aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/staging/lustre/lustre/include/lustre_mdc.h
blob: 468f36344a34d86275ae9a0b09abda6318f967e5 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * 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.
 *
 * 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).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright (c) 2011, 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lustre/include/lustre_mdc.h
 *
 * MDS data structures.
 * See also lustre_idl.h for wire formats of requests.
 */

#ifndef _LUSTRE_MDC_H
#define _LUSTRE_MDC_H

/** \defgroup mdc mdc
 *
 * @{
 */

#include <linux/fs.h>
#include <linux/dcache.h>
#include <linux/lustre_intent.h>
#include <lustre_handles.h>
#include <linux/libcfs/libcfs.h>
#include <obd_class.h>
#include <lustre/lustre_idl.h>
#include <lustre_lib.h>
#include <lustre_dlm.h>
#include <lustre_export.h>

struct ptlrpc_client;
struct obd_export;
struct ptlrpc_request;
struct obd_device;

struct mdc_rpc_lock {
	struct mutex		rpcl_mutex;
	struct lookup_intent	*rpcl_it;
	int			rpcl_fakes;
};

#define MDC_FAKE_RPCL_IT ((void *)0x2c0012bfUL)

static inline void mdc_init_rpc_lock(struct mdc_rpc_lock *lck)
{
	mutex_init(&lck->rpcl_mutex);
	lck->rpcl_it = NULL;
}

static inline void mdc_get_rpc_lock(struct mdc_rpc_lock *lck,
				    struct lookup_intent *it)
{
	if (it != NULL && (it->it_op == IT_GETATTR || it->it_op == IT_LOOKUP ||
			   it->it_op == IT_LAYOUT))
		return;

	/* This would normally block until the existing request finishes.
	 * If fail_loc is set it will block until the regular request is
	 * done, then set rpcl_it to MDC_FAKE_RPCL_IT.  Once that is set
	 * it will only be cleared when all fake requests are finished.
	 * Only when all fake requests are finished can normal requests
	 * be sent, to ensure they are recoverable again. */
 again:
	mutex_lock(&lck->rpcl_mutex);

	if (CFS_FAIL_CHECK_QUIET(OBD_FAIL_MDC_RPCS_SEM)) {
		lck->rpcl_it = MDC_FAKE_RPCL_IT;
		lck->rpcl_fakes++;
		mutex_unlock(&lck->rpcl_mutex);
		return;
	}

	/* This will only happen when the CFS_FAIL_CHECK() was
	 * just turned off but there are still requests in progress.
	 * Wait until they finish.  It doesn't need to be efficient
	 * in this extremely rare case, just have low overhead in
	 * the common case when it isn't true. */
	while (unlikely(lck->rpcl_it == MDC_FAKE_RPCL_IT)) {
		mutex_unlock(&lck->rpcl_mutex);
		schedule_timeout(cfs_time_seconds(1) / 4);
		goto again;
	}

	LASSERT(lck->rpcl_it == NULL);
	lck->rpcl_it = it;
}

static inline void mdc_put_rpc_lock(struct mdc_rpc_lock *lck,
				    struct lookup_intent *it)
{
	if (it != NULL && (it->it_op == IT_GETATTR || it->it_op == IT_LOOKUP ||
			   it->it_op == IT_LAYOUT))
		return;

	if (lck->rpcl_it == MDC_FAKE_RPCL_IT) { /* OBD_FAIL_MDC_RPCS_SEM */
		mutex_lock(&lck->rpcl_mutex);

		LASSERTF(lck->rpcl_fakes > 0, "%d\n", lck->rpcl_fakes);
		lck->rpcl_fakes--;

		if (lck->rpcl_fakes == 0)
			lck->rpcl_it = NULL;

	} else {
		LASSERTF(it == lck->rpcl_it, "%p != %p\n", it, lck->rpcl_it);
		lck->rpcl_it = NULL;
	}

	mutex_unlock(&lck->rpcl_mutex);
}

static inline void mdc_update_max_ea_from_body(struct obd_export *exp,
					       struct mdt_body *body)
{
	if (body->valid & OBD_MD_FLMODEASIZE) {
		if (exp->exp_obd->u.cli.cl_max_mds_easize < body->max_mdsize)
			exp->exp_obd->u.cli.cl_max_mds_easize =
						body->max_mdsize;
		if (exp->exp_obd->u.cli.cl_max_mds_cookiesize <
						body->max_cookiesize)
			exp->exp_obd->u.cli.cl_max_mds_cookiesize =
						body->max_cookiesize;
	}
}


struct mdc_cache_waiter {
	struct list_head	      mcw_entry;
	wait_queue_head_t	     mcw_waitq;
};

/* mdc/mdc_locks.c */
int it_disposition(struct lookup_intent *it, int flag);
void it_clear_disposition(struct lookup_intent *it, int flag);
void it_set_disposition(struct lookup_intent *it, int flag);
int it_open_error(int phase, struct lookup_intent *it);

static inline bool cl_is_lov_delay_create(unsigned int flags)
{
	return (flags & O_LOV_DELAY_CREATE) == O_LOV_DELAY_CREATE;
}

static inline void cl_lov_delay_create_clear(unsigned int *flags)
{
	if ((*flags & O_LOV_DELAY_CREATE) == O_LOV_DELAY_CREATE)
		*flags &= ~O_LOV_DELAY_CREATE;
}

/** @} mdc */

#endif