[deliverable/linux.git] / fs / orangefs / waitqueue.c

/*
 * (C) 2001 Clemson University and The University of Chicago
 * (C) 2011 Omnibond Systems
 *
 * Changes by Acxiom Corporation to implement generic service_operation()
 * function, Copyright Acxiom Corporation, 2005.
 *
 * See COPYING in top-level directory.
 */

/*
 *  In-kernel waitqueue operations.
 */

#include "protocol.h"
#include "orangefs-kernel.h"
#include "orangefs-bufmap.h"

static int wait_for_cancellation_downcall(struct orangefs_kernel_op_s *);
static int wait_for_matching_downcall(struct orangefs_kernel_op_s *);

/*
 * What we do in this function is to walk the list of operations that are
 * present in the request queue and mark them as purged.
 * NOTE: This is called from the device close after client-core has
 * guaranteed that no new operations could appear on the list since the
 * client-core is anyway going to exit.
 */
void purge_waiting_ops(void)
{
	struct orangefs_kernel_op_s *op;

	spin_lock(&orangefs_request_list_lock);
	list_for_each_entry(op, &orangefs_request_list, list) {
		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "pvfs2-client-core: purging op tag %llu %s\n",
			     llu(op->tag),
			     get_opname_string(op));
		spin_lock(&op->lock);
		set_op_state_purged(op);
		spin_unlock(&op->lock);
	}
	spin_unlock(&orangefs_request_list_lock);
}

static inline void
add_op_to_request_list(struct orangefs_kernel_op_s *op)
{
	spin_lock(&orangefs_request_list_lock);
	spin_lock(&op->lock);
	set_op_state_waiting(op);
	list_add_tail(&op->list, &orangefs_request_list);
	spin_unlock(&orangefs_request_list_lock);
	spin_unlock(&op->lock);
	wake_up_interruptible(&orangefs_request_list_waitq);
}

static inline
void add_priority_op_to_request_list(struct orangefs_kernel_op_s *op)
{
	spin_lock(&orangefs_request_list_lock);
	spin_lock(&op->lock);
	set_op_state_waiting(op);

	list_add(&op->list, &orangefs_request_list);
	spin_unlock(&orangefs_request_list_lock);
	spin_unlock(&op->lock);
	wake_up_interruptible(&orangefs_request_list_waitq);
}

/*
 * submits a ORANGEFS operation and waits for it to complete
 *
 * Note op->downcall.status will contain the status of the operation (in
 * errno format), whether provided by pvfs2-client or a result of failure to
 * service the operation.  If the caller wishes to distinguish, then
 * op->state can be checked to see if it was serviced or not.
 *
 * Returns contents of op->downcall.status for convenience
 */
int service_operation(struct orangefs_kernel_op_s *op,
		      const char *op_name,
		      int flags)
{
	/* flags to modify behavior */
	sigset_t orig_sigset;
	int ret = 0;

	DEFINE_WAIT(wait_entry);

	op->upcall.tgid = current->tgid;
	op->upcall.pid = current->pid;

retry_servicing:
	op->downcall.status = 0;
	gossip_debug(GOSSIP_WAIT_DEBUG,
		     "orangefs: service_operation: %s %p\n",
		     op_name,
		     op);
	gossip_debug(GOSSIP_WAIT_DEBUG,
		     "orangefs: operation posted by process: %s, pid: %i\n",
		     current->comm,
		     current->pid);

	/* mask out signals if this operation is not to be interrupted */
	if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
		orangefs_block_signals(&orig_sigset);

	if (!(flags & ORANGEFS_OP_NO_SEMAPHORE)) {
		ret = mutex_lock_interruptible(&request_mutex);
		/*
		 * check to see if we were interrupted while waiting for
		 * semaphore
		 */
		if (ret < 0) {
			if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
				orangefs_set_signals(&orig_sigset);
			op->downcall.status = ret;
			gossip_debug(GOSSIP_WAIT_DEBUG,
				     "orangefs: service_operation interrupted.\n");
			return ret;
		}
	}

	gossip_debug(GOSSIP_WAIT_DEBUG,
		     "%s:About to call is_daemon_in_service().\n",
		     __func__);

	if (is_daemon_in_service() < 0) {
		/*
		 * By incrementing the per-operation attempt counter, we
		 * directly go into the timeout logic while waiting for
		 * the matching downcall to be read
		 */
		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "%s:client core is NOT in service(%d).\n",
			     __func__,
			     is_daemon_in_service());
		op->attempts++;
	}

	/* queue up the operation */
	if (flags & ORANGEFS_OP_PRIORITY) {
		add_priority_op_to_request_list(op);
	} else {
		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "%s:About to call add_op_to_request_list().\n",
			     __func__);
		add_op_to_request_list(op);
	}

	if (!(flags & ORANGEFS_OP_NO_SEMAPHORE))
		mutex_unlock(&request_mutex);

