[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_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));
		set_op_state_purged(op);
	}
	spin_unlock(&orangefs_request_list_lock);
}

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

static inline void
add_op_to_request_list(struct orangefs_kernel_op_s *op)
{
	spin_lock(&orangefs_request_list_lock);
	__add_op_to_request_list(op);
	spin_unlock(&orangefs_request_list_lock);
}

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;

	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) {
			WARN_ON(1);
			/*
			 * 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(
				ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS * HZ);

			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;
}

bool orangefs_cancel_op_in_progress(struct orangefs_kernel_op_s *op)
{
	u64 tag = op->tag;
	if (!op_state_in_progress(op))
		return false;

	op->slot_to_free = op->upcall.req.io.buf_index;
	memset(&op->upcall, 0, sizeof(op->upcall));
	memset(&op->downcall, 0, sizeof(op->downcall));
	op->upcall.type = ORANGEFS_VFS_OP_CANCEL;
	op->upcall.req.cancel.op_tag = tag;
	op->downcall.type = ORANGEFS_VFS_OP_INVALID;
	op->downcall.status = -1;
	orangefs_new_tag(op);

	spin_lock(&orangefs_request_list_lock);
	/* orangefs_request_list_lock is enough of a barrier here */
	if (!__is_daemon_in_service()) {
		spin_unlock(&orangefs_request_list_lock);
		return false;
	}
	__add_op_to_request_list(op);
	spin_unlock(&orangefs_request_list_lock);

	gossip_debug(GOSSIP_UTILS_DEBUG,
		     "Attempting ORANGEFS operation cancellation of tag %llu\n",
		     llu(tag));
	return true;
}

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.
	 *
	 * Called with op->lock held.
	 */
	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;
		}

		if (unlikely(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;
		}

		/*
		 * if this was our first attempt and client-core
		 * has not purged our operation, we are happy to
		 * simply wait
		 */
		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(op_timeout_secs * HZ)) {
				gossip_debug(GOSSIP_WAIT_DEBUG,
					     "*** %s:"
					     " operation timed out (tag"
					     " %llu, %p, att %d)\n",
					     __func__,
					     llu(op->tag),
					     op,
					     op->attempts);
				ret = -ETIMEDOUT;
				spin_lock(&op->lock);
				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;
			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);
	}

