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 <linux/signal.h>
46 #include <libcfs/libcfs.h>
47 #include <lustre/lustre_idl.h>
48 #include <lustre_ver.h>
49 #include <lustre_cfg.h>
52 struct ptlrpc_request;
56 #include <lustre_ha.h>
57 #include <lustre_net.h>
59 #define LI_POISON 0x5a5a5a5a
60 #if BITS_PER_LONG > 32
61 # define LL_POISON 0x5a5a5a5a5a5a5a5aL
63 # define LL_POISON 0x5a5a5a5aL
65 #define LP_POISON ((void *)LL_POISON)
67 #ifdef HAVE_SERVER_SUPPORT
68 int rev_import_init(struct obd_export *exp);
69 int target_handle_connect(struct ptlrpc_request *req);
70 int target_handle_disconnect(struct ptlrpc_request *req);
71 void target_destroy_export(struct obd_export *exp);
72 int target_handle_ping(struct ptlrpc_request *req);
73 void target_committed_to_req(struct ptlrpc_request *req);
74 void target_cancel_recovery_timer(struct obd_device *obd);
75 void target_stop_recovery_thread(struct obd_device *obd);
76 void target_cleanup_recovery(struct obd_device *obd);
77 int target_queue_recovery_request(struct ptlrpc_request *req,
78 struct obd_device *obd);
79 int target_bulk_io(struct obd_export *exp, struct ptlrpc_bulk_desc *desc,
80 struct l_wait_info *lwi);
83 int target_pack_pool_reply(struct ptlrpc_request *req);
84 int do_set_info_async(struct obd_import *imp,
85 int opcode, int version,
86 size_t keylen, void *key,
87 size_t vallen, void *val,
88 struct ptlrpc_request_set *set);
90 void target_send_reply(struct ptlrpc_request *req, int rc, int fail_id);
93 * l_wait_event is a flexible sleeping function, permitting simple caller
94 * configuration of interrupt and timeout sensitivity along with actions to
95 * be performed in the event of either exception.
97 * The first form of usage looks like this:
99 * struct l_wait_info lwi = LWI_TIMEOUT_INTR(timeout, timeout_handler,
100 * intr_handler, callback_data);
101 * rc = l_wait_event(waitq, condition, &lwi);
103 * l_wait_event() makes the current process wait on 'waitq' until 'condition'
104 * is TRUE or a "killable" signal (SIGTERM, SIKGILL, SIGINT) is pending. It
105 * returns 0 to signify 'condition' is TRUE, but if a signal wakes it before
106 * 'condition' becomes true, it optionally calls the specified 'intr_handler'
107 * if not NULL, and returns -EINTR.
109 * If a non-zero timeout is specified, signals are ignored until the timeout
110 * has expired. At this time, if 'timeout_handler' is not NULL it is called.
111 * If it returns FALSE l_wait_event() continues to wait as described above with
112 * signals enabled. Otherwise it returns -ETIMEDOUT.
114 * LWI_INTR(intr_handler, callback_data) is shorthand for
115 * LWI_TIMEOUT_INTR(0, NULL, intr_handler, callback_data)
117 * The second form of usage looks like this:
119 * struct l_wait_info lwi = LWI_TIMEOUT(timeout, timeout_handler);
120 * rc = l_wait_event(waitq, condition, &lwi);
122 * This form is the same as the first except that it COMPLETELY IGNORES
123 * SIGNALS. The caller must therefore beware that if 'timeout' is zero, or if
124 * 'timeout_handler' is not NULL and returns FALSE, then the ONLY thing that
125 * can unblock the current process is 'condition' becoming TRUE.
127 * Another form of usage is:
128 * struct l_wait_info lwi = LWI_TIMEOUT_INTERVAL(timeout, interval,
130 * rc = l_wait_event(waitq, condition, &lwi);
131 * This is the same as previous case, but condition is checked once every
132 * 'interval' jiffies (if non-zero).
134 * Subtle synchronization point: this macro does *not* necessary takes
135 * wait-queue spin-lock before returning, and, hence, following idiom is safe
136 * ONLY when caller provides some external locking:
140 * l_wait_event(&obj->wq, ....); (1)
142 * wake_up(&obj->wq): (2)
143 * spin_lock(&q->lock); (2.1)
144 * __wake_up_common(q, ...); (2.2)
145 * spin_unlock(&q->lock, flags); (2.3)
147 * OBD_FREE_PTR(obj); (3)
149 * As l_wait_event() may "short-cut" execution and return without taking
150 * wait-queue spin-lock, some additional synchronization is necessary to
151 * guarantee that step (3) can begin only after (2.3) finishes.
153 * XXX nikita: some ptlrpc daemon threads have races of that sort.
