]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blame - drivers/staging/lustre/lustre/include/lustre_lib.h
sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched...
[mirror_ubuntu-artful-kernel.git] / drivers / staging / lustre / lustre / include / lustre_lib.h
CommitLineData
d7e09d03
PT
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
6a5b99a4 18 * http://www.gnu.org/licenses/gpl-2.0.html
d7e09d03 19 *
d7e09d03
PT
20 * GPL HEADER END
21 */
22/*
23 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
25 *
26 * Copyright (c) 2011, 2012, Intel Corporation.
27 */
28/*
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
31 *
32 * lustre/include/lustre_lib.h
33 *
34 * Basic Lustre library routines.
35 */
36
37#ifndef _LUSTRE_LIB_H
38#define _LUSTRE_LIB_H
39
40/** \defgroup lib lib
41 *
42 * @{
43 */
44
174cd4b1 45#include <linux/sched/signal.h>
376ef86b
JH
46#include <linux/signal.h>
47#include <linux/types.h>
9fdaf8c0 48#include "../../include/linux/libcfs/libcfs.h"
1accaadf
GKH
49#include "lustre/lustre_idl.h"
50#include "lustre_ver.h"
51#include "lustre_cfg.h"
d7e09d03
PT
52
53/* target.c */
54struct ptlrpc_request;
55struct obd_export;
56struct lu_target;
57struct l_wait_info;
1accaadf
GKH
58#include "lustre_ha.h"
59#include "lustre_net.h"
d7e09d03 60
376ef86b
JH
61#define LI_POISON 0x5a5a5a5a
62#if BITS_PER_LONG > 32
63# define LL_POISON 0x5a5a5a5a5a5a5a5aL
64#else
65# define LL_POISON 0x5a5a5a5aL
66#endif
67#define LP_POISON ((void *)LL_POISON)
d7e09d03
PT
68
69int target_pack_pool_reply(struct ptlrpc_request *req);
70int do_set_info_async(struct obd_import *imp,
71 int opcode, int version,
21aef7d9
OD
72 u32 keylen, void *key,
73 u32 vallen, void *val,
d7e09d03
PT
74 struct ptlrpc_request_set *set);
75
d7e09d03
PT
76void target_send_reply(struct ptlrpc_request *req, int rc, int fail_id);
77
d7e09d03
PT
78/*
79 * l_wait_event is a flexible sleeping function, permitting simple caller
80 * configuration of interrupt and timeout sensitivity along with actions to
81 * be performed in the event of either exception.
82 *
83 * The first form of usage looks like this:
84 *
85 * struct l_wait_info lwi = LWI_TIMEOUT_INTR(timeout, timeout_handler,
86 * intr_handler, callback_data);
87 * rc = l_wait_event(waitq, condition, &lwi);
88 *
89 * l_wait_event() makes the current process wait on 'waitq' until 'condition'
90 * is TRUE or a "killable" signal (SIGTERM, SIKGILL, SIGINT) is pending. It
91 * returns 0 to signify 'condition' is TRUE, but if a signal wakes it before
92 * 'condition' becomes true, it optionally calls the specified 'intr_handler'
93 * if not NULL, and returns -EINTR.
94 *
95 * If a non-zero timeout is specified, signals are ignored until the timeout
96 * has expired. At this time, if 'timeout_handler' is not NULL it is called.
97 * If it returns FALSE l_wait_event() continues to wait as described above with
98 * signals enabled. Otherwise it returns -ETIMEDOUT.
99 *
100 * LWI_INTR(intr_handler, callback_data) is shorthand for
101 * LWI_TIMEOUT_INTR(0, NULL, intr_handler, callback_data)
102 *
103 * The second form of usage looks like this:
104 *
105 * struct l_wait_info lwi = LWI_TIMEOUT(timeout, timeout_handler);
106 * rc = l_wait_event(waitq, condition, &lwi);
107 *
108 * This form is the same as the first except that it COMPLETELY IGNORES
109 * SIGNALS. The caller must therefore beware that if 'timeout' is zero, or if
110 * 'timeout_handler' is not NULL and returns FALSE, then the ONLY thing that
111 * can unblock the current process is 'condition' becoming TRUE.
112 *
113 * Another form of usage is:
114 * struct l_wait_info lwi = LWI_TIMEOUT_INTERVAL(timeout, interval,
115 * timeout_handler);
116 * rc = l_wait_event(waitq, condition, &lwi);
117 * This is the same as previous case, but condition is checked once every
118 * 'interval' jiffies (if non-zero).
