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zfcp_erp.c

/*
 * This file is part of the zfcp device driver for
 * FCP adapters for IBM System z9 and zSeries.
 *
 * (C) Copyright IBM Corp. 2002, 2006
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#define ZFCP_LOG_AREA               ZFCP_LOG_AREA_ERP

#include "zfcp_ext.h"

static int zfcp_erp_adisc(struct zfcp_port *);
static void zfcp_erp_adisc_handler(unsigned long);

static int zfcp_erp_adapter_reopen_internal(struct zfcp_adapter *, int);
static int zfcp_erp_port_forced_reopen_internal(struct zfcp_port *, int);
static int zfcp_erp_port_reopen_internal(struct zfcp_port *, int);
static int zfcp_erp_unit_reopen_internal(struct zfcp_unit *, int);

static int zfcp_erp_port_reopen_all_internal(struct zfcp_adapter *, int);
static int zfcp_erp_unit_reopen_all_internal(struct zfcp_port *, int);

static void zfcp_erp_adapter_block(struct zfcp_adapter *, int);
static void zfcp_erp_adapter_unblock(struct zfcp_adapter *);
static void zfcp_erp_port_block(struct zfcp_port *, int);
static void zfcp_erp_port_unblock(struct zfcp_port *);
static void zfcp_erp_unit_block(struct zfcp_unit *, int);
static void zfcp_erp_unit_unblock(struct zfcp_unit *);

static int zfcp_erp_thread(void *);

static int zfcp_erp_strategy(struct zfcp_erp_action *);

static int zfcp_erp_strategy_do_action(struct zfcp_erp_action *);
static int zfcp_erp_strategy_memwait(struct zfcp_erp_action *);
static int zfcp_erp_strategy_check_target(struct zfcp_erp_action *, int);
static int zfcp_erp_strategy_check_unit(struct zfcp_unit *, int);
static int zfcp_erp_strategy_check_port(struct zfcp_port *, int);
static int zfcp_erp_strategy_check_adapter(struct zfcp_adapter *, int);
static int zfcp_erp_strategy_statechange(int, u32, struct zfcp_adapter *,
                               struct zfcp_port *,
                               struct zfcp_unit *, int);
static int zfcp_erp_strategy_statechange_detected(atomic_t *, u32);
static int zfcp_erp_strategy_followup_actions(int, struct zfcp_adapter *,
                                    struct zfcp_port *,
                                    struct zfcp_unit *, int);
static int zfcp_erp_strategy_check_queues(struct zfcp_adapter *);
static int zfcp_erp_strategy_check_action(struct zfcp_erp_action *, int);

static int zfcp_erp_adapter_strategy(struct zfcp_erp_action *);
static int zfcp_erp_adapter_strategy_generic(struct zfcp_erp_action *, int);
static int zfcp_erp_adapter_strategy_close(struct zfcp_erp_action *);
static int zfcp_erp_adapter_strategy_open(struct zfcp_erp_action *);
static int zfcp_erp_adapter_strategy_open_qdio(struct zfcp_erp_action *);
static int zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *);
static int zfcp_erp_adapter_strategy_open_fsf_xconfig(struct zfcp_erp_action *);
static int zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *);
static int zfcp_erp_adapter_strategy_open_fsf_statusread(
      struct zfcp_erp_action *);

static int zfcp_erp_port_forced_strategy(struct zfcp_erp_action *);
static int zfcp_erp_port_forced_strategy_close(struct zfcp_erp_action *);

static int zfcp_erp_port_strategy(struct zfcp_erp_action *);
static int zfcp_erp_port_strategy_clearstati(struct zfcp_port *);
static int zfcp_erp_port_strategy_close(struct zfcp_erp_action *);
static int zfcp_erp_port_strategy_open(struct zfcp_erp_action *);
static int zfcp_erp_port_strategy_open_nameserver(struct zfcp_erp_action *);
static int zfcp_erp_port_strategy_open_nameserver_wakeup(
      struct zfcp_erp_action *);
static int zfcp_erp_port_strategy_open_common(struct zfcp_erp_action *);
static int zfcp_erp_port_strategy_open_common_lookup(struct zfcp_erp_action *);
static int zfcp_erp_port_strategy_open_port(struct zfcp_erp_action *);

static int zfcp_erp_unit_strategy(struct zfcp_erp_action *);
static int zfcp_erp_unit_strategy_clearstati(struct zfcp_unit *);
static int zfcp_erp_unit_strategy_close(struct zfcp_erp_action *);
static int zfcp_erp_unit_strategy_open(struct zfcp_erp_action *);

static void zfcp_erp_action_dismiss_adapter(struct zfcp_adapter *);
static void zfcp_erp_action_dismiss_port(struct zfcp_port *);
static void zfcp_erp_action_dismiss_unit(struct zfcp_unit *);
static void zfcp_erp_action_dismiss(struct zfcp_erp_action *);

static int zfcp_erp_action_enqueue(int, struct zfcp_adapter *,
                           struct zfcp_port *, struct zfcp_unit *);
static int zfcp_erp_action_dequeue(struct zfcp_erp_action *);
static void zfcp_erp_action_cleanup(int, struct zfcp_adapter *,
                            struct zfcp_port *, struct zfcp_unit *,
                            int);

static void zfcp_erp_action_ready(struct zfcp_erp_action *);
static int  zfcp_erp_action_exists(struct zfcp_erp_action *);

static void zfcp_erp_action_to_ready(struct zfcp_erp_action *);
static void zfcp_erp_action_to_running(struct zfcp_erp_action *);

static void zfcp_erp_memwait_handler(unsigned long);

/**
 * zfcp_close_qdio - close qdio queues for an adapter
 */
static void zfcp_close_qdio(struct zfcp_adapter *adapter)
{
      struct zfcp_qdio_queue *req_queue;
      int first, count;

      if (!atomic_test_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status))
            return;

      /* clear QDIOUP flag, thus do_QDIO is not called during qdio_shutdown */
      req_queue = &adapter->request_queue;
      write_lock_irq(&req_queue->queue_lock);
      atomic_clear_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
      write_unlock_irq(&req_queue->queue_lock);

      debug_text_event(adapter->erp_dbf, 3, "qdio_down2a");
      while (qdio_shutdown(adapter->ccw_device,
                       QDIO_FLAG_CLEANUP_USING_CLEAR) == -EINPROGRESS)
            msleep(1000);
      debug_text_event(adapter->erp_dbf, 3, "qdio_down2b");

      /* cleanup used outbound sbals */
      count = atomic_read(&req_queue->free_count);
      if (count < QDIO_MAX_BUFFERS_PER_Q) {
            first = (req_queue->free_index+count) % QDIO_MAX_BUFFERS_PER_Q;
            count = QDIO_MAX_BUFFERS_PER_Q - count;
            zfcp_qdio_zero_sbals(req_queue->buffer, first, count);
      }
      req_queue->free_index = 0;
      atomic_set(&req_queue->free_count, 0);
      req_queue->distance_from_int = 0;
      adapter->response_queue.free_index = 0;
      atomic_set(&adapter->response_queue.free_count, 0);
}

/**
 * zfcp_close_fsf - stop FSF operations for an adapter
 *
 * Dismiss and cleanup all pending fsf_reqs (this wakes up all initiators of
 * requests waiting for completion; especially this returns SCSI commands
 * with error state).
 */
static void zfcp_close_fsf(struct zfcp_adapter *adapter)
{
      /* close queues to ensure that buffers are not accessed by adapter */
      zfcp_close_qdio(adapter);
      zfcp_fsf_req_dismiss_all(adapter);
      /* reset FSF request sequence number */
      adapter->fsf_req_seq_no = 0;
      /* all ports and units are closed */
      zfcp_erp_modify_adapter_status(adapter,
                               ZFCP_STATUS_COMMON_OPEN, ZFCP_CLEAR);
}

/**
 * zfcp_fsf_request_timeout_handler - called if a request timed out
 * @data: pointer to adapter for handler function
 *
 * This function needs to be called if requests (ELS, Generic Service,
 * or SCSI commands) exceed a certain time limit. The assumption is
 * that after the time limit the adapter get stuck. So we trigger a reopen of
 * the adapter.
 */
static void zfcp_fsf_request_timeout_handler(unsigned long data)
{
      struct zfcp_adapter *adapter = (struct zfcp_adapter *) data;
      zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED);
}

void zfcp_fsf_start_timer(struct zfcp_fsf_req *fsf_req, unsigned long timeout)
{
      fsf_req->timer.function = zfcp_fsf_request_timeout_handler;
      fsf_req->timer.data = (unsigned long) fsf_req->adapter;
      fsf_req->timer.expires = jiffies + timeout;
      add_timer(&fsf_req->timer);
}

/*
 * function:
 *
 * purpose: called if an adapter failed,
 *          initiates adapter recovery which is done
 *          asynchronously
 *
 * returns: 0     - initiated action successfully
 *          <0    - failed to initiate action
 */
static int
zfcp_erp_adapter_reopen_internal(struct zfcp_adapter *adapter, int clear_mask)
{
      int retval;

      debug_text_event(adapter->erp_dbf, 5, "a_ro");
      ZFCP_LOG_DEBUG("reopen adapter %s\n",
                   zfcp_get_busid_by_adapter(adapter));

      zfcp_erp_adapter_block(adapter, clear_mask);

      if (atomic_test_mask(ZFCP_STATUS_COMMON_ERP_FAILED, &adapter->status)) {
            ZFCP_LOG_DEBUG("skipped reopen of failed adapter %s\n",
                         zfcp_get_busid_by_adapter(adapter));
            debug_text_event(adapter->erp_dbf, 5, "a_ro_f");
            /* ensure propagation of failed status to new devices */
            zfcp_erp_adapter_failed(adapter);
            retval = -EIO;
            goto out;
      }
      retval = zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER,
                               adapter, NULL, NULL);

 out:
      return retval;
}

/*
 * function:
 *
 * purpose: Wrappper for zfcp_erp_adapter_reopen_internal
 *              used to ensure the correct locking
 *
 * returns: 0     - initiated action successfully
 *          <0    - failed to initiate action
 */
int
zfcp_erp_adapter_reopen(struct zfcp_adapter *adapter, int clear_mask)
{
      int retval;
      unsigned long flags;

      read_lock_irqsave(&zfcp_data.config_lock, flags);
      write_lock(&adapter->erp_lock);
      retval = zfcp_erp_adapter_reopen_internal(adapter, clear_mask);
      write_unlock(&adapter->erp_lock);
      read_unlock_irqrestore(&zfcp_data.config_lock, flags);

      return retval;
}

int
zfcp_erp_adapter_shutdown(struct zfcp_adapter *adapter, int clear_mask)
{
      int retval;

      retval = zfcp_erp_adapter_reopen(adapter,
                               ZFCP_STATUS_COMMON_RUNNING |
                               ZFCP_STATUS_COMMON_ERP_FAILED |
                               clear_mask);

      return retval;
}

int
zfcp_erp_port_shutdown(struct zfcp_port *port, int clear_mask)
{
      int retval;

      retval = zfcp_erp_port_reopen(port,
                              ZFCP_STATUS_COMMON_RUNNING |
                              ZFCP_STATUS_COMMON_ERP_FAILED |
                              clear_mask);

      return retval;
}

int
zfcp_erp_unit_shutdown(struct zfcp_unit *unit, int clear_mask)
{
      int retval;

      retval = zfcp_erp_unit_reopen(unit,
                              ZFCP_STATUS_COMMON_RUNNING |
                              ZFCP_STATUS_COMMON_ERP_FAILED |
                              clear_mask);

      return retval;
}


/**
 * zfcp_erp_adisc - send ADISC ELS command
 * @port: port structure
 */
static int
zfcp_erp_adisc(struct zfcp_port *port)
{
      struct zfcp_adapter *adapter = port->adapter;
      struct zfcp_send_els *send_els;
      struct zfcp_ls_adisc *adisc;
      void *address = NULL;
      int retval = 0;

      send_els = kzalloc(sizeof(struct zfcp_send_els), GFP_ATOMIC);
      if (send_els == NULL)
            goto nomem;

      send_els->req = kmalloc(sizeof(struct scatterlist), GFP_ATOMIC);
      if (send_els->req == NULL)
            goto nomem;
      sg_init_table(send_els->req, 1);

      send_els->resp = kmalloc(sizeof(struct scatterlist), GFP_ATOMIC);
      if (send_els->resp == NULL)
            goto nomem;
      sg_init_table(send_els->resp, 1);

      address = (void *) get_zeroed_page(GFP_ATOMIC);
      if (address == NULL)
            goto nomem;

      zfcp_address_to_sg(address, send_els->req, sizeof(struct zfcp_ls_adisc));
      address += PAGE_SIZE >> 1;
      zfcp_address_to_sg(address, send_els->resp, sizeof(struct zfcp_ls_adisc_acc));
      send_els->req_count = send_els->resp_count = 1;

      send_els->adapter = adapter;
      send_els->port = port;
      send_els->d_id = port->d_id;
      send_els->handler = zfcp_erp_adisc_handler;
      send_els->handler_data = (unsigned long) send_els;

      adisc = zfcp_sg_to_address(send_els->req);
      send_els->ls_code = adisc->code = ZFCP_LS_ADISC;

      /* acc. to FC-FS, hard_nport_id in ADISC should not be set for ports
         without FC-AL-2 capability, so we don't set it */
      adisc->wwpn = fc_host_port_name(adapter->scsi_host);
      adisc->wwnn = fc_host_node_name(adapter->scsi_host);
      adisc->nport_id = fc_host_port_id(adapter->scsi_host);
      ZFCP_LOG_INFO("ADISC request from s_id 0x%06x to d_id 0x%06x "
                  "(wwpn=0x%016Lx, wwnn=0x%016Lx, "
                  "hard_nport_id=0x%06x, nport_id=0x%06x)\n",
                  adisc->nport_id, send_els->d_id, (wwn_t) adisc->wwpn,
                  (wwn_t) adisc->wwnn, adisc->hard_nport_id,
                  adisc->nport_id);

      retval = zfcp_fsf_send_els(send_els);
      if (retval != 0) {
            ZFCP_LOG_NORMAL("error: initiation of Send ELS failed for port "
                        "0x%06x on adapter %s\n", send_els->d_id,
                        zfcp_get_busid_by_adapter(adapter));
            goto freemem;
      }

      goto out;

 nomem:
      retval = -ENOMEM;
 freemem:
      if (address != NULL)
            __free_pages(sg_page(send_els->req), 0);
      if (send_els != NULL) {
            kfree(send_els->req);
            kfree(send_els->resp);
            kfree(send_els);
      }
 out:
      return retval;
}


/**
 * zfcp_erp_adisc_handler - handler for ADISC ELS command
 * @data: pointer to struct zfcp_send_els
 *
 * If ADISC failed (LS_RJT or timed out) forced reopen of the port is triggered.
 */
static void
zfcp_erp_adisc_handler(unsigned long data)
{
      struct zfcp_send_els *send_els;
      struct zfcp_port *port;
      struct zfcp_adapter *adapter;
      u32 d_id;
      struct zfcp_ls_adisc_acc *adisc;

      send_els = (struct zfcp_send_els *) data;
      adapter = send_els->adapter;
      port = send_els->port;
      d_id = send_els->d_id;