	/*
	 * If we are asked to service an asynchronous operation from
	 * VFS perspective, we are done.
	 */
	if (flags & ORANGEFS_OP_ASYNC)
		return 0;

	if (flags & ORANGEFS_OP_CANCELLATION) {
		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "%s:"
			     "About to call wait_for_cancellation_downcall.\n",
			     __func__);
		ret = wait_for_cancellation_downcall(op);
	} else {
		ret = wait_for_matching_downcall(op);
	}

	if (ret < 0) {
		/* failed to get matching downcall */
		if (ret == -ETIMEDOUT) {
			gossip_err("orangefs: %s -- wait timed out; aborting attempt.\n",
				   op_name);
		}
		op->downcall.status = ret;
	} else {
		/* got matching downcall; make sure status is in errno format */
		op->downcall.status =
		    orangefs_normalize_to_errno(op->downcall.status);
		ret = op->downcall.status;
	}

	if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
		orangefs_set_signals(&orig_sigset);

	BUG_ON(ret != op->downcall.status);
	/* retry if operation has not been serviced and if requested */
	if (!op_state_serviced(op) && op->downcall.status == -EAGAIN) {
		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "orangefs: tag %llu (%s)"
			     " -- operation to be retried (%d attempt)\n",
			     llu(op->tag),
			     op_name,
			     op->attempts + 1);

		if (!op->uses_shared_memory)
			/*
			 * this operation doesn't use the shared memory
			 * system
			 */
			goto retry_servicing;

		/* op uses shared memory */
		if (orangefs_get_bufmap_init() == 0) {
			/*
			 * This operation uses the shared memory system AND
			 * the system is not yet ready. This situation occurs
			 * when the client-core is restarted AND there were
			 * operations waiting to be processed or were already
			 * in process.
			 */
			gossip_debug(GOSSIP_WAIT_DEBUG,
				     "uses_shared_memory is true.\n");
			gossip_debug(GOSSIP_WAIT_DEBUG,
				     "Client core in-service status(%d).\n",
				     is_daemon_in_service());
			gossip_debug(GOSSIP_WAIT_DEBUG, "bufmap_init:%d.\n",
				     orangefs_get_bufmap_init());
			gossip_debug(GOSSIP_WAIT_DEBUG,
				     "operation's status is 0x%0x.\n",
				     op->op_state);

			/*
			 * let process sleep for a few seconds so shared
			 * memory system can be initialized.
			 */
			prepare_to_wait(&orangefs_bufmap_init_waitq,
					&wait_entry,
					TASK_INTERRUPTIBLE);

			/*
			 * Wait for orangefs_bufmap_initialize() to wake me up
			 * within the allotted time.
			 */
			ret = schedule_timeout(MSECS_TO_JIFFIES
				(1000 * ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS));

			gossip_debug(GOSSIP_WAIT_DEBUG,
				     "Value returned from schedule_timeout:"
				     "%d.\n",
				     ret);
			gossip_debug(GOSSIP_WAIT_DEBUG,
				     "Is shared memory available? (%d).\n",
				     orangefs_get_bufmap_init());

			finish_wait(&orangefs_bufmap_init_waitq, &wait_entry);

			if (orangefs_get_bufmap_init() == 0) {
				gossip_err("%s:The shared memory system has not started in %d seconds after the client core restarted.  Aborting user's request(%s).\n",
					   __func__,
					   ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS,
					   get_opname_string(op));
				return -EIO;
			}

			/*
			 * Return to the calling function and re-populate a
			 * shared memory buffer.
			 */
			return -EAGAIN;
		}
	}

	gossip_debug(GOSSIP_WAIT_DEBUG,
		     "orangefs: service_operation %s returning: %d for %p.\n",
		     op_name,
		     ret,
		     op);
	return ret;
}

static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op)
{
	/*
	 * handle interrupted cases depending on what state we were in when
	 * the interruption is detected.  there is a coarse grained lock
	 * across the operation.
	 *
	 * NOTE: be sure not to reverse lock ordering by locking an op lock
	 * while holding the request_list lock.  Here, we first lock the op
	 * and then lock the appropriate list.
	 */
	if (!op) {
		gossip_debug(GOSSIP_WAIT_DEBUG,
			    "%s: op is null, ignoring\n",
			     __func__);
		return;
	}

