/* * GPL HEADER START * * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 only, * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License version 2 for more details (a copy is included * in the LICENSE file that accompanied this code). * * You should have received a copy of the GNU General Public License * version 2 along with this program; If not, see * http://www.gnu.org/licenses/gpl-2.0.html * * GPL HEADER END */ /* * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved. * Use is subject to license terms. * * Copyright (c) 2011, 2014, Intel Corporation. */ /* * This file is part of Lustre, http://www.lustre.org/ * Lustre is a trademark of Sun Microsystems, Inc. * * lustre/include/lustre_lib.h * * Basic Lustre library routines. */ #ifndef _LUSTRE_LIB_H #define _LUSTRE_LIB_H /** \defgroup lib lib * * @{ */ #include #include #include #include #include /* target.c */ struct ptlrpc_request; struct obd_export; struct lu_target; struct l_wait_info; #include #include #define LI_POISON 0x5a5a5a5a #if BITS_PER_LONG > 32 # define LL_POISON 0x5a5a5a5a5a5a5a5aL #else # define LL_POISON 0x5a5a5a5aL #endif #define LP_POISON ((void *)LL_POISON) #ifdef HAVE_SERVER_SUPPORT int rev_import_init(struct obd_export *exp); int target_handle_connect(struct ptlrpc_request *req); int target_handle_disconnect(struct ptlrpc_request *req); void target_destroy_export(struct obd_export *exp); int target_handle_ping(struct ptlrpc_request *req); void target_committed_to_req(struct ptlrpc_request *req); void target_cancel_recovery_timer(struct obd_device *obd); void target_stop_recovery_thread(struct obd_device *obd); void target_cleanup_recovery(struct obd_device *obd); int target_queue_recovery_request(struct ptlrpc_request *req, struct obd_device *obd); int target_bulk_io(struct obd_export *exp, struct ptlrpc_bulk_desc *desc, struct l_wait_info *lwi); #endif int target_pack_pool_reply(struct ptlrpc_request *req); int do_set_info_async(struct obd_import *imp, int opcode, int version, size_t keylen, void *key, size_t vallen, void *val, struct ptlrpc_request_set *set); void target_send_reply(struct ptlrpc_request *req, int rc, int fail_id); /* * l_wait_event is a flexible sleeping function, permitting simple caller * configuration of interrupt and timeout sensitivity along with actions to * be performed in the event of either exception. * * The first form of usage looks like this: * * struct l_wait_info lwi = LWI_TIMEOUT_INTR(timeout, timeout_handler, * intr_handler, callback_data); * rc = l_wait_event(waitq, condition, &lwi); * * l_wait_event() makes the current process wait on 'waitq' until 'condition' * is TRUE or a "killable" signal (SIGTERM, SIKGILL, SIGINT) is pending. It * returns 0 to signify 'condition' is TRUE, but if a signal wakes it before * 'condition' becomes true, it optionally calls the specified 'intr_handler' * if not NULL, and returns -EINTR. * * If a non-zero timeout is specified, signals are ignored until the timeout * has expired. At this time, if 'timeout_handler' is not NULL it is called. * If it returns FALSE l_wait_event() continues to wait as described above with * signals enabled. Otherwise it returns -ETIMEDOUT. * * LWI_INTR(intr_handler, callback_data) is shorthand for * LWI_TIMEOUT_INTR(0, NULL, intr_handler, callback_data) * * The second form of usage looks like this: * * struct l_wait_info lwi = LWI_TIMEOUT(timeout, timeout_handler); * rc = l_wait_event(waitq, condition, &lwi); * * This form is the same as the first except that it COMPLETELY IGNORES * SIGNALS. The caller must therefore beware that if 'timeout' is zero, or if * 'timeout_handler' is not NULL and returns FALSE, then the ONLY thing that * can unblock the current process is 'condition' becoming TRUE. * * Another form of usage is: * struct l_wait_info lwi = LWI_TIMEOUT_INTERVAL(timeout, interval, * timeout_handler); * rc = l_wait_event(waitq, condition, &lwi); * This is the same as previous case, but condition is checked once every * 'interval' jiffies (if non-zero). * * Subtle synchronization point: this macro does *not* necessary takes * wait-queue spin-lock before returning, and, hence, following idiom is safe * ONLY when caller provides some external locking: * * Thread1 Thread2 * * l_wait_event(&obj->wq, ....); (1) * * wake_up(&obj->wq): (2) * spin_lock(&q->lock); (2.1) * __wake_up_common(q, ...); (2.2) * spin_unlock(&q->lock, flags); (2.3) * * OBD_FREE_PTR(obj); (3) * * As l_wait_event() may "short-cut" execution and return without taking * wait-queue spin-lock, some additional synchronization is necessary to * guarantee that step (3) can begin only after (2.3) finishes. * * XXX nikita: some ptlrpc daemon threads have races of that sort. * */ static inline int back_to_sleep(void *arg) { return 0; } #define LWI_ON_SIGNAL_NOOP ((void (*)(void *))(-1)) struct l_wait_info { cfs_duration_t lwi_timeout; cfs_duration_t lwi_interval; int lwi_allow_intr; int (*lwi_on_timeout)(void *); void (*lwi_on_signal)(void *); void *lwi_cb_data; }; /* NB: LWI_TIMEOUT ignores signals completely */ #define LWI_TIMEOUT(time, cb, data) \ ((struct l_wait_info) { \ .lwi_timeout = time, \ .lwi_on_timeout = cb, \ .lwi_cb_data = data, \ .lwi_interval = 0, \ .lwi_allow_intr = 0 \ }) #define LWI_TIMEOUT_INTERVAL(time, interval, cb, data) \ ((struct l_wait_info) { \ .lwi_timeout = time, \ .lwi_on_timeout = cb, \ .lwi_cb_data = data, \ .lwi_interval = interval, \ .lwi_allow_intr = 0 \ }) #define LWI_TIMEOUT_INTR(time, time_cb, sig_cb, data) \ ((struct l_wait_info) { \ .lwi_timeout = time, \ .lwi_on_timeout = time_cb, \ .lwi_on_signal = sig_cb, \ .lwi_cb_data = data, \ .lwi_interval = 0, \ .lwi_allow_intr = 0 \ }) #define LWI_TIMEOUT_INTR_ALL(time, time_cb, sig_cb, data) \ ((struct l_wait_info) { \ .lwi_timeout = time, \ .lwi_on_timeout = time_cb, \ .lwi_on_signal = sig_cb, \ .lwi_cb_data = data, \ .lwi_interval = 0, \ .lwi_allow_intr = 1 \ }) #define LWI_INTR(cb, data) LWI_TIMEOUT_INTR(0, NULL, cb, data) #define LUSTRE_FATAL_SIGS \ (sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGTERM) | \ sigmask(SIGQUIT) | sigmask(SIGALRM)) /* * Wait Queue */ #ifndef HAVE___ADD_WAIT_QUEUE_EXCLUSIVE static inline void __add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait) { wait->flags |= WQ_FLAG_EXCLUSIVE; __add_wait_queue(q, wait); } #endif /* HAVE___ADD_WAIT_QUEUE_EXCLUSIVE */ /** * wait_queue_t of Linux (version < 2.6.34) is a FIFO list for exclusively * waiting threads, which is not always desirable because all threads will * be waken up again and again, even user only needs a few of them to be * active most time. This is not good for performance because cache can * be polluted by different threads. * * LIFO list can resolve this problem because we always wakeup the most * recent active thread by default. * * NB: please don't call