[SCSI] zfcp: remove union zfcp_req_data, use unit refcount for FCP commands

o union zfcp_req_data removed
o increment unit refcount when processing FCP commands
 (This fixes a theoretical race: When all scsi commands of a unit
  are aborted and the scsi_device is removed then the unit could be
  removed before all fsf_requests of that unit are completely processed.)

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 50 insertions, 51 deletions

diff --git a/drivers/s390/scsi/zfcp_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index c007b6424e74..64e2c3480189 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -821,7 +821,7 @@ zfcp_fsf_status_read(struct zfcp_adapter *adapter, int req_flags)
                 goto failed_buf;
         }
         memset(status_buffer, 0, sizeof (struct fsf_status_read_buffer));
-        fsf_req->data.status_read.buffer = status_buffer;
+        fsf_req->data = (unsigned long) status_buffer;
 
         /* insert pointer to respective buffer */
         sbale = zfcp_qdio_sbale_curr(fsf_req);
@@ -859,7 +859,7 @@ zfcp_fsf_status_read_port_closed(struct zfcp_fsf_req *fsf_req)
         struct zfcp_port *port;
         unsigned long flags;
 
-        status_buffer = fsf_req->data.status_read.buffer;
+        status_buffer = (struct fsf_status_read_buffer *) fsf_req->data;
         adapter = fsf_req->adapter;
 
         read_lock_irqsave(&zfcp_data.config_lock, flags);
@@ -918,7 +918,7 @@ zfcp_fsf_status_read_handler(struct zfcp_fsf_req *fsf_req)
         int retval = 0;
         struct zfcp_adapter *adapter = fsf_req->adapter;
         struct fsf_status_read_buffer *status_buffer =
-            fsf_req->data.status_read.buffer;
+                (struct fsf_status_read_buffer *) fsf_req->data;
 
         if (fsf_req->status & ZFCP_STATUS_FSFREQ_DISMISSED) {
                 mempool_free(status_buffer, adapter->pool.data_status_read);
@@ -1093,7 +1093,7 @@ zfcp_fsf_abort_fcp_command(unsigned long old_req_id,
         sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
         sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
 
-        fsf_req->data.abort_fcp_command.unit = unit;
+        fsf_req->data = (unsigned long) unit;
 
         /* set handles of unit and its parent port in QTCB */
         fsf_req->qtcb->header.lun_handle = unit->handle;
@@ -1139,7 +1139,7 @@ static int
 zfcp_fsf_abort_fcp_command_handler(struct zfcp_fsf_req *new_fsf_req)
 {
         int retval = -EINVAL;
-        struct zfcp_unit *unit = new_fsf_req->data.abort_fcp_command.unit;
+        struct zfcp_unit *unit;
         unsigned char status_qual =
             new_fsf_req->qtcb->header.fsf_status_qual.word[0];
 
@@ -1150,6 +1150,8 @@ zfcp_fsf_abort_fcp_command_handler(struct zfcp_fsf_req *new_fsf_req)
                 goto skip_fsfstatus;
         }
 
+        unit = (struct zfcp_unit *) new_fsf_req->data;
+
         /* evaluate FSF status in QTCB */
         switch (new_fsf_req->qtcb->header.fsf_status) {
 
@@ -1414,7 +1416,7 @@ zfcp_fsf_send_ct(struct zfcp_send_ct *ct, mempool_t *pool,
         fsf_req->qtcb->header.port_handle = port->handle;
         fsf_req->qtcb->bottom.support.service_class = adapter->fc_service_class;
         fsf_req->qtcb->bottom.support.timeout = ct->timeout;
-        fsf_req->data.send_ct = ct;
+        fsf_req->data = (unsigned long) ct;
 
         /* start QDIO request for this FSF request */
         ret = zfcp_fsf_req_send(fsf_req, ct->timer);
@@ -1445,10 +1447,10 @@ zfcp_fsf_send_ct(struct zfcp_send_ct *ct, mempool_t *pool,
  * zfcp_fsf_send_ct_handler - handler for Generic Service requests
  * @fsf_req: pointer to struct zfcp_fsf_req
  *
- * Data specific for the Generic Service request is passed by
- * fsf_req->data.send_ct
- * Usually a specific handler for the request is called via
- * fsf_req->data.send_ct->handler at end of this function.
+ * Data specific for the Generic Service request is passed using
+ * fsf_req->data. There we find the pointer to struct zfcp_send_ct.
+ * Usually a specific handler for the CT request is called which is
+ * found in this structure.
  */
 static int
 zfcp_fsf_send_ct_handler(struct zfcp_fsf_req *fsf_req)
@@ -1462,7 +1464,7 @@ zfcp_fsf_send_ct_handler(struct zfcp_fsf_req *fsf_req)
         u16 subtable, rule, counter;
 