	/*
	 * one more sanity check, make sure it's in one of the possible states
	 * or don't try to cancel it
	 */
	if (!(op_state_waiting(op) ||
	      op_state_in_progress(op) ||
	      op_state_serviced(op) ||
	      op_state_purged(op))) {
		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "%s: op %p not in a valid state (%0x), "
			     "ignoring\n",
			     __func__,
			     op,
			     op->op_state);
		return;
	}

	spin_lock(&op->lock);
	op->op_state |= OP_VFS_STATE_GIVEN_UP;

	if (op_state_waiting(op)) {
		/*
		 * upcall hasn't been read; remove op from upcall request
		 * list.
		 */
		spin_unlock(&op->lock);
		spin_lock(&orangefs_request_list_lock);
		list_del(&op->list);
		spin_unlock(&orangefs_request_list_lock);
		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "Interrupted: Removed op %p from request_list\n",
			     op);
	} else if (op_state_in_progress(op)) {
		/* op must be removed from the in progress htable */
		spin_unlock(&op->lock);
		spin_lock(&htable_ops_in_progress_lock);
		list_del(&op->list);
		spin_unlock(&htable_ops_in_progress_lock);
		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "Interrupted: Removed op %p"
			     " from htable_ops_in_progress\n",
			     op);
	} else if (!op_state_serviced(op)) {
		spin_unlock(&op->lock);
		gossip_err("interrupted operation is in a weird state 0x%x\n",
			   op->op_state);
	} else {
		/*
		 * It is not intended for execution to flow here,
		 * but having this unlock here makes sparse happy.
		 */
		gossip_err("%s: can't get here.\n", __func__);
		spin_unlock(&op->lock);
	}
}

/*
 * sleeps on waitqueue waiting for matching downcall.
 * if client-core finishes servicing, then we are good to go.
 * else if client-core exits, we get woken up here, and retry with a timeout
 *
 * Post when this call returns to the caller, the specified op will no
 * longer be on any list or htable.
 *
 * Returns 0 on success and -errno on failure
 * Errors are:
 * EAGAIN in case we want the caller to requeue and try again..
 * EINTR/EIO/ETIMEDOUT indicating we are done trying to service this
 * operation since client-core seems to be exiting too often
 * or if we were interrupted.
 */
static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op)
{
	int ret = -EINVAL;
	DEFINE_WAIT(wait_entry);

	while (1) {
		spin_lock(&op->lock);
		prepare_to_wait(&op->waitq, &wait_entry, TASK_INTERRUPTIBLE);
		if (op_state_serviced(op)) {
			spin_unlock(&op->lock);
			ret = 0;
			break;
		}
		spin_unlock(&op->lock);

		if (!signal_pending(current)) {
			/*
			 * if this was our first attempt and client-core
			 * has not purged our operation, we are happy to
			 * simply wait
			 */
			spin_lock(&op->lock);
			if (op->attempts == 0 && !op_state_purged(op)) {
				spin_unlock(&op->lock);
				schedule();
			} else {
				spin_unlock(&op->lock);
				/*
				 * subsequent attempts, we retry exactly once
				 * with timeouts
				 */
				if (!schedule_timeout(MSECS_TO_JIFFIES
				      (1000 * op_timeout_secs))) {
					gossip_debug(GOSSIP_WAIT_DEBUG,
						     "*** %s:"
						     " operation timed out (tag"
						     " %llu, %p, att %d)\n",
						     __func__,
						     llu(op->tag),
						     op,
						     op->attempts);
					ret = -ETIMEDOUT;
					orangefs_clean_up_interrupted_operation
					    (op);
					break;
				}
			}
			spin_lock(&op->lock);
			op->attempts++;
			/*
			 * if the operation was purged in the meantime, it
			 * is better to requeue it afresh but ensure that
			 * we have not been purged repeatedly. This could
			 * happen if client-core crashes when an op
			 * is being serviced, so we requeue the op, client
			 * core crashes again so we requeue the op, client
			 * core starts, and so on...
			 */
			if (op_state_purged(op)) {
				ret = (op->attempts < ORANGEFS_PURGE_RETRY_COUNT) ?
					 -EAGAIN :
					 -EIO;
				spin_unlock(&op->lock);
				gossip_debug(GOSSIP_WAIT_DEBUG,
					     "*** %s:"
					     " operation purged (tag "
					     "%llu, %p, att %d)\n",
					     __func__,
					     llu(op->tag),
					     op,
					     op->attempts);
				orangefs_clean_up_interrupted_operation(op);
				break;
			}
			spin_unlock(&op->lock);
			continue;
		}

