[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, 4 insertions, 5 deletions

diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 7da2fad8f51..e45a08d6c98 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -461,7 +461,8 @@ struct zfcp_adapter {
         u32                     hardware_version;  /* of FCP channel */
         u16                     timer_ticks;       /* time int for a tick */
         struct Scsi_Host        *scsi_host;        /* Pointer to mid-layer */
-        struct list_head        port_list_head;    /* remote port list */
+        struct list_head        port_list;         /* remote port list */
+        rwlock_t                port_list_lock;    /* port list lock */
         unsigned long           req_no;            /* unique FSF req number */
         struct list_head        *req_list;         /* list of pending reqs */
         spinlock_t              req_list_lock;     /* request list lock */
@@ -504,7 +505,8 @@ struct zfcp_port {
         wait_queue_head_t      remove_wq;      /* can be used to wait for
                                                   refcount drop to zero */
         struct zfcp_adapter    *adapter;       /* adapter used to access port */
-        struct list_head       unit_list_head; /* head of logical unit list */
+        struct list_head        unit_list;      /* head of logical unit list */
+        rwlock_t                unit_list_lock; /* unit list lock */
         atomic_t               status;         /* status of this remote port */
         u64                    wwnn;           /* WWNN if known */
         u64                    wwpn;           /* WWPN */
@@ -601,9 +603,6 @@ struct zfcp_fsf_req {
 struct zfcp_data {
         struct scsi_host_template scsi_host_template;
         struct scsi_transport_template *scsi_transport_template;
-        rwlock_t                config_lock;        /* serialises changes
-                                                       to adapter/port/unit
-                                                       lists */
         struct mutex            config_mutex;
         struct kmem_cache       *gpn_ft_cache;
         struct kmem_cache       *qtcb_cache;