diff --git a/drivers/staging/lustre/lustre/include/lustre_lib.h b/drivers/staging/lustre/lustre/include/lustre_lib.h index ccc1a329e42b..1efd86f18c1f 100644 --- a/drivers/staging/lustre/lustre/include/lustre_lib.h +++ b/drivers/staging/lustre/lustre/include/lustre_lib.h @@ -76,123 +76,6 @@ int do_set_info_async(struct obd_import *imp, 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) - * - * kfree(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. - * - */ - -#define LWI_ON_SIGNAL_NOOP ((void (*)(void *))(-1)) - -struct l_wait_info { - long lwi_timeout; - long 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)) @@ -201,138 +84,6 @@ static inline int l_fatal_signal_pending(struct task_struct *p) return signal_pending(p) && sigtestsetmask(&p->pending.signal, LUSTRE_FATAL_SIGS); } -/** - * wait_queue_entry_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_entry_t __wait; \ - long __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 && (__timeout == 0 || __allow_intr)) \ - __blocked = cfs_block_sigsinv(LUSTRE_FATAL_SIGS); \ - else \ - __blocked = cfs_block_sigsinv(0); \ - \ - for (;;) { \ - if (condition) \ - break; \ - \ - set_current_state(TASK_INTERRUPTIBLE); \ - \ - if (__timeout == 0) { \ - schedule(); \ - } else { \ - long interval = info->lwi_interval ? \ - min_t(long, \ - info->lwi_interval, __timeout) : \ - __timeout; \ - long remaining = schedule_timeout(interval);\ - __timeout = cfs_time_sub(__timeout, \ - cfs_time_sub(interval, remaining));\ - if (__timeout == 0) { \ - if (!info->lwi_on_timeout || \ - info->lwi_on_timeout(info->lwi_cb_data)) { \ - ret = -ETIMEDOUT; \ - break; \ - } \ - /* Take signals after the timeout expires. */ \ - if (info->lwi_on_signal) \ - (void)cfs_block_sigsinv(LUSTRE_FATAL_SIGS);\ - } \ - } \ - \ - set_current_state(TASK_RUNNING); \ - \ - if (condition) \ - break; \ - if (signal_pending(current)) { \ - if (info->lwi_on_signal && \ - (__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); \ - \ - 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; \ -}) - /** @} lib */