[SCSI] zfcp: Replace config semaphore with mutex

The config semaphore is only used as a mutex, so replace it with a
simple mutex.

Reviewed-by: Swen Schillig <swen@vnet.ibm.com>
Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

5 files changed, 32 insertions, 33 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index d1e75d36ed1a..8e989159e4ed 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -84,7 +84,7 @@ static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
         struct zfcp_port *port;
         struct zfcp_unit *unit;
 
-        down(&zfcp_data.config_sema);
+        mutex_lock(&zfcp_data.config_mutex);
         read_lock_irq(&zfcp_data.config_lock);
         adapter = zfcp_get_adapter_by_busid(busid);
         if (adapter)
@@ -99,20 +99,20 @@ static void __init zfcp_init_device_configure(char *busid, u64 wwpn, u64 lun)
         unit = zfcp_unit_enqueue(port, lun);
         if (IS_ERR(unit))
                 goto out_unit;
-        up(&zfcp_data.config_sema);
+        mutex_unlock(&zfcp_data.config_mutex);
         ccw_device_set_online(adapter->ccw_device);
 
         zfcp_erp_wait(adapter);
         flush_work(&unit->scsi_work);
 
-        down(&zfcp_data.config_sema);
+        mutex_lock(&zfcp_data.config_mutex);
         zfcp_unit_put(unit);
 out_unit:
         zfcp_port_put(port);
 out_port:
         zfcp_adapter_put(adapter);
 out_adapter:
-        up(&zfcp_data.config_sema);
+        mutex_unlock(&zfcp_data.config_mutex);
         return;
 }
 
@@ -176,7 +176,7 @@ static int __init zfcp_module_init(void)
         if (!zfcp_data.gid_pn_cache)
                 goto out_gid_cache;
 
-        sema_init(&zfcp_data.config_sema, 1);
+        mutex_init(&zfcp_data.config_mutex);
         rwlock_init(&zfcp_data.config_lock);
 
         zfcp_data.scsi_transport_template =
@@ -266,7 +266,7 @@ static void zfcp_sysfs_unit_release(struct device *dev)
  * @port: pointer to port where unit is added
  * @fcp_lun: FCP LUN of unit to be enqueued
  * Returns: pointer to enqueued unit on success, ERR_PTR on error
- * Locks: config_sema must be held to serialize changes to the unit list
+ * Locks: config_mutex must be held to serialize changes to the unit list
  *
  * Sets up some unit internal structures and creates sysfs entry.
  */
@@ -356,7 +356,7 @@ void zfcp_unit_dequeue(struct zfcp_unit *unit)
 
 static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
 {
-        /* must only be called with zfcp_data.config_sema taken */
+        /* must only be called with zfcp_data.config_mutex taken */
         adapter->pool.erp_req =
                 mempool_create_kmalloc_pool(1, sizeof(struct zfcp_fsf_req));
         if (!adapter->pool.erp_req)
@@ -404,7 +404,7 @@ static int zfcp_allocate_low_mem_buffers(struct zfcp_adapter *adapter)
 
 static void zfcp_free_low_mem_buffers(struct zfcp_adapter *adapter)
 {
-        /* zfcp_data.config_sema must be held */
+        /* zfcp_data.config_mutex must be held */
         if (adapter->pool.erp_req)
                 mempool_destroy(adapter->pool.erp_req);
         if (adapter->pool.scsi_req)
@@ -491,7 +491,7 @@ static void zfcp_destroy_adapter_work_queue(struct zfcp_adapter *adapter)
  * Enqueues an adapter at the end of the adapter list in the driver data.
  * All adapter internal structures are set up.
  * Proc-fs entries are also created.
- * locks:       config_sema must be held to serialise changes to the adapter list
+ * locks: config_mutex must be held to serialize changes to the adapter list
  */
 int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 {
@@ -499,7 +499,7 @@ int zfcp_adapter_enqueue(struct ccw_device *ccw_device)
 
         /*
          * Note: It is safe to release the list_lock, as any list changes
-         * are protected by the config_sema, which must be held to get here
+         * are protected by the config_mutex, which must be held to get here
          */
 
         adapter = kzalloc(sizeof(struct zfcp_adapter), GFP_KERNEL);
@@ -630,7 +630,7 @@ static void zfcp_sysfs_port_release(struct device *dev)
  * @status: initial status for the port
  * @d_id: destination id of the remote port to be enqueued
  * Returns: pointer to enqueued port on success, ERR_PTR on error
- * Locks: config_sema must be held to serialize changes to the port list
+ * Locks: config_mutex must be held to serialize changes to the port list
  *
  * All port internal structures are set up and the sysfs entry is generated.
  * d_id is used to enqueue ports with a well known address like the Directory
diff --git a/drivers/s390/scsi/zfcp_ccw.c b/drivers/s390/scsi/zfcp_ccw.c
index 82ae6ed7ef83..0c90f8e71605 100644
--- a/drivers/s390/scsi/zfcp_ccw.c
+++ b/drivers/s390/scsi/zfcp_ccw.c
@@ -21,12 +21,12 @@ static int zfcp_ccw_suspend(struct ccw_device *cdev)
         if (!adapter)
                 return 0;
 