      /* request rejected or timed out */
      if (send_els->status != 0) {
            ZFCP_LOG_NORMAL("ELS request rejected/timed out, "
                        "force physical port reopen "
                        "(adapter %s, port d_id=0x%06x)\n",
                        zfcp_get_busid_by_adapter(adapter), d_id);
            debug_text_event(adapter->erp_dbf, 3, "forcreop");
            if (zfcp_erp_port_forced_reopen(port, 0))
                  ZFCP_LOG_NORMAL("failed reopen of port "
                              "(adapter %s, wwpn=0x%016Lx)\n",
                              zfcp_get_busid_by_port(port),
                              port->wwpn);
            goto out;
      }

      adisc = zfcp_sg_to_address(send_els->resp);

      ZFCP_LOG_INFO("ADISC response from d_id 0x%06x to s_id "
                  "0x%06x (wwpn=0x%016Lx, wwnn=0x%016Lx, "
                  "hard_nport_id=0x%06x, nport_id=0x%06x)\n",
                  d_id, fc_host_port_id(adapter->scsi_host),
                  (wwn_t) adisc->wwpn, (wwn_t) adisc->wwnn,
                  adisc->hard_nport_id, adisc->nport_id);

      /* set wwnn for port */
      if (port->wwnn == 0)
            port->wwnn = adisc->wwnn;

      if (port->wwpn != adisc->wwpn) {
            ZFCP_LOG_NORMAL("d_id assignment changed, reopening "
                        "port (adapter %s, wwpn=0x%016Lx, "
                        "adisc_resp_wwpn=0x%016Lx)\n",
                        zfcp_get_busid_by_port(port),
                        port->wwpn, (wwn_t) adisc->wwpn);
            if (zfcp_erp_port_reopen(port, 0))
                  ZFCP_LOG_NORMAL("failed reopen of port "
                              "(adapter %s, wwpn=0x%016Lx)\n",
                              zfcp_get_busid_by_port(port),
                              port->wwpn);
      }

 out:
      zfcp_port_put(port);
      __free_pages(sg_page(send_els->req), 0);
      kfree(send_els->req);
      kfree(send_els->resp);
      kfree(send_els);
}


/**
 * zfcp_test_link - lightweight link test procedure
 * @port: port to be tested
 *
 * Test status of a link to a remote port using the ELS command ADISC.
 */
int
zfcp_test_link(struct zfcp_port *port)
{
      int retval;

      zfcp_port_get(port);
      retval = zfcp_erp_adisc(port);
      if (retval != 0) {
            zfcp_port_put(port);
            ZFCP_LOG_NORMAL("reopen needed for port 0x%016Lx "
                        "on adapter %s\n ", port->wwpn,
                        zfcp_get_busid_by_port(port));
            retval = zfcp_erp_port_forced_reopen(port, 0);
            if (retval != 0) {
                  ZFCP_LOG_NORMAL("reopen of remote port 0x%016Lx "
                              "on adapter %s failed\n", port->wwpn,
                              zfcp_get_busid_by_port(port));
                  retval = -EPERM;
            }
      }

      return retval;
}


/*
 * function:
 *
 * purpose: called if a port failed to be opened normally
 *          initiates Forced Reopen recovery which is done
 *          asynchronously
 *
 * returns: 0     - initiated action successfully
 *          <0    - failed to initiate action
 */
static int
zfcp_erp_port_forced_reopen_internal(struct zfcp_port *port, int clear_mask)
{
      int retval;
      struct zfcp_adapter *adapter = port->adapter;

      debug_text_event(adapter->erp_dbf, 5, "pf_ro");
      debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));

      ZFCP_LOG_DEBUG("forced reopen of port 0x%016Lx on adapter %s\n",
                   port->wwpn, zfcp_get_busid_by_port(port));

      zfcp_erp_port_block(port, clear_mask);

      if (atomic_test_mask(ZFCP_STATUS_COMMON_ERP_FAILED, &port->status)) {
            ZFCP_LOG_DEBUG("skipped forced reopen of failed port 0x%016Lx "
                         "on adapter %s\n", port->wwpn,
                         zfcp_get_busid_by_port(port));
            debug_text_event(adapter->erp_dbf, 5, "pf_ro_f");
            debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));
            retval = -EIO;
            goto out;
      }

      retval = zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT_FORCED,
                               port->adapter, port, NULL);

 out:
      return retval;
}

/*
 * function:
 *
 * purpose: Wrappper for zfcp_erp_port_forced_reopen_internal
 *              used to ensure the correct locking
 *
 * returns: 0     - initiated action successfully
 *          <0    - failed to initiate action
 */
int
zfcp_erp_port_forced_reopen(struct zfcp_port *port, int clear_mask)
{
      int retval;
      unsigned long flags;
      struct zfcp_adapter *adapter;

      adapter = port->adapter;
      read_lock_irqsave(&zfcp_data.config_lock, flags);
      write_lock(&adapter->erp_lock);
      retval = zfcp_erp_port_forced_reopen_internal(port, clear_mask);
      write_unlock(&adapter->erp_lock);
      read_unlock_irqrestore(&zfcp_data.config_lock, flags);

      return retval;
}

/*
 * function:
 *
 * purpose: called if a port is to be opened
 *          initiates Reopen recovery which is done
 *          asynchronously
 *
 * returns: 0     - initiated action successfully
 *          <0    - failed to initiate action
 */
static int
zfcp_erp_port_reopen_internal(struct zfcp_port *port, int clear_mask)
{
      int retval;
      struct zfcp_adapter *adapter = port->adapter;

      debug_text_event(adapter->erp_dbf, 5, "p_ro");
      debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));

      ZFCP_LOG_DEBUG("reopen of port 0x%016Lx on adapter %s\n",
                   port->wwpn, zfcp_get_busid_by_port(port));

      zfcp_erp_port_block(port, clear_mask);

      if (atomic_test_mask(ZFCP_STATUS_COMMON_ERP_FAILED, &port->status)) {
            ZFCP_LOG_DEBUG("skipped reopen of failed port 0x%016Lx "
                         "on adapter %s\n", port->wwpn,
                         zfcp_get_busid_by_port(port));
            debug_text_event(adapter->erp_dbf, 5, "p_ro_f");
            debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));
            /* ensure propagation of failed status to new devices */
            zfcp_erp_port_failed(port);
            retval = -EIO;
            goto out;
      }

      retval = zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_PORT,
                               port->adapter, port, NULL);

 out:
      return retval;
}

/**
 * zfcp_erp_port_reopen - initiate reopen of a remote port
 * @port: port to be reopened
 * @clear_mask: specifies flags in port status to be cleared
 * Return: 0 on success, < 0 on error
 *
 * This is a wrappper function for zfcp_erp_port_reopen_internal. It ensures
 * correct locking. An error recovery task is initiated to do the reopen.
 * To wait for the completion of the reopen zfcp_erp_wait should be used.
 */
int
zfcp_erp_port_reopen(struct zfcp_port *port, int clear_mask)
{
      int retval;
      unsigned long flags;
      struct zfcp_adapter *adapter = port->adapter;

      read_lock_irqsave(&zfcp_data.config_lock, flags);
      write_lock(&adapter->erp_lock);
      retval = zfcp_erp_port_reopen_internal(port, clear_mask);
      write_unlock(&adapter->erp_lock);
      read_unlock_irqrestore(&zfcp_data.config_lock, flags);

      return retval;
}

/*
 * function:
 *
 * purpose: called if a unit is to be opened
 *          initiates Reopen recovery which is done
 *          asynchronously
 *
 * returns: 0     - initiated action successfully
 *          <0    - failed to initiate action
 */
static int
zfcp_erp_unit_reopen_internal(struct zfcp_unit *unit, int clear_mask)
{
      int retval;
      struct zfcp_adapter *adapter = unit->port->adapter;

      debug_text_event(adapter->erp_dbf, 5, "u_ro");
      debug_event(adapter->erp_dbf, 5, &unit->fcp_lun, sizeof (fcp_lun_t));
      ZFCP_LOG_DEBUG("reopen of unit 0x%016Lx on port 0x%016Lx "
                   "on adapter %s\n", unit->fcp_lun,
                   unit->port->wwpn, zfcp_get_busid_by_unit(unit));

      zfcp_erp_unit_block(unit, clear_mask);

      if (atomic_test_mask(ZFCP_STATUS_COMMON_ERP_FAILED, &unit->status)) {
            ZFCP_LOG_DEBUG("skipped reopen of failed unit 0x%016Lx "
                         "on port 0x%016Lx on adapter %s\n",
                         unit->fcp_lun, unit->port->wwpn,
                         zfcp_get_busid_by_unit(unit));
            debug_text_event(adapter->erp_dbf, 5, "u_ro_f");
            debug_event(adapter->erp_dbf, 5, &unit->fcp_lun,
                      sizeof (fcp_lun_t));
            retval = -EIO;
            goto out;
      }

      retval = zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_UNIT,
                               unit->port->adapter, unit->port, unit);
 out:
      return retval;
}

/**
 * zfcp_erp_unit_reopen - initiate reopen of a unit
 * @unit: unit to be reopened
 * @clear_mask: specifies flags in unit status to be cleared
 * Return: 0 on success, < 0 on error
 *
 * This is a wrappper for zfcp_erp_unit_reopen_internal. It ensures correct
 * locking. An error recovery task is initiated to do the reopen.
 * To wait for the completion of the reopen zfcp_erp_wait should be used.
 */
int
zfcp_erp_unit_reopen(struct zfcp_unit *unit, int clear_mask)
{
      int retval;
      unsigned long flags;
      struct zfcp_adapter *adapter;
      struct zfcp_port *port;

      port = unit->port;
      adapter = port->adapter;

      read_lock_irqsave(&zfcp_data.config_lock, flags);
      write_lock(&adapter->erp_lock);
      retval = zfcp_erp_unit_reopen_internal(unit, clear_mask);
      write_unlock(&adapter->erp_lock);
      read_unlock_irqrestore(&zfcp_data.config_lock, flags);

      return retval;
}

/**
 * zfcp_erp_adapter_block - mark adapter as blocked, block scsi requests
 */
static void zfcp_erp_adapter_block(struct zfcp_adapter *adapter, int clear_mask)
{
      debug_text_event(adapter->erp_dbf, 6, "a_bl");
      zfcp_erp_modify_adapter_status(adapter,
                               ZFCP_STATUS_COMMON_UNBLOCKED |
                               clear_mask, ZFCP_CLEAR);
}

/**
 * zfcp_erp_adapter_unblock - mark adapter as unblocked, allow scsi requests
 */
static void zfcp_erp_adapter_unblock(struct zfcp_adapter *adapter)
{
      debug_text_event(adapter->erp_dbf, 6, "a_ubl");
      atomic_set_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status);
}

/*
 * function:
 *
 * purpose: disable I/O,
 *          return any open requests and clean them up,
 *          aim: no pending and incoming I/O
 *
 * returns:
 */
static void
zfcp_erp_port_block(struct zfcp_port *port, int clear_mask)
{
      struct zfcp_adapter *adapter = port->adapter;

      debug_text_event(adapter->erp_dbf, 6, "p_bl");
      debug_event(adapter->erp_dbf, 6, &port->wwpn, sizeof (wwn_t));
      zfcp_erp_modify_port_status(port,
                            ZFCP_STATUS_COMMON_UNBLOCKED | clear_mask,
                            ZFCP_CLEAR);
}

/*
 * function:
 *
 * purpose: enable I/O
 *
 * returns:
 */
static void
zfcp_erp_port_unblock(struct zfcp_port *port)
{
      struct zfcp_adapter *adapter = port->adapter;

      debug_text_event(adapter->erp_dbf, 6, "p_ubl");
      debug_event(adapter->erp_dbf, 6, &port->wwpn, sizeof (wwn_t));
      atomic_set_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &port->status);
}

/*
 * function:
 *
 * purpose: disable I/O,
 *          return any open requests and clean them up,
 *          aim: no pending and incoming I/O
 *
 * returns:
 */
static void
zfcp_erp_unit_block(struct zfcp_unit *unit, int clear_mask)
{
      struct zfcp_adapter *adapter = unit->port->adapter;

      debug_text_event(adapter->erp_dbf, 6, "u_bl");
      debug_event(adapter->erp_dbf, 6, &unit->fcp_lun, sizeof (fcp_lun_t));
      zfcp_erp_modify_unit_status(unit,
                            ZFCP_STATUS_COMMON_UNBLOCKED | clear_mask,
                            ZFCP_CLEAR);
}

/*
 * function:
 *
 * purpose: enable I/O
 *
 * returns:
 */
static void
zfcp_erp_unit_unblock(struct zfcp_unit *unit)
{
      struct zfcp_adapter *adapter = unit->port->adapter;

      debug_text_event(adapter->erp_dbf, 6, "u_ubl");
      debug_event(adapter->erp_dbf, 6, &unit->fcp_lun, sizeof (fcp_lun_t));
      atomic_set_mask(ZFCP_STATUS_COMMON_UNBLOCKED, &unit->status);
}

static void
zfcp_erp_action_ready(struct zfcp_erp_action *erp_action)
{
      struct zfcp_adapter *adapter = erp_action->adapter;

      debug_text_event(adapter->erp_dbf, 4, "a_ar");
      debug_event(adapter->erp_dbf, 4, &erp_action->action, sizeof (int));

      zfcp_erp_action_to_ready(erp_action);
      up(&adapter->erp_ready_sem);
}

/*
 * function:
 *
 * purpose:
 *
 * returns: <0                erp_action not found in any list
 *          ZFCP_ERP_ACTION_READY   erp_action is in ready list
 *          ZFCP_ERP_ACTION_RUNNING erp_action is in running list
 *
 * locks:   erp_lock must be held
 */
static int
zfcp_erp_action_exists(struct zfcp_erp_action *erp_action)
{
      int retval = -EINVAL;
      struct list_head *entry;
      struct zfcp_erp_action *entry_erp_action;
      struct zfcp_adapter *adapter = erp_action->adapter;

      /* search in running list */
      list_for_each(entry, &adapter->erp_running_head) {
            entry_erp_action =
                list_entry(entry, struct zfcp_erp_action, list);
            if (entry_erp_action == erp_action) {
                  retval = ZFCP_ERP_ACTION_RUNNING;
                  goto out;
            }
      }
      /* search in ready list */
      list_for_each(entry, &adapter->erp_ready_head) {
            entry_erp_action =
                list_entry(entry, struct zfcp_erp_action, list);
            if (entry_erp_action == erp_action) {
                  retval = ZFCP_ERP_ACTION_READY;
                  goto out;
            }
      }

 out:
      return retval;
}

/*
 * purpose: checks current status of action (timed out, dismissed, ...)
 *          and does appropriate preparations (dismiss fsf request, ...)
 *
 * locks:   called under erp_lock (disabled interrupts)
 */
static void
zfcp_erp_strategy_check_fsfreq(struct zfcp_erp_action *erp_action)
{
      struct zfcp_adapter *adapter = erp_action->adapter;

      if (erp_action->fsf_req) {
            /* take lock to ensure that request is not deleted meanwhile */
            spin_lock(&adapter->req_list_lock);
            if (zfcp_reqlist_find(adapter, erp_action->fsf_req->req_id)) {
                  /* fsf_req still exists */
                  debug_text_event(adapter->erp_dbf, 3, "a_ca_req");
                  debug_event(adapter->erp_dbf, 3, &erp_action->fsf_req,
                            sizeof (unsigned long));
                  /* dismiss fsf_req of timed out/dismissed erp_action */
                  if (erp_action->status & (ZFCP_STATUS_ERP_DISMISSED |
                                      ZFCP_STATUS_ERP_TIMEDOUT)) {
                        debug_text_event(adapter->erp_dbf, 3,
                                     "a_ca_disreq");
                        erp_action->fsf_req->status |=
                              ZFCP_STATUS_FSFREQ_DISMISSED;
                  }
                  if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT) {
                        ZFCP_LOG_NORMAL("error: erp step timed out "
                                    "(action=%d, fsf_req=%p)\n ",
                                    erp_action->action,
                                    erp_action->fsf_req);
                  }
                  /*
                   * If fsf_req is neither dismissed nor completed
                   * then keep it running asynchronously and don't mess
                   * with the association of erp_action and fsf_req.
                   */
                  if (erp_action->fsf_req->status &
                              (ZFCP_STATUS_FSFREQ_COMPLETED |
                                     ZFCP_STATUS_FSFREQ_DISMISSED)) {
                        /* forget about association between fsf_req
                           and erp_action */
                        erp_action->fsf_req = NULL;
                  }
            } else {
                  debug_text_event(adapter->erp_dbf, 3, "a_ca_gonereq");
                  /*
                   * even if this fsf_req has gone, forget about
                   * association between erp_action and fsf_req
                   */
                  erp_action->fsf_req = NULL;
            }
            spin_unlock(&adapter->req_list_lock);
      } else
            debug_text_event(adapter->erp_dbf, 3, "a_ca_noreq");
}