		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "*** %s:"
			     " operation interrupted by a signal (tag "
			     "%llu, op %p)\n",
			     __func__,
			     llu(op->tag),
			     op);
		orangefs_clean_up_interrupted_operation(op);
		ret = -EINTR;
		break;
	}

	spin_lock(&op->lock);
	finish_wait(&op->waitq, &wait_entry);
	spin_unlock(&op->lock);

	return ret;
}

/*
 * similar to wait_for_matching_downcall(), but used in the special case
 * of I/O cancellations.
 *
 * Note we need a special wait function because if this is called we already
 *      know that a signal is pending in current and need to service the
 *      cancellation upcall anyway.  the only way to exit this is to either
 *      timeout or have the cancellation be serviced properly.
 */
static int wait_for_cancellation_downcall(struct orangefs_kernel_op_s *op)
{
	int ret = -EINVAL;
	DEFINE_WAIT(wait_entry);

	while (1) {
		spin_lock(&op->lock);
		prepare_to_wait(&op->waitq, &wait_entry, TASK_INTERRUPTIBLE);
		if (op_state_serviced(op)) {
			gossip_debug(GOSSIP_WAIT_DEBUG,
				     "%s:op-state is SERVICED.\n",
				     __func__);
			spin_unlock(&op->lock);
			ret = 0;
			break;
		}
		spin_unlock(&op->lock);

		if (signal_pending(current)) {
			gossip_debug(GOSSIP_WAIT_DEBUG,
				     "%s:operation interrupted by a signal (tag"
				     " %llu, op %p)\n",
				     __func__,
				     llu(op->tag),
				     op);
			orangefs_clean_up_interrupted_operation(op);
			ret = -EINTR;
			break;
		}

		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "%s:About to call schedule_timeout.\n",
			     __func__);
		ret =
		    schedule_timeout(MSECS_TO_JIFFIES(1000 * op_timeout_secs));

		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "%s:Value returned from schedule_timeout(%d).\n",
			     __func__,
			     ret);
		if (!ret) {
			gossip_debug(GOSSIP_WAIT_DEBUG,
				     "%s:*** operation timed out: %p\n",
				     __func__,
				     op);
			orangefs_clean_up_interrupted_operation(op);
			ret = -ETIMEDOUT;
			break;
		}

		gossip_debug(GOSSIP_WAIT_DEBUG,
			     "%s:Breaking out of loop, regardless of value returned by schedule_timeout.\n",
			     __func__);
		ret = -ETIMEDOUT;
		break;
	}

	spin_lock(&op->lock);
	finish_wait(&op->waitq, &wait_entry);
	spin_unlock(&op->lock);

	gossip_debug(GOSSIP_WAIT_DEBUG,
		     "%s:returning ret(%d)\n",
		     __func__,
		     ret);