-        down(&zfcp_data.config_sema);
+        mutex_lock(&zfcp_data.config_mutex);
 
         zfcp_erp_adapter_shutdown(adapter, 0, "ccsusp1", NULL);
         zfcp_erp_wait(adapter);
 
-        up(&zfcp_data.config_sema);
+        mutex_unlock(&zfcp_data.config_mutex);
 
         return 0;
 }
@@ -98,7 +98,7 @@ static void zfcp_ccw_remove(struct ccw_device *ccw_device)
 
         ccw_device_set_offline(ccw_device);
 
-        down(&zfcp_data.config_sema);
+        mutex_lock(&zfcp_data.config_mutex);
         adapter = dev_get_drvdata(&ccw_device->dev);
         if (!adapter)
                 goto out;
@@ -128,7 +128,7 @@ static void zfcp_ccw_remove(struct ccw_device *ccw_device)
         zfcp_adapter_dequeue(adapter);
 
 out:
-        up(&zfcp_data.config_sema);
+        mutex_unlock(&zfcp_data.config_mutex);
 }
 
 /**
@@ -149,7 +149,7 @@ static int zfcp_ccw_set_online(struct ccw_device *ccw_device)
         struct zfcp_adapter *adapter;
         int ret = 0;
 
-        down(&zfcp_data.config_sema);
+        mutex_lock(&zfcp_data.config_mutex);
         adapter = dev_get_drvdata(&ccw_device->dev);
 
         if (!adapter) {
@@ -173,7 +173,7 @@ static int zfcp_ccw_set_online(struct ccw_device *ccw_device)
                                 "ccsonl2", NULL);
         zfcp_erp_wait(adapter);
 out:
-        up(&zfcp_data.config_sema);
+        mutex_unlock(&zfcp_data.config_mutex);
         if (!ret)
                 flush_work(&adapter->scan_work);
         return ret;
@@ -190,14 +190,14 @@ static int zfcp_ccw_set_offline(struct ccw_device *ccw_device)
 {
         struct zfcp_adapter *adapter;
 
-        down(&zfcp_data.config_sema);
+        mutex_lock(&zfcp_data.config_mutex);
         adapter = dev_get_drvdata(&ccw_device->dev);
         if (!adapter)
                 goto out;
 
         zfcp_erp_adapter_shutdown(adapter, 0, "ccsoff1", NULL);
         zfcp_erp_wait(adapter);
-        up(&zfcp_data.config_sema);
+        mutex_unlock(&zfcp_data.config_mutex);
 out:
         return 0;
 }
@@ -251,12 +251,12 @@ static void zfcp_ccw_shutdown(struct ccw_device *cdev)
 {
         struct zfcp_adapter *adapter;
 
-        down(&zfcp_data.config_sema);
+        mutex_lock(&zfcp_data.config_mutex);
         adapter = dev_get_drvdata(&cdev->dev);
         zfcp_erp_adapter_shutdown(adapter, 0, "ccshut1", NULL);
         zfcp_erp_wait(adapter);
         zfcp_erp_thread_kill(adapter);
-        up(&zfcp_data.config_sema);
+        mutex_unlock(&zfcp_data.config_mutex);
 }
 
 static struct ccw_driver zfcp_ccw_driver = {
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 99830758e873..cc98eead2c3c 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -604,8 +604,7 @@ struct zfcp_data {
         rwlock_t                config_lock;        /* serialises changes
                                                        to adapter/port/unit
                                                        lists */
-        struct semaphore        config_sema;        /* serialises configuration
-                                                       changes */
+        struct mutex            config_mutex;
         struct kmem_cache       *gpn_ft_cache;
         struct kmem_cache       *qtcb_cache;
         struct kmem_cache       *sr_buffer_cache;
diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c
index 82f148d09968..722f22de8753 100644
--- a/drivers/s390/scsi/zfcp_fc.c
+++ b/drivers/s390/scsi/zfcp_fc.c
@@ -613,7 +613,7 @@ static int zfcp_fc_eval_gpn_ft(struct zfcp_gpn_ft *gpn_ft, int max_entries)
                 return -E2BIG;
         }
 