/**
 * zfcp_erp_async_handler_nolock - complete erp_action
 *
 * Used for normal completion, time-out, dismissal and failure after
 * low memory condition.
 */
static void zfcp_erp_async_handler_nolock(struct zfcp_erp_action *erp_action,
                                unsigned long set_mask)
{
      struct zfcp_adapter *adapter = erp_action->adapter;

      if (zfcp_erp_action_exists(erp_action) == ZFCP_ERP_ACTION_RUNNING) {
            debug_text_event(adapter->erp_dbf, 2, "a_asyh_ex");
            debug_event(adapter->erp_dbf, 2, &erp_action->action,
                      sizeof (int));
            erp_action->status |= set_mask;
            zfcp_erp_action_ready(erp_action);
      } else {
            /* action is ready or gone - nothing to do */
            debug_text_event(adapter->erp_dbf, 3, "a_asyh_gone");
            debug_event(adapter->erp_dbf, 3, &erp_action->action,
                      sizeof (int));
      }
}

/**
 * zfcp_erp_async_handler - wrapper for erp_async_handler_nolock w/ locking
 */
void zfcp_erp_async_handler(struct zfcp_erp_action *erp_action,
                      unsigned long set_mask)
{
      struct zfcp_adapter *adapter = erp_action->adapter;
      unsigned long flags;

      write_lock_irqsave(&adapter->erp_lock, flags);
      zfcp_erp_async_handler_nolock(erp_action, set_mask);
      write_unlock_irqrestore(&adapter->erp_lock, flags);
}

/*
 * purpose: is called for erp_action which was slept waiting for
 *          memory becoming avaliable,
 *          will trigger that this action will be continued
 */
static void
zfcp_erp_memwait_handler(unsigned long data)
{
      struct zfcp_erp_action *erp_action = (struct zfcp_erp_action *) data;
      struct zfcp_adapter *adapter = erp_action->adapter;

      debug_text_event(adapter->erp_dbf, 2, "a_mwh");
      debug_event(adapter->erp_dbf, 2, &erp_action->action, sizeof (int));

      zfcp_erp_async_handler(erp_action, 0);
}

/*
 * purpose: is called if an asynchronous erp step timed out,
 *          action gets an appropriate flag and will be processed
 *          accordingly
 */
static void zfcp_erp_timeout_handler(unsigned long data)
{
      struct zfcp_erp_action *erp_action = (struct zfcp_erp_action *) data;
      struct zfcp_adapter *adapter = erp_action->adapter;

      debug_text_event(adapter->erp_dbf, 2, "a_th");
      debug_event(adapter->erp_dbf, 2, &erp_action->action, sizeof (int));

      zfcp_erp_async_handler(erp_action, ZFCP_STATUS_ERP_TIMEDOUT);
}

/**
 * zfcp_erp_action_dismiss - dismiss an erp_action
 *
 * adapter->erp_lock must be held
 *
 * Dismissal of an erp_action is usually required if an erp_action of
 * higher priority is generated.
 */
static void zfcp_erp_action_dismiss(struct zfcp_erp_action *erp_action)
{
      struct zfcp_adapter *adapter = erp_action->adapter;

      debug_text_event(adapter->erp_dbf, 2, "a_adis");
      debug_event(adapter->erp_dbf, 2, &erp_action->action, sizeof (int));

      erp_action->status |= ZFCP_STATUS_ERP_DISMISSED;
      if (zfcp_erp_action_exists(erp_action) == ZFCP_ERP_ACTION_RUNNING)
            zfcp_erp_action_ready(erp_action);
}

int
zfcp_erp_thread_setup(struct zfcp_adapter *adapter)
{
      int retval = 0;

      atomic_clear_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_UP, &adapter->status);

      retval = kernel_thread(zfcp_erp_thread, adapter, SIGCHLD);
      if (retval < 0) {
            ZFCP_LOG_NORMAL("error: creation of erp thread failed for "
                        "adapter %s\n",
                        zfcp_get_busid_by_adapter(adapter));
            debug_text_event(adapter->erp_dbf, 5, "a_thset_fail");
      } else {
            wait_event(adapter->erp_thread_wqh,
                     atomic_test_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_UP,
                                  &adapter->status));
            debug_text_event(adapter->erp_dbf, 5, "a_thset_ok");
      }

      return (retval < 0);
}

/*
 * function:
 *
 * purpose:
 *
 * returns:
 *
 * context: process (i.e. proc-fs or rmmod/insmod)
 *
 * note:    The caller of this routine ensures that the specified
 *          adapter has been shut down and that this operation
 *          has been completed. Thus, there are no pending erp_actions
 *          which would need to be handled here.
 */
int
zfcp_erp_thread_kill(struct zfcp_adapter *adapter)
{
      int retval = 0;

      atomic_set_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_KILL, &adapter->status);
      up(&adapter->erp_ready_sem);

      wait_event(adapter->erp_thread_wqh,
               !atomic_test_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_UP,
                             &adapter->status));

      atomic_clear_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_KILL,
                    &adapter->status);

      debug_text_event(adapter->erp_dbf, 5, "a_thki_ok");

      return retval;
}

/*
 * purpose: is run as a kernel thread,
 *          goes through list of error recovery actions of associated adapter
 *          and delegates single action to execution
 *
 * returns: 0
 */
static int
zfcp_erp_thread(void *data)
{
      struct zfcp_adapter *adapter = (struct zfcp_adapter *) data;
      struct list_head *next;
      struct zfcp_erp_action *erp_action;
      unsigned long flags;

      daemonize("zfcperp%s", zfcp_get_busid_by_adapter(adapter));
      /* Block all signals */
      siginitsetinv(&current->blocked, 0);
      atomic_set_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_UP, &adapter->status);
      debug_text_event(adapter->erp_dbf, 5, "a_th_run");
      wake_up(&adapter->erp_thread_wqh);

      while (!atomic_test_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_KILL,
                         &adapter->status)) {

            write_lock_irqsave(&adapter->erp_lock, flags);
            next = adapter->erp_ready_head.next;
            write_unlock_irqrestore(&adapter->erp_lock, flags);

            if (next != &adapter->erp_ready_head) {
                  erp_action =
                      list_entry(next, struct zfcp_erp_action, list);
                  /*
                   * process action (incl. [re]moving it
                   * from 'ready' queue)
                   */
                  zfcp_erp_strategy(erp_action);
            }

            /*
             * sleep as long as there is nothing to do, i.e.
             * no action in 'ready' queue to be processed and
             * thread is not to be killed
             */
            down_interruptible(&adapter->erp_ready_sem);
            debug_text_event(adapter->erp_dbf, 5, "a_th_woken");
      }

      atomic_clear_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_UP, &adapter->status);
      debug_text_event(adapter->erp_dbf, 5, "a_th_stop");
      wake_up(&adapter->erp_thread_wqh);

      return 0;
}

/*
 * function:
 *
 * purpose: drives single error recovery action and schedules higher and
 *          subordinate actions, if necessary
 *
 * returns: ZFCP_ERP_CONTINUES      - action continues (asynchronously)
 *          ZFCP_ERP_SUCCEEDED      - action finished successfully (deqd)
 *          ZFCP_ERP_FAILED         - action finished unsuccessfully (deqd)
 *          ZFCP_ERP_EXIT           - action finished (dequeued), offline
 *          ZFCP_ERP_DISMISSED      - action canceled (dequeued)
 */
static int
zfcp_erp_strategy(struct zfcp_erp_action *erp_action)
{
      int retval = 0;
      struct zfcp_adapter *adapter = erp_action->adapter;
      struct zfcp_port *port = erp_action->port;
      struct zfcp_unit *unit = erp_action->unit;
      int action = erp_action->action;
      u32 status = erp_action->status;
      unsigned long flags;

      /* serialise dismissing, timing out, moving, enqueueing */
      read_lock_irqsave(&zfcp_data.config_lock, flags);
      write_lock(&adapter->erp_lock);

      /* dequeue dismissed action and leave, if required */
      retval = zfcp_erp_strategy_check_action(erp_action, retval);
      if (retval == ZFCP_ERP_DISMISSED) {
            debug_text_event(adapter->erp_dbf, 4, "a_st_dis1");
            goto unlock;
      }

      /*
       * move action to 'running' queue before processing it
       * (to avoid a race condition regarding moving the
       * action to the 'running' queue and back)
       */
      zfcp_erp_action_to_running(erp_action);

      /*
       * try to process action as far as possible,
       * no lock to allow for blocking operations (kmalloc, qdio, ...),
       * afterwards the lock is required again for the following reasons:
       * - dequeueing of finished action and enqueueing of
       *   follow-up actions must be atomic so that any other
       *   reopen-routine does not believe there is nothing to do
       *   and that it is safe to enqueue something else,
       * - we want to force any control thread which is dismissing
       *   actions to finish this before we decide about
       *   necessary steps to be taken here further
       */
      write_unlock(&adapter->erp_lock);
      read_unlock_irqrestore(&zfcp_data.config_lock, flags);
      retval = zfcp_erp_strategy_do_action(erp_action);
      read_lock_irqsave(&zfcp_data.config_lock, flags);
      write_lock(&adapter->erp_lock);

      /*
       * check for dismissed status again to avoid follow-up actions,
       * failing of targets and so on for dismissed actions,
       * we go through down() here because there has been an up()
       */
      if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED)
            retval = ZFCP_ERP_CONTINUES;

      switch (retval) {
      case ZFCP_ERP_NOMEM:
            /* no memory to continue immediately, let it sleep */
            if (!(erp_action->status & ZFCP_STATUS_ERP_LOWMEM)) {
                  ++adapter->erp_low_mem_count;
                  erp_action->status |= ZFCP_STATUS_ERP_LOWMEM;
            }
            /* This condition is true if there is no memory available
               for any erp_action on this adapter. This implies that there
               are no elements in the memory pool(s) left for erp_actions.
               This might happen if an erp_action that used a memory pool
               element was timed out.
             */
            if (adapter->erp_total_count == adapter->erp_low_mem_count) {
                  debug_text_event(adapter->erp_dbf, 3, "a_st_lowmem");
                  ZFCP_LOG_NORMAL("error: no mempool elements available, "
                              "restarting I/O on adapter %s "
                              "to free mempool\n",
                              zfcp_get_busid_by_adapter(adapter));
                  zfcp_erp_adapter_reopen_internal(adapter, 0);
            } else {
            debug_text_event(adapter->erp_dbf, 2, "a_st_memw");
            retval = zfcp_erp_strategy_memwait(erp_action);
            }
            goto unlock;
      case ZFCP_ERP_CONTINUES:
            /* leave since this action runs asynchronously */
            debug_text_event(adapter->erp_dbf, 6, "a_st_cont");
            if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
                  --adapter->erp_low_mem_count;
                  erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
            }
            goto unlock;
      }
      /* ok, finished action (whatever its result is) */

      /* check for unrecoverable targets */
      retval = zfcp_erp_strategy_check_target(erp_action, retval);

      /* action must be dequeued (here to allow for further ones) */
      zfcp_erp_action_dequeue(erp_action);

      /*
       * put this target through the erp mill again if someone has
       * requested to change the status of a target being online
       * to offline or the other way around
       * (old retval is preserved if nothing has to be done here)
       */
      retval = zfcp_erp_strategy_statechange(action, status, adapter,
                                     port, unit, retval);

      /*
       * leave if target is in permanent error state or if
       * action is repeated in order to process state change
       */
      if (retval == ZFCP_ERP_EXIT) {
            debug_text_event(adapter->erp_dbf, 2, "a_st_exit");
            goto unlock;
      }

      /* trigger follow up actions */
      zfcp_erp_strategy_followup_actions(action, adapter, port, unit, retval);

 unlock:
      write_unlock(&adapter->erp_lock);
      read_unlock_irqrestore(&zfcp_data.config_lock, flags);

      if (retval != ZFCP_ERP_CONTINUES)
            zfcp_erp_action_cleanup(action, adapter, port, unit, retval);

      /*
       * a few tasks remain when the erp queues are empty
       * (don't do that if the last action evaluated was dismissed
       * since this clearly indicates that there is more to come) :
       * - close the name server port if it is open yet
       *   (enqueues another [probably] final action)
       * - otherwise, wake up whoever wants to be woken when we are
       *   done with erp
       */
      if (retval != ZFCP_ERP_DISMISSED)
            zfcp_erp_strategy_check_queues(adapter);

      debug_text_event(adapter->erp_dbf, 6, "a_st_done");

      return retval;
}

/*
 * function:
 *
 * purpose:
 *
 * returns: ZFCP_ERP_DISMISSED      - if action has been dismissed
 *          retval                  - otherwise
 */
static int
zfcp_erp_strategy_check_action(struct zfcp_erp_action *erp_action, int retval)
{
      struct zfcp_adapter *adapter = erp_action->adapter;

      zfcp_erp_strategy_check_fsfreq(erp_action);

      debug_event(adapter->erp_dbf, 5, &erp_action->action, sizeof (int));
      if (erp_action->status & ZFCP_STATUS_ERP_DISMISSED) {
            debug_text_event(adapter->erp_dbf, 3, "a_stcd_dis");
            zfcp_erp_action_dequeue(erp_action);
            retval = ZFCP_ERP_DISMISSED;
      } else
            debug_text_event(adapter->erp_dbf, 5, "a_stcd_nodis");

      return retval;
}

static int
zfcp_erp_strategy_do_action(struct zfcp_erp_action *erp_action)
{
      int retval = ZFCP_ERP_FAILED;
      struct zfcp_adapter *adapter = erp_action->adapter;

