示例#1
0
文件: zcons.c 项目: andreiw/polaris
/*
 * wput(9E) is symmetric for master and slave sides, so this handles both
 * without splitting the codepath.
 *
 * zc_wput() looks at the other side; if there is no process holding that
 * side open, it frees the message.  This prevents processes from hanging
 * if no one is holding open the console.  Otherwise, it putnext's high
 * priority messages, putnext's normal messages if possible, and otherwise
 * enqueues the messages; in the case that something is enqueued, wsrv(9E)
 * will take care of eventually shuttling I/O to the other side.
 */
static void
zc_wput(queue_t *qp, mblk_t *mp)
{
	unsigned char type = mp->b_datap->db_type;

	ASSERT(qp->q_ptr);

	DBG1("entering zc_wput, %s side", zc_side(qp));

	if (zc_switch(RD(qp)) == NULL) {
		DBG1("wput to %s side (no one listening)", zc_side(qp));
		switch (type) {
		case M_FLUSH:
			handle_mflush(qp, mp);
			break;
		case M_IOCTL:
			miocnak(qp, mp, 0, 0);
			break;
		default:
			freemsg(mp);
			break;
		}
		return;
	}

	if (type >= QPCTL) {
		DBG1("(hipri) wput, %s side", zc_side(qp));
		switch (type) {
		case M_READ:		/* supposedly from ldterm? */
			DBG("zc_wput: tossing M_READ\n");
			freemsg(mp);
			break;
		case M_FLUSH:
			handle_mflush(qp, mp);
			break;
		default:
			/*
			 * Put this to the other side.
			 */
			ASSERT(zc_switch(RD(qp)) != NULL);
			putnext(zc_switch(RD(qp)), mp);
			break;
		}
		DBG1("done (hipri) wput, %s side", zc_side(qp));
		return;
	}

	/*
	 * Only putnext if there isn't already something in the queue.
	 * otherwise things would wind up out of order.
	 */
	if (qp->q_first == NULL && bcanputnext(RD(zc_switch(qp)), mp->b_band)) {
		DBG("wput: putting message to other side\n");
		putnext(RD(zc_switch(qp)), mp);
	} else {
		DBG("wput: putting msg onto queue\n");
		(void) putq(qp, mp);
	}
	DBG1("done wput, %s side", zc_side(qp));
}
示例#2
0
/*
 * wput(9E) is symmetric for master and slave sides, so this handles both
 * without splitting the codepath.  (The only exception to this is the
 * processing of zcons ioctls, which is restricted to the master side.)
 *
 * zc_wput() looks at the other side; if there is no process holding that
 * side open, it frees the message.  This prevents processes from hanging
 * if no one is holding open the console.  Otherwise, it putnext's high
 * priority messages, putnext's normal messages if possible, and otherwise
 * enqueues the messages; in the case that something is enqueued, wsrv(9E)
 * will take care of eventually shuttling I/O to the other side.
 */
static void
zc_wput(queue_t *qp, mblk_t *mp)
{
	unsigned char type = mp->b_datap->db_type;
	zc_state_t *zcs;
	struct iocblk *iocbp;
	file_t *slave_filep;
	struct snode *slave_snodep;
	int slave_fd;

	ASSERT(qp->q_ptr);

	DBG1("entering zc_wput, %s side", zc_side(qp));

	/*
	 * Process zcons ioctl messages if qp is the master console's write
	 * queue.
	 */
	zcs = (zc_state_t *)qp->q_ptr;
	if (zcs->zc_master_rdq != NULL && qp == WR(zcs->zc_master_rdq) &&
	    type == M_IOCTL) {
		iocbp = (struct iocblk *)(void *)mp->b_rptr;
		switch (iocbp->ioc_cmd) {
		case ZC_HOLDSLAVE:
			/*
			 * Hold the slave's vnode and increment the refcount
			 * of the snode.  If the vnode is already held, then
			 * indicate success.
			 */
			if (iocbp->ioc_count != TRANSPARENT) {
				miocack(qp, mp, 0, EINVAL);
				return;
			}
			if (zcs->zc_slave_vnode != NULL) {
				miocack(qp, mp, 0, 0);
				return;
			}

			/*
			 * The process that passed the ioctl must be running in
			 * the global zone.
			 */
			if (curzone != global_zone) {
				miocack(qp, mp, 0, EINVAL);
				return;
			}