non-exclusive & exclusive wait on the same * waitq if add_wait_queue_exclusive_head is used. */ #define add_wait_queue_exclusive_head(waitq, link) \ { \ unsigned long flags; \ \ spin_lock_irqsave(&((waitq)->lock), flags); \ __add_wait_queue_exclusive(waitq, link); \ spin_unlock_irqrestore(&((waitq)->lock), flags); \ } /* * wait for @condition to become true, but no longer than timeout, specified * by @info. */ #define __l_wait_event(wq, condition, info, ret, l_add_wait) \ do { \ wait_queue_t __wait; \ cfs_duration_t __timeout = info->lwi_timeout; \ sigset_t __blocked; \ int __allow_intr = info->lwi_allow_intr; \ \ ret = 0; \ if (condition) \ break; \ \ init_waitqueue_entry(&__wait, current); \ l_add_wait(&wq, &__wait); \ \ /* Block all signals (just the non-fatal ones if no timeout). */ \ if (info->lwi_on_signal != NULL && (__timeout == 0 || __allow_intr)) \ __blocked = cfs_block_sigsinv(LUSTRE_FATAL_SIGS); \ else \ __blocked = cfs_block_sigsinv(0); \ \ for (;;) { \ set_current_state(TASK_INTERRUPTIBLE); \ \ if (condition) \ break; \ \ if (__timeout == 0) { \ schedule(); \ } else { \ cfs_duration_t interval = info->lwi_interval? \ min_t(cfs_duration_t, \ info->lwi_interval,__timeout):\ __timeout; \ cfs_duration_t remaining = schedule_timeout(interval); \ __timeout = cfs_time_sub(__timeout, \ cfs_time_sub(interval, remaining));\ if (__timeout == 0) { \ if (info->lwi_on_timeout == NULL || \ info->lwi_on_timeout(info->lwi_cb_data)) { \ ret = -ETIMEDOUT; \ break; \ } \ /* Take signals after the timeout expires. */ \ if (info->lwi_on_signal != NULL) \ (void)cfs_block_sigsinv(LUSTRE_FATAL_SIGS);\ } \ } \ \ if (condition) \ break; \ if (signal_pending(current)) { \ if (info->lwi_on_signal != NULL && \ (__timeout == 0 || __allow_intr)) { \ if (info->lwi_on_signal != LWI_ON_SIGNAL_NOOP) \ info->lwi_on_signal(info->lwi_cb_data);\ ret = -EINTR; \ break; \ } \ /* We have to do this here because some signals */ \ /* are not blockable - ie from strace(1). */ \ /* In these cases we want to schedule_timeout() */ \ /* again, because we don't want that to return */ \ /* -EINTR when the RPC actually succeeded. */ \ /* the recalc_sigpending() below will deliver the */ \ /* signal properly. */ \ cfs_clear_sigpending(); \ } \ } \ \ cfs_restore_sigs(__blocked); \ \ set_current_state(TASK_RUNNING); \ remove_wait_queue(&wq, &__wait); \ } while (0) #define l_wait_event(wq, condition, info) \ ({ \ int __ret; \ struct l_wait_info *__info = (info); \ \ __l_wait_event(wq, condition, __info, \ __ret, add_wait_queue); \ __ret; \ }) #define l_wait_event_exclusive(wq, condition, info) \ ({ \ int __ret; \ struct l_wait_info *__info = (info); \ \ __l_wait_event(wq, condition, __info, \ __ret, add_wait_queue_exclusive); \ __ret; \ }) #define l_wait_event_exclusive_head(wq, condition, info) \ ({ \ int __ret; \ struct l_wait_info *__info = (info); \ \ __l_wait_event(wq, condition, __info, \ __ret, add_wait_queue_exclusive_head); \ __ret; \ }) #define l_wait_condition(wq, condition) \ ({ \ struct l_wait_info lwi = { 0 }; \ l_wait_event(wq, condition, &lwi); \ }) #define l_wait_condition_exclusive(wq, condition) \ ({ \ struct l_wait_info lwi = { 0 }; \ l_wait_event_exclusive(wq, condition, &lwi); \ }) #define l_wait_condition_exclusive_head(wq, condition) \ ({ \ struct l_wait_info lwi = { 0 }; \ l_wait_event_exclusive_head(wq, condition, &lwi); \ }) /** @} lib */ #endif /* _LUSTRE_LIB_H */