      /*
       * try to execute/continue action as far as possible,
       * note: no lock in subsequent strategy routines
       * (this allows these routine to call schedule, e.g.
       * kmalloc with such flags or qdio_initialize & friends)
       * Note: in case of timeout, the seperate strategies will fail
       * anyhow. No need for a special action. Even worse, a nameserver
       * failure would not wake up waiting ports without the call.
       */
      switch (erp_action->action) {

      case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
            retval = zfcp_erp_adapter_strategy(erp_action);
            break;

      case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
            retval = zfcp_erp_port_forced_strategy(erp_action);
            break;

      case ZFCP_ERP_ACTION_REOPEN_PORT:
            retval = zfcp_erp_port_strategy(erp_action);
            break;

      case ZFCP_ERP_ACTION_REOPEN_UNIT:
            retval = zfcp_erp_unit_strategy(erp_action);
            break;

      default:
            debug_text_exception(adapter->erp_dbf, 1, "a_stda_bug");
            debug_event(adapter->erp_dbf, 1, &erp_action->action,
                      sizeof (int));
            ZFCP_LOG_NORMAL("bug: unknown erp action requested on "
                        "adapter %s (action=%d)\n",
                        zfcp_get_busid_by_adapter(erp_action->adapter),
                        erp_action->action);
      }

      return retval;
}

/*
 * function:
 *
 * purpose: triggers retry of this action after a certain amount of time
 *          by means of timer provided by erp_action
 *
 * returns: ZFCP_ERP_CONTINUES - erp_action sleeps in erp running queue
 */
static int
zfcp_erp_strategy_memwait(struct zfcp_erp_action *erp_action)
{
      int retval = ZFCP_ERP_CONTINUES;
      struct zfcp_adapter *adapter = erp_action->adapter;

      debug_text_event(adapter->erp_dbf, 6, "a_mwinit");
      debug_event(adapter->erp_dbf, 6, &erp_action->action, sizeof (int));
      init_timer(&erp_action->timer);
      erp_action->timer.function = zfcp_erp_memwait_handler;
      erp_action->timer.data = (unsigned long) erp_action;
      erp_action->timer.expires = jiffies + ZFCP_ERP_MEMWAIT_TIMEOUT;
      add_timer(&erp_action->timer);

      return retval;
}

/*
 * function:    zfcp_erp_adapter_failed
 *
 * purpose:     sets the adapter and all underlying devices to ERP_FAILED
 *
 */
void
zfcp_erp_adapter_failed(struct zfcp_adapter *adapter)
{
      zfcp_erp_modify_adapter_status(adapter,
                               ZFCP_STATUS_COMMON_ERP_FAILED, ZFCP_SET);
      ZFCP_LOG_NORMAL("adapter erp failed on adapter %s\n",
                  zfcp_get_busid_by_adapter(adapter));
      debug_text_event(adapter->erp_dbf, 2, "a_afail");
}

/*
 * function:    zfcp_erp_port_failed
 *
 * purpose:     sets the port and all underlying devices to ERP_FAILED
 *
 */
void
zfcp_erp_port_failed(struct zfcp_port *port)
{
      zfcp_erp_modify_port_status(port,
                            ZFCP_STATUS_COMMON_ERP_FAILED, ZFCP_SET);

      if (atomic_test_mask(ZFCP_STATUS_PORT_WKA, &port->status))
            ZFCP_LOG_NORMAL("port erp failed (adapter %s, "
                        "port d_id=0x%06x)\n",
                        zfcp_get_busid_by_port(port), port->d_id);
      else
            ZFCP_LOG_NORMAL("port erp failed (adapter %s, wwpn=0x%016Lx)\n",
                        zfcp_get_busid_by_port(port), port->wwpn);

      debug_text_event(port->adapter->erp_dbf, 2, "p_pfail");
      debug_event(port->adapter->erp_dbf, 2, &port->wwpn, sizeof (wwn_t));
}

/*
 * function:    zfcp_erp_unit_failed
 *
 * purpose:     sets the unit to ERP_FAILED
 *
 */
void
zfcp_erp_unit_failed(struct zfcp_unit *unit)
{
      zfcp_erp_modify_unit_status(unit,
                            ZFCP_STATUS_COMMON_ERP_FAILED, ZFCP_SET);

      ZFCP_LOG_NORMAL("unit erp failed on unit 0x%016Lx on port 0x%016Lx "
                  " on adapter %s\n", unit->fcp_lun,
                  unit->port->wwpn, zfcp_get_busid_by_unit(unit));
      debug_text_event(unit->port->adapter->erp_dbf, 2, "u_ufail");
      debug_event(unit->port->adapter->erp_dbf, 2,
                &unit->fcp_lun, sizeof (fcp_lun_t));
}

/*
 * function:      zfcp_erp_strategy_check_target
 *
 * purpose: increments the erp action count on the device currently in
 *              recovery if the action failed or resets the count in case of
 *              success. If a maximum count is exceeded the device is marked
 *              as ERP_FAILED.
 *          The 'blocked' state of a target which has been recovered
 *              successfully is reset.
 *
 * returns: ZFCP_ERP_CONTINUES      - action continues (not considered)
 *          ZFCP_ERP_SUCCEEDED      - action finished successfully
 *          ZFCP_ERP_EXIT           - action failed and will not continue
 */
static int
zfcp_erp_strategy_check_target(struct zfcp_erp_action *erp_action, int result)
{
      struct zfcp_adapter *adapter = erp_action->adapter;
      struct zfcp_port *port = erp_action->port;
      struct zfcp_unit *unit = erp_action->unit;

      debug_text_event(adapter->erp_dbf, 5, "a_stct_norm");
      debug_event(adapter->erp_dbf, 5, &erp_action->action, sizeof (int));
      debug_event(adapter->erp_dbf, 5, &result, sizeof (int));

      switch (erp_action->action) {

      case ZFCP_ERP_ACTION_REOPEN_UNIT:
            result = zfcp_erp_strategy_check_unit(unit, result);
            break;

      case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
      case ZFCP_ERP_ACTION_REOPEN_PORT:
            result = zfcp_erp_strategy_check_port(port, result);
            break;

      case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
            result = zfcp_erp_strategy_check_adapter(adapter, result);
            break;
      }

      return result;
}

static int
zfcp_erp_strategy_statechange(int action,
                        u32 status,
                        struct zfcp_adapter *adapter,
                        struct zfcp_port *port,
                        struct zfcp_unit *unit, int retval)
{
      debug_text_event(adapter->erp_dbf, 3, "a_stsc");
      debug_event(adapter->erp_dbf, 3, &action, sizeof (int));

      switch (action) {

      case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
            if (zfcp_erp_strategy_statechange_detected(&adapter->status,
                                             status)) {
                  zfcp_erp_adapter_reopen_internal(adapter, ZFCP_STATUS_COMMON_ERP_FAILED);
                  retval = ZFCP_ERP_EXIT;
            }
            break;

      case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
      case ZFCP_ERP_ACTION_REOPEN_PORT:
            if (zfcp_erp_strategy_statechange_detected(&port->status,
                                             status)) {
                  zfcp_erp_port_reopen_internal(port, ZFCP_STATUS_COMMON_ERP_FAILED);
                  retval = ZFCP_ERP_EXIT;
            }
            break;

      case ZFCP_ERP_ACTION_REOPEN_UNIT:
            if (zfcp_erp_strategy_statechange_detected(&unit->status,
                                             status)) {
                  zfcp_erp_unit_reopen_internal(unit, ZFCP_STATUS_COMMON_ERP_FAILED);
                  retval = ZFCP_ERP_EXIT;
            }
            break;
      }

      return retval;
}

static int
zfcp_erp_strategy_statechange_detected(atomic_t * target_status, u32 erp_status)
{
      return
          /* take it online */
          (atomic_test_mask(ZFCP_STATUS_COMMON_RUNNING, target_status) &&
           (ZFCP_STATUS_ERP_CLOSE_ONLY & erp_status)) ||
          /* take it offline */
          (!atomic_test_mask(ZFCP_STATUS_COMMON_RUNNING, target_status) &&
           !(ZFCP_STATUS_ERP_CLOSE_ONLY & erp_status));
}

static int
zfcp_erp_strategy_check_unit(struct zfcp_unit *unit, int result)
{
      debug_text_event(unit->port->adapter->erp_dbf, 5, "u_stct");
      debug_event(unit->port->adapter->erp_dbf, 5, &unit->fcp_lun,
                sizeof (fcp_lun_t));

      switch (result) {
      case ZFCP_ERP_SUCCEEDED :
            atomic_set(&unit->erp_counter, 0);
            zfcp_erp_unit_unblock(unit);
            break;
      case ZFCP_ERP_FAILED :
            atomic_inc(&unit->erp_counter);
            if (atomic_read(&unit->erp_counter) > ZFCP_MAX_ERPS)
                  zfcp_erp_unit_failed(unit);
            break;
      case ZFCP_ERP_EXIT :
            /* nothing */
            break;
      }

      if (atomic_test_mask(ZFCP_STATUS_COMMON_ERP_FAILED, &unit->status)) {
            zfcp_erp_unit_block(unit, 0); /* for ZFCP_ERP_SUCCEEDED */
            result = ZFCP_ERP_EXIT;
      }

      return result;
}

static int
zfcp_erp_strategy_check_port(struct zfcp_port *port, int result)
{
      debug_text_event(port->adapter->erp_dbf, 5, "p_stct");
      debug_event(port->adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));

      switch (result) {
      case ZFCP_ERP_SUCCEEDED :
            atomic_set(&port->erp_counter, 0);
            zfcp_erp_port_unblock(port);
            break;
      case ZFCP_ERP_FAILED :
            atomic_inc(&port->erp_counter);
            if (atomic_read(&port->erp_counter) > ZFCP_MAX_ERPS)
                  zfcp_erp_port_failed(port);
            break;
      case ZFCP_ERP_EXIT :
            /* nothing */
            break;
      }

      if (atomic_test_mask(ZFCP_STATUS_COMMON_ERP_FAILED, &port->status)) {
            zfcp_erp_port_block(port, 0); /* for ZFCP_ERP_SUCCEEDED */
            result = ZFCP_ERP_EXIT;
      }

      return result;
}

static int
zfcp_erp_strategy_check_adapter(struct zfcp_adapter *adapter, int result)
{
      debug_text_event(adapter->erp_dbf, 5, "a_stct");

      switch (result) {
      case ZFCP_ERP_SUCCEEDED :
            atomic_set(&adapter->erp_counter, 0);
            zfcp_erp_adapter_unblock(adapter);
            break;
      case ZFCP_ERP_FAILED :
            atomic_inc(&adapter->erp_counter);
            if (atomic_read(&adapter->erp_counter) > ZFCP_MAX_ERPS)
                  zfcp_erp_adapter_failed(adapter);
            break;
      case ZFCP_ERP_EXIT :
            /* nothing */
            break;
      }

      if (atomic_test_mask(ZFCP_STATUS_COMMON_ERP_FAILED, &adapter->status)) {
            zfcp_erp_adapter_block(adapter, 0); /* for ZFCP_ERP_SUCCEEDED */
            result = ZFCP_ERP_EXIT;
      }

      return result;
}

struct zfcp_erp_add_work {
      struct zfcp_unit  *unit;
      struct work_struct work;
};

/**
 * zfcp_erp_scsi_scan
 * @data: pointer to a struct zfcp_erp_add_work
 *
 * Registers a logical unit with the SCSI stack.
 */
static void zfcp_erp_scsi_scan(struct work_struct *work)
{
      struct zfcp_erp_add_work *p =
            container_of(work, struct zfcp_erp_add_work, work);
      struct zfcp_unit *unit = p->unit;
      struct fc_rport *rport = unit->port->rport;
      scsi_scan_target(&rport->dev, 0, rport->scsi_target_id,
                   unit->scsi_lun, 0);
      atomic_clear_mask(ZFCP_STATUS_UNIT_SCSI_WORK_PENDING, &unit->status);
      wake_up(&unit->scsi_scan_wq);
      zfcp_unit_put(unit);
      kfree(p);
}

/**
 * zfcp_erp_schedule_work
 * @unit: pointer to unit which should be registered with SCSI stack
 *
 * Schedules work which registers a unit with the SCSI stack
 */
static void
zfcp_erp_schedule_work(struct zfcp_unit *unit)
{
      struct zfcp_erp_add_work *p;

      p = kzalloc(sizeof(*p), GFP_KERNEL);
      if (!p) {
            ZFCP_LOG_NORMAL("error: Out of resources. Could not register "
                        "the FCP-LUN 0x%Lx connected to "
                        "the port with WWPN 0x%Lx connected to "
                        "the adapter %s with the SCSI stack.\n",
                        unit->fcp_lun,
                        unit->port->wwpn,
                        zfcp_get_busid_by_unit(unit));
            return;
      }

      zfcp_unit_get(unit);
      atomic_set_mask(ZFCP_STATUS_UNIT_SCSI_WORK_PENDING, &unit->status);
      INIT_WORK(&p->work, zfcp_erp_scsi_scan);
      p->unit = unit;
      schedule_work(&p->work);
}

/*
 * function:
 *
 * purpose: remaining things in good cases,
 *          escalation in bad cases
 *
 * returns:
 */
static int
zfcp_erp_strategy_followup_actions(int action,
                           struct zfcp_adapter *adapter,
                           struct zfcp_port *port,
                           struct zfcp_unit *unit, int status)
{
      debug_text_event(adapter->erp_dbf, 5, "a_stfol");
      debug_event(adapter->erp_dbf, 5, &action, sizeof (int));

      /* initiate follow-up actions depending on success of finished action */
      switch (action) {

      case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
            if (status == ZFCP_ERP_SUCCEEDED)
                  zfcp_erp_port_reopen_all_internal(adapter, 0);
            else
                  zfcp_erp_adapter_reopen_internal(adapter, 0);
            break;

      case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
            if (status == ZFCP_ERP_SUCCEEDED)
                  zfcp_erp_port_reopen_internal(port, 0);
            else
                  zfcp_erp_adapter_reopen_internal(adapter, 0);
            break;

      case ZFCP_ERP_ACTION_REOPEN_PORT:
            if (status == ZFCP_ERP_SUCCEEDED)
                  zfcp_erp_unit_reopen_all_internal(port, 0);
            else
                  zfcp_erp_port_forced_reopen_internal(port, 0);
            break;

      case ZFCP_ERP_ACTION_REOPEN_UNIT:
            /* Nothing to do if status == ZFCP_ERP_SUCCEEDED */
            if (status != ZFCP_ERP_SUCCEEDED)
                  zfcp_erp_port_reopen_internal(unit->port, 0);
            break;
      }

      return 0;
}

static int
zfcp_erp_strategy_check_queues(struct zfcp_adapter *adapter)
{
      unsigned long flags;

      read_lock_irqsave(&zfcp_data.config_lock, flags);
      read_lock(&adapter->erp_lock);
      if (list_empty(&adapter->erp_ready_head) &&
          list_empty(&adapter->erp_running_head)) {
                  debug_text_event(adapter->erp_dbf, 4, "a_cq_wake");
                  atomic_clear_mask(ZFCP_STATUS_ADAPTER_ERP_PENDING,
                                &adapter->status);
                  wake_up(&adapter->erp_done_wqh);
      } else
            debug_text_event(adapter->erp_dbf, 5, "a_cq_notempty");
      read_unlock(&adapter->erp_lock);
      read_unlock_irqrestore(&zfcp_data.config_lock, flags);

      return 0;
}

/**
 * zfcp_erp_wait - wait for completion of error recovery on an adapter
 * @adapter: adapter for which to wait for completion of its error recovery
 * Return: 0
 */
int
zfcp_erp_wait(struct zfcp_adapter *adapter)
{
      int retval = 0;

      wait_event(adapter->erp_done_wqh,
               !atomic_test_mask(ZFCP_STATUS_ADAPTER_ERP_PENDING,
                             &adapter->status));

      return retval;
}

void
zfcp_erp_modify_adapter_status(struct zfcp_adapter *adapter,
                         u32 mask, int set_or_clear)
{
      struct zfcp_port *port;
      u32 common_mask = mask & ZFCP_COMMON_FLAGS;

      if (set_or_clear == ZFCP_SET) {
            atomic_set_mask(mask, &adapter->status);
            debug_text_event(adapter->erp_dbf, 3, "a_mod_as_s");
      } else {
            atomic_clear_mask(mask, &adapter->status);
            if (mask & ZFCP_STATUS_COMMON_ERP_FAILED)
                  atomic_set(&adapter->erp_counter, 0);
            debug_text_event(adapter->erp_dbf, 3, "a_mod_as_c");
      }
      debug_event(adapter->erp_dbf, 3, &mask, sizeof (u32));

