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LU-2332 osc: solve a race in client obd list lock
[fs/lustre-release.git] / lustre / include / linux / obd.h
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) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
28  * Use is subject to license terms.
29  *
30  * Copyright (c) 2011, 2012, Intel Corporation.
31  */
32 /*
33  * This file is part of Lustre, http://www.lustre.org/
34  * Lustre is a trademark of Sun Microsystems, Inc.
35  */
36
37 #ifndef __LINUX_OBD_H
38 #define __LINUX_OBD_H
39
40 #ifndef __OBD_H
41 #error Do not #include this file directly. #include <obd.h> instead
42 #endif
43
44 #include <obd_support.h>
45
46 #ifdef __KERNEL__
47 # include <linux/fs.h>
48 # include <linux/list.h>
49 # include <linux/sched.h>  /* for struct task_struct, for current.h */
50 # include <linux/proc_fs.h>
51 # include <linux/mount.h>
52 # include <linux/lustre_intent.h>
53 #endif
54
55 struct ll_iattr {
56         struct iattr    iattr;
57         unsigned int    ia_attr_flags;
58 };
59
60 #ifdef __KERNEL__
61 #define CLIENT_OBD_LIST_LOCK_DEBUG 1
62 #endif
63
64 typedef struct {
65         spinlock_t              lock;
66
67 #ifdef CLIENT_OBD_LIST_LOCK_DEBUG
68         unsigned long       time;
69         struct task_struct *task;
70         const char         *func;
71         int                 line;
72 #endif
73 } client_obd_lock_t;
74
75 #ifdef CLIENT_OBD_LIST_LOCK_DEBUG
76 static inline void __client_obd_list_lock(client_obd_lock_t *lock,
77                                           const char *func, int line)
78 {
79         unsigned long cur = jiffies;
80         while (1) {
81                 if (spin_trylock(&lock->lock)) {
82                         LASSERT(lock->task == NULL);
83                         lock->task = current;
84                         lock->func = func;
85                         lock->line = line;
86                         lock->time = jiffies;
87                         break;
88                 }
89
90                 if ((jiffies - cur > 5 * CFS_HZ) &&
91                     (jiffies - lock->time > 5 * CFS_HZ)) {
92                         struct task_struct *task = lock->task;
93
94                         if (task == NULL)
95                                 continue;
96
97                         LCONSOLE_WARN("%s:%d: lock %p was acquired"
98                                       " by <%s:%d:%s:%d> for %lu seconds.\n",
99                                       current->comm, current->pid,
100                                       lock, task->comm, task->pid,
101                                       lock->func, lock->line,
102                                       (jiffies - lock->time) / CFS_HZ);
103                         LCONSOLE_WARN("====== for process holding the "
104                                       "lock =====\n");
105                         libcfs_debug_dumpstack(task);
106                         LCONSOLE_WARN("====== for current process =====\n");
107                         libcfs_debug_dumpstack(NULL);
108                         LCONSOLE_WARN("====== end =======\n");
109                         cfs_pause(1000 * CFS_HZ);
110                 }
111                 cpu_relax();
112         }
113 }
114
115 #define client_obd_list_lock(lock) \
116         __client_obd_list_lock(lock, __FUNCTION__, __LINE__)
117
118 static inline void client_obd_list_unlock(client_obd_lock_t *lock)
119 {
120         LASSERT(lock->task != NULL);
121         lock->task = NULL;
122         lock->time = jiffies;
123         spin_unlock(&lock->lock);
124 }
125
126 #else /* ifdef CLIENT_OBD_LIST_LOCK_DEBUG */
127 static inline void client_obd_list_lock(client_obd_lock_t *lock)
128 {
129         spin_lock(&lock->lock);
130 }
131
132 static inline void client_obd_list_unlock(client_obd_lock_t *lock)
133 {
134         spin_unlock(&lock->lock);
135 }
136
137 #endif /* ifdef CLIENT_OBD_LIST_LOCK_DEBUG */
138
139 static inline void client_obd_list_lock_init(client_obd_lock_t *lock)
140 {
141         spin_lock_init(&lock->lock);
142 }
143
144 static inline void client_obd_list_lock_done(client_obd_lock_t *lock)
145 {}
146
147 #if defined(__KERNEL__) && !defined(HAVE_ADLER)
148 /* zlib_adler() is an inline function defined in zutil.h */
149 #define HAVE_ADLER
150 #endif
151 #endif /* __LINUX_OBD_H */