119 *
120 * Subtle synchronization point: this macro does *not* necessary takes
121 * wait-queue spin-lock before returning, and, hence, following idiom is safe
122 * ONLY when caller provides some external locking:
123 *
124 * Thread1 Thread2
125 *
126 * l_wait_event(&obj->wq, ....); (1)
127 *
128 * wake_up(&obj->wq): (2)
129 * spin_lock(&q->lock); (2.1)
130 * __wake_up_common(q, ...); (2.2)
131 * spin_unlock(&q->lock, flags); (2.3)
132 *
c0a2472f 133 * kfree(obj); (3)
d7e09d03
PT
134 *
135 * As l_wait_event() may "short-cut" execution and return without taking
136 * wait-queue spin-lock, some additional synchronization is necessary to
137 * guarantee that step (3) can begin only after (2.3) finishes.
138 *
139 * XXX nikita: some ptlrpc daemon threads have races of that sort.
140 *
141 */
142static inline int back_to_sleep(void *arg)
143{
144 return 0;
145}
146
147#define LWI_ON_SIGNAL_NOOP ((void (*)(void *))(-1))
148
149struct l_wait_info {
b2d201bd
GKH
150 long lwi_timeout;
151 long lwi_interval;
d7e09d03
PT
152 int lwi_allow_intr;
153 int (*lwi_on_timeout)(void *);
154 void (*lwi_on_signal)(void *);
155 void *lwi_cb_data;
156};
157
158/* NB: LWI_TIMEOUT ignores signals completely */
159#define LWI_TIMEOUT(time, cb, data) \
160((struct l_wait_info) { \
161 .lwi_timeout = time, \
162 .lwi_on_timeout = cb, \
163 .lwi_cb_data = data, \
164 .lwi_interval = 0, \
165 .lwi_allow_intr = 0 \
166})
167
168#define LWI_TIMEOUT_INTERVAL(time, interval, cb, data) \
169((struct l_wait_info) { \
170 .lwi_timeout = time, \
171 .lwi_on_timeout = cb, \
172 .lwi_cb_data = data, \
173 .lwi_interval = interval, \
174 .lwi_allow_intr = 0 \
175})
176
177#define LWI_TIMEOUT_INTR(time, time_cb, sig_cb, data) \
178((struct l_wait_info) { \
179 .lwi_timeout = time, \
180 .lwi_on_timeout = time_cb, \
181 .lwi_on_signal = sig_cb, \
182 .lwi_cb_data = data, \
183 .lwi_interval = 0, \
184 .lwi_allow_intr = 0 \
185})
186
187#define LWI_TIMEOUT_INTR_ALL(time, time_cb, sig_cb, data) \
188((struct l_wait_info) { \
189 .lwi_timeout = time, \
190 .lwi_on_timeout = time_cb, \
191 .lwi_on_signal = sig_cb, \
192 .lwi_cb_data = data, \
193 .lwi_interval = 0, \
194 .lwi_allow_intr = 1 \
195})
196
197#define LWI_INTR(cb, data) LWI_TIMEOUT_INTR(0, NULL, cb, data)
198
376ef86b
JH
199#define LUSTRE_FATAL_SIGS (sigmask(SIGKILL) | sigmask(SIGINT) | \
200 sigmask(SIGTERM) | sigmask(SIGQUIT) | \
201 sigmask(SIGALRM))
202
564f5d6e
JS
203/**
204 * wait_queue_t of Linux (version < 2.6.34) is a FIFO list for exclusively
205 * waiting threads, which is not always desirable because all threads will
206 * be waken up again and again, even user only needs a few of them to be
207 * active most time. This is not good for performance because cache can
208 * be polluted by different threads.
209 *
210 * LIFO list can resolve this problem because we always wakeup the most
211 * recent active thread by default.
212 *
213 * NB: please don't call non-exclusive & exclusive wait on the same
214 * waitq if add_wait_queue_exclusive_head is used.
215 */
216#define add_wait_queue_exclusive_head(waitq, link) \
217{ \
218 unsigned long flags; \
219 \
220 spin_lock_irqsave(&((waitq)->lock), flags); \
221 __add_wait_queue_exclusive(waitq, link); \
222 spin_unlock_irqrestore(&((waitq)->lock), flags); \
223}
224
d7e09d03
PT
225/*
226 * wait for @condition to become true, but no longer than timeout, specified
227 * by @info.
