4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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.
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).
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.gnu.org/licenses/gpl-2.0.html
23 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
26 * Copyright (c) 2011, 2014, Intel Corporation.
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
32 * lustre/include/lustre_lib.h
34 * Basic Lustre library routines.
45 #include <libcfs/libcfs.h>
46 #include <lustre/lustre_idl.h>
47 #include <lustre_ver.h>
48 #include <uapi/linux/lustre_cfg.h>
51 struct ptlrpc_request;
55 #include <lustre_ha.h>
56 #include <lustre_net.h>
58 #define LI_POISON 0x5a5a5a5a
59 #if BITS_PER_LONG > 32
60 # define LL_POISON 0x5a5a5a5a5a5a5a5aL
62 # define LL_POISON 0x5a5a5a5aL
64 #define LP_POISON ((void *)LL_POISON)
66 #ifdef HAVE_SERVER_SUPPORT
67 int rev_import_init(struct obd_export *exp);
68 int target_handle_connect(struct ptlrpc_request *req);
69 int target_handle_disconnect(struct ptlrpc_request *req);
70 void target_destroy_export(struct obd_export *exp);
71 int target_handle_ping(struct ptlrpc_request *req);
72 void target_committed_to_req(struct ptlrpc_request *req);
73 void target_cancel_recovery_timer(struct obd_device *obd);
74 void target_stop_recovery_thread(struct obd_device *obd);
75 void target_cleanup_recovery(struct obd_device *obd);
76 int target_queue_recovery_request(struct ptlrpc_request *req,
77 struct obd_device *obd);
78 int target_bulk_io(struct obd_export *exp, struct ptlrpc_bulk_desc *desc,
79 struct l_wait_info *lwi);
82 int target_pack_pool_reply(struct ptlrpc_request *req);
83 int do_set_info_async(struct obd_import *imp,
84 int opcode, int version,
85 size_t keylen, void *key,
86 size_t vallen, void *val,
87 struct ptlrpc_request_set *set);
89 void target_send_reply(struct ptlrpc_request *req, int rc, int fail_id);
92 * l_wait_event is a flexible sleeping function, permitting simple caller
93 * configuration of interrupt and timeout sensitivity along with actions to
94 * be performed in the event of either exception.
96 * The first form of usage looks like this:
98 * struct l_wait_info lwi = LWI_TIMEOUT_INTR(timeout, timeout_handler,
99 * intr_handler, callback_data);
100 * rc = l_wait_event(waitq, condition, &lwi);
102 * l_wait_event() makes the current process wait on 'waitq' until 'condition'
103 * is TRUE or a "killable" signal (SIGTERM, SIKGILL, SIGINT) is pending. It
104 * returns 0 to signify 'condition' is TRUE, but if a signal wakes it before
105 * 'condition' becomes true, it optionally calls the specified 'intr_handler'
106 * if not NULL, and returns -EINTR.
108 * If a non-zero timeout is specified, signals are ignored until the timeout
109 * has expired. At this time, if 'timeout_handler' is not NULL it is called.
110 * If it returns FALSE l_wait_event() continues to wait as described above with
111 * signals enabled. Otherwise it returns -ETIMEDOUT.
113 * LWI_INTR(intr_handler, callback_data) is shorthand for
114 * LWI_TIMEOUT_INTR(0, NULL, intr_handler, callback_data)
116 * The second form of usage looks like this:
118 * struct l_wait_info lwi = LWI_TIMEOUT(timeout, timeout_handler);
119 * rc = l_wait_event(waitq, condition, &lwi);
121 * This form is the same as the first except that it COMPLETELY IGNORES
122 * SIGNALS. The caller must therefore beware that if 'timeout' is zero, or if
123 * 'timeout_handler' is not NULL and returns FALSE, then the ONLY thing that
124 * can unblock the current process is 'condition' becoming TRUE.