	return ret;
}
Commit	Line	Data
1182fca3 MM	1	/*
	2	* (C) 2001 Clemson University and The University of Chicago
	3	* (C) 2011 Omnibond Systems
	4	*
	5	* Changes by Acxiom Corporation to implement generic service_operation()
	6	* function, Copyright Acxiom Corporation, 2005.
	7	*
	8	* See COPYING in top-level directory.
	9	*/
	10
	11	/*
	12	* In-kernel waitqueue operations.
	13	*/
	14
	15	#include "protocol.h"
575e9461 MM	16	#include "orangefs-kernel.h"
575e9461 MM	17	#include "orangefs-bufmap.h"
1182fca3	18
ade3d781 AV	19	static int wait_for_cancellation_downcall(struct orangefs_kernel_op_s *);
	20	static int wait_for_matching_downcall(struct orangefs_kernel_op_s *);
	21
1182fca3 MM	22	/*
	23	* What we do in this function is to walk the list of operations that are
	24	* present in the request queue and mark them as purged.
	25	* NOTE: This is called from the device close after client-core has
	26	* guaranteed that no new operations could appear on the list since the
	27	* client-core is anyway going to exit.
	28	*/
	29	void purge_waiting_ops(void)
	30	{
8bb8aefd	31	struct orangefs_kernel_op_s *op;
1182fca3	32
8bb8aefd YL	33	spin_lock(&orangefs_request_list_lock);
8bb8aefd YL	34	list_for_each_entry(op, &orangefs_request_list, list) {
1182fca3 MM	35	gossip_debug(GOSSIP_WAIT_DEBUG,
	36	"pvfs2-client-core: purging op tag %llu %s\n",
	37	llu(op->tag),
	38	get_opname_string(op));
	39	spin_lock(&op->lock);
	40	set_op_state_purged(op);
	41	spin_unlock(&op->lock);
1182fca3	42	}
8bb8aefd	43	spin_unlock(&orangefs_request_list_lock);
1182fca3 MM	44	}
1182fca3 MM	45
fc916da5 AV	46	static inline void
	47	add_op_to_request_list(struct orangefs_kernel_op_s *op)
	48	{
	49	spin_lock(&orangefs_request_list_lock);
	50	spin_lock(&op->lock);
	51	set_op_state_waiting(op);
	52	list_add_tail(&op->list, &orangefs_request_list);
	53	spin_unlock(&orangefs_request_list_lock);
	54	spin_unlock(&op->lock);
	55	wake_up_interruptible(&orangefs_request_list_waitq);
	56	}
	57
	58	static inline
	59	void add_priority_op_to_request_list(struct orangefs_kernel_op_s *op)
	60	{
	61	spin_lock(&orangefs_request_list_lock);
	62	spin_lock(&op->lock);
	63	set_op_state_waiting(op);
	64
	65	list_add(&op->list, &orangefs_request_list);
	66	spin_unlock(&orangefs_request_list_lock);
	67	spin_unlock(&op->lock);
	68	wake_up_interruptible(&orangefs_request_list_waitq);
	69	}
	70
1182fca3	71	/*
8bb8aefd	72	* submits a ORANGEFS operation and waits for it to complete
1182fca3 MM	73	*
	74	* Note op->downcall.status will contain the status of the operation (in
	75	* errno format), whether provided by pvfs2-client or a result of failure to
	76	* service the operation. If the caller wishes to distinguish, then
	77	* op->state can be checked to see if it was serviced or not.
	78	*
	79	* Returns contents of op->downcall.status for convenience
	80	*/
8bb8aefd	81	int service_operation(struct orangefs_kernel_op_s *op,
1182fca3 MM	82	const char *op_name,
	83	int flags)
	84	{
	85	/* flags to modify behavior */
	86	sigset_t orig_sigset;
	87	int ret = 0;
	88
ce6c414e	89	DEFINE_WAIT(wait_entry);
1182fca3 MM	90
	91	op->upcall.tgid = current->tgid;
	92	op->upcall.pid = current->pid;
	93
	94	retry_servicing:
	95	op->downcall.status = 0;
	96	gossip_debug(GOSSIP_WAIT_DEBUG,
8bb8aefd	97	"orangefs: service_operation: %s %p\n",
1182fca3 MM	98	op_name,
	99	op);
	100	gossip_debug(GOSSIP_WAIT_DEBUG,
8bb8aefd	101	"orangefs: operation posted by process: %s, pid: %i\n",
1182fca3 MM	102	current->comm,
	103	current->pid);
	104
	105	/* mask out signals if this operation is not to be interrupted */
8bb8aefd	106	if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
c146c0b8	107	orangefs_block_signals(&orig_sigset);
1182fca3	108
8bb8aefd	109	if (!(flags & ORANGEFS_OP_NO_SEMAPHORE)) {
1182fca3 MM	110	ret = mutex_lock_interruptible(&request_mutex);
	111	/*
	112	* check to see if we were interrupted while waiting for
	113	* semaphore
	114	*/
	115	if (ret < 0) {
8bb8aefd	116	if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
c146c0b8	117	orangefs_set_signals(&orig_sigset);
1182fca3 MM	118	op->downcall.status = ret;
1182fca3 MM	119	gossip_debug(GOSSIP_WAIT_DEBUG,
8bb8aefd	120	"orangefs: service_operation interrupted.\n");