			/*
			 * The calling process must pass a file descriptor for
			 * the slave device.
			 */
			slave_fd =
			    (int)(intptr_t)*(caddr_t *)(void *)mp->b_cont->
			    b_rptr;
			slave_filep = getf(slave_fd);
			if (slave_filep == NULL) {
				miocack(qp, mp, 0, EINVAL);
				return;
			}
			if (ZC_STATE_TO_SLAVEDEV(zcs) !=
			    slave_filep->f_vnode->v_rdev) {
				releasef(slave_fd);
				miocack(qp, mp, 0, EINVAL);
				return;
			}

			/*
			 * Get a reference to the slave's vnode.  Also bump the
			 * reference count on the associated snode.
			 */
			ASSERT(vn_matchops(slave_filep->f_vnode,
			    spec_getvnodeops()));
			zcs->zc_slave_vnode = slave_filep->f_vnode;
			VN_HOLD(zcs->zc_slave_vnode);
			slave_snodep = VTOCS(zcs->zc_slave_vnode);
			mutex_enter(&slave_snodep->s_lock);
			++slave_snodep->s_count;
			mutex_exit(&slave_snodep->s_lock);
			releasef(slave_fd);
			miocack(qp, mp, 0, 0);
			return;
		case ZC_RELEASESLAVE:
			/*
			 * Release the master's handle on the slave's vnode.
			 * If there isn't a handle for the vnode, then indicate
			 * success.
			 */
			if (iocbp->ioc_count != TRANSPARENT) {
				miocack(qp, mp, 0, EINVAL);
				return;
			}
			if (zcs->zc_slave_vnode == NULL) {
				miocack(qp, mp, 0, 0);
				return;
			}

			/*
			 * The process that passed the ioctl must be running in
			 * the global zone.
			 */
			if (curzone != global_zone) {
				miocack(qp, mp, 0, EINVAL);
				return;
			}

			/*
			 * The process that passed the ioctl must have provided
			 * a file descriptor for the slave device.  Make sure
			 * this is correct.
			 */
			slave_fd =
			    (int)(intptr_t)*(caddr_t *)(void *)mp->b_cont->
			    b_rptr;
			slave_filep = getf(slave_fd);
			if (slave_filep == NULL) {
				miocack(qp, mp, 0, EINVAL);
				return;
			}
			if (zcs->zc_slave_vnode->v_rdev !=
			    slave_filep->f_vnode->v_rdev) {
				releasef(slave_fd);
				miocack(qp, mp, 0, EINVAL);
				return;
			}

			/*
			 * Decrement the snode's reference count and release the
			 * vnode.
			 */
			ASSERT(vn_matchops(slave_filep->f_vnode,
			    spec_getvnodeops()));
			slave_snodep = VTOCS(zcs->zc_slave_vnode);
			mutex_enter(&slave_snodep->s_lock);
			--slave_snodep->s_count;
			mutex_exit(&slave_snodep->s_lock);
			VN_RELE(zcs->zc_slave_vnode);
			zcs->zc_slave_vnode = NULL;
			releasef(slave_fd);
			miocack(qp, mp, 0, 0);
			return;
		default:
			break;
		}
	}

	if (zc_switch(RD(qp)) == NULL) {
		DBG1("wput to %s side (no one listening)", zc_side(qp));
		switch (type) {
		case M_FLUSH:
			handle_mflush(qp, mp);
			break;
		case M_IOCTL:
			miocnak(qp, mp, 0, 0);
			break;
		default:
			freemsg(mp);
			break;
		}
		return;
	}

	if (type >= QPCTL) {
		DBG1("(hipri) wput, %s side", zc_side(qp));
		switch (type) {
		case M_READ:		/* supposedly from ldterm? */
			DBG("zc_wput: tossing M_READ\n");
			freemsg(mp);
			break;
		case M_FLUSH:
			handle_mflush(qp, mp);
			break;
		default:
			/*
			 * Put this to the other side.
			 */
			ASSERT(zc_switch(RD(qp)) != NULL);
			putnext(zc_switch(RD(qp)), mp);
			break;
		}
		DBG1("done (hipri) wput, %s side", zc_side(qp));
		return;
	}

	/*
	 * Only putnext if there isn't already something in the queue.
	 * otherwise things would wind up out of order.
	 */
	if (qp->q_first == NULL && bcanputnext(RD(zc_switch(qp)), mp->b_band)) {
		DBG("wput: putting message to other side\n");
		putnext(RD(zc_switch(qp)), mp);
	} else {
		DBG("wput: putting msg onto queue\n");
		(void) putq(qp, mp);
	}
	DBG1("done wput, %s side", zc_side(qp));
}