156 static inline int back_to_sleep(void *arg)
161 #define LWI_ON_SIGNAL_NOOP ((void (*)(void *))(-1))
164 cfs_duration_t lwi_timeout;
165 cfs_duration_t lwi_interval;
167 int (*lwi_on_timeout)(void *);
168 void (*lwi_on_signal)(void *);
172 /* NB: LWI_TIMEOUT ignores signals completely */
173 #define LWI_TIMEOUT(time, cb, data) \
174 ((struct l_wait_info) { \
175 .lwi_timeout = time, \
176 .lwi_on_timeout = cb, \
177 .lwi_cb_data = data, \
179 .lwi_allow_intr = 0 \
182 #define LWI_TIMEOUT_INTERVAL(time, interval, cb, data) \
183 ((struct l_wait_info) { \
184 .lwi_timeout = time, \
185 .lwi_on_timeout = cb, \
186 .lwi_cb_data = data, \
187 .lwi_interval = interval, \
188 .lwi_allow_intr = 0 \
191 #define LWI_TIMEOUT_INTR(time, time_cb, sig_cb, data) \
192 ((struct l_wait_info) { \
193 .lwi_timeout = time, \
194 .lwi_on_timeout = time_cb, \
195 .lwi_on_signal = sig_cb, \
196 .lwi_cb_data = data, \
198 .lwi_allow_intr = 0 \
201 #define LWI_TIMEOUT_INTR_ALL(time, time_cb, sig_cb, data) \
202 ((struct l_wait_info) { \
203 .lwi_timeout = time, \
204 .lwi_on_timeout = time_cb, \
205 .lwi_on_signal = sig_cb, \
206 .lwi_cb_data = data, \
208 .lwi_allow_intr = 1 \
211 #define LWI_INTR(cb, data) LWI_TIMEOUT_INTR(0, NULL, cb, data)
213 #define LUSTRE_FATAL_SIGS \
214 (sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGTERM) | \
215 sigmask(SIGQUIT) | sigmask(SIGALRM))
220 #ifndef HAVE___ADD_WAIT_QUEUE_EXCLUSIVE
221 static inline void __add_wait_queue_exclusive(wait_queue_head_t *q,
224 wait->flags |= WQ_FLAG_EXCLUSIVE;
225 __add_wait_queue(q, wait);
227 #endif /* HAVE___ADD_WAIT_QUEUE_EXCLUSIVE */
230 * wait_queue_t of Linux (version < 2.6.34) is a FIFO list for exclusively
231 * waiting threads, which is not always desirable because all threads will
232 * be waken up again and again, even user only needs a few of them to be
233 * active most time. This is not good for performance because cache can
234 * be polluted by different threads.
236 * LIFO list can resolve this problem because we always wakeup the most
237 * recent active thread by default.
239 * NB: please don't call non-exclusive & exclusive wait on the same
240 * waitq if add_wait_queue_exclusive_head is used.
242 #define add_wait_queue_exclusive_head(waitq, link) \
244 unsigned long flags; \
246 spin_lock_irqsave(&((waitq)->lock), flags); \
247 __add_wait_queue_exclusive(waitq, link); \
248 spin_unlock_irqrestore(&((waitq)->lock), flags); \
252 * wait for @condition to become true, but no longer than timeout, specified
255 #define __l_wait_event(wq, condition, info, ret, l_add_wait) \
257 wait_queue_t __wait; \
258 cfs_duration_t __timeout = info->lwi_timeout; \
259 sigset_t __blocked; \
260 int __allow_intr = info->lwi_allow_intr; \
266 init_waitqueue_entry(&__wait, current); \
267 l_add_wait(&wq, &__wait); \
269 /* Block all signals (just the non-fatal ones if no timeout). */ \
270 if (info->lwi_on_signal != NULL && (__timeout == 0 || __allow_intr)) \
271 __blocked = cfs_block_sigsinv(LUSTRE_FATAL_SIGS); \
273 __blocked = cfs_block_sigsinv(0); \
276 set_current_state(TASK_INTERRUPTIBLE); \
281 if (__timeout == 0) { \
284 cfs_duration_t interval = info->lwi_interval? \
285 min_t(cfs_duration_t, \
286 info->lwi_interval,__timeout):\
288 cfs_duration_t remaining = schedule_timeout(interval); \
289 __timeout = cfs_time_sub(__timeout, \
290 cfs_time_sub(interval, remaining));\
291 if (__timeout == 0) { \
292 if (info->lwi_on_timeout == NULL || \
293 info->lwi_on_timeout(info->lwi_cb_data)) { \
297 /* Take signals after the timeout expires. */ \
298 if (info->lwi_on_signal != NULL) \
299 (void)cfs_block_sigsinv(LUSTRE_FATAL_SIGS);\
305 if (signal_pending(current)) { \
306 if (info->lwi_on_signal != NULL && \
307 (__timeout == 0 || __allow_intr)) { \
308 if (info->lwi_on_signal != LWI_ON_SIGNAL_NOOP) \
309 info->lwi_on_signal(info->lwi_cb_data);\
313 /* We have to do this here because some signals */ \
314 /* are not blockable - ie from strace(1). */ \
315 /* In these cases we want to schedule_timeout() */ \
316 /* again, because we don't want that to return */ \
317 /* -EINTR when the RPC actually succeeded. */ \
318 /* the recalc_sigpending() below will deliver the */ \
319 /* signal properly. */ \
320 cfs_clear_sigpending(); \
324 cfs_restore_sigs(__blocked); \
326 set_current_state(TASK_RUNNING); \
327 remove_wait_queue(&wq, &__wait); \
331 #define l_wait_event(wq, condition, info) \
334 struct l_wait_info *__info = (info); \
336 __l_wait_event(wq, condition, __info, \
337 __ret, add_wait_queue); \
341 #define l_wait_event_exclusive(wq, condition, info) \
344 struct l_wait_info *__info = (info); \
346 __l_wait_event(wq, condition, __info, \
347 __ret, add_wait_queue_exclusive); \
351 #define l_wait_event_exclusive_head(wq, condition, info) \
354 struct l_wait_info *__info = (info); \
356 __l_wait_event(wq, condition, __info, \
357 __ret, add_wait_queue_exclusive_head); \
361 #define l_wait_condition(wq, condition) \
363 struct l_wait_info lwi = { 0 }; \
364 l_wait_event(wq, condition, &lwi); \
367 #define l_wait_condition_exclusive(wq, condition) \
369 struct l_wait_info lwi = { 0 }; \
370 l_wait_event_exclusive(wq, condition, &lwi); \
373 #define l_wait_condition_exclusive_head(wq, condition) \
375 struct l_wait_info lwi = { 0 }; \
376 l_wait_event_exclusive_head(wq, condition, &lwi); \
381 #endif /* _LUSTRE_LIB_H */