1182fca3 MM	121	return ret;
	122	}
	123	}
	124
	125	gossip_debug(GOSSIP_WAIT_DEBUG,
	126	"%s:About to call is_daemon_in_service().\n",
	127	__func__);
	128
	129	if (is_daemon_in_service() < 0) {
	130	/*
	131	* By incrementing the per-operation attempt counter, we
	132	* directly go into the timeout logic while waiting for
	133	* the matching downcall to be read
	134	*/
	135	gossip_debug(GOSSIP_WAIT_DEBUG,
	136	"%s:client core is NOT in service(%d).\n",
	137	__func__,
	138	is_daemon_in_service());
	139	op->attempts++;
	140	}
	141
	142	/* queue up the operation */
8bb8aefd	143	if (flags & ORANGEFS_OP_PRIORITY) {
1182fca3 MM	144	add_priority_op_to_request_list(op);
	145	} else {
	146	gossip_debug(GOSSIP_WAIT_DEBUG,
	147	"%s:About to call add_op_to_request_list().\n",
	148	__func__);
	149	add_op_to_request_list(op);
	150	}
	151
8bb8aefd	152	if (!(flags & ORANGEFS_OP_NO_SEMAPHORE))
1182fca3 MM	153	mutex_unlock(&request_mutex);
	154
	155	/*
	156	* If we are asked to service an asynchronous operation from
	157	* VFS perspective, we are done.
	158	*/
8bb8aefd	159	if (flags & ORANGEFS_OP_ASYNC)
1182fca3 MM	160	return 0;
1182fca3 MM	161
8bb8aefd	162	if (flags & ORANGEFS_OP_CANCELLATION) {
1182fca3 MM	163	gossip_debug(GOSSIP_WAIT_DEBUG,
	164	"%s:"
	165	"About to call wait_for_cancellation_downcall.\n",
	166	__func__);
	167	ret = wait_for_cancellation_downcall(op);
	168	} else {
	169	ret = wait_for_matching_downcall(op);
	170	}
	171
	172	if (ret < 0) {
	173	/* failed to get matching downcall */
	174	if (ret == -ETIMEDOUT) {
8bb8aefd	175	gossip_err("orangefs: %s -- wait timed out; aborting attempt.\n",
1182fca3 MM	176	op_name);
	177	}
	178	op->downcall.status = ret;
	179	} else {
	180	/* got matching downcall; make sure status is in errno format */
	181	op->downcall.status =
8bb8aefd	182	orangefs_normalize_to_errno(op->downcall.status);
1182fca3 MM	183	ret = op->downcall.status;
	184	}
	185
8bb8aefd	186	if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
c146c0b8	187	orangefs_set_signals(&orig_sigset);
1182fca3 MM	188
	189	BUG_ON(ret != op->downcall.status);
	190	/* retry if operation has not been serviced and if requested */
	191	if (!op_state_serviced(op) && op->downcall.status == -EAGAIN) {
	192	gossip_debug(GOSSIP_WAIT_DEBUG,
8bb8aefd	193	"orangefs: tag %llu (%s)"
1182fca3 MM	194	" -- operation to be retried (%d attempt)\n",
	195	llu(op->tag),
	196	op_name,
	197	op->attempts + 1);
	198
	199	if (!op->uses_shared_memory)
	200	/*
	201	* this operation doesn't use the shared memory
	202	* system
	203	*/
	204	goto retry_servicing;
	205
	206	/* op uses shared memory */
7d221485	207	if (orangefs_get_bufmap_init() == 0) {
1182fca3 MM	208	/*
	209	* This operation uses the shared memory system AND
	210	* the system is not yet ready. This situation occurs
	211	* when the client-core is restarted AND there were
	212	* operations waiting to be processed or were already
	213	* in process.
	214	*/
	215	gossip_debug(GOSSIP_WAIT_DEBUG,
	216	"uses_shared_memory is true.\n");
	217	gossip_debug(GOSSIP_WAIT_DEBUG,
	218	"Client core in-service status(%d).\n",
	219	is_daemon_in_service());
	220	gossip_debug(GOSSIP_WAIT_DEBUG, "bufmap_init:%d.\n",
7d221485	221	orangefs_get_bufmap_init());
1182fca3 MM	222	gossip_debug(GOSSIP_WAIT_DEBUG,
	223	"operation's status is 0x%0x.\n",
	224	op->op_state);
	225
	226	/*
	227	* let process sleep for a few seconds so shared
	228	* memory system can be initialized.
	229	*/
ce6c414e MM	230	prepare_to_wait(&orangefs_bufmap_init_waitq,
	231	&wait_entry,
	232	TASK_INTERRUPTIBLE);
1182fca3	233
1182fca3	234	/*
8bb8aefd	235	* Wait for orangefs_bufmap_initialize() to wake me up
1182fca3 MM	236	* within the allotted time.
	237	*/
	238	ret = schedule_timeout(MSECS_TO_JIFFIES
8bb8aefd	239	(1000 * ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS));
1182fca3 MM	240
	241	gossip_debug(GOSSIP_WAIT_DEBUG,
	242	"Value returned from schedule_timeout:"
	243	"%d.\n",
	244	ret);
	245	gossip_debug(GOSSIP_WAIT_DEBUG,
	246	"Is shared memory available? (%d).\n",
7d221485	247	orangefs_get_bufmap_init());
1182fca3	248
ce6c414e	249	finish_wait(&orangefs_bufmap_init_waitq, &wait_entry);
1182fca3	250
7d221485	251	if (orangefs_get_bufmap_init() == 0) {