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

	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_matching_downcall(struct orangefs_kernel_op_s *);
ade3d781 AV	20
1182fca3 MM	21	/*
	22	* What we do in this function is to walk the list of operations that are
	23	* present in the request queue and mark them as purged.
	24	* NOTE: This is called from the device close after client-core has
	25	* guaranteed that no new operations could appear on the list since the
	26	* client-core is anyway going to exit.
	27	*/
	28	void purge_waiting_ops(void)
	29	{
8bb8aefd	30	struct orangefs_kernel_op_s *op;
1182fca3	31
8bb8aefd YL	32	spin_lock(&orangefs_request_list_lock);
8bb8aefd YL	33	list_for_each_entry(op, &orangefs_request_list, list) {
1182fca3 MM	34	gossip_debug(GOSSIP_WAIT_DEBUG,
	35	"pvfs2-client-core: purging op tag %llu %s\n",
	36	llu(op->tag),
	37	get_opname_string(op));
1182fca3	38	set_op_state_purged(op);
1182fca3	39	}
8bb8aefd	40	spin_unlock(&orangefs_request_list_lock);
1182fca3 MM	41	}
1182fca3 MM	42
fc916da5	43	static inline void
78699e29	44	__add_op_to_request_list(struct orangefs_kernel_op_s *op)
fc916da5	45	{
fc916da5 AV	46	spin_lock(&op->lock);
	47	set_op_state_waiting(op);
	48	list_add_tail(&op->list, &orangefs_request_list);
fc916da5 AV	49	spin_unlock(&op->lock);
	50	wake_up_interruptible(&orangefs_request_list_waitq);
	51	}
	52
78699e29 AV	53	static inline void
	54	add_op_to_request_list(struct orangefs_kernel_op_s *op)
	55	{
	56	spin_lock(&orangefs_request_list_lock);
	57	__add_op_to_request_list(op);
	58	spin_unlock(&orangefs_request_list_lock);
	59	}
	60
fc916da5 AV	61	static inline
	62	void add_priority_op_to_request_list(struct orangefs_kernel_op_s *op)
	63	{
	64	spin_lock(&orangefs_request_list_lock);
	65	spin_lock(&op->lock);
	66	set_op_state_waiting(op);
	67
	68	list_add(&op->list, &orangefs_request_list);
	69	spin_unlock(&orangefs_request_list_lock);
	70	spin_unlock(&op->lock);
	71	wake_up_interruptible(&orangefs_request_list_waitq);
	72	}
	73
1182fca3	74	/*
8bb8aefd	75	* submits a ORANGEFS operation and waits for it to complete
1182fca3 MM	76	*
	77	* Note op->downcall.status will contain the status of the operation (in
	78	* errno format), whether provided by pvfs2-client or a result of failure to
	79	* service the operation. If the caller wishes to distinguish, then
	80	* op->state can be checked to see if it was serviced or not.
	81	*
	82	* Returns contents of op->downcall.status for convenience
	83	*/
8bb8aefd	84	int service_operation(struct orangefs_kernel_op_s *op,
1182fca3 MM	85	const char *op_name,
	86	int flags)
	87	{
	88	/* flags to modify behavior */
	89	sigset_t orig_sigset;
	90	int ret = 0;
	91
ce6c414e	92	DEFINE_WAIT(wait_entry);
1182fca3 MM	93
	94	op->upcall.tgid = current->tgid;
	95	op->upcall.pid = current->pid;
	96
	97	retry_servicing:
	98	op->downcall.status = 0;
	99	gossip_debug(GOSSIP_WAIT_DEBUG,
8bb8aefd	100	"orangefs: service_operation: %s %p\n",
1182fca3 MM	101	op_name,
	102	op);
	103	gossip_debug(GOSSIP_WAIT_DEBUG,
8bb8aefd	104	"orangefs: operation posted by process: %s, pid: %i\n",
1182fca3 MM	105	current->comm,
	106	current->pid);
	107
	108	/* mask out signals if this operation is not to be interrupted */
8bb8aefd	109	if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
c146c0b8	110	orangefs_block_signals(&orig_sigset);
1182fca3	111
8bb8aefd	112	if (!(flags & ORANGEFS_OP_NO_SEMAPHORE)) {
1182fca3 MM	113	ret = mutex_lock_interruptible(&request_mutex);
	114	/*
	115	* check to see if we were interrupted while waiting for
	116	* semaphore
	117	*/
	118	if (ret < 0) {