126 * Another form of usage is:
127 * struct l_wait_info lwi = LWI_TIMEOUT_INTERVAL(timeout, interval,
129 * rc = l_wait_event(waitq, condition, &lwi);
130 * This is the same as previous case, but condition is checked once every
131 * 'interval' jiffies (if non-zero).
133 * Subtle synchronization point: this macro does *not* necessary takes
134 * wait-queue spin-lock before returning, and, hence, following idiom is safe
135 * ONLY when caller provides some external locking:
139 * l_wait_event(&obj->wq, ....); (1)
141 * wake_up(&obj->wq): (2)
142 * spin_lock(&q->lock); (2.1)
143 * __wake_up_common(q, ...); (2.2)
144 * spin_unlock(&q->lock, flags); (2.3)
146 * OBD_FREE_PTR(obj); (3)
148 * As l_wait_event() may "short-cut" execution and return without taking
149 * wait-queue spin-lock, some additional synchronization is necessary to
150 * guarantee that step (3) can begin only after (2.3) finishes.
152 * XXX nikita: some ptlrpc daemon threads have races of that sort.
155 static inline int back_to_sleep(void *arg)
160 #define LWI_ON_SIGNAL_NOOP ((void (*)(void *))(-1))
163 cfs_duration_t lwi_timeout;
164 cfs_duration_t lwi_interval;
166 int (*lwi_on_timeout)(void *);
167 void (*lwi_on_signal)(void *);
171 /* NB: LWI_TIMEOUT ignores signals completely */
172 #define LWI_TIMEOUT(time, cb, data) \
173 ((struct l_wait_info) { \
174 .lwi_timeout = time, \
175 .lwi_on_timeout = cb, \
176 .lwi_cb_data = data, \
178 .lwi_allow_intr = 0 \
181 #define LWI_TIMEOUT_INTERVAL(time, interval, cb, data) \
182 ((struct l_wait_info) { \
183 .lwi_timeout = time, \
184 .lwi_on_timeout = cb, \
185 .lwi_cb_data = data, \
186 .lwi_interval = interval, \
187 .lwi_allow_intr = 0 \
190 #define LWI_TIMEOUT_INTR(time, time_cb, sig_cb, data) \
191 ((struct l_wait_info) { \
192 .lwi_timeout = time, \
193 .lwi_on_timeout = time_cb, \
194 .lwi_on_signal = sig_cb, \
195 .lwi_cb_data = data, \
197 .lwi_allow_intr = 0 \
200 #define LWI_TIMEOUT_INTR_ALL(time, time_cb, sig_cb, data) \
201 ((struct l_wait_info) { \
202 .lwi_timeout = time, \
203 .lwi_on_timeout = time_cb, \
204 .lwi_on_signal = sig_cb, \
205 .lwi_cb_data = data, \
207 .lwi_allow_intr = 1 \
210 #define LWI_INTR(cb, data) LWI_TIMEOUT_INTR(0, NULL, cb, data)
212 #define LUSTRE_FATAL_SIGS \
213 (sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGTERM) | \
214 sigmask(SIGQUIT) | sigmask(SIGALRM))
219 #ifndef HAVE___ADD_WAIT_QUEUE_EXCLUSIVE
220 static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
223 wait->flags |= WQ_FLAG_EXCLUSIVE;
224 __add_wait_queue(q, wait);
226 #endif /* HAVE___ADD_WAIT_QUEUE_EXCLUSIVE */
229 * wait_queue_t of Linux (version < 2.6.34) is a FIFO list for exclusively
230 * waiting threads, which is not always desirable because all threads will
231 * be waken up again and again, even user only needs a few of them to be
232 * active most time. This is not good for performance because cache can
233 * be polluted by different threads.
235 * LIFO list can resolve this problem because we always wakeup the most
236 * recent active thread by default.
238 * NB: please don't call non-exclusive & exclusive wait on the same
239 * waitq if add_wait_queue_exclusive_head is used.