         adapter = fsf_req->adapter;
-        send_ct = fsf_req->data.send_ct;
+        send_ct = (struct zfcp_send_ct *) fsf_req->data;
         port = send_ct->port;
         header = &fsf_req->qtcb->header;
         bottom = &fsf_req->qtcb->bottom.support;
@@ -1714,7 +1716,7 @@ zfcp_fsf_send_els(struct zfcp_send_els *els)
         fsf_req->qtcb->bottom.support.d_id = d_id;
         fsf_req->qtcb->bottom.support.service_class = adapter->fc_service_class;
         fsf_req->qtcb->bottom.support.timeout = ZFCP_ELS_TIMEOUT;
-        fsf_req->data.send_els = els;
+        fsf_req->data = (unsigned long) els;
 
         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
 
@@ -1746,10 +1748,10 @@ zfcp_fsf_send_els(struct zfcp_send_els *els)
  * zfcp_fsf_send_els_handler - handler for ELS commands
  * @fsf_req: pointer to struct zfcp_fsf_req
  *
- * Data specific for the ELS command is passed by
- * fsf_req->data.send_els
- * Usually a specific handler for the command is called via
- * fsf_req->data.send_els->handler at end of this function.
+ * Data specific for the ELS command is passed using
+ * fsf_req->data. There we find the pointer to struct zfcp_send_els.
+ * Usually a specific handler for the ELS command is called which is
+ * found in this structure.
  */
 static int zfcp_fsf_send_els_handler(struct zfcp_fsf_req *fsf_req)
 {
@@ -1762,7 +1764,7 @@ static int zfcp_fsf_send_els_handler(struct zfcp_fsf_req *fsf_req)
         int retval = -EINVAL;
         u16 subtable, rule, counter;
 
-        send_els = fsf_req->data.send_els;
+        send_els = (struct zfcp_send_els *) fsf_req->data;
         adapter = send_els->adapter;
         port = send_els->port;
         d_id = send_els->d_id;
@@ -2211,12 +2213,12 @@ zfcp_fsf_exchange_port_data(struct zfcp_adapter *adapter,
                 goto out;
         }
 
+        fsf_req->data = (unsigned long) data;
+
         sbale = zfcp_qdio_sbale_req(fsf_req, fsf_req->sbal_curr, 0);
         sbale[0].flags |= SBAL_FLAGS0_TYPE_READ;
         sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
 
-        fsf_req->data.port_data = data;
-
         init_timer(timer);
         timer->function = zfcp_fsf_request_timeout_handler;
         timer->data = (unsigned long) adapter;
@@ -2257,7 +2259,9 @@ static void
 zfcp_fsf_exchange_port_data_handler(struct zfcp_fsf_req *fsf_req)
 {
         struct fsf_qtcb_bottom_port *bottom;
-        struct fsf_qtcb_bottom_port *data = fsf_req->data.port_data;
+        struct fsf_qtcb_bottom_port *data;
+
+        data = (struct fsf_qtcb_bottom_port*) fsf_req->data;
 
         if (fsf_req->status & ZFCP_STATUS_FSFREQ_ERROR)
                 return;
@@ -2312,7 +2316,7 @@ zfcp_fsf_open_port(struct zfcp_erp_action *erp_action)
 
         erp_action->fsf_req->qtcb->bottom.support.d_id = erp_action->port->d_id;
         atomic_set_mask(ZFCP_STATUS_COMMON_OPENING, &erp_action->port->status);
-        erp_action->fsf_req->data.open_port.port = erp_action->port;
+        erp_action->fsf_req->data = (unsigned long) erp_action->port;
         erp_action->fsf_req->erp_action = erp_action;
 
         /* start QDIO request for this FSF request */
@@ -2353,7 +2357,7 @@ zfcp_fsf_open_port_handler(struct zfcp_fsf_req *fsf_req)
         struct fsf_qtcb_header *header;
         u16 subtable, rule, counter;
 