8bb8aefd	119	if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
c146c0b8	120	orangefs_set_signals(&orig_sigset);
1182fca3 MM	121	op->downcall.status = ret;
1182fca3 MM	122	gossip_debug(GOSSIP_WAIT_DEBUG,
8bb8aefd	123	"orangefs: service_operation interrupted.\n");
1182fca3 MM	124	return ret;
	125	}
	126	}
	127
	128	gossip_debug(GOSSIP_WAIT_DEBUG,
	129	"%s:About to call is_daemon_in_service().\n",
	130	__func__);
	131
	132	if (is_daemon_in_service() < 0) {
	133	/*
	134	* By incrementing the per-operation attempt counter, we
	135	* directly go into the timeout logic while waiting for
	136	* the matching downcall to be read
	137	*/
	138	gossip_debug(GOSSIP_WAIT_DEBUG,
	139	"%s:client core is NOT in service(%d).\n",
	140	__func__,
	141	is_daemon_in_service());
	142	op->attempts++;
	143	}
	144
	145	/* queue up the operation */
8bb8aefd	146	if (flags & ORANGEFS_OP_PRIORITY) {
1182fca3 MM	147	add_priority_op_to_request_list(op);
	148	} else {
	149	gossip_debug(GOSSIP_WAIT_DEBUG,
	150	"%s:About to call add_op_to_request_list().\n",
	151	__func__);
	152	add_op_to_request_list(op);
	153	}
	154
8bb8aefd	155	if (!(flags & ORANGEFS_OP_NO_SEMAPHORE))
1182fca3 MM	156	mutex_unlock(&request_mutex);
	157
	158	/*
	159	* If we are asked to service an asynchronous operation from
	160	* VFS perspective, we are done.
	161	*/
8bb8aefd	162	if (flags & ORANGEFS_OP_ASYNC)
1182fca3 MM	163	return 0;
1182fca3 MM	164
78699e29	165	ret = wait_for_matching_downcall(op);
1182fca3 MM	166
	167	if (ret < 0) {
	168	/* failed to get matching downcall */
	169	if (ret == -ETIMEDOUT) {
8bb8aefd	170	gossip_err("orangefs: %s -- wait timed out; aborting attempt.\n",
1182fca3 MM	171	op_name);
	172	}
	173	op->downcall.status = ret;
	174	} else {
	175	/* got matching downcall; make sure status is in errno format */
	176	op->downcall.status =
8bb8aefd	177	orangefs_normalize_to_errno(op->downcall.status);
1182fca3 MM	178	ret = op->downcall.status;
	179	}
	180
8bb8aefd	181	if (!(flags & ORANGEFS_OP_INTERRUPTIBLE))
c146c0b8	182	orangefs_set_signals(&orig_sigset);
1182fca3 MM	183
	184	BUG_ON(ret != op->downcall.status);
	185	/* retry if operation has not been serviced and if requested */
	186	if (!op_state_serviced(op) && op->downcall.status == -EAGAIN) {
	187	gossip_debug(GOSSIP_WAIT_DEBUG,
8bb8aefd	188	"orangefs: tag %llu (%s)"
1182fca3 MM	189	" -- operation to be retried (%d attempt)\n",
	190	llu(op->tag),
	191	op_name,
	192	op->attempts + 1);
	193
	194	if (!op->uses_shared_memory)
	195	/*
	196	* this operation doesn't use the shared memory
	197	* system
	198	*/
	199	goto retry_servicing;
	200
	201	/* op uses shared memory */
7d221485	202	if (orangefs_get_bufmap_init() == 0) {
6ebcc3fc	203	WARN_ON(1);
1182fca3 MM	204	/*
	205	* This operation uses the shared memory system AND
	206	* the system is not yet ready. This situation occurs
	207	* when the client-core is restarted AND there were
	208	* operations waiting to be processed or were already
	209	* in process.
	210	*/
	211	gossip_debug(GOSSIP_WAIT_DEBUG,
	212	"uses_shared_memory is true.\n");
	213	gossip_debug(GOSSIP_WAIT_DEBUG,
	214	"Client core in-service status(%d).\n",
	215	is_daemon_in_service());
	216	gossip_debug(GOSSIP_WAIT_DEBUG, "bufmap_init:%d.\n",
7d221485	217	orangefs_get_bufmap_init());
1182fca3 MM	218	gossip_debug(GOSSIP_WAIT_DEBUG,
	219	"operation's status is 0x%0x.\n",
	220	op->op_state);
	221
	222	/*
	223	* let process sleep for a few seconds so shared
	224	* memory system can be initialized.
	225	*/
ce6c414e MM	226	prepare_to_wait(&orangefs_bufmap_init_waitq,
	227	&wait_entry,