      /* Deal with all underlying devices, only pass common_mask */
      if (common_mask)
            list_for_each_entry(port, &adapter->port_list_head, list)
                zfcp_erp_modify_port_status(port, common_mask,
                                    set_or_clear);
}

/*
 * function:      zfcp_erp_modify_port_status
 *
 * purpose: sets the port and all underlying devices to ERP_FAILED
 *
 */
void
zfcp_erp_modify_port_status(struct zfcp_port *port, u32 mask, int set_or_clear)
{
      struct zfcp_unit *unit;
      u32 common_mask = mask & ZFCP_COMMON_FLAGS;

      if (set_or_clear == ZFCP_SET) {
            atomic_set_mask(mask, &port->status);
            debug_text_event(port->adapter->erp_dbf, 3, "p_mod_ps_s");
      } else {
            atomic_clear_mask(mask, &port->status);
            if (mask & ZFCP_STATUS_COMMON_ERP_FAILED)
                  atomic_set(&port->erp_counter, 0);
            debug_text_event(port->adapter->erp_dbf, 3, "p_mod_ps_c");
      }
      debug_event(port->adapter->erp_dbf, 3, &port->wwpn, sizeof (wwn_t));
      debug_event(port->adapter->erp_dbf, 3, &mask, sizeof (u32));

      /* Modify status of all underlying devices, only pass common mask */
      if (common_mask)
            list_for_each_entry(unit, &port->unit_list_head, list)
                zfcp_erp_modify_unit_status(unit, common_mask,
                                    set_or_clear);
}

/*
 * function:      zfcp_erp_modify_unit_status
 *
 * purpose: sets the unit to ERP_FAILED
 *
 */
void
zfcp_erp_modify_unit_status(struct zfcp_unit *unit, u32 mask, int set_or_clear)
{
      if (set_or_clear == ZFCP_SET) {
            atomic_set_mask(mask, &unit->status);
            debug_text_event(unit->port->adapter->erp_dbf, 3, "u_mod_us_s");
      } else {
            atomic_clear_mask(mask, &unit->status);
            if (mask & ZFCP_STATUS_COMMON_ERP_FAILED) {
                  atomic_set(&unit->erp_counter, 0);
            }
            debug_text_event(unit->port->adapter->erp_dbf, 3, "u_mod_us_c");
      }
      debug_event(unit->port->adapter->erp_dbf, 3, &unit->fcp_lun,
                sizeof (fcp_lun_t));
      debug_event(unit->port->adapter->erp_dbf, 3, &mask, sizeof (u32));
}

/*
 * function:
 *
 * purpose: Wrappper for zfcp_erp_port_reopen_all_internal
 *              used to ensure the correct locking
 *
 * returns: 0     - initiated action successfully
 *          <0    - failed to initiate action
 */
int
zfcp_erp_port_reopen_all(struct zfcp_adapter *adapter, int clear_mask)
{
      int retval;
      unsigned long flags;

      read_lock_irqsave(&zfcp_data.config_lock, flags);
      write_lock(&adapter->erp_lock);
      retval = zfcp_erp_port_reopen_all_internal(adapter, clear_mask);
      write_unlock(&adapter->erp_lock);
      read_unlock_irqrestore(&zfcp_data.config_lock, flags);

      return retval;
}

static int
zfcp_erp_port_reopen_all_internal(struct zfcp_adapter *adapter, int clear_mask)
{
      int retval = 0;
      struct zfcp_port *port;

      list_for_each_entry(port, &adapter->port_list_head, list)
            if (!atomic_test_mask(ZFCP_STATUS_PORT_WKA, &port->status))
                  zfcp_erp_port_reopen_internal(port, clear_mask);

      return retval;
}

/*
 * function:
 *
 * purpose:
 *
 * returns: FIXME
 */
static int
zfcp_erp_unit_reopen_all_internal(struct zfcp_port *port, int clear_mask)
{
      int retval = 0;
      struct zfcp_unit *unit;

      list_for_each_entry(unit, &port->unit_list_head, list)
          zfcp_erp_unit_reopen_internal(unit, clear_mask);

      return retval;
}

/*
 * function:
 *
 * purpose: this routine executes the 'Reopen Adapter' action
 *          (the entire action is processed synchronously, since
 *          there are no actions which might be run concurrently
 *          per definition)
 *
 * returns: ZFCP_ERP_SUCCEEDED      - action finished successfully
 *          ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_adapter_strategy(struct zfcp_erp_action *erp_action)
{
      int retval;
      struct zfcp_adapter *adapter = erp_action->adapter;

      retval = zfcp_erp_adapter_strategy_close(erp_action);
      if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
            retval = ZFCP_ERP_EXIT;
      else
            retval = zfcp_erp_adapter_strategy_open(erp_action);

      debug_text_event(adapter->erp_dbf, 3, "a_ast/ret");
      debug_event(adapter->erp_dbf, 3, &erp_action->action, sizeof (int));
      debug_event(adapter->erp_dbf, 3, &retval, sizeof (int));

      if (retval == ZFCP_ERP_FAILED) {
            ZFCP_LOG_INFO("Waiting to allow the adapter %s "
                        "to recover itself\n",
                        zfcp_get_busid_by_adapter(adapter));
            msleep(jiffies_to_msecs(ZFCP_TYPE2_RECOVERY_TIME));
      }

      return retval;
}

/*
 * function:
 *
 * purpose:
 *
 * returns: ZFCP_ERP_SUCCEEDED      - action finished successfully
 *              ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_adapter_strategy_close(struct zfcp_erp_action *erp_action)
{
      int retval;

      atomic_set_mask(ZFCP_STATUS_COMMON_CLOSING,
                  &erp_action->adapter->status);
      retval = zfcp_erp_adapter_strategy_generic(erp_action, 1);
      atomic_clear_mask(ZFCP_STATUS_COMMON_CLOSING,
                    &erp_action->adapter->status);

      return retval;
}

/*
 * function:
 *
 * purpose:
 *
 * returns: ZFCP_ERP_SUCCEEDED      - action finished successfully
 *              ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_adapter_strategy_open(struct zfcp_erp_action *erp_action)
{
      int retval;

      atomic_set_mask(ZFCP_STATUS_COMMON_OPENING,
                  &erp_action->adapter->status);
      retval = zfcp_erp_adapter_strategy_generic(erp_action, 0);
      atomic_clear_mask(ZFCP_STATUS_COMMON_OPENING,
                    &erp_action->adapter->status);

      return retval;
}

/*
 * function:    zfcp_register_adapter
 *
 * purpose: allocate the irq associated with this devno and register
 *          the FSF adapter with the SCSI stack
 *
 * returns:
 */
static int
zfcp_erp_adapter_strategy_generic(struct zfcp_erp_action *erp_action, int close)
{
      int retval = ZFCP_ERP_SUCCEEDED;

      if (close)
            goto close_only;

      retval = zfcp_erp_adapter_strategy_open_qdio(erp_action);
      if (retval != ZFCP_ERP_SUCCEEDED)
            goto failed_qdio;

      retval = zfcp_erp_adapter_strategy_open_fsf(erp_action);
      if (retval != ZFCP_ERP_SUCCEEDED)
            goto failed_openfcp;

      atomic_set_mask(ZFCP_STATUS_COMMON_OPEN, &erp_action->adapter->status);
      goto out;

 close_only:
      atomic_clear_mask(ZFCP_STATUS_COMMON_OPEN,
                    &erp_action->adapter->status);

 failed_openfcp:
      zfcp_close_fsf(erp_action->adapter);
 failed_qdio:
      atomic_clear_mask(ZFCP_STATUS_ADAPTER_XCONFIG_OK |
                    ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED |
                    ZFCP_STATUS_ADAPTER_XPORT_OK,
                    &erp_action->adapter->status);
 out:
      return retval;
}

/*
 * function:    zfcp_qdio_init
 *
 * purpose: setup QDIO operation for specified adapter
 *
 * returns: 0 - successful setup
 *          !0 - failed setup
 */
static int
zfcp_erp_adapter_strategy_open_qdio(struct zfcp_erp_action *erp_action)
{
      int retval;
      int i;
      volatile struct qdio_buffer_element *sbale;
      struct zfcp_adapter *adapter = erp_action->adapter;

      if (atomic_test_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status)) {
            ZFCP_LOG_NORMAL("bug: second attempt to set up QDIO on "
                        "adapter %s\n",
                        zfcp_get_busid_by_adapter(adapter));
            goto failed_sanity;
      }

      if (qdio_establish(&adapter->qdio_init_data) != 0) {
            ZFCP_LOG_INFO("error: establishment of QDIO queues failed "
                        "on adapter %s\n",
                        zfcp_get_busid_by_adapter(adapter));
            goto failed_qdio_establish;
      }
      debug_text_event(adapter->erp_dbf, 3, "qdio_est");

      if (qdio_activate(adapter->ccw_device, 0) != 0) {
            ZFCP_LOG_INFO("error: activation of QDIO queues failed "
                        "on adapter %s\n",
                        zfcp_get_busid_by_adapter(adapter));
            goto failed_qdio_activate;
      }
      debug_text_event(adapter->erp_dbf, 3, "qdio_act");

      /*
       * put buffers into response queue,
       */
      for (i = 0; i < QDIO_MAX_BUFFERS_PER_Q; i++) {
            sbale = &(adapter->response_queue.buffer[i]->element[0]);
            sbale->length = 0;
            sbale->flags = SBAL_FLAGS_LAST_ENTRY;
            sbale->addr = NULL;
      }

      ZFCP_LOG_TRACE("calling do_QDIO on adapter %s (flags=0x%x, "
                   "queue_no=%i, index_in_queue=%i, count=%i)\n",
                   zfcp_get_busid_by_adapter(adapter),
                   QDIO_FLAG_SYNC_INPUT, 0, 0, QDIO_MAX_BUFFERS_PER_Q);

      retval = do_QDIO(adapter->ccw_device,
                   QDIO_FLAG_SYNC_INPUT,
                   0, 0, QDIO_MAX_BUFFERS_PER_Q, NULL);

      if (retval) {
            ZFCP_LOG_NORMAL("bug: setup of QDIO failed (retval=%d)\n",
                        retval);
            goto failed_do_qdio;
      } else {
            adapter->response_queue.free_index = 0;
            atomic_set(&adapter->response_queue.free_count, 0);
            ZFCP_LOG_DEBUG("%i buffers successfully enqueued to "
                         "response queue\n", QDIO_MAX_BUFFERS_PER_Q);
      }
      /* set index of first avalable SBALS / number of available SBALS */
      adapter->request_queue.free_index = 0;
      atomic_set(&adapter->request_queue.free_count, QDIO_MAX_BUFFERS_PER_Q);
      adapter->request_queue.distance_from_int = 0;

      /* initialize waitqueue used to wait for free SBALs in requests queue */
      init_waitqueue_head(&adapter->request_wq);

      /* ok, we did it - skip all cleanups for different failures */
      atomic_set_mask(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status);
      retval = ZFCP_ERP_SUCCEEDED;
      goto out;

 failed_do_qdio:
      /* NOP */

 failed_qdio_activate:
      debug_text_event(adapter->erp_dbf, 3, "qdio_down1a");
      while (qdio_shutdown(adapter->ccw_device,
                       QDIO_FLAG_CLEANUP_USING_CLEAR) == -EINPROGRESS)
            msleep(1000);
      debug_text_event(adapter->erp_dbf, 3, "qdio_down1b");

 failed_qdio_establish:
 failed_sanity:
      retval = ZFCP_ERP_FAILED;

 out:
      return retval;
}


static int
zfcp_erp_adapter_strategy_open_fsf(struct zfcp_erp_action *erp_action)
{
      int retval;

      retval = zfcp_erp_adapter_strategy_open_fsf_xconfig(erp_action);
      if (retval == ZFCP_ERP_FAILED)
            return ZFCP_ERP_FAILED;

      retval = zfcp_erp_adapter_strategy_open_fsf_xport(erp_action);
      if (retval == ZFCP_ERP_FAILED)
            return ZFCP_ERP_FAILED;

      return zfcp_erp_adapter_strategy_open_fsf_statusread(erp_action);
}

static int
zfcp_erp_adapter_strategy_open_fsf_xconfig(struct zfcp_erp_action *erp_action)
{
      int retval = ZFCP_ERP_SUCCEEDED;
      int retries;
      int sleep = ZFCP_EXCHANGE_CONFIG_DATA_FIRST_SLEEP;
      struct zfcp_adapter *adapter = erp_action->adapter;

      atomic_clear_mask(ZFCP_STATUS_ADAPTER_XCONFIG_OK, &adapter->status);

      for (retries = ZFCP_EXCHANGE_CONFIG_DATA_RETRIES; retries; retries--) {
            atomic_clear_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
                          &adapter->status);
            ZFCP_LOG_DEBUG("Doing exchange config data\n");
            write_lock_irq(&adapter->erp_lock);
            zfcp_erp_action_to_running(erp_action);
            write_unlock_irq(&adapter->erp_lock);
            if (zfcp_fsf_exchange_config_data(erp_action)) {
                  retval = ZFCP_ERP_FAILED;
                  debug_text_event(adapter->erp_dbf, 5, "a_fstx_xf");
                  ZFCP_LOG_INFO("error:  initiation of exchange of "
                              "configuration data failed for "
                              "adapter %s\n",
                              zfcp_get_busid_by_adapter(adapter));
                  break;
            }
            debug_text_event(adapter->erp_dbf, 6, "a_fstx_xok");
            ZFCP_LOG_DEBUG("Xchange underway\n");

            /*
             * Why this works:
             * Both the normal completion handler as well as the timeout
             * handler will do an 'up' when the 'exchange config data'
             * request completes or times out. Thus, the signal to go on
             * won't be lost utilizing this semaphore.
             * Furthermore, this 'adapter_reopen' action is
             * guaranteed to be the only action being there (highest action
             * which prevents other actions from being created).
             * Resulting from that, the wake signal recognized here
             * _must_ be the one belonging to the 'exchange config
             * data' request.
             */
            down(&adapter->erp_ready_sem);
            if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT) {
                  ZFCP_LOG_INFO("error: exchange of configuration data "
                              "for adapter %s timed out\n",
                              zfcp_get_busid_by_adapter(adapter));
                  break;
            }

            if (!atomic_test_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
                             &adapter->status))
                  break;

