3 files changed, 27 insertions, 45 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index ed9a8a1517c6..e8f39f02bc3b 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -529,7 +529,7 @@ int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
                 goto generic_services_failed;
 
         init_waitqueue_head(&adapter->remove_wq);
-        init_waitqueue_head(&adapter->erp_thread_wqh);
+        init_waitqueue_head(&adapter->erp_ready_wq);
         init_waitqueue_head(&adapter->erp_done_wqh);
 
         INIT_LIST_HEAD(&adapter->port_list_head);
@@ -541,8 +541,6 @@ int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
         rwlock_init(&adapter->erp_lock);
         rwlock_init(&adapter->abort_lock);
 
-        sema_init(&adapter->erp_ready_sem, 0);
-
         INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
         INIT_WORK(&adapter->scan_work, _zfcp_fc_scan_ports_later);
 
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 9a8ff0553421..ce65d88e280c 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -222,8 +222,6 @@ struct zfcp_ls_adisc {
 #define ZFCP_STATUS_ADAPTER_QDIOUP              0x00000002
 #define ZFCP_STATUS_ADAPTER_XCONFIG_OK          0x00000008
 #define ZFCP_STATUS_ADAPTER_HOST_CON_INIT       0x00000010
-#define ZFCP_STATUS_ADAPTER_ERP_THREAD_UP       0x00000020
-#define ZFCP_STATUS_ADAPTER_ERP_THREAD_KILL     0x00000080
 #define ZFCP_STATUS_ADAPTER_ERP_PENDING         0x00000100
 #define ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED      0x00000200
 
@@ -481,10 +479,9 @@ struct zfcp_adapter {
         atomic_t                status;            /* status of this adapter */
         struct list_head        erp_ready_head;    /* error recovery for this
                                                       adapter/devices */
+        wait_queue_head_t       erp_ready_wq;
         struct list_head        erp_running_head;
         rwlock_t                erp_lock;
-        struct semaphore        erp_ready_sem;
-        wait_queue_head_t       erp_thread_wqh;
         wait_queue_head_t       erp_done_wqh;
         struct zfcp_erp_action  erp_action;        /* pending error recovery */
         atomic_t                erp_counter;
@@ -492,6 +489,7 @@ struct zfcp_adapter {
                                                       actions */
         u32                     erp_low_mem_count; /* nr of erp actions waiting
                                                       for memory */
+        struct task_struct      *erp_thread;
         struct zfcp_wka_ports   *gs;               /* generic services */
         struct zfcp_dbf         *dbf;              /* debug traces */
         struct zfcp_adapter_mempool     pool;      /* Adapter memory pools */
diff --git a/drivers/s390/scsi/zfcp_erp.c b/drivers/s390/scsi/zfcp_erp.c
index 373567eda8f6..577e15708598 100644
--- a/drivers/s390/scsi/zfcp_erp.c
+++ b/drivers/s390/scsi/zfcp_erp.c
@@ -9,6 +9,7 @@
 #define KMSG_COMPONENT "zfcp"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
+#include <linux/kthread.h>
 #include "zfcp_ext.h"
 
 #define ZFCP_MAX_ERPS                   3
@@ -75,7 +76,7 @@ static void zfcp_erp_action_ready(struct zfcp_erp_action *act)
 
         list_move(&act->list, &act->adapter->erp_ready_head);
         zfcp_dbf_rec_action("erardy1", act);
-        up(&adapter->erp_ready_sem);
+        wake_up(&adapter->erp_ready_wq);
         zfcp_dbf_rec_thread("erardy2", adapter->dbf);
 }
 
@@ -212,8 +213,7 @@ static int zfcp_erp_action_enqueue(int want, struct zfcp_adapter *adapter,
         int retval = 1, need;
         struct zfcp_erp_action *act = NULL;
 
-        if (!(atomic_read(&adapter->status) &
-              ZFCP_STATUS_ADAPTER_ERP_THREAD_UP))
+        if (!adapter->erp_thread)
                 return -EIO;
 
         need = zfcp_erp_required_act(want, adapter, port, unit);
@@ -226,7 +226,7 @@ static int zfcp_erp_action_enqueue(int want, struct zfcp_adapter *adapter,
                 goto out;
         ++adapter->erp_total_count;
         list_add_tail(&act->list, &adapter->erp_ready_head);
-        up(&adapter->erp_ready_sem);
+        wake_up(&adapter->erp_ready_wq);
         zfcp_dbf_rec_thread("eracte1", adapter->dbf);
         retval = 0;
  out:
@@ -641,7 +641,8 @@ static int zfcp_erp_adapter_strat_fsf_xconf(struct zfcp_erp_action *erp_action)
                 }
 
