staging: lustre: remove l_wait_event() and related code (058643de) · Commits · 戴 / test

drivers/staging/lustre/lustre/include/lustre_lib.h

+0 −249

Original line number	Diff line number	Diff line
		@@ -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 */

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