-        port = fsf_req->data.open_port.port;
+        port = (struct zfcp_port *) fsf_req->data;
         header = &fsf_req->qtcb->header;
 
         if (fsf_req->status & ZFCP_STATUS_FSFREQ_ERROR) {
@@ -2566,7 +2570,7 @@ zfcp_fsf_close_port(struct zfcp_erp_action *erp_action)
         sbale[1].flags |= SBAL_FLAGS_LAST_ENTRY;
 
         atomic_set_mask(ZFCP_STATUS_COMMON_CLOSING, &erp_action->port->status);
-        erp_action->fsf_req->data.close_port.port = erp_action->port;
+        erp_action->fsf_req->data = (unsigned long) erp_action->port;
         erp_action->fsf_req->erp_action = erp_action;
         erp_action->fsf_req->qtcb->header.port_handle =
             erp_action->port->handle;
@@ -2606,7 +2610,7 @@ zfcp_fsf_close_port_handler(struct zfcp_fsf_req *fsf_req)
         int retval = -EINVAL;
         struct zfcp_port *port;
 
-        port = fsf_req->data.close_port.port;
+        port = (struct zfcp_port *) fsf_req->data;
 
         if (fsf_req->status & ZFCP_STATUS_FSFREQ_ERROR) {
                 /* don't change port status in our bookkeeping */
@@ -2703,7 +2707,7 @@ zfcp_fsf_close_physical_port(struct zfcp_erp_action *erp_action)
         atomic_set_mask(ZFCP_STATUS_PORT_PHYS_CLOSING,
                         &erp_action->port->status);
         /* save a pointer to this port */
-        erp_action->fsf_req->data.close_physical_port.port = erp_action->port;
+        erp_action->fsf_req->data = (unsigned long) erp_action->port;
         /* port to be closeed */
         erp_action->fsf_req->qtcb->header.port_handle =
             erp_action->port->handle;
@@ -2747,7 +2751,7 @@ zfcp_fsf_close_physical_port_handler(struct zfcp_fsf_req *fsf_req)
         struct fsf_qtcb_header *header;
         u16 subtable, rule, counter;
 
-        port = fsf_req->data.close_physical_port.port;
+        port = (struct zfcp_port *) fsf_req->data;
         header = &fsf_req->qtcb->header;
 
         if (fsf_req->status & ZFCP_STATUS_FSFREQ_ERROR) {
@@ -2911,7 +2915,7 @@ zfcp_fsf_open_unit(struct zfcp_erp_action *erp_action)
         erp_action->fsf_req->qtcb->bottom.support.option =
                 FSF_OPEN_LUN_SUPPRESS_BOXING;
         atomic_set_mask(ZFCP_STATUS_COMMON_OPENING, &erp_action->unit->status);
-        erp_action->fsf_req->data.open_unit.unit = erp_action->unit;
+        erp_action->fsf_req->data = (unsigned long) erp_action->unit;
         erp_action->fsf_req->erp_action = erp_action;
 
         /* start QDIO request for this FSF request */
@@ -2957,7 +2961,7 @@ zfcp_fsf_open_unit_handler(struct zfcp_fsf_req *fsf_req)
         u16 subtable, rule, counter;
         u32 allowed, exclusive, readwrite;
 
-        unit = fsf_req->data.open_unit.unit;
+        unit = (struct zfcp_unit *) fsf_req->data;
 
         if (fsf_req->status & ZFCP_STATUS_FSFREQ_ERROR) {
                 /* don't change unit status in our bookkeeping */
@@ -3242,7 +3246,7 @@ zfcp_fsf_close_unit(struct zfcp_erp_action *erp_action)
             erp_action->port->handle;
         erp_action->fsf_req->qtcb->header.lun_handle = erp_action->unit->handle;
         atomic_set_mask(ZFCP_STATUS_COMMON_CLOSING, &erp_action->unit->status);
-        erp_action->fsf_req->data.close_unit.unit = erp_action->unit;
+        erp_action->fsf_req->data = (unsigned long) erp_action->unit;
         erp_action->fsf_req->erp_action = erp_action;
 
         /* start QDIO request for this FSF request */
@@ -3281,7 +3285,7 @@ zfcp_fsf_close_unit_handler(struct zfcp_fsf_req *fsf_req)
         int retval = -EINVAL;
         struct zfcp_unit *unit;
 
-        unit = fsf_req->data.close_unit.unit;   /* restore unit */
+        unit = (struct zfcp_unit *) fsf_req->data;
 
         if (fsf_req->status & ZFCP_STATUS_FSFREQ_ERROR) {
                 /* don't change unit status in our bookkeeping */
@@ -3436,21 +3440,14 @@ zfcp_fsf_send_fcp_command_task(struct zfcp_adapter *adapter,
                 goto failed_req_create;
         }
 
-        /*
-         * associate FSF request with SCSI request
-         * (need this for look up on abort)
-         */
-        fsf_req->data.send_fcp_command_task.fsf_req = fsf_req;
-        scsi_cmnd->host_scribble = (char *) &(fsf_req->data);
+        zfcp_unit_get(unit);
+        fsf_req->unit = unit;
 
