[SCSI] zfcp: Replace global config_lock with local list locks

The global config_lock was used to protect the configuration organized
in independent lists. It is not necessary to have a lock on driver
level for this purpose.  This patch replaces the global config_lock
with a set of local list locks.

Signed-off-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>

1 files changed, 20 insertions, 28 deletions

diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index d31000886ca8..8430b518357e 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -153,15 +153,14 @@ static ssize_t zfcp_sysfs_port_remove_store(struct device *dev,
                 goto out;
         }
 
-        write_lock_irq(&zfcp_data.config_lock);
         port = zfcp_get_port_by_wwpn(adapter, wwpn);
-        if (port && (atomic_read(&port->refcount) == 0)) {
-                zfcp_port_get(port);
+        if (port && (atomic_read(&port->refcount) == 1)) {
                 atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &port->status);
+                write_lock_irq(&adapter->port_list_lock);
                 list_move(&port->list, &port_remove_lh);
+                write_unlock_irq(&adapter->port_list_lock);
         } else
                 port = NULL;
-        write_unlock_irq(&zfcp_data.config_lock);
 
         if (!port) {
                 retval = -ENXIO;
@@ -253,35 +252,28 @@ static ssize_t zfcp_sysfs_unit_remove_store(struct device *dev,
                 goto out;
         }
 
-        write_lock_irq(&zfcp_data.config_lock);
         unit = zfcp_get_unit_by_lun(port, fcp_lun);
-        if (unit) {
-                write_unlock_irq(&zfcp_data.config_lock);
-                /* wait for possible timeout during SCSI probe */
-                flush_work(&unit->scsi_work);
-                write_lock_irq(&zfcp_data.config_lock);
-
-                if (atomic_read(&unit->refcount) == 0) {
-                        zfcp_unit_get(unit);
-                        atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE,
-                                        &unit->status);
-                        list_move(&unit->list, &unit_remove_lh);
-                } else {
-                        unit = NULL;
-                }
-        }
-
-        write_unlock_irq(&zfcp_data.config_lock);
-
         if (!unit) {
-                retval = -ENXIO;
+                retval = -EINVAL;
                 goto out;
         }
 
-        zfcp_erp_unit_shutdown(unit, 0, "syurs_1", NULL);
-        zfcp_erp_wait(unit->port->adapter);
-        zfcp_unit_put(unit);
-        zfcp_unit_dequeue(unit);
+        /* wait for possible timeout during SCSI probe */
+        flush_work(&unit->scsi_work);
+
+        if (atomic_read(&unit->refcount) == 1) {
+                atomic_set_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
+
+                write_lock_irq(&port->unit_list_lock);
+                list_move(&unit->list, &unit_remove_lh);
+                write_unlock_irq(&port->unit_list_lock);
+
+                zfcp_erp_unit_shutdown(unit, 0, "syurs_1", NULL);
+                zfcp_erp_wait(unit->port->adapter);
+                zfcp_unit_put(unit);
+                zfcp_unit_dequeue(unit);
+        } else
+                zfcp_unit_put(unit);
 out:
         mutex_unlock(&zfcp_data.config_mutex);
         return retval ? retval : (ssize_t) count;