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.sun.com/software/products/lustre/docs/GPLv2.pdf
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
27 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
30 * Copyright (c) 2011, 2014, Intel Corporation.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
36 * lustre/include/lustre_lib.h
38 * Basic Lustre library routines.
49 #include <linux/signal.h>
50 #include <libcfs/libcfs.h>
51 #include <lustre/lustre_idl.h>
52 #include <lustre_ver.h>
53 #include <lustre_cfg.h>
56 struct ptlrpc_request;
60 #include <lustre_ha.h>
61 #include <lustre_net.h>
63 #ifdef HAVE_SERVER_SUPPORT
64 void target_client_add_cb(struct obd_device *obd, __u64 transno, void *cb_data,
66 int rev_import_init(struct obd_export *exp);
67 int target_handle_connect(struct ptlrpc_request *req);
68 int target_handle_disconnect(struct ptlrpc_request *req);
69 void target_destroy_export(struct obd_export *exp);
70 int target_handle_ping(struct ptlrpc_request *req);
71 void target_committed_to_req(struct ptlrpc_request *req);
72 void target_cancel_recovery_timer(struct obd_device *obd);
73 void target_stop_recovery_thread(struct obd_device *obd);
74 void target_cleanup_recovery(struct obd_device *obd);
75 int target_queue_recovery_request(struct ptlrpc_request *req,
76 struct obd_device *obd);
77 int target_bulk_io(struct obd_export *exp, struct ptlrpc_bulk_desc *desc,
78 struct l_wait_info *lwi);
81 int target_pack_pool_reply(struct ptlrpc_request *req);
82 int do_set_info_async(struct obd_import *imp,
83 int opcode, int version,
84 size_t keylen, void *key,
85 size_t vallen, void *val,
86 struct ptlrpc_request_set *set);
88 void target_send_reply(struct ptlrpc_request *req, int rc, int fail_id);
91 * l_wait_event is a flexible sleeping function, permitting simple caller
92 * configuration of interrupt and timeout sensitivity along with actions to
93 * be performed in the event of either exception.
95 * The first form of usage looks like this:
97 * struct l_wait_info lwi = LWI_TIMEOUT_INTR(timeout, timeout_handler,
98 * intr_handler, callback_data);
99 * rc = l_wait_event(waitq, condition, &lwi);
101 * l_wait_event() makes the current process wait on 'waitq' until 'condition'
102 * is TRUE or a "killable" signal (SIGTERM, SIKGILL, SIGINT) is pending. It
103 * returns 0 to signify 'condition' is TRUE, but if a signal wakes it before
104 * 'condition' becomes true, it optionally calls the specified 'intr_handler'
105 * if not NULL, and returns -EINTR.
107 * If a non-zero timeout is specified, signals are ignored until the timeout
108 * has expired. At this time, if 'timeout_handler' is not NULL it is called.
109 * If it returns FALSE l_wait_event() continues to wait as described above with
110 * signals enabled. Otherwise it returns -ETIMEDOUT.
112 * LWI_INTR(intr_handler, callback_data) is shorthand for
113 * LWI_TIMEOUT_INTR(0, NULL, intr_handler, callback_data)
115 * The second form of usage looks like this:
117 * struct l_wait_info lwi = LWI_TIMEOUT(timeout, timeout_handler);
118 * rc = l_wait_event(waitq, condition, &lwi);
120 * This form is the same as the first except that it COMPLETELY IGNORES
121 * SIGNALS. The caller must therefore beware that if 'timeout' is zero, or if
122 * 'timeout_handler' is not NULL and returns FALSE, then the ONLY thing that
123 * can unblock the current process is 'condition' becoming TRUE.
125 * Another form of usage is:
126 * struct l_wait_info lwi = LWI_TIMEOUT_INTERVAL(timeout, interval,
128 * rc = l_wait_event(waitq, condition, &lwi);
129 * This is the same as previous case, but condition is checked once every
130 * 'interval' jiffies (if non-zero).
132 * Subtle synchronization point: this macro does *not* necessary takes
133 * wait-queue spin-lock before returning, and, hence, following idiom is safe
134 * ONLY when caller provides some external locking:
138 * l_wait_event(&obj->wq, ....); (1)
140 * wake_up(&obj->wq): (2)
141 * spin_lock(&q->lock); (2.1)
142 * __wake_up_common(q, ...); (2.2)
143 * spin_unlock(&q->lock, flags); (2.3)
145 * OBD_FREE_PTR(obj); (3)
147 * As l_wait_event() may "short-cut" execution and return without taking
148 * wait-queue spin-lock, some additional synchronization is necessary to
149 * guarantee that step (3) can begin only after (2.3) finishes.
151 * XXX nikita: some ptlrpc daemon threads have races of that sort.