                 zfcp_dbf_rec_thread_lock("erasfx1", adapter->dbf);
-                down(&adapter->erp_ready_sem);
+                wait_event(adapter->erp_ready_wq,
+                           !list_empty(&adapter->erp_ready_head));
                 zfcp_dbf_rec_thread_lock("erasfx2", adapter->dbf);
                 if (erp_action->status & ZFCP_STATUS_ERP_TIMEDOUT)
                         break;
@@ -682,7 +683,8 @@ static int zfcp_erp_adapter_strategy_open_fsf_xport(struct zfcp_erp_action *act)
                 return ZFCP_ERP_FAILED;
 
         zfcp_dbf_rec_thread_lock("erasox1", adapter->dbf);
-        down(&adapter->erp_ready_sem);
+        wait_event(adapter->erp_ready_wq,
+                   !list_empty(&adapter->erp_ready_head));
         zfcp_dbf_rec_thread_lock("erasox2", adapter->dbf);
         if (act->status & ZFCP_STATUS_ERP_TIMEDOUT)
                 return ZFCP_ERP_FAILED;
@@ -1285,21 +1287,17 @@ static int zfcp_erp_thread(void *data)
         struct list_head *next;
         struct zfcp_erp_action *act;
         unsigned long flags;
-        int ignore;
-
-        daemonize("zfcperp%s", dev_name(&adapter->ccw_device->dev));
-        /* Block all signals */
-        siginitsetinv(&current->blocked, 0);
-        atomic_set_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_UP, &adapter->status);
-        wake_up(&adapter->erp_thread_wqh);
-
-        while (!(atomic_read(&adapter->status) &
-                 ZFCP_STATUS_ADAPTER_ERP_THREAD_KILL)) {
 
+        for (;;) {
                 zfcp_dbf_rec_thread_lock("erthrd1", adapter->dbf);
-                ignore = down_interruptible(&adapter->erp_ready_sem);
+                wait_event_interruptible(adapter->erp_ready_wq,
+                           !list_empty(&adapter->erp_ready_head) ||
+                           kthread_should_stop());
                 zfcp_dbf_rec_thread_lock("erthrd2", adapter->dbf);
 
+                if (kthread_should_stop())
+                        break;
+
                 write_lock_irqsave(&adapter->erp_lock, flags);
                 next = adapter->erp_ready_head.next;
                 write_unlock_irqrestore(&adapter->erp_lock, flags);
@@ -1313,9 +1311,6 @@ static int zfcp_erp_thread(void *data)
                 }
         }
 
-        atomic_clear_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_UP, &adapter->status);
-        wake_up(&adapter->erp_thread_wqh);
-
         return 0;
 }
 
@@ -1327,18 +1322,17 @@ static int zfcp_erp_thread(void *data)
  */
 int zfcp_erp_thread_setup(struct zfcp_adapter *adapter)
 {
-        int retval;
+        struct task_struct *thread;
 
-        atomic_clear_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_UP, &adapter->status);
-        retval = kernel_thread(zfcp_erp_thread, adapter, SIGCHLD);
-        if (retval < 0) {
+        thread = kthread_run(zfcp_erp_thread, adapter, "zfcperp%s",
+                             dev_name(&adapter->ccw_device->dev));
+        if (IS_ERR(thread)) {
                 dev_err(&adapter->ccw_device->dev,
                         "Creating an ERP thread for the FCP device failed.\n");
-                return retval;
+                return PTR_ERR(thread);
         }
-        wait_event(adapter->erp_thread_wqh,
-                   atomic_read(&adapter->status) &
-                        ZFCP_STATUS_ADAPTER_ERP_THREAD_UP);
+
+        adapter->erp_thread = thread;
         return 0;
 }
 
@@ -1353,16 +1347,8 @@ int zfcp_erp_thread_setup(struct zfcp_adapter *adapter)
  */
 void zfcp_erp_thread_kill(struct zfcp_adapter *adapter)
 {
-        atomic_set_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_KILL, &adapter->status);
-        up(&adapter->erp_ready_sem);
-        zfcp_dbf_rec_thread_lock("erthrk1", adapter->dbf);
-
-        wait_event(adapter->erp_thread_wqh,
-                   !(atomic_read(&adapter->status) &
-                                ZFCP_STATUS_ADAPTER_ERP_THREAD_UP));
-
-        atomic_clear_mask(ZFCP_STATUS_ADAPTER_ERP_THREAD_KILL,
-                          &adapter->status);
+        kthread_stop(adapter->erp_thread);
+        adapter->erp_thread = NULL;
 }
 
 /**