	228	TASK_INTERRUPTIBLE);
1182fca3	229
1182fca3	230	/*
8bb8aefd	231	* Wait for orangefs_bufmap_initialize() to wake me up
1182fca3 MM	232	* within the allotted time.
1182fca3 MM	233	*/
727cbfea AV	234	ret = schedule_timeout(
727cbfea AV	235	ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS * HZ);
1182fca3 MM	236
	237	gossip_debug(GOSSIP_WAIT_DEBUG,
	238	"Value returned from schedule_timeout:"
	239	"%d.\n",
	240	ret);
	241	gossip_debug(GOSSIP_WAIT_DEBUG,
	242	"Is shared memory available? (%d).\n",
7d221485	243	orangefs_get_bufmap_init());
1182fca3	244
ce6c414e	245	finish_wait(&orangefs_bufmap_init_waitq, &wait_entry);
1182fca3	246
7d221485	247	if (orangefs_get_bufmap_init() == 0) {
1182fca3 MM	248	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	249	__func__,
8bb8aefd	250	ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS,
1182fca3 MM	251	get_opname_string(op));
	252	return -EIO;
	253	}
	254
	255	/*
	256	* Return to the calling function and re-populate a
	257	* shared memory buffer.
	258	*/
	259	return -EAGAIN;
	260	}
	261	}
	262
	263	gossip_debug(GOSSIP_WAIT_DEBUG,
8bb8aefd	264	"orangefs: service_operation %s returning: %d for %p.\n",
1182fca3 MM	265	op_name,
	266	ret,
	267	op);
	268	return ret;
	269	}
	270
78699e29 AV	271	bool orangefs_cancel_op_in_progress(struct orangefs_kernel_op_s *op)
	272	{
	273	u64 tag = op->tag;
	274	if (!op_state_in_progress(op))
	275	return false;
	276
	277	op->slot_to_free = op->upcall.req.io.buf_index;
	278	memset(&op->upcall, 0, sizeof(op->upcall));
	279	memset(&op->downcall, 0, sizeof(op->downcall));
	280	op->upcall.type = ORANGEFS_VFS_OP_CANCEL;
	281	op->upcall.req.cancel.op_tag = tag;
	282	op->downcall.type = ORANGEFS_VFS_OP_INVALID;
	283	op->downcall.status = -1;
	284	orangefs_new_tag(op);
	285
	286	spin_lock(&orangefs_request_list_lock);
	287	/* orangefs_request_list_lock is enough of a barrier here */
	288	if (!__is_daemon_in_service()) {
	289	spin_unlock(&orangefs_request_list_lock);
	290	return false;
	291	}
	292	__add_op_to_request_list(op);
	293	spin_unlock(&orangefs_request_list_lock);
	294
	295	gossip_debug(GOSSIP_UTILS_DEBUG,
	296	"Attempting ORANGEFS operation cancellation of tag %llu\n",
	297	llu(tag));
	298	return true;
	299	}
	300
e07db0a2	301	static void orangefs_clean_up_interrupted_operation(struct orangefs_kernel_op_s *op)
1182fca3 MM	302	{
	303	/*
	304	* handle interrupted cases depending on what state we were in when
	305	* the interruption is detected. there is a coarse grained lock
	306	* across the operation.
	307	*
eab9b389	308	* Called with op->lock held.
1182fca3	309	*/
ed42fe05	310	op->op_state \|= OP_VFS_STATE_GIVEN_UP;
1182fca3 MM	311
	312	if (op_state_waiting(op)) {
	313	/*
	314	* upcall hasn't been read; remove op from upcall request
	315	* list.
	316	*/
	317	spin_unlock(&op->lock);
ed42fe05 AV	318	spin_lock(&orangefs_request_list_lock);
	319	list_del(&op->list);
	320	spin_unlock(&orangefs_request_list_lock);
1182fca3 MM	321	gossip_debug(GOSSIP_WAIT_DEBUG,
	322	"Interrupted: Removed op %p from request_list\n",
	323	op);
	324	} else if (op_state_in_progress(op)) {
	325	/* op must be removed from the in progress htable */
	326	spin_unlock(&op->lock);
	327	spin_lock(&htable_ops_in_progress_lock);
	328	list_del(&op->list);
	329	spin_unlock(&htable_ops_in_progress_lock);
	330	gossip_debug(GOSSIP_WAIT_DEBUG,
	331	"Interrupted: Removed op %p"
	332	" from htable_ops_in_progress\n",
	333	op);
	334	} else if (!op_state_serviced(op)) {
	335	spin_unlock(&op->lock);
	336	gossip_err("interrupted operation is in a weird state 0x%x\n",
	337	op->op_state);
