/* * (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 *, long, bool);static void orangefs_clean_up_interrupted_operation(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);		gossip_debug(GOSSIP_DEV_DEBUG,			     "%s: op:%s: op_state:%d: process:%s:\n",			     __func__,			     get_opname_string(op),			     op->op_state,			     current->comm);	}	spin_unlock(&orangefs_request_list_lock);} /* * 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){	long timeout = MAX_SCHEDULE_TIMEOUT;	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,		     "%s: %s op:%p: process:%s: pid:%d:\n",		     __func__,		     op_name,		     op,		     current->comm,		     current->pid); 	/*	 * If ORANGEFS_OP_NO_MUTEX was set in flags, we need to avoid	 * acquiring the request_mutex because we're servicing a	 * high priority remount operation and the request_mutex is	 * already taken.	 */	if (!(flags & ORANGEFS_OP_NO_MUTEX)) {		if (flags & ORANGEFS_OP_INTERRUPTIBLE)			ret = mutex_lock_interruptible(&orangefs_request_mutex);		else			ret = mutex_lock_killable(&orangefs_request_mutex);		/*		 * check to see if we were interrupted while waiting for		 * mutex		 */		if (ret < 0) {			op->downcall.status = ret;			gossip_debug(GOSSIP_WAIT_DEBUG,				     "%s: service_operation interrupted.\n",				     __func__);			return ret;		}	} 	/* queue up the operation */	spin_lock(&orangefs_request_list_lock);	spin_lock(&op->lock);	set_op_state_waiting(op);	gossip_debug(GOSSIP_DEV_DEBUG,		     "%s: op:%s: op_state:%d: process:%s:\n",		     __func__,		     get_opname_string(op),		     op->op_state,		     current->comm);	/* add high priority remount op to the front of the line. */	if (flags & ORANGEFS_OP_PRIORITY)		list_add(&op->list, &orangefs_request_list);	else		list_add_tail(&op->list, &orangefs_request_list);	spin_unlock(&op->lock);	wake_up_interruptible(&orangefs_request_list_waitq);	if (!__is_daemon_in_service()) {		gossip_debug(GOSSIP_WAIT_DEBUG,			     "%s:client core is NOT in service.\n",			     __func__);		/*		 * Don't wait for the userspace component to return if		 * the filesystem is being umounted anyway.		 */		if (op->upcall.type == ORANGEFS_VFS_OP_FS_UMOUNT)			timeout = 0;		else			timeout = op_timeout_secs * HZ;	}	spin_unlock(&orangefs_request_list_lock); 	if (!(flags & ORANGEFS_OP_NO_MUTEX))		mutex_unlock(&orangefs_request_mutex); 	ret = wait_for_matching_downcall(op, timeout,					 flags & ORANGEFS_OP_INTERRUPTIBLE); 	gossip_debug(GOSSIP_WAIT_DEBUG,		     "%s: wait_for_matching_downcall returned %d for %p\n",		     __func__,		     ret,		     op); 	/* got matching downcall; make sure status is in errno format */	if (!ret) {		spin_unlock(&op->lock);		op->downcall.status =		    orangefs_normalize_to_errno(op->downcall.status);		ret = op->downcall.status;		goto out;	} 	/* failed to get matching downcall */	if (ret == -ETIMEDOUT) {		gossip_err("%s: %s -- wait timed out; aborting attempt.\n",			   __func__,			   op_name);	} 	/*	 * remove a waiting op from the request list or	 * remove an in-progress op from the in-progress list.	 */	orangefs_clean_up_interrupted_operation(op); 	op->downcall.status = ret;	/* retry if operation has not been serviced and if requested */	if (ret == -EAGAIN) {		op->attempts++;		timeout = op_timeout_secs * HZ;		gossip_debug(GOSSIP_WAIT_DEBUG,			     "orangefs: tag %llu (%s)"			     " -- operation to be retried (%d attempt)\n",			     llu(op->tag),			     op_name,			     op->attempts); 		/*		 * io ops (ops that use the shared memory buffer) have		 * to be returned to their caller for a retry. Other ops		 * can just be recycled here.		 */		if (!op->uses_shared_memory)			goto retry_servicing;	} out:	gossip_debug(GOSSIP_WAIT_DEBUG,		     "%s: %s returning: %d for %p.\n",		     __func__,		     op_name,		     ret,		     op);	return ret;} /* This can get called on an I/O op if it had a bad service_operation. */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;	}	spin_lock(&op->lock);	set_op_state_waiting(op);	gossip_debug(GOSSIP_DEV_DEBUG,		     "%s: op:%s: op_state:%d: process:%s:\n",		     __func__,		     get_opname_string(op),		     op->op_state,		     current->comm);	list_add(&op->list, &orangefs_request_list);	spin_unlock(&op->lock);	spin_unlock(&orangefs_request_list_lock); 	gossip_debug(GOSSIP_WAIT_DEBUG,		     "Attempting ORANGEFS operation cancellation of tag %llu\n",		     llu(tag));	return true;} /* * Change an op to the "given up" state and remove it from its list. */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.	 *	 * Called with op->lock held.	 */ 	/*	 * List manipulation code elsewhere will ignore ops that	 * have been given up upon.	 */	op->op_state |= OP_VFS_STATE_GIVEN_UP; 	if (list_empty(&op->list)) {		/* caught copying to/from daemon */		BUG_ON(op_state_serviced(op));		spin_unlock(&op->lock);		wait_for_completion(&op->waitq);	} else 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_init(&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(&orangefs_htable_ops_in_progress_lock);		list_del_init(&op->list);		spin_unlock(&orangefs_htable_ops_in_progress_lock);		gossip_debug(GOSSIP_WAIT_DEBUG,			     "Interrupted: Removed op %p"			     " from htable_ops_in_progress\n",			     op);	} else {		spin_unlock(&op->lock);		gossip_err("interrupted operation is in a weird state 0x%x\n",			   op->op_state);	}	reinit_completion(&op->waitq);} /* * 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 * * When this call returns to the caller, the specified op will no * longer be in either the in_progress hash table or on the request list. * * 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. * * Returns with op->lock taken. */static int wait_for_matching_downcall(struct orangefs_kernel_op_s *op,				      long timeout,				      bool interruptible){	long n; 	/*	 * There's a "schedule_timeout" inside of these wait	 * primitives, during which the op is out of the hands of the	 * user process that needs something done and is being	 * manipulated by the client-core process.	 */	if (interruptible)		n = wait_for_completion_interruptible_timeout(&op->waitq,							      timeout);	else		n = wait_for_completion_killable_timeout(&op->waitq, timeout); 	spin_lock(&op->lock); 	if (op_state_serviced(op))		return 0; 	if (unlikely(n < 0)) {		gossip_debug(GOSSIP_WAIT_DEBUG,			     "%s: operation interrupted, tag %llu, %p\n",			     __func__,			     llu(op->tag),			     op);		return -EINTR;	}	if (op_state_purged(op)) {		gossip_debug(GOSSIP_WAIT_DEBUG,			     "%s: operation purged, tag %llu, %p, %d\n",			     __func__,			     llu(op->tag),			     op,			     op->attempts);		return (op->attempts < ORANGEFS_PURGE_RETRY_COUNT) ?			 -EAGAIN :			 -EIO;	}	/* must have timed out, then... */	gossip_debug(GOSSIP_WAIT_DEBUG,		     "%s: operation timed out, tag %llu, %p, %d)\n",		     __func__,		     llu(op->tag),		     op,		     op->attempts);	return -ETIMEDOUT;}