-        /*
-         * associate SCSI command with FSF request
-         * (need this for look up on normal command completion)
-         */
-        fsf_req->data.send_fcp_command_task.scsi_cmnd = scsi_cmnd;
-        fsf_req->data.send_fcp_command_task.start_jiffies = jiffies;
-        fsf_req->data.send_fcp_command_task.unit = unit;
-        ZFCP_LOG_DEBUG("unit=%p, fcp_lun=0x%016Lx\n", unit, unit->fcp_lun);
+        /* associate FSF request with SCSI request (for look up on abort) */
+        scsi_cmnd->host_scribble = (char *) fsf_req;
+
+        /* associate SCSI command with FSF request */
+        fsf_req->data = (unsigned long) scsi_cmnd;
 
         /* set handles of unit and its parent port in QTCB */
         fsf_req->qtcb->header.lun_handle = unit->handle;
@@ -3584,6 +3581,7 @@ zfcp_fsf_send_fcp_command_task(struct zfcp_adapter *adapter,
  send_failed:
  no_fit:
  failed_scsi_cmnd:
+        zfcp_unit_put(unit);
         zfcp_fsf_req_free(fsf_req);
         fsf_req = NULL;
         scsi_cmnd->host_scribble = NULL;
@@ -3640,7 +3638,7 @@ zfcp_fsf_send_fcp_command_task_management(struct zfcp_adapter *adapter,
          * hold a pointer to the unit being target of this
          * task management request
          */
-        fsf_req->data.send_fcp_command_task_management.unit = unit;
+        fsf_req->data = (unsigned long) unit;
 
         /* set FSF related fields in QTCB */
         fsf_req->qtcb->header.lun_handle = unit->handle;
@@ -3706,9 +3704,9 @@ zfcp_fsf_send_fcp_command_handler(struct zfcp_fsf_req *fsf_req)
         header = &fsf_req->qtcb->header;
 
         if (unlikely(fsf_req->status & ZFCP_STATUS_FSFREQ_TASK_MANAGEMENT))
-                unit = fsf_req->data.send_fcp_command_task_management.unit;
+                unit = (struct zfcp_unit *) fsf_req->data;
         else
-                unit = fsf_req->data.send_fcp_command_task.unit;
+                unit = fsf_req->unit;
 
         if (unlikely(fsf_req->status & ZFCP_STATUS_FSFREQ_ERROR)) {
                 /* go directly to calls of special handlers */
@@ -3947,6 +3945,8 @@ zfcp_fsf_send_fcp_command_handler(struct zfcp_fsf_req *fsf_req)
                     zfcp_fsf_send_fcp_command_task_management_handler(fsf_req);
         } else {
                 retval = zfcp_fsf_send_fcp_command_task_handler(fsf_req);
+                fsf_req->unit = NULL;
+                zfcp_unit_put(unit);
         }
         return retval;
 }
@@ -3970,10 +3970,10 @@ zfcp_fsf_send_fcp_command_task_handler(struct zfcp_fsf_req *fsf_req)
         u32 sns_len;
         char *fcp_rsp_info = zfcp_get_fcp_rsp_info_ptr(fcp_rsp_iu);
         unsigned long flags;
-        struct zfcp_unit *unit = fsf_req->data.send_fcp_command_task.unit;
+        struct zfcp_unit *unit = fsf_req->unit;
 
         read_lock_irqsave(&fsf_req->adapter->abort_lock, flags);
-        scpnt = fsf_req->data.send_fcp_command_task.scsi_cmnd;
+        scpnt = (struct scsi_cmnd *) fsf_req->data;
         if (unlikely(!scpnt)) {
                 ZFCP_LOG_DEBUG
                     ("Command with fsf_req %p is not associated to "
@@ -4198,8 +4198,7 @@ zfcp_fsf_send_fcp_command_task_management_handler(struct zfcp_fsf_req *fsf_req)
         struct fcp_rsp_iu *fcp_rsp_iu = (struct fcp_rsp_iu *)
             &(fsf_req->qtcb->bottom.io.fcp_rsp);
         char *fcp_rsp_info = zfcp_get_fcp_rsp_info_ptr(fcp_rsp_iu);
-        struct zfcp_unit *unit =
-            fsf_req->data.send_fcp_command_task_management.unit;
+        struct zfcp_unit *unit = (struct zfcp_unit *) fsf_req->data;
 
         del_timer(&fsf_req->adapter->scsi_er_timer);
         if (fsf_req->status & ZFCP_STATUS_FSFREQ_ERROR) {