84d02150 MM	338	} else {
	339	/*
	340	* It is not intended for execution to flow here,
	341	* but having this unlock here makes sparse happy.
	342	*/
	343	gossip_err("%s: can't get here.\n", __func__);
	344	spin_unlock(&op->lock);
1182fca3 MM	345	}
	346	}
	347
	348	/*
	349	* sleeps on waitqueue waiting for matching downcall.
	350	* if client-core finishes servicing, then we are good to go.
	351	* else if client-core exits, we get woken up here, and retry with a timeout
	352	*
	353	* Post when this call returns to the caller, the specified op will no
	354	* longer be on any list or htable.
	355	*
	356	* Returns 0 on success and -errno on failure
	357	* Errors are:
	358	* EAGAIN in case we want the caller to requeue and try again..
	359	* EINTR/EIO/ETIMEDOUT indicating we are done trying to service this
	360	* operation since client-core seems to be exiting too often
	361	* or if we were interrupted.
	362	*/
b7ae37b0	363	static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op)
1182fca3 MM	364	{
1182fca3 MM	365	int ret = -EINVAL;
ce6c414e	366	DEFINE_WAIT(wait_entry);
1182fca3 MM	367
1182fca3 MM	368	while (1) {
1182fca3	369	spin_lock(&op->lock);
ce6c414e	370	prepare_to_wait(&op->waitq, &wait_entry, TASK_INTERRUPTIBLE);
1182fca3 MM	371	if (op_state_serviced(op)) {
	372	spin_unlock(&op->lock);
	373	ret = 0;
	374	break;
	375	}
1182fca3	376
70c6ea26 AV	377	if (unlikely(signal_pending(current))) {
	378	gossip_debug(GOSSIP_WAIT_DEBUG,
	379	"*** %s:"
	380	" operation interrupted by a signal (tag "
	381	"%llu, op %p)\n",
	382	__func__,
	383	llu(op->tag),
	384	op);
	385	orangefs_clean_up_interrupted_operation(op);
	386	ret = -EINTR;
	387	break;
	388	}
	389
	390	/*
	391	* if this was our first attempt and client-core
	392	* has not purged our operation, we are happy to
	393	* simply wait
	394	*/
70c6ea26 AV	395	if (op->attempts == 0 && !op_state_purged(op)) {
	396	spin_unlock(&op->lock);
	397	schedule();
	398	} else {
	399	spin_unlock(&op->lock);
1182fca3	400	/*
70c6ea26 AV	401	* subsequent attempts, we retry exactly once
70c6ea26 AV	402	* with timeouts
1182fca3	403	*/
727cbfea	404	if (!schedule_timeout(op_timeout_secs * HZ)) {
1182fca3 MM	405	gossip_debug(GOSSIP_WAIT_DEBUG,
1182fca3 MM	406	"*** %s:"
70c6ea26 AV	407	" operation timed out (tag"
70c6ea26 AV	408	" %llu, %p, att %d)\n",
1182fca3 MM	409	__func__,
	410	llu(op->tag),
	411	op,
	412	op->attempts);
70c6ea26	413	ret = -ETIMEDOUT;
eab9b389	414	spin_lock(&op->lock);
8bb8aefd	415	orangefs_clean_up_interrupted_operation(op);
1182fca3 MM	416	break;
1182fca3 MM	417	}
70c6ea26 AV	418	}
	419	spin_lock(&op->lock);
	420	op->attempts++;
	421	/*
	422	* if the operation was purged in the meantime, it
	423	* is better to requeue it afresh but ensure that
	424	* we have not been purged repeatedly. This could
	425	* happen if client-core crashes when an op
	426	* is being serviced, so we requeue the op, client
	427	* core crashes again so we requeue the op, client
	428	* core starts, and so on...
	429	*/
	430	if (op_state_purged(op)) {
	431	ret = (op->attempts < ORANGEFS_PURGE_RETRY_COUNT) ?
	432	-EAGAIN :
	433	-EIO;
70c6ea26 AV	434	gossip_debug(GOSSIP_WAIT_DEBUG,
	435	"*** %s:"
	436	" operation purged (tag "
	437	"%llu, %p, att %d)\n",
	438	__func__,
	439	llu(op->tag),
	440	op,
	441	op->attempts);
	442	orangefs_clean_up_interrupted_operation(op);
	443	break;
1182fca3	444	}
70c6ea26	445	spin_unlock(&op->lock);
1182fca3 MM	446	}
1182fca3 MM	447
1182fca3	448	spin_lock(&op->lock);
ce6c414e	449	finish_wait(&op->waitq, &wait_entry);
1182fca3 MM	450	spin_unlock(&op->lock);
	451
	452	return ret;
	453	}