            ZFCP_LOG_DEBUG("host connection still initialising... "
                         "waiting and retrying...\n");
            /* sleep a little bit before retry */
            msleep(jiffies_to_msecs(sleep));
            sleep *= 2;
      }

      atomic_clear_mask(ZFCP_STATUS_ADAPTER_HOST_CON_INIT,
                    &adapter->status);

      if (!atomic_test_mask(ZFCP_STATUS_ADAPTER_XCONFIG_OK,
                        &adapter->status)) {
            ZFCP_LOG_INFO("error: exchange of configuration data for "
                        "adapter %s failed\n",
                        zfcp_get_busid_by_adapter(adapter));
            retval = ZFCP_ERP_FAILED;
      }

      return retval;
}

static int
zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *erp_action)
{
      int ret;
      struct zfcp_adapter *adapter;

      adapter = erp_action->adapter;
      atomic_clear_mask(ZFCP_STATUS_ADAPTER_XPORT_OK, &adapter->status);

      write_lock_irq(&adapter->erp_lock);
      zfcp_erp_action_to_running(erp_action);
      write_unlock_irq(&adapter->erp_lock);

      ret = zfcp_fsf_exchange_port_data(erp_action);
      if (ret == -EOPNOTSUPP) {
            debug_text_event(adapter->erp_dbf, 3, "a_xport_notsupp");
            return ZFCP_ERP_SUCCEEDED;
      } else if (ret) {
            debug_text_event(adapter->erp_dbf, 3, "a_xport_failed");
            return ZFCP_ERP_FAILED;
      }
      debug_text_event(adapter->erp_dbf, 6, "a_xport_ok");

      ret = ZFCP_ERP_SUCCEEDED;
      down(&adapter->erp_ready_sem);
      if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT) {
            ZFCP_LOG_INFO("error: exchange port data timed out (adapter "
                        "%s)\n", zfcp_get_busid_by_adapter(adapter));
            ret = ZFCP_ERP_FAILED;
      }

      /* don't treat as error for the sake of compatibility */
      if (!atomic_test_mask(ZFCP_STATUS_ADAPTER_XPORT_OK, &adapter->status))
            ZFCP_LOG_INFO("warning: exchange port data failed (adapter "
                        "%s\n", zfcp_get_busid_by_adapter(adapter));

      return ret;
}

static int
zfcp_erp_adapter_strategy_open_fsf_statusread(struct zfcp_erp_action
                                    *erp_action)
{
      int retval = ZFCP_ERP_SUCCEEDED;
      int temp_ret;
      struct zfcp_adapter *adapter = erp_action->adapter;
      int i;

      adapter->status_read_failed = 0;
      for (i = 0; i < ZFCP_STATUS_READS_RECOM; i++) {
            temp_ret = zfcp_fsf_status_read(adapter, ZFCP_WAIT_FOR_SBAL);
            if (temp_ret < 0) {
                  ZFCP_LOG_INFO("error: set-up of unsolicited status "
                              "notification failed on adapter %s\n",
                              zfcp_get_busid_by_adapter(adapter));
                  retval = ZFCP_ERP_FAILED;
                  i--;
                  break;
            }
      }

      return retval;
}

/*
 * function:
 *
 * purpose: this routine executes the 'Reopen Physical Port' action
 *
 * returns: ZFCP_ERP_CONTINUES      - action continues (asynchronously)
 *          ZFCP_ERP_SUCCEEDED      - action finished successfully
 *          ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_port_forced_strategy(struct zfcp_erp_action *erp_action)
{
      int retval = ZFCP_ERP_FAILED;
      struct zfcp_port *port = erp_action->port;
      struct zfcp_adapter *adapter = erp_action->adapter;

      switch (erp_action->step) {

            /*
             * FIXME:
             * the ULP spec. begs for waiting for oustanding commands
             */
      case ZFCP_ERP_STEP_UNINITIALIZED:
            zfcp_erp_port_strategy_clearstati(port);
            /*
             * it would be sufficient to test only the normal open flag
             * since the phys. open flag cannot be set if the normal
             * open flag is unset - however, this is for readabilty ...
             */
            if (atomic_test_mask((ZFCP_STATUS_PORT_PHYS_OPEN |
                              ZFCP_STATUS_COMMON_OPEN),
                               &port->status)) {
                  ZFCP_LOG_DEBUG("port 0x%016Lx is open -> trying "
                               "close physical\n", port->wwpn);
                  retval =
                      zfcp_erp_port_forced_strategy_close(erp_action);
            } else
                  retval = ZFCP_ERP_FAILED;
            break;

      case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
            if (atomic_test_mask(ZFCP_STATUS_PORT_PHYS_OPEN,
                             &port->status)) {
                  ZFCP_LOG_DEBUG("close physical failed for port "
                               "0x%016Lx\n", port->wwpn);
                  retval = ZFCP_ERP_FAILED;
            } else
                  retval = ZFCP_ERP_SUCCEEDED;
            break;
      }

      debug_text_event(adapter->erp_dbf, 3, "p_pfst/ret");
      debug_event(adapter->erp_dbf, 3, &port->wwpn, sizeof (wwn_t));
      debug_event(adapter->erp_dbf, 3, &erp_action->action, sizeof (int));
      debug_event(adapter->erp_dbf, 3, &retval, sizeof (int));

      return retval;
}

/*
 * function:
 *
 * purpose: this routine executes the 'Reopen Port' action
 *
 * returns: ZFCP_ERP_CONTINUES      - action continues (asynchronously)
 *          ZFCP_ERP_SUCCEEDED      - action finished successfully
 *          ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_port_strategy(struct zfcp_erp_action *erp_action)
{
      int retval = ZFCP_ERP_FAILED;
      struct zfcp_port *port = erp_action->port;
      struct zfcp_adapter *adapter = erp_action->adapter;

      switch (erp_action->step) {

            /*
             * FIXME:
             * the ULP spec. begs for waiting for oustanding commands
             */
      case ZFCP_ERP_STEP_UNINITIALIZED:
            zfcp_erp_port_strategy_clearstati(port);
            if (atomic_test_mask(ZFCP_STATUS_COMMON_OPEN, &port->status)) {
                  ZFCP_LOG_DEBUG("port 0x%016Lx is open -> trying "
                               "close\n", port->wwpn);
                  retval = zfcp_erp_port_strategy_close(erp_action);
                  goto out;
            }           /* else it's already closed, open it */
            break;

      case ZFCP_ERP_STEP_PORT_CLOSING:
            if (atomic_test_mask(ZFCP_STATUS_COMMON_OPEN, &port->status)) {
                  ZFCP_LOG_DEBUG("close failed for port 0x%016Lx\n",
                               port->wwpn);
                  retval = ZFCP_ERP_FAILED;
                  goto out;
            }           /* else it's closed now, open it */
            break;
      }
      if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
            retval = ZFCP_ERP_EXIT;
      else
            retval = zfcp_erp_port_strategy_open(erp_action);

 out:
      debug_text_event(adapter->erp_dbf, 3, "p_pst/ret");
      debug_event(adapter->erp_dbf, 3, &port->wwpn, sizeof (wwn_t));
      debug_event(adapter->erp_dbf, 3, &erp_action->action, sizeof (int));
      debug_event(adapter->erp_dbf, 3, &retval, sizeof (int));

      return retval;
}

static int
zfcp_erp_port_strategy_open(struct zfcp_erp_action *erp_action)
{
      int retval;

      if (atomic_test_mask(ZFCP_STATUS_PORT_WKA,
                       &erp_action->port->status))
            retval = zfcp_erp_port_strategy_open_nameserver(erp_action);
      else
            retval = zfcp_erp_port_strategy_open_common(erp_action);

      return retval;
}

static int
zfcp_erp_port_strategy_open_common(struct zfcp_erp_action *erp_action)
{
      int retval = 0;
      struct zfcp_adapter *adapter = erp_action->adapter;
      struct zfcp_port *port = erp_action->port;

      switch (erp_action->step) {

      case ZFCP_ERP_STEP_UNINITIALIZED:
      case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
      case ZFCP_ERP_STEP_PORT_CLOSING:
            if (fc_host_port_type(adapter->scsi_host) == FC_PORTTYPE_PTP) {
                  if (port->wwpn != adapter->peer_wwpn) {
                        ZFCP_LOG_NORMAL("Failed to open port 0x%016Lx "
                                    "on adapter %s.\nPeer WWPN "
                                    "0x%016Lx does not match\n",
                                    port->wwpn,
                                    zfcp_get_busid_by_adapter(adapter),
                                    adapter->peer_wwpn);
                        zfcp_erp_port_failed(port);
                        retval = ZFCP_ERP_FAILED;
                        break;
                  }
                  port->d_id = adapter->peer_d_id;
                  atomic_set_mask(ZFCP_STATUS_PORT_DID_DID, &port->status);
                  retval = zfcp_erp_port_strategy_open_port(erp_action);
                  break;
            }
            if (!(adapter->nameserver_port)) {
                  retval = zfcp_nameserver_enqueue(adapter);
                  if (retval != 0) {
                        ZFCP_LOG_NORMAL("error: nameserver port "
                                    "unavailable for adapter %s\n",
                                    zfcp_get_busid_by_adapter(adapter));
                        retval = ZFCP_ERP_FAILED;
                        break;
                  }
            }
            if (!atomic_test_mask(ZFCP_STATUS_COMMON_UNBLOCKED,
                              &adapter->nameserver_port->status)) {
                  ZFCP_LOG_DEBUG("nameserver port is not open -> open "
                               "nameserver port\n");
                  /* nameserver port may live again */
                  atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING,
                              &adapter->nameserver_port->status);
                  if (zfcp_erp_port_reopen(adapter->nameserver_port, 0)
                      >= 0) {
                        erp_action->step =
                              ZFCP_ERP_STEP_NAMESERVER_OPEN;
                        retval = ZFCP_ERP_CONTINUES;
                  } else
                        retval = ZFCP_ERP_FAILED;
                  break;
            }
            /* else nameserver port is already open, fall through */
      case ZFCP_ERP_STEP_NAMESERVER_OPEN:
            if (!atomic_test_mask(ZFCP_STATUS_COMMON_OPEN,
                              &adapter->nameserver_port->status)) {
                  ZFCP_LOG_DEBUG("open failed for nameserver port\n");
                  retval = ZFCP_ERP_FAILED;
            } else {
                  ZFCP_LOG_DEBUG("nameserver port is open -> "
                               "nameserver look-up for port 0x%016Lx\n",
                               port->wwpn);
                  retval = zfcp_erp_port_strategy_open_common_lookup
                        (erp_action);
            }
            break;

      case ZFCP_ERP_STEP_NAMESERVER_LOOKUP:
            if (!atomic_test_mask(ZFCP_STATUS_PORT_DID_DID, &port->status)) {
                  if (atomic_test_mask
                      (ZFCP_STATUS_PORT_INVALID_WWPN, &port->status)) {
                        ZFCP_LOG_DEBUG("nameserver look-up failed "
                                     "for port 0x%016Lx "
                                     "(misconfigured WWPN?)\n",
                                     port->wwpn);
                        zfcp_erp_port_failed(port);
                        retval = ZFCP_ERP_EXIT;
                  } else {
                        ZFCP_LOG_DEBUG("nameserver look-up failed for "
                                     "port 0x%016Lx\n", port->wwpn);
                        retval = ZFCP_ERP_FAILED;
                  }
            } else {
                  ZFCP_LOG_DEBUG("port 0x%016Lx has d_id=0x%06x -> "
                               "trying open\n", port->wwpn, port->d_id);
                  retval = zfcp_erp_port_strategy_open_port(erp_action);
            }
            break;

      case ZFCP_ERP_STEP_PORT_OPENING:
            /* D_ID might have changed during open */
            if (atomic_test_mask((ZFCP_STATUS_COMMON_OPEN |
                              ZFCP_STATUS_PORT_DID_DID),
                             &port->status)) {
                  ZFCP_LOG_DEBUG("port 0x%016Lx is open\n", port->wwpn);
                  retval = ZFCP_ERP_SUCCEEDED;
            } else {
                  ZFCP_LOG_DEBUG("open failed for port 0x%016Lx\n",
                               port->wwpn);
                  retval = ZFCP_ERP_FAILED;
            }
            break;

      default:
            ZFCP_LOG_NORMAL("bug: unknown erp step 0x%08x\n",
                        erp_action->step);
            retval = ZFCP_ERP_FAILED;
      }

      return retval;
}

static int
zfcp_erp_port_strategy_open_nameserver(struct zfcp_erp_action *erp_action)
{
      int retval;
      struct zfcp_port *port = erp_action->port;

      switch (erp_action->step) {

      case ZFCP_ERP_STEP_UNINITIALIZED:
      case ZFCP_ERP_STEP_PHYS_PORT_CLOSING:
      case ZFCP_ERP_STEP_PORT_CLOSING:
            ZFCP_LOG_DEBUG("port 0x%016Lx has d_id=0x%06x -> trying open\n",
                         port->wwpn, port->d_id);
            retval = zfcp_erp_port_strategy_open_port(erp_action);
            break;

      case ZFCP_ERP_STEP_PORT_OPENING:
            if (atomic_test_mask(ZFCP_STATUS_COMMON_OPEN, &port->status)) {
                  ZFCP_LOG_DEBUG("WKA port is open\n");
                  retval = ZFCP_ERP_SUCCEEDED;
            } else {
                  ZFCP_LOG_DEBUG("open failed for WKA port\n");
                  retval = ZFCP_ERP_FAILED;
            }
            /* this is needed anyway (dont care for retval of wakeup) */
            ZFCP_LOG_DEBUG("continue other open port operations\n");
            zfcp_erp_port_strategy_open_nameserver_wakeup(erp_action);
            break;

      default:
            ZFCP_LOG_NORMAL("bug: unknown erp step 0x%08x\n",
                        erp_action->step);
            retval = ZFCP_ERP_FAILED;
      }

      return retval;
}

/*
 * function:
 *
 * purpose: makes the erp thread continue with reopen (physical) port
 *          actions which have been paused until the name server port
 *          is opened (or failed)
 *
 * returns: 0     (a kind of void retval, its not used)
 */
static int
zfcp_erp_port_strategy_open_nameserver_wakeup(struct zfcp_erp_action
                                    *ns_erp_action)
{
      int retval = 0;
      unsigned long flags;
      struct zfcp_adapter *adapter = ns_erp_action->adapter;
      struct zfcp_erp_action *erp_action, *tmp;

      read_lock_irqsave(&adapter->erp_lock, flags);
      list_for_each_entry_safe(erp_action, tmp, &adapter->erp_running_head,
                         list) {
            debug_text_event(adapter->erp_dbf, 4, "p_pstnsw_n");
            debug_event(adapter->erp_dbf, 4, &erp_action->port->wwpn,
                      sizeof (wwn_t));
            if (erp_action->step == ZFCP_ERP_STEP_NAMESERVER_OPEN) {
                  debug_text_event(adapter->erp_dbf, 3, "p_pstnsw_w");
                  debug_event(adapter->erp_dbf, 3,
                            &erp_action->port->wwpn, sizeof (wwn_t));
                  if (atomic_test_mask(
                            ZFCP_STATUS_COMMON_ERP_FAILED,
                            &adapter->nameserver_port->status))
                        zfcp_erp_port_failed(erp_action->port);
                  zfcp_erp_action_ready(erp_action);
            }
      }
      read_unlock_irqrestore(&adapter->erp_lock, flags);

      return retval;
}

/*
 * function:
 *
 * purpose:
 *
 * returns: ZFCP_ERP_CONTINUES      - action continues (asynchronously)
 *          ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_port_forced_strategy_close(struct zfcp_erp_action *erp_action)
{
      int retval;
      struct zfcp_adapter *adapter = erp_action->adapter;
      struct zfcp_port *port = erp_action->port;

      retval = zfcp_fsf_close_physical_port(erp_action);
      if (retval == -ENOMEM) {
            debug_text_event(adapter->erp_dbf, 5, "o_pfstc_nomem");
            debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));
            retval = ZFCP_ERP_NOMEM;
            goto out;
      }
      erp_action->step = ZFCP_ERP_STEP_PHYS_PORT_CLOSING;
      if (retval != 0) {
            debug_text_event(adapter->erp_dbf, 5, "o_pfstc_cpf");
            debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));
            /* could not send 'open', fail */
            retval = ZFCP_ERP_FAILED;
            goto out;
      }
      debug_text_event(adapter->erp_dbf, 6, "o_pfstc_cpok");
      debug_event(adapter->erp_dbf, 6, &port->wwpn, sizeof (wwn_t));
      retval = ZFCP_ERP_CONTINUES;
 out:
      return retval;
}

static int
zfcp_erp_port_strategy_clearstati(struct zfcp_port *port)
{
      int retval = 0;
      struct zfcp_adapter *adapter = port->adapter;

      debug_text_event(adapter->erp_dbf, 5, "p_pstclst");
      debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));

      atomic_clear_mask(ZFCP_STATUS_COMMON_OPENING |
                    ZFCP_STATUS_COMMON_CLOSING |
                    ZFCP_STATUS_COMMON_ACCESS_DENIED |
                    ZFCP_STATUS_PORT_DID_DID |
                    ZFCP_STATUS_PORT_PHYS_CLOSING |
                    ZFCP_STATUS_PORT_INVALID_WWPN,
                    &port->status);
      return retval;
}