1182fca3 MM	252	gossip_err("%s:The shared memory system has not started in %d seconds after the client core restarted. Aborting user's request(%s).\n",
1182fca3 MM	253	__func__,
8bb8aefd	254	ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS,
1182fca3 MM	255	get_opname_string(op));
	256	return -EIO;
	257	}
	258
	259	/*
	260	* Return to the calling function and re-populate a
	261	* shared memory buffer.
	262	*/
	263	return -EAGAIN;
	264	}
	265	}
	266
	267	gossip_debug(GOSSIP_WAIT_DEBUG,
8bb8aefd	268	"orangefs: service_operation %s returning: %d for %p.\n",
1182fca3 MM	269	op_name,
	270	ret,
	271	op);
	272	return ret;
	273	}
	274
e07db0a2	275	static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op)
1182fca3 MM	276	{
	277	/*
	278	* handle interrupted cases depending on what state we were in when
	279	* the interruption is detected. there is a coarse grained lock
	280	* across the operation.
	281	*
	282	* NOTE: be sure not to reverse lock ordering by locking an op lock
	283	* while holding the request_list lock. Here, we first lock the op
	284	* and then lock the appropriate list.
	285	*/
	286	if (!op) {
	287	gossip_debug(GOSSIP_WAIT_DEBUG,
	288	"%s: op is null, ignoring\n",
	289	__func__);
	290	return;
	291	}
	292
	293	/*
	294	* one more sanity check, make sure it's in one of the possible states
	295	* or don't try to cancel it
	296	*/
	297	if (!(op_state_waiting(op) \|\|
	298	op_state_in_progress(op) \|\|
	299	op_state_serviced(op) \|\|
	300	op_state_purged(op))) {
	301	gossip_debug(GOSSIP_WAIT_DEBUG,
	302	"%s: op %p not in a valid state (%0x), "
	303	"ignoring\n",
	304	__func__,
	305	op,
	306	op->op_state);
	307	return;
	308	}
	309
	310	spin_lock(&op->lock);
ed42fe05	311	op->op_state \|= OP_VFS_STATE_GIVEN_UP;
1182fca3 MM	312
	313	if (op_state_waiting(op)) {
	314	/*
	315	* upcall hasn't been read; remove op from upcall request
	316	* list.
	317	*/
	318	spin_unlock(&op->lock);
ed42fe05 AV	319	spin_lock(&orangefs_request_list_lock);
	320	list_del(&op->list);
	321	spin_unlock(&orangefs_request_list_lock);
1182fca3 MM	322	gossip_debug(GOSSIP_WAIT_DEBUG,
	323	"Interrupted: Removed op %p from request_list\n",
	324	op);
	325	} else if (op_state_in_progress(op)) {
	326	/* op must be removed from the in progress htable */
	327	spin_unlock(&op->lock);
	328	spin_lock(&htable_ops_in_progress_lock);
	329	list_del(&op->list);
	330	spin_unlock(&htable_ops_in_progress_lock);
	331	gossip_debug(GOSSIP_WAIT_DEBUG,
	332	"Interrupted: Removed op %p"
	333	" from htable_ops_in_progress\n",
	334	op);
	335	} else if (!op_state_serviced(op)) {
	336	spin_unlock(&op->lock);
	337	gossip_err("interrupted operation is in a weird state 0x%x\n",
	338	op->op_state);
84d02150 MM	339	} else {
	340	/*
	341	* It is not intended for execution to flow here,
	342	* but having this unlock here makes sparse happy.
	343	*/
	344	gossip_err("%s: can't get here.\n", __func__);
	345	spin_unlock(&op->lock);
1182fca3 MM	346	}
	347	}
	348
	349	/*
	350	* sleeps on waitqueue waiting for matching downcall.
	351	* if client-core finishes servicing, then we are good to go.
	352	* else if client-core exits, we get woken up here, and retry with a timeout
	353	*
	354	* Post when this call returns to the caller, the specified op will no
	355	* longer be on any list or htable.
	356	*
	357	* Returns 0 on success and -errno on failure
	358	* Errors are:
	359	* EAGAIN in case we want the caller to requeue and try again..
	360	* EINTR/EIO/ETIMEDOUT indicating we are done trying to service this
	361	* operation since client-core seems to be exiting too often
	362	* or if we were interrupted.
	363	*/
b7ae37b0	364	static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op)
1182fca3 MM	365	{
1182fca3 MM	366	int ret = -EINVAL;
ce6c414e	367	DEFINE_WAIT(wait_entry);
1182fca3 MM	368
1182fca3 MM	369	while (1) {
1182fca3	370	spin_lock(&op->lock);
ce6c414e	371	prepare_to_wait(&op->waitq, &wait_entry, TASK_INTERRUPTIBLE);
1182fca3 MM	372	if (op_state_serviced(op)) {
	373	spin_unlock(&op->lock);
	374	ret = 0;
	375	break;
	376	}
	377	spin_unlock(&op->lock);
	378
	379	if (!signal_pending(current)) {
	380	/*
	381	* if this was our first attempt and client-core
	382	* has not purged our operation, we are happy to
	383	* simply wait
	384	*/