241 #define add_wait_queue_exclusive_head(waitq, link) \
243 unsigned long flags; \
245 spin_lock_irqsave(&((waitq)->lock), flags); \
246 __add_wait_queue_exclusive(waitq, link); \
247 spin_unlock_irqrestore(&((waitq)->lock), flags); \
251 * wait for @condition to become true, but no longer than timeout, specified
254 #define __l_wait_event(wq, condition, info, ret, l_add_wait) \
256 wait_queue_t __wait; \
257 cfs_duration_t __timeout = info->lwi_timeout; \
258 sigset_t __blocked; \
259 int __allow_intr = info->lwi_allow_intr; \
265 init_waitqueue_entry(&__wait, current); \
266 l_add_wait(&wq, &__wait); \
268 /* Block all signals (just the non-fatal ones if no timeout). */ \
269 if (info->lwi_on_signal != NULL && (__timeout == 0 || __allow_intr)) \
270 __blocked = cfs_block_sigsinv(LUSTRE_FATAL_SIGS); \
272 __blocked = cfs_block_sigsinv(0); \
275 set_current_state(TASK_INTERRUPTIBLE); \
280 if (__timeout == 0) { \
283 cfs_duration_t interval = info->lwi_interval? \
284 min_t(cfs_duration_t, \
285 info->lwi_interval,__timeout):\
287 cfs_duration_t remaining = schedule_timeout(interval); \
288 __timeout = cfs_time_sub(__timeout, \
289 cfs_time_sub(interval, remaining));\
290 if (__timeout == 0) { \
291 if (info->lwi_on_timeout == NULL || \
292 info->lwi_on_timeout(info->lwi_cb_data)) { \
296 /* Take signals after the timeout expires. */ \
297 if (info->lwi_on_signal != NULL) \
298 (void)cfs_block_sigsinv(LUSTRE_FATAL_SIGS);\
304 if (signal_pending(current)) { \
305 if (info->lwi_on_signal != NULL && \
306 (__timeout == 0 || __allow_intr)) { \
307 if (info->lwi_on_signal != LWI_ON_SIGNAL_NOOP) \
308 info->lwi_on_signal(info->lwi_cb_data);\
312 /* We have to do this here because some signals */ \
313 /* are not blockable - ie from strace(1). */ \
314 /* In these cases we want to schedule_timeout() */ \
315 /* again, because we don't want that to return */ \
316 /* -EINTR when the RPC actually succeeded. */ \
317 /* the recalc_sigpending() below will deliver the */ \
318 /* signal properly. */ \
319 cfs_clear_sigpending(); \
323 cfs_restore_sigs(__blocked); \
325 set_current_state(TASK_RUNNING); \
326 remove_wait_queue(&wq, &__wait); \
330 #define l_wait_event(wq, condition, info) \
333 struct l_wait_info *__info = (info); \
335 __l_wait_event(wq, condition, __info, \
336 __ret, add_wait_queue); \
340 #define l_wait_event_exclusive(wq, condition, info) \
343 struct l_wait_info *__info = (info); \
345 __l_wait_event(wq, condition, __info, \
346 __ret, add_wait_queue_exclusive); \
350 #define l_wait_event_exclusive_head(wq, condition, info) \
353 struct l_wait_info *__info = (info); \
355 __l_wait_event(wq, condition, __info, \
356 __ret, add_wait_queue_exclusive_head); \
360 #define l_wait_condition(wq, condition) \
362 struct l_wait_info lwi = { 0 }; \
363 l_wait_event(wq, condition, &lwi); \
366 #define l_wait_condition_exclusive(wq, condition) \
368 struct l_wait_info lwi = { 0 }; \
369 l_wait_event_exclusive(wq, condition, &lwi); \
372 #define l_wait_condition_exclusive_head(wq, condition) \
374 struct l_wait_info lwi = { 0 }; \
375 l_wait_event_exclusive_head(wq, condition, &lwi); \
380 #endif /* _LUSTRE_LIB_H */