-        down(&zfcp_data.config_sema);
+        mutex_lock(&zfcp_data.config_mutex);
 
         /* first entry is the header */
         for (x = 1; x < max_entries && !last; x++) {
@@ -647,7 +647,7 @@ static int zfcp_fc_eval_gpn_ft(struct zfcp_gpn_ft *gpn_ft, int max_entries)
         zfcp_erp_wait(adapter);
         list_for_each_entry_safe(port, tmp, &adapter->port_list_head, list)
                 zfcp_fc_validate_port(port);
-        up(&zfcp_data.config_sema);
+        mutex_unlock(&zfcp_data.config_mutex);
         return ret;
 }
 
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index c86496bb608b..079a8cf518a3 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -88,7 +88,7 @@ static ssize_t zfcp_sysfs_##_feat##_failed_store(struct device *dev,	       \
         unsigned long val;                                                     \
         int retval = 0;                                                        \
                                                                                \
-        down(&zfcp_data.config_sema);                                          \
+        mutex_lock(&zfcp_data.config_mutex);                                   \
         if (atomic_read(&_feat->status) & ZFCP_STATUS_COMMON_REMOVE) {         \
                 retval = -EBUSY;                                               \
                 goto out;                                                      \
@@ -105,7 +105,7 @@ static ssize_t zfcp_sysfs_##_feat##_failed_store(struct device *dev,	       \
                                   _reopen_id, NULL);                           \
         zfcp_erp_wait(_adapter);                                               \
 out:                                                                           \
-        up(&zfcp_data.config_sema);                                            \
+        mutex_unlock(&zfcp_data.config_mutex);                                 \
         return retval ? retval : (ssize_t) count;                              \
 }                                                                              \
 static ZFCP_DEV_ATTR(_feat, failed, S_IWUSR | S_IRUGO,                         \
@@ -142,7 +142,7 @@ static ssize_t zfcp_sysfs_port_remove_store(struct device *dev,
         int retval = 0;
         LIST_HEAD(port_remove_lh);
 
-        down(&zfcp_data.config_sema);
+        mutex_lock(&zfcp_data.config_mutex);
         if (atomic_read(&adapter->status) & ZFCP_STATUS_COMMON_REMOVE) {
                 retval = -EBUSY;
                 goto out;
@@ -173,7 +173,7 @@ static ssize_t zfcp_sysfs_port_remove_store(struct device *dev,
         zfcp_port_put(port);
         zfcp_port_dequeue(port);
  out:
-        up(&zfcp_data.config_sema);
+        mutex_unlock(&zfcp_data.config_mutex);
         return retval ? retval : (ssize_t) count;
 }
 static ZFCP_DEV_ATTR(adapter, port_remove, S_IWUSR, NULL,
@@ -207,7 +207,7 @@ static ssize_t zfcp_sysfs_unit_add_store(struct device *dev,
         u64 fcp_lun;
         int retval = -EINVAL;
 
-        down(&zfcp_data.config_sema);
+        mutex_lock(&zfcp_data.config_mutex);
         if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_REMOVE) {
                 retval = -EBUSY;
                 goto out;
@@ -226,7 +226,7 @@ static ssize_t zfcp_sysfs_unit_add_store(struct device *dev,
         zfcp_erp_wait(unit->port->adapter);
         zfcp_unit_put(unit);
 out:
-        up(&zfcp_data.config_sema);
+        mutex_unlock(&zfcp_data.config_mutex);
         return retval ? retval : (ssize_t) count;
 }
 static DEVICE_ATTR(unit_add, S_IWUSR, NULL, zfcp_sysfs_unit_add_store);
@@ -241,7 +241,7 @@ static ssize_t zfcp_sysfs_unit_remove_store(struct device *dev,
         int retval = 0;
         LIST_HEAD(unit_remove_lh);
 
-        down(&zfcp_data.config_sema);
+        mutex_lock(&zfcp_data.config_mutex);
         if (atomic_read(&port->status) & ZFCP_STATUS_COMMON_REMOVE) {
                 retval = -EBUSY;
                 goto out;
@@ -282,7 +282,7 @@ static ssize_t zfcp_sysfs_unit_remove_store(struct device *dev,
         zfcp_unit_put(unit);
         zfcp_unit_dequeue(unit);
 out:
-        up(&zfcp_data.config_sema);
+        mutex_unlock(&zfcp_data.config_mutex);
         return retval ? retval : (ssize_t) count;
 }
 static DEVICE_ATTR(unit_remove, S_IWUSR, NULL, zfcp_sysfs_unit_remove_store);