	385	spin_lock(&op->lock);
	386	if (op->attempts == 0 && !op_state_purged(op)) {
	387	spin_unlock(&op->lock);
	388	schedule();
	389	} else {
	390	spin_unlock(&op->lock);
	391	/*
	392	* subsequent attempts, we retry exactly once
	393	* with timeouts
	394	*/
	395	if (!schedule_timeout(MSECS_TO_JIFFIES
	396	(1000 * op_timeout_secs))) {
	397	gossip_debug(GOSSIP_WAIT_DEBUG,
	398	"*** %s:"
	399	" operation timed out (tag"
	400	" %llu, %p, att %d)\n",
	401	__func__,
	402	llu(op->tag),
	403	op,
	404	op->attempts);
	405	ret = -ETIMEDOUT;
8bb8aefd	406	orangefs_clean_up_interrupted_operation
1182fca3 MM	407	(op);
	408	break;
	409	}
	410	}
	411	spin_lock(&op->lock);
	412	op->attempts++;
	413	/*
	414	* if the operation was purged in the meantime, it
	415	* is better to requeue it afresh but ensure that
	416	* we have not been purged repeatedly. This could
	417	* happen if client-core crashes when an op
	418	* is being serviced, so we requeue the op, client
	419	* core crashes again so we requeue the op, client
	420	* core starts, and so on...
	421	*/
	422	if (op_state_purged(op)) {
8bb8aefd	423	ret = (op->attempts < ORANGEFS_PURGE_RETRY_COUNT) ?
1182fca3 MM	424	-EAGAIN :
	425	-EIO;
	426	spin_unlock(&op->lock);
	427	gossip_debug(GOSSIP_WAIT_DEBUG,
	428	"*** %s:"
	429	" operation purged (tag "
	430	"%llu, %p, att %d)\n",
	431	__func__,
	432	llu(op->tag),
	433	op,
	434	op->attempts);
8bb8aefd	435	orangefs_clean_up_interrupted_operation(op);
1182fca3 MM	436	break;
	437	}
	438	spin_unlock(&op->lock);
	439	continue;
	440	}
	441
	442	gossip_debug(GOSSIP_WAIT_DEBUG,
	443	"*** %s:"
	444	" operation interrupted by a signal (tag "
	445	"%llu, op %p)\n",
	446	__func__,
	447	llu(op->tag),
	448	op);
8bb8aefd	449	orangefs_clean_up_interrupted_operation(op);
1182fca3 MM	450	ret = -EINTR;
	451	break;
	452	}
	453
1182fca3	454	spin_lock(&op->lock);
ce6c414e	455	finish_wait(&op->waitq, &wait_entry);
1182fca3 MM	456	spin_unlock(&op->lock);
	457
	458	return ret;
	459	}
	460
	461	/*
	462	* similar to wait_for_matching_downcall(), but used in the special case
	463	* of I/O cancellations.
	464	*
	465	* Note we need a special wait function because if this is called we already
	466	* know that a signal is pending in current and need to service the
	467	* cancellation upcall anyway. the only way to exit this is to either
	468	* timeout or have the cancellation be serviced properly.
	469	*/
b7ae37b0	470	static int wait_for_cancellation_downcall(struct orangefs_kernel_op_s *op)
1182fca3 MM	471	{
1182fca3 MM	472	int ret = -EINVAL;
ce6c414e	473	DEFINE_WAIT(wait_entry);
1182fca3 MM	474
1182fca3 MM	475	while (1) {
1182fca3	476	spin_lock(&op->lock);
ce6c414e	477	prepare_to_wait(&op->waitq, &wait_entry, TASK_INTERRUPTIBLE);
1182fca3 MM	478	if (op_state_serviced(op)) {
	479	gossip_debug(GOSSIP_WAIT_DEBUG,
	480	"%s:op-state is SERVICED.\n",
	481	__func__);
	482	spin_unlock(&op->lock);
	483	ret = 0;
	484	break;
	485	}
	486	spin_unlock(&op->lock);
	487
	488	if (signal_pending(current)) {
	489	gossip_debug(GOSSIP_WAIT_DEBUG,
	490	"%s:operation interrupted by a signal (tag"
	491	" %llu, op %p)\n",
	492	__func__,
	493	llu(op->tag),
	494	op);
8bb8aefd	495	orangefs_clean_up_interrupted_operation(op);
1182fca3 MM	496	ret = -EINTR;
	497	break;
	498	}
	499
	500	gossip_debug(GOSSIP_WAIT_DEBUG,
	501	"%s:About to call schedule_timeout.\n",
	502	__func__);
	503	ret =
	504	schedule_timeout(MSECS_TO_JIFFIES(1000 * op_timeout_secs));
	505
	506	gossip_debug(GOSSIP_WAIT_DEBUG,
	507	"%s:Value returned from schedule_timeout(%d).\n",
	508	__func__,
	509	ret);
	510	if (!ret) {
	511	gossip_debug(GOSSIP_WAIT_DEBUG,
	512	"%s:*** operation timed out: %p\n",
	513	__func__,
	514	op);
8bb8aefd	515	orangefs_clean_up_interrupted_operation(op);
1182fca3 MM	516	ret = -ETIMEDOUT;
	517	break;
	518	}
	519
	520	gossip_debug(GOSSIP_WAIT_DEBUG,
	521	"%s:Breaking out of loop, regardless of value returned by schedule_timeout.\n",
	522	__func__);
	523	ret = -ETIMEDOUT;
	524	break;
	525	}
	526
1182fca3	527	spin_lock(&op->lock);
ce6c414e	528	finish_wait(&op->waitq, &wait_entry);
1182fca3 MM	529	spin_unlock(&op->lock);
	530
	531	gossip_debug(GOSSIP_WAIT_DEBUG,
	532	"%s:returning ret(%d)\n",
	533	__func__,
	534	ret);
	535
	536	return ret;
	537	}