228 */
229#define __l_wait_event(wq, condition, info, ret, l_add_wait) \
230do { \
231 wait_queue_t __wait; \
b2d201bd 232 long __timeout = info->lwi_timeout; \
d7e09d03
PT
233 sigset_t __blocked; \
234 int __allow_intr = info->lwi_allow_intr; \
235 \
236 ret = 0; \
237 if (condition) \
238 break; \
239 \
9e795d35 240 init_waitqueue_entry(&__wait, current); \
d7e09d03
PT
241 l_add_wait(&wq, &__wait); \
242 \
243 /* Block all signals (just the non-fatal ones if no timeout). */ \
d2a13989 244 if (info->lwi_on_signal && (__timeout == 0 || __allow_intr)) \
d7e09d03
PT
245 __blocked = cfs_block_sigsinv(LUSTRE_FATAL_SIGS); \
246 else \
247 __blocked = cfs_block_sigsinv(0); \
248 \
249 for (;;) { \
d7e09d03
PT
250 if (condition) \
251 break; \
252 \
65609bd6
OD
253 set_current_state(TASK_INTERRUPTIBLE); \
254 \
d7e09d03 255 if (__timeout == 0) { \
65609bd6 256 schedule(); \
d7e09d03 257 } else { \
b2952d62 258 long interval = info->lwi_interval ? \
b2d201bd 259 min_t(long, \
b2952d62 260 info->lwi_interval, __timeout) : \
d7e09d03 261 __timeout; \
b2d201bd 262 long remaining = schedule_timeout(interval);\
d7e09d03
PT
263 __timeout = cfs_time_sub(__timeout, \
264 cfs_time_sub(interval, remaining));\
265 if (__timeout == 0) { \
d2a13989 266 if (!info->lwi_on_timeout || \
d7e09d03
PT
267 info->lwi_on_timeout(info->lwi_cb_data)) { \
268 ret = -ETIMEDOUT; \
269 break; \
270 } \
271 /* Take signals after the timeout expires. */ \
d2a13989 272 if (info->lwi_on_signal) \
d7e09d03
PT
273 (void)cfs_block_sigsinv(LUSTRE_FATAL_SIGS);\
274 } \
275 } \
276 \
65609bd6
OD
277 set_current_state(TASK_RUNNING); \
278 \
d7e09d03
PT
279 if (condition) \
280 break; \
9af4826a 281 if (signal_pending(current)) { \
d2a13989 282 if (info->lwi_on_signal && \
d7e09d03
PT
283 (__timeout == 0 || __allow_intr)) { \
284 if (info->lwi_on_signal != LWI_ON_SIGNAL_NOOP) \
285 info->lwi_on_signal(info->lwi_cb_data);\
286 ret = -EINTR; \
287 break; \
288 } \
289 /* We have to do this here because some signals */ \
290 /* are not blockable - ie from strace(1). */ \
291 /* In these cases we want to schedule_timeout() */ \
292 /* again, because we don't want that to return */ \
293 /* -EINTR when the RPC actually succeeded. */ \
294 /* the recalc_sigpending() below will deliver the */ \
295 /* signal properly. */ \
296 cfs_clear_sigpending(); \
297 } \
298 } \
299 \
300 cfs_restore_sigs(__blocked); \
301 \
d7e09d03
PT
302 remove_wait_queue(&wq, &__wait); \
303} while (0)
304
d7e09d03
PT
305#define l_wait_event(wq, condition, info) \
306({ \
307 int __ret; \
308 struct l_wait_info *__info = (info); \
309 \
310 __l_wait_event(wq, condition, __info, \
311 __ret, add_wait_queue); \
312 __ret; \
313})
314
315#define l_wait_event_exclusive(wq, condition, info) \
316({ \
317 int __ret; \
318 struct l_wait_info *__info = (info); \
319 \
320 __l_wait_event(wq, condition, __info, \
321 __ret, add_wait_queue_exclusive); \
322 __ret; \
323})
324
325#define l_wait_event_exclusive_head(wq, condition, info) \
326({ \
327 int __ret; \
328 struct l_wait_info *__info = (info); \
329 \
330 __l_wait_event(wq, condition, __info, \
331 __ret, add_wait_queue_exclusive_head); \
332 __ret; \
333})
334
335#define l_wait_condition(wq, condition) \
336({ \
337 struct l_wait_info lwi = { 0 }; \
338 l_wait_event(wq, condition, &lwi); \
339})
340
341#define l_wait_condition_exclusive(wq, condition) \
342({ \
343 struct l_wait_info lwi = { 0 }; \
344 l_wait_event_exclusive(wq, condition, &lwi); \
345})
346
347#define l_wait_condition_exclusive_head(wq, condition) \
348({ \
349 struct l_wait_info lwi = { 0 }; \
350 l_wait_event_exclusive_head(wq, condition, &lwi); \
351})
352
d7e09d03
PT
353/** @} lib */
354
355#endif /* _LUSTRE_LIB_H */