/*
 * function:
 *
 * purpose:
 *
 * returns: ZFCP_ERP_CONTINUES      - action continues (asynchronously)
 *          ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_port_strategy_close(struct zfcp_erp_action *erp_action)
{
      int retval;
      struct zfcp_adapter *adapter = erp_action->adapter;
      struct zfcp_port *port = erp_action->port;

      retval = zfcp_fsf_close_port(erp_action);
      if (retval == -ENOMEM) {
            debug_text_event(adapter->erp_dbf, 5, "p_pstc_nomem");
            debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));
            retval = ZFCP_ERP_NOMEM;
            goto out;
      }
      erp_action->step = ZFCP_ERP_STEP_PORT_CLOSING;
      if (retval != 0) {
            debug_text_event(adapter->erp_dbf, 5, "p_pstc_cpf");
            debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));
            /* could not send 'close', fail */
            retval = ZFCP_ERP_FAILED;
            goto out;
      }
      debug_text_event(adapter->erp_dbf, 6, "p_pstc_cpok");
      debug_event(adapter->erp_dbf, 6, &port->wwpn, sizeof (wwn_t));
      retval = ZFCP_ERP_CONTINUES;
 out:
      return retval;
}

/*
 * function:
 *
 * purpose:
 *
 * returns: ZFCP_ERP_CONTINUES      - action continues (asynchronously)
 *          ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_port_strategy_open_port(struct zfcp_erp_action *erp_action)
{
      int retval;
      struct zfcp_adapter *adapter = erp_action->adapter;
      struct zfcp_port *port = erp_action->port;

      retval = zfcp_fsf_open_port(erp_action);
      if (retval == -ENOMEM) {
            debug_text_event(adapter->erp_dbf, 5, "p_psto_nomem");
            debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));
            retval = ZFCP_ERP_NOMEM;
            goto out;
      }
      erp_action->step = ZFCP_ERP_STEP_PORT_OPENING;
      if (retval != 0) {
            debug_text_event(adapter->erp_dbf, 5, "p_psto_opf");
            debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));
            /* could not send 'open', fail */
            retval = ZFCP_ERP_FAILED;
            goto out;
      }
      debug_text_event(adapter->erp_dbf, 6, "p_psto_opok");
      debug_event(adapter->erp_dbf, 6, &port->wwpn, sizeof (wwn_t));
      retval = ZFCP_ERP_CONTINUES;
 out:
      return retval;
}

/*
 * function:
 *
 * purpose:
 *
 * returns: ZFCP_ERP_CONTINUES      - action continues (asynchronously)
 *          ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_port_strategy_open_common_lookup(struct zfcp_erp_action *erp_action)
{
      int retval;
      struct zfcp_adapter *adapter = erp_action->adapter;
      struct zfcp_port *port = erp_action->port;

      retval = zfcp_ns_gid_pn_request(erp_action);
      if (retval == -ENOMEM) {
            debug_text_event(adapter->erp_dbf, 5, "p_pstn_nomem");
            debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));
            retval = ZFCP_ERP_NOMEM;
            goto out;
      }
      erp_action->step = ZFCP_ERP_STEP_NAMESERVER_LOOKUP;
      if (retval != 0) {
            debug_text_event(adapter->erp_dbf, 5, "p_pstn_ref");
            debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));
            /* could not send nameserver request, fail */
            retval = ZFCP_ERP_FAILED;
            goto out;
      }
      debug_text_event(adapter->erp_dbf, 6, "p_pstn_reok");
      debug_event(adapter->erp_dbf, 6, &port->wwpn, sizeof (wwn_t));
      retval = ZFCP_ERP_CONTINUES;
 out:
      return retval;
}

/*
 * function:
 *
 * purpose: this routine executes the 'Reopen Unit' action
 *          currently no retries
 *
 * returns: ZFCP_ERP_CONTINUES      - action continues (asynchronously)
 *          ZFCP_ERP_SUCCEEDED      - action finished successfully
 *          ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_unit_strategy(struct zfcp_erp_action *erp_action)
{
      int retval = ZFCP_ERP_FAILED;
      struct zfcp_unit *unit = erp_action->unit;
      struct zfcp_adapter *adapter = erp_action->adapter;

      switch (erp_action->step) {

            /*
             * FIXME:
             * the ULP spec. begs for waiting for oustanding commands
             */
      case ZFCP_ERP_STEP_UNINITIALIZED:
            zfcp_erp_unit_strategy_clearstati(unit);
            if (atomic_test_mask(ZFCP_STATUS_COMMON_OPEN, &unit->status)) {
                  ZFCP_LOG_DEBUG("unit 0x%016Lx is open -> "
                               "trying close\n", unit->fcp_lun);
                  retval = zfcp_erp_unit_strategy_close(erp_action);
                  break;
            }
            /* else it's already closed, fall through */
      case ZFCP_ERP_STEP_UNIT_CLOSING:
            if (atomic_test_mask(ZFCP_STATUS_COMMON_OPEN, &unit->status)) {
                  ZFCP_LOG_DEBUG("close failed for unit 0x%016Lx\n",
                               unit->fcp_lun);
                  retval = ZFCP_ERP_FAILED;
            } else {
                  if (erp_action->status & ZFCP_STATUS_ERP_CLOSE_ONLY)
                        retval = ZFCP_ERP_EXIT;
                  else {
                        ZFCP_LOG_DEBUG("unit 0x%016Lx is not open -> "
                                     "trying open\n", unit->fcp_lun);
                        retval =
                            zfcp_erp_unit_strategy_open(erp_action);
                  }
            }
            break;

      case ZFCP_ERP_STEP_UNIT_OPENING:
            if (atomic_test_mask(ZFCP_STATUS_COMMON_OPEN, &unit->status)) {
                  ZFCP_LOG_DEBUG("unit 0x%016Lx is open\n",
                               unit->fcp_lun);
                  retval = ZFCP_ERP_SUCCEEDED;
            } else {
                  ZFCP_LOG_DEBUG("open failed for unit 0x%016Lx\n",
                               unit->fcp_lun);
                  retval = ZFCP_ERP_FAILED;
            }
            break;
      }

      debug_text_event(adapter->erp_dbf, 3, "u_ust/ret");
      debug_event(adapter->erp_dbf, 3, &unit->fcp_lun, sizeof (fcp_lun_t));
      debug_event(adapter->erp_dbf, 3, &erp_action->action, sizeof (int));
      debug_event(adapter->erp_dbf, 3, &retval, sizeof (int));
      return retval;
}

static int
zfcp_erp_unit_strategy_clearstati(struct zfcp_unit *unit)
{
      int retval = 0;
      struct zfcp_adapter *adapter = unit->port->adapter;

      debug_text_event(adapter->erp_dbf, 5, "u_ustclst");
      debug_event(adapter->erp_dbf, 5, &unit->fcp_lun, sizeof (fcp_lun_t));

      atomic_clear_mask(ZFCP_STATUS_COMMON_OPENING |
                    ZFCP_STATUS_COMMON_CLOSING |
                    ZFCP_STATUS_COMMON_ACCESS_DENIED |
                    ZFCP_STATUS_UNIT_SHARED |
                    ZFCP_STATUS_UNIT_READONLY,
                    &unit->status);

      return retval;
}

/*
 * function:
 *
 * purpose:
 *
 * returns: ZFCP_ERP_CONTINUES      - action continues (asynchronously)
 *          ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_unit_strategy_close(struct zfcp_erp_action *erp_action)
{
      int retval;
      struct zfcp_adapter *adapter = erp_action->adapter;
      struct zfcp_unit *unit = erp_action->unit;

      retval = zfcp_fsf_close_unit(erp_action);
      if (retval == -ENOMEM) {
            debug_text_event(adapter->erp_dbf, 5, "u_ustc_nomem");
            debug_event(adapter->erp_dbf, 5, &unit->fcp_lun,
                      sizeof (fcp_lun_t));
            retval = ZFCP_ERP_NOMEM;
            goto out;
      }
      erp_action->step = ZFCP_ERP_STEP_UNIT_CLOSING;
      if (retval != 0) {
            debug_text_event(adapter->erp_dbf, 5, "u_ustc_cuf");
            debug_event(adapter->erp_dbf, 5, &unit->fcp_lun,
                      sizeof (fcp_lun_t));
            /* could not send 'close', fail */
            retval = ZFCP_ERP_FAILED;
            goto out;
      }
      debug_text_event(adapter->erp_dbf, 6, "u_ustc_cuok");
      debug_event(adapter->erp_dbf, 6, &unit->fcp_lun, sizeof (fcp_lun_t));
      retval = ZFCP_ERP_CONTINUES;

 out:
      return retval;
}

/*
 * function:
 *
 * purpose:
 *
 * returns: ZFCP_ERP_CONTINUES      - action continues (asynchronously)
 *          ZFCP_ERP_FAILED         - action finished unsuccessfully
 */
static int
zfcp_erp_unit_strategy_open(struct zfcp_erp_action *erp_action)
{
      int retval;
      struct zfcp_adapter *adapter = erp_action->adapter;
      struct zfcp_unit *unit = erp_action->unit;

      retval = zfcp_fsf_open_unit(erp_action);
      if (retval == -ENOMEM) {
            debug_text_event(adapter->erp_dbf, 5, "u_usto_nomem");
            debug_event(adapter->erp_dbf, 5, &unit->fcp_lun,
                      sizeof (fcp_lun_t));
            retval = ZFCP_ERP_NOMEM;
            goto out;
      }
      erp_action->step = ZFCP_ERP_STEP_UNIT_OPENING;
      if (retval != 0) {
            debug_text_event(adapter->erp_dbf, 5, "u_usto_ouf");
            debug_event(adapter->erp_dbf, 5, &unit->fcp_lun,
                      sizeof (fcp_lun_t));
            /* could not send 'open', fail */
            retval = ZFCP_ERP_FAILED;
            goto out;
      }
      debug_text_event(adapter->erp_dbf, 6, "u_usto_ouok");
      debug_event(adapter->erp_dbf, 6, &unit->fcp_lun, sizeof (fcp_lun_t));
      retval = ZFCP_ERP_CONTINUES;
 out:
      return retval;
}

void zfcp_erp_start_timer(struct zfcp_fsf_req *fsf_req)
{
      BUG_ON(!fsf_req->erp_action);
      fsf_req->timer.function = zfcp_erp_timeout_handler;
      fsf_req->timer.data = (unsigned long) fsf_req->erp_action;
      fsf_req->timer.expires = jiffies + ZFCP_ERP_FSFREQ_TIMEOUT;
      add_timer(&fsf_req->timer);
}

/*
 * function:
 *
 * purpose: enqueue the specified error recovery action, if needed
 *
 * returns:
 */
static int
zfcp_erp_action_enqueue(int action,
                  struct zfcp_adapter *adapter,
                  struct zfcp_port *port, struct zfcp_unit *unit)
{
      int retval = 1;
      struct zfcp_erp_action *erp_action = NULL;
      int stronger_action = 0;
      u32 status = 0;

      /*
       * We need some rules here which check whether we really need
       * this action or whether we should just drop it.
       * E.g. if there is a unfinished 'Reopen Port' request then we drop a
       * 'Reopen Unit' request for an associated unit since we can't
       * satisfy this request now. A 'Reopen Port' action will trigger
       * 'Reopen Unit' actions when it completes.
       * Thus, there are only actions in the queue which can immediately be
       * executed. This makes the processing of the action queue more
       * efficient.
       */

      if (!atomic_test_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_UP,
                        &adapter->status))
            return -EIO;

      debug_event(adapter->erp_dbf, 4, &action, sizeof (int));
      /* check whether we really need this */
      switch (action) {
      case ZFCP_ERP_ACTION_REOPEN_UNIT:
            if (atomic_test_mask
                (ZFCP_STATUS_COMMON_ERP_INUSE, &unit->status)) {
                  debug_text_event(adapter->erp_dbf, 4, "u_actenq_drp");
                  debug_event(adapter->erp_dbf, 4, &port->wwpn,
                            sizeof (wwn_t));
                  debug_event(adapter->erp_dbf, 4, &unit->fcp_lun,
                            sizeof (fcp_lun_t));
                  goto out;
            }
            if (!atomic_test_mask
                (ZFCP_STATUS_COMMON_RUNNING, &port->status) ||
                atomic_test_mask
                (ZFCP_STATUS_COMMON_ERP_FAILED, &port->status)) {
                  goto out;
            }
            if (!atomic_test_mask
                (ZFCP_STATUS_COMMON_UNBLOCKED, &port->status)) {
                  stronger_action = ZFCP_ERP_ACTION_REOPEN_PORT;
                  unit = NULL;
            }
            /* fall through !!! */

      case ZFCP_ERP_ACTION_REOPEN_PORT:
            if (atomic_test_mask
                (ZFCP_STATUS_COMMON_ERP_INUSE, &port->status)) {
                  debug_text_event(adapter->erp_dbf, 4, "p_actenq_drp");
                  debug_event(adapter->erp_dbf, 4, &port->wwpn,
                            sizeof (wwn_t));
                  goto out;
            }
            /* fall through !!! */

      case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
            if (atomic_test_mask(ZFCP_STATUS_COMMON_ERP_INUSE,
                             &port->status)) {
                  if (port->erp_action.action !=
                      ZFCP_ERP_ACTION_REOPEN_PORT_FORCED) {
                        ZFCP_LOG_INFO("dropped erp action %i (port "
                                    "0x%016Lx, action in use: %i)\n",
                                    action, port->wwpn,
                                    port->erp_action.action);
                        debug_text_event(adapter->erp_dbf, 4,
                                     "pf_actenq_drp");
                  } else
                        debug_text_event(adapter->erp_dbf, 4,
                                     "pf_actenq_drpcp");
                  debug_event(adapter->erp_dbf, 4, &port->wwpn,
                            sizeof (wwn_t));
                  goto out;
            }
            if (!atomic_test_mask
                (ZFCP_STATUS_COMMON_RUNNING, &adapter->status) ||
                atomic_test_mask
                (ZFCP_STATUS_COMMON_ERP_FAILED, &adapter->status)) {
                  goto out;
            }
            if (!atomic_test_mask
                (ZFCP_STATUS_COMMON_UNBLOCKED, &adapter->status)) {
                  stronger_action = ZFCP_ERP_ACTION_REOPEN_ADAPTER;
                  port = NULL;
            }
            /* fall through !!! */

      case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
            if (atomic_test_mask
                (ZFCP_STATUS_COMMON_ERP_INUSE, &adapter->status)) {
                  debug_text_event(adapter->erp_dbf, 4, "a_actenq_drp");
                  goto out;
            }
            break;

      default:
            debug_text_exception(adapter->erp_dbf, 1, "a_actenq_bug");
            debug_event(adapter->erp_dbf, 1, &action, sizeof (int));
            ZFCP_LOG_NORMAL("bug: unknown erp action requested "
                        "on adapter %s (action=%d)\n",
                        zfcp_get_busid_by_adapter(adapter), action);
            goto out;
      }