154 static inline int back_to_sleep(void *arg)
159 #define LWI_ON_SIGNAL_NOOP ((void (*)(void *))(-1))
162 cfs_duration_t lwi_timeout;
163 cfs_duration_t lwi_interval;
165 int (*lwi_on_timeout)(void *);
166 void (*lwi_on_signal)(void *);
170 /* NB: LWI_TIMEOUT ignores signals completely */
171 #define LWI_TIMEOUT(time, cb, data) \
172 ((struct l_wait_info) { \
173 .lwi_timeout = time, \
174 .lwi_on_timeout = cb, \
175 .lwi_cb_data = data, \
177 .lwi_allow_intr = 0 \
180 #define LWI_TIMEOUT_INTERVAL(time, interval, cb, data) \
181 ((struct l_wait_info) { \
182 .lwi_timeout = time, \
183 .lwi_on_timeout = cb, \
184 .lwi_cb_data = data, \
185 .lwi_interval = interval, \
186 .lwi_allow_intr = 0 \
189 #define LWI_TIMEOUT_INTR(time, time_cb, sig_cb, data) \
190 ((struct l_wait_info) { \
191 .lwi_timeout = time, \
192 .lwi_on_timeout = time_cb, \
193 .lwi_on_signal = sig_cb, \
194 .lwi_cb_data = data, \
196 .lwi_allow_intr = 0 \
199 #define LWI_TIMEOUT_INTR_ALL(time, time_cb, sig_cb, data) \
200 ((struct l_wait_info) { \
201 .lwi_timeout = time, \
202 .lwi_on_timeout = time_cb, \
203 .lwi_on_signal = sig_cb, \
204 .lwi_cb_data = data, \
206 .lwi_allow_intr = 1 \
209 #define LWI_INTR(cb, data) LWI_TIMEOUT_INTR(0, NULL, cb, data)
211 #define LUSTRE_FATAL_SIGS \
212 (sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGTERM) | \
213 sigmask(SIGQUIT) | sigmask(SIGALRM))
218 #ifndef HAVE___ADD_WAIT_QUEUE_EXCLUSIVE
219 static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
222 wait->flags |= WQ_FLAG_EXCLUSIVE;
223 __add_wait_queue(q, wait);
225 #endif /* HAVE___ADD_WAIT_QUEUE_EXCLUSIVE */
228 * wait_queue_t of Linux (version < 2.6.34) is a FIFO list for exclusively
229 * waiting threads, which is not always desirable because all threads will
230 * be waken up again and again, even user only needs a few of them to be
231 * active most time. This is not good for performance because cache can
232 * be polluted by different threads.
234 * LIFO list can resolve this problem because we always wakeup the most
235 * recent active thread by default.
237 * NB: please don't call non-exclusive & exclusive wait on the same
238 * waitq if add_wait_queue_exclusive_head is used.
240 #define add_wait_queue_exclusive_head(waitq, link) \
242 unsigned long flags; \
244 spin_lock_irqsave(&((waitq)->lock), flags); \
245 __add_wait_queue_exclusive(waitq, link); \
246 spin_unlock_irqrestore(&((waitq)->lock), flags); \
250 * wait for @condition to become true, but no longer than timeout, specified
253 #define __l_wait_event(wq, condition, info, ret, l_add_wait) \
255 wait_queue_t __wait; \
256 cfs_duration_t __timeout = info->lwi_timeout; \
257 sigset_t __blocked; \
258 int __allow_intr = info->lwi_allow_intr; \
264 init_waitqueue_entry(&__wait, current); \
265 l_add_wait(&wq, &__wait); \
267 /* Block all signals (just the non-fatal ones if no timeout). */ \
268 if (info->lwi_on_signal != NULL && (__timeout == 0 || __allow_intr)) \
269 __blocked = cfs_block_sigsinv(LUSTRE_FATAL_SIGS); \
271 __blocked = cfs_block_sigsinv(0); \
274 set_current_state(TASK_INTERRUPTIBLE); \
279 if (__timeout == 0) { \
282 cfs_duration_t interval = info->lwi_interval? \
283 min_t(cfs_duration_t, \
284 info->lwi_interval,__timeout):\
286 cfs_duration_t remaining = schedule_timeout(interval); \
287 __timeout = cfs_time_sub(__timeout, \
288 cfs_time_sub(interval, remaining));\
289 if (__timeout == 0) { \
290 if (info->lwi_on_timeout == NULL || \
291 info->lwi_on_timeout(info->lwi_cb_data)) { \
295 /* Take signals after the timeout expires. */ \
296 if (info->lwi_on_signal != NULL) \
297 (void)cfs_block_sigsinv(LUSTRE_FATAL_SIGS);\
303 if (signal_pending(current)) { \
304 if (info->lwi_on_signal != NULL && \
305 (__timeout == 0 || __allow_intr)) { \
306 if (info->lwi_on_signal != LWI_ON_SIGNAL_NOOP) \
307 info->lwi_on_signal(info->lwi_cb_data);\
311 /* We have to do this here because some signals */ \
312 /* are not blockable - ie from strace(1). */ \
313 /* In these cases we want to schedule_timeout() */ \
314 /* again, because we don't want that to return */ \
315 /* -EINTR when the RPC actually succeeded. */ \
316 /* the recalc_sigpending() below will deliver the */ \
317 /* signal properly. */ \
318 cfs_clear_sigpending(); \
322 cfs_restore_sigs(__blocked); \
324 set_current_state(TASK_RUNNING); \
325 remove_wait_queue(&wq, &__wait); \
329 #define l_wait_event(wq, condition, info) \
332 struct l_wait_info *__info = (info); \
334 __l_wait_event(wq, condition, __info, \
335 __ret, add_wait_queue); \
339 #define l_wait_event_exclusive(wq, condition, info) \
342 struct l_wait_info *__info = (info); \
344 __l_wait_event(wq, condition, __info, \
345 __ret, add_wait_queue_exclusive); \
349 #define l_wait_event_exclusive_head(wq, condition, info) \
352 struct l_wait_info *__info = (info); \
354 __l_wait_event(wq, condition, __info, \
355 __ret, add_wait_queue_exclusive_head); \
359 #define l_wait_condition(wq, condition) \
361 struct l_wait_info lwi = { 0 }; \
362 l_wait_event(wq, condition, &lwi); \
365 #define l_wait_condition_exclusive(wq, condition) \
367 struct l_wait_info lwi = { 0 }; \
368 l_wait_event_exclusive(wq, condition, &lwi); \
371 #define l_wait_condition_exclusive_head(wq, condition) \
373 struct l_wait_info lwi = { 0 }; \
374 l_wait_event_exclusive_head(wq, condition, &lwi); \
379 #endif /* _LUSTRE_LIB_H */