when the CFS_FAIL_CHECK() was
105 * just turned off but there are still requests in progress.
106 * Wait until they finish. It doesn't need to be efficient
107 * in this extremely rare case, just have low overhead in
108 * the common case when it isn't true. */
109 while (unlikely(lck->rpcl_it == MDC_FAKE_RPCL_IT)) {
110 mutex_unlock(&lck->rpcl_mutex);
111 schedule_timeout(cfs_time_seconds(1) / 4);
112 goto again;
113 }
114
115 LASSERT(lck->rpcl_it == NULL);
116 lck->rpcl_it = it;
117 }
118
mdc_put_rpc_lock(struct mdc_rpc_lock * lck,struct lookup_intent * it)119 static inline void mdc_put_rpc_lock(struct mdc_rpc_lock *lck,
120 struct lookup_intent *it)
121 {
122 if (it != NULL && (it->it_op == IT_GETATTR || it->it_op == IT_LOOKUP ||
123 it->it_op == IT_LAYOUT))
124 return;
125
126 if (lck->rpcl_it == MDC_FAKE_RPCL_IT) { /* OBD_FAIL_MDC_RPCS_SEM */
127 mutex_lock(&lck->rpcl_mutex);
128
129 LASSERTF(lck->rpcl_fakes > 0, "%d\n", lck->rpcl_fakes);
130 lck->rpcl_fakes--;
131
132 if (lck->rpcl_fakes == 0)
133 lck->rpcl_it = NULL;
134
135 } else {
136 LASSERTF(it == lck->rpcl_it, "%p != %p\n", it, lck->rpcl_it);
137 lck->rpcl_it = NULL;
138 }
139
140 mutex_unlock(&lck->rpcl_mutex);
141 }
142
143 /* Update the maximum observed easize and cookiesize. The default easize
144 * and cookiesize is initialized to the minimum value but allowed to grow
145 * up to a single page in size if required to handle the common case.
146 */
mdc_update_max_ea_from_body(struct obd_export * exp,struct mdt_body * body)147 static inline void mdc_update_max_ea_from_body(struct obd_export *exp,
148 struct mdt_body *body)
149 {
150 if (body->valid & OBD_MD_FLMODEASIZE) {
151 struct client_obd *cli = &exp->exp_obd->u.cli;
152
153 if (cli->cl_max_mds_easize < body->max_mdsize) {
154 cli->cl_max_mds_easize = body->max_mdsize;
155 cli->cl_default_mds_easize =
156 min_t(__u32, body->max_mdsize, PAGE_CACHE_SIZE);
157 }
158 if (cli->cl_max_mds_cookiesize < body->max_cookiesize) {
159 cli->cl_max_mds_cookiesize = body->max_cookiesize;
160 cli->cl_default_mds_cookiesize =
161 min_t(__u32, body->max_cookiesize, PAGE_CACHE_SIZE);
162 }
163 }
164 }
165
166 struct mdc_cache_waiter {
167 struct list_head mcw_entry;
168 wait_queue_head_t mcw_waitq;
169 };
170
171 /* mdc/mdc_locks.c */
172 int it_disposition(struct lookup_intent *it, int flag);
173 void it_clear_disposition(struct lookup_intent *it, int flag);
174 void it_set_disposition(struct lookup_intent *it, int flag);
175 int it_open_error(int phase, struct lookup_intent *it);
176
cl_is_lov_delay_create(unsigned int flags)177 static inline bool cl_is_lov_delay_create(unsigned int flags)
178 {
179 return (flags & O_LOV_DELAY_CREATE) == O_LOV_DELAY_CREATE;
180 }
181
cl_lov_delay_create_clear(unsigned int * flags)182 static inline void cl_lov_delay_create_clear(unsigned int *flags)
183 {
184 if ((*flags & O_LOV_DELAY_CREATE) == O_LOV_DELAY_CREATE)
185 *flags &= ~O_LOV_DELAY_CREATE;
186 }
187
188 /** @} mdc */
189
190 #endif
191