      /* check whether we need something stronger first */
      if (stronger_action) {
            debug_text_event(adapter->erp_dbf, 4, "a_actenq_str");
            debug_event(adapter->erp_dbf, 4, &stronger_action,
                      sizeof (int));
            ZFCP_LOG_DEBUG("stronger erp action %d needed before "
                         "erp action %d on adapter %s\n",
                         stronger_action, action,
                         zfcp_get_busid_by_adapter(adapter));
            action = stronger_action;
      }

      /* mark adapter to have some error recovery pending */
      atomic_set_mask(ZFCP_STATUS_ADAPTER_ERP_PENDING, &adapter->status);

      /* setup error recovery action */
      switch (action) {

      case ZFCP_ERP_ACTION_REOPEN_UNIT:
            zfcp_unit_get(unit);
            atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &unit->status);
            erp_action = &unit->erp_action;
            if (!atomic_test_mask
                (ZFCP_STATUS_COMMON_RUNNING, &unit->status))
                  status = ZFCP_STATUS_ERP_CLOSE_ONLY;
            break;

      case ZFCP_ERP_ACTION_REOPEN_PORT:
      case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
            zfcp_port_get(port);
            zfcp_erp_action_dismiss_port(port);
            atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &port->status);
            erp_action = &port->erp_action;
            if (!atomic_test_mask
                (ZFCP_STATUS_COMMON_RUNNING, &port->status))
                  status = ZFCP_STATUS_ERP_CLOSE_ONLY;
            break;

      case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
            zfcp_adapter_get(adapter);
            zfcp_erp_action_dismiss_adapter(adapter);
            atomic_set_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &adapter->status);
            erp_action = &adapter->erp_action;
            if (!atomic_test_mask
                (ZFCP_STATUS_COMMON_RUNNING, &adapter->status))
                  status = ZFCP_STATUS_ERP_CLOSE_ONLY;
            break;
      }

      debug_text_event(adapter->erp_dbf, 4, "a_actenq");

      memset(erp_action, 0, sizeof (struct zfcp_erp_action));
      erp_action->adapter = adapter;
      erp_action->port = port;
      erp_action->unit = unit;
      erp_action->action = action;
      erp_action->status = status;

      ++adapter->erp_total_count;

      /* finally put it into 'ready' queue and kick erp thread */
      list_add_tail(&erp_action->list, &adapter->erp_ready_head);
      up(&adapter->erp_ready_sem);
      retval = 0;
 out:
      return retval;
}

static int
zfcp_erp_action_dequeue(struct zfcp_erp_action *erp_action)
{
      int retval = 0;
      struct zfcp_adapter *adapter = erp_action->adapter;

      --adapter->erp_total_count;
      if (erp_action->status & ZFCP_STATUS_ERP_LOWMEM) {
            --adapter->erp_low_mem_count;
            erp_action->status &= ~ZFCP_STATUS_ERP_LOWMEM;
      }

      debug_text_event(adapter->erp_dbf, 4, "a_actdeq");
      debug_event(adapter->erp_dbf, 4, &erp_action->action, sizeof (int));
      list_del(&erp_action->list);
      switch (erp_action->action) {
      case ZFCP_ERP_ACTION_REOPEN_UNIT:
            atomic_clear_mask(ZFCP_STATUS_COMMON_ERP_INUSE,
                          &erp_action->unit->status);
            break;
      case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
      case ZFCP_ERP_ACTION_REOPEN_PORT:
            atomic_clear_mask(ZFCP_STATUS_COMMON_ERP_INUSE,
                          &erp_action->port->status);
            break;
      case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
            atomic_clear_mask(ZFCP_STATUS_COMMON_ERP_INUSE,
                          &erp_action->adapter->status);
            break;
      default:
            /* bug */
            break;
      }
      return retval;
}

/**
 * zfcp_erp_action_cleanup
 *
 * Register unit with scsi stack if appropriate and fix reference counts.
 * Note: Temporary units are not registered with scsi stack.
 */
static void
zfcp_erp_action_cleanup(int action, struct zfcp_adapter *adapter,
                  struct zfcp_port *port, struct zfcp_unit *unit,
                  int result)
{
      switch (action) {
      case ZFCP_ERP_ACTION_REOPEN_UNIT:
            if ((result == ZFCP_ERP_SUCCEEDED)
                && (!atomic_test_mask(ZFCP_STATUS_UNIT_TEMPORARY,
                                &unit->status))
                && !unit->device
                && port->rport) {
                  atomic_set_mask(ZFCP_STATUS_UNIT_REGISTERED,
                              &unit->status);
                  if (atomic_test_mask(ZFCP_STATUS_UNIT_SCSI_WORK_PENDING,
                                   &unit->status) == 0)
                        zfcp_erp_schedule_work(unit);
            }
            zfcp_unit_put(unit);
            break;
      case ZFCP_ERP_ACTION_REOPEN_PORT_FORCED:
      case ZFCP_ERP_ACTION_REOPEN_PORT:
            if (atomic_test_mask(ZFCP_STATUS_PORT_NO_WWPN,
                             &port->status)) {
                  zfcp_port_put(port);
                  break;
            }

            if ((result == ZFCP_ERP_SUCCEEDED)
                && !port->rport) {
                  struct fc_rport_identifiers ids;
                  ids.node_name = port->wwnn;
                  ids.port_name = port->wwpn;
                  ids.port_id = port->d_id;
                  ids.roles = FC_RPORT_ROLE_FCP_TARGET;
                  port->rport =
                        fc_remote_port_add(adapter->scsi_host, 0, &ids);
                  if (!port->rport)
                        ZFCP_LOG_NORMAL("failed registration of rport"
                                    "(adapter %s, wwpn=0x%016Lx)\n",
                                    zfcp_get_busid_by_port(port),
                                    port->wwpn);
                  else {
                        scsi_target_unblock(&port->rport->dev);
                        port->rport->maxframe_size = port->maxframe_size;
                        port->rport->supported_classes =
                              port->supported_classes;
                  }
            }
            if ((result != ZFCP_ERP_SUCCEEDED) && port->rport) {
                  fc_remote_port_delete(port->rport);
                  port->rport = NULL;
            }
            zfcp_port_put(port);
            break;
      case ZFCP_ERP_ACTION_REOPEN_ADAPTER:
            if (result != ZFCP_ERP_SUCCEEDED) {
                  list_for_each_entry(port, &adapter->port_list_head, list)
                        if (port->rport &&
                            !atomic_test_mask(ZFCP_STATUS_PORT_WKA,
                                          &port->status)) {
                              fc_remote_port_delete(port->rport);
                              port->rport = NULL;
                        }
            }
            zfcp_adapter_put(adapter);
            break;
      default:
            break;
      }
}


static void zfcp_erp_action_dismiss_adapter(struct zfcp_adapter *adapter)
{
      struct zfcp_port *port;

      debug_text_event(adapter->erp_dbf, 5, "a_actab");
      if (atomic_test_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &adapter->status))
            zfcp_erp_action_dismiss(&adapter->erp_action);
      else
            list_for_each_entry(port, &adapter->port_list_head, list)
                zfcp_erp_action_dismiss_port(port);
}

static void zfcp_erp_action_dismiss_port(struct zfcp_port *port)
{
      struct zfcp_unit *unit;
      struct zfcp_adapter *adapter = port->adapter;

      debug_text_event(adapter->erp_dbf, 5, "p_actab");
      debug_event(adapter->erp_dbf, 5, &port->wwpn, sizeof (wwn_t));
      if (atomic_test_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &port->status))
            zfcp_erp_action_dismiss(&port->erp_action);
      else
            list_for_each_entry(unit, &port->unit_list_head, list)
                zfcp_erp_action_dismiss_unit(unit);
}

static void zfcp_erp_action_dismiss_unit(struct zfcp_unit *unit)
{
      struct zfcp_adapter *adapter = unit->port->adapter;

      debug_text_event(adapter->erp_dbf, 5, "u_actab");
      debug_event(adapter->erp_dbf, 5, &unit->fcp_lun, sizeof (fcp_lun_t));
      if (atomic_test_mask(ZFCP_STATUS_COMMON_ERP_INUSE, &unit->status))
            zfcp_erp_action_dismiss(&unit->erp_action);
}

static void zfcp_erp_action_to_running(struct zfcp_erp_action *erp_action)
{
      struct zfcp_adapter *adapter = erp_action->adapter;

      debug_text_event(adapter->erp_dbf, 6, "a_toru");
      debug_event(adapter->erp_dbf, 6, &erp_action->action, sizeof (int));
      list_move(&erp_action->list, &erp_action->adapter->erp_running_head);
}

static void zfcp_erp_action_to_ready(struct zfcp_erp_action *erp_action)
{
      struct zfcp_adapter *adapter = erp_action->adapter;

      debug_text_event(adapter->erp_dbf, 6, "a_tore");
      debug_event(adapter->erp_dbf, 6, &erp_action->action, sizeof (int));
      list_move(&erp_action->list, &erp_action->adapter->erp_ready_head);
}

void
zfcp_erp_port_boxed(struct zfcp_port *port)
{
      struct zfcp_adapter *adapter = port->adapter;
      unsigned long flags;

      debug_text_event(adapter->erp_dbf, 3, "p_access_boxed");
      debug_event(adapter->erp_dbf, 3, &port->wwpn, sizeof(wwn_t));
      read_lock_irqsave(&zfcp_data.config_lock, flags);
      zfcp_erp_modify_port_status(port,
                  ZFCP_STATUS_COMMON_ACCESS_BOXED,
                  ZFCP_SET);
      read_unlock_irqrestore(&zfcp_data.config_lock, flags);
      zfcp_erp_port_reopen(port, ZFCP_STATUS_COMMON_ERP_FAILED);
}

void
zfcp_erp_unit_boxed(struct zfcp_unit *unit)
{
      struct zfcp_adapter *adapter = unit->port->adapter;

      debug_text_event(adapter->erp_dbf, 3, "u_access_boxed");
      debug_event(adapter->erp_dbf, 3, &unit->fcp_lun, sizeof(fcp_lun_t));
      zfcp_erp_modify_unit_status(unit,
                  ZFCP_STATUS_COMMON_ACCESS_BOXED,
                  ZFCP_SET);
      zfcp_erp_unit_reopen(unit, ZFCP_STATUS_COMMON_ERP_FAILED);
}

void
zfcp_erp_port_access_denied(struct zfcp_port *port)
{
      struct zfcp_adapter *adapter = port->adapter;
      unsigned long flags;

      debug_text_event(adapter->erp_dbf, 3, "p_access_denied");
      debug_event(adapter->erp_dbf, 3, &port->wwpn, sizeof(wwn_t));
      read_lock_irqsave(&zfcp_data.config_lock, flags);
      zfcp_erp_modify_port_status(port,
                  ZFCP_STATUS_COMMON_ERP_FAILED |
                  ZFCP_STATUS_COMMON_ACCESS_DENIED,
                  ZFCP_SET);
      read_unlock_irqrestore(&zfcp_data.config_lock, flags);
}

void
zfcp_erp_unit_access_denied(struct zfcp_unit *unit)
{
      struct zfcp_adapter *adapter = unit->port->adapter;

      debug_text_event(adapter->erp_dbf, 3, "u_access_denied");
      debug_event(adapter->erp_dbf, 3, &unit->fcp_lun, sizeof(fcp_lun_t));
      zfcp_erp_modify_unit_status(unit,
                  ZFCP_STATUS_COMMON_ERP_FAILED |
                  ZFCP_STATUS_COMMON_ACCESS_DENIED,
                  ZFCP_SET);
}

void
zfcp_erp_adapter_access_changed(struct zfcp_adapter *adapter)
{
      struct zfcp_port *port;
      unsigned long flags;

      if (adapter->connection_features & FSF_FEATURE_NPIV_MODE)
            return;

      debug_text_event(adapter->erp_dbf, 3, "a_access_recover");
      debug_event(adapter->erp_dbf, 3, zfcp_get_busid_by_adapter(adapter), 8);

      read_lock_irqsave(&zfcp_data.config_lock, flags);
      if (adapter->nameserver_port)
            zfcp_erp_port_access_changed(adapter->nameserver_port);
      list_for_each_entry(port, &adapter->port_list_head, list)
            if (port != adapter->nameserver_port)
                  zfcp_erp_port_access_changed(port);
      read_unlock_irqrestore(&zfcp_data.config_lock, flags);
}

void
zfcp_erp_port_access_changed(struct zfcp_port *port)
{
      struct zfcp_adapter *adapter = port->adapter;
      struct zfcp_unit *unit;

      debug_text_event(adapter->erp_dbf, 3, "p_access_recover");
      debug_event(adapter->erp_dbf, 3, &port->wwpn, sizeof(wwn_t));

      if (!atomic_test_mask(ZFCP_STATUS_COMMON_ACCESS_DENIED,
                        &port->status) &&
          !atomic_test_mask(ZFCP_STATUS_COMMON_ACCESS_BOXED,
                        &port->status)) {
            if (!atomic_test_mask(ZFCP_STATUS_PORT_WKA, &port->status))
                  list_for_each_entry(unit, &port->unit_list_head, list)
                        zfcp_erp_unit_access_changed(unit);
            return;
      }

      ZFCP_LOG_NORMAL("reopen of port 0x%016Lx on adapter %s "
                  "(due to ACT update)\n",
                  port->wwpn, zfcp_get_busid_by_adapter(adapter));
      if (zfcp_erp_port_reopen(port, ZFCP_STATUS_COMMON_ERP_FAILED) != 0)
            ZFCP_LOG_NORMAL("failed reopen of port"
                        "(adapter %s, wwpn=0x%016Lx)\n",
                        zfcp_get_busid_by_adapter(adapter), port->wwpn);
}

void
zfcp_erp_unit_access_changed(struct zfcp_unit *unit)
{
      struct zfcp_adapter *adapter = unit->port->adapter;

      debug_text_event(adapter->erp_dbf, 3, "u_access_recover");
      debug_event(adapter->erp_dbf, 3, &unit->fcp_lun, sizeof(fcp_lun_t));

      if (!atomic_test_mask(ZFCP_STATUS_COMMON_ACCESS_DENIED,
                        &unit->status) &&
          !atomic_test_mask(ZFCP_STATUS_COMMON_ACCESS_BOXED,
                        &unit->status))
            return;

      ZFCP_LOG_NORMAL("reopen of unit 0x%016Lx on port 0x%016Lx "
                  " on adapter %s (due to ACT update)\n",
                  unit->fcp_lun, unit->port->wwpn,
                  zfcp_get_busid_by_adapter(adapter));
      if (zfcp_erp_unit_reopen(unit, ZFCP_STATUS_COMMON_ERP_FAILED) != 0)
            ZFCP_LOG_NORMAL("failed reopen of unit (adapter %s, "
                        "wwpn=0x%016Lx, fcp_lun=0x%016Lx)\n",
                        zfcp_get_busid_by_adapter(adapter),
                        unit->port->wwpn, unit->fcp_lun);
}

#undef ZFCP_LOG_AREA

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