[SCSI] zfcp: Improve ELS ADISC handling

Introduce kmem_cache for ELS ADISC data to guarantee the required
hardware alignment and free the allocated memory in case the send
failes.

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>

3 files changed, 17 insertions, 3 deletions

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 58bb17732f56..9d0c941b7d33 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -179,6 +179,11 @@ static int __init zfcp_module_init(void)
         if (!zfcp_data.gid_pn_cache)
                 goto out_gid_cache;
 
+        zfcp_data.adisc_cache = zfcp_cache_hw_align("zfcp_adisc",
+                                        sizeof(struct zfcp_fc_els_adisc));
+        if (!zfcp_data.adisc_cache)
+                goto out_adisc_cache;
+
         zfcp_data.scsi_transport_template =
                 fc_attach_transport(&zfcp_transport_functions);
         if (!zfcp_data.scsi_transport_template)
@@ -206,6 +211,8 @@ out_ccw_register:
 out_misc:
         fc_release_transport(zfcp_data.scsi_transport_template);
 out_transport:
+        kmem_cache_destroy(zfcp_data.adisc_cache);
+out_adisc_cache:
         kmem_cache_destroy(zfcp_data.gid_pn_cache);
 out_gid_cache:
         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
@@ -224,6 +231,7 @@ static void __exit zfcp_module_exit(void)
         ccw_driver_unregister(&zfcp_ccw_driver);
         misc_deregister(&zfcp_cfdc_misc);
         fc_release_transport(zfcp_data.scsi_transport_template);
+        kmem_cache_destroy(zfcp_data.adisc_cache);
         kmem_cache_destroy(zfcp_data.gid_pn_cache);
         kmem_cache_destroy(zfcp_data.sr_buffer_cache);
         kmem_cache_destroy(zfcp_data.qtcb_cache);
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index 21b29804a7a6..469d57f105db 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -347,6 +347,7 @@ struct zfcp_data {
         struct kmem_cache       *qtcb_cache;
         struct kmem_cache       *sr_buffer_cache;
         struct kmem_cache       *gid_pn_cache;
+        struct kmem_cache       *adisc_cache;
 };
 
 /********************** ZFCP SPECIFIC DEFINES ********************************/
diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c
index 6d5ccc053e3a..ac5e3b7a3576 100644
--- a/drivers/s390/scsi/zfcp_fc.c
+++ b/drivers/s390/scsi/zfcp_fc.c
@@ -389,15 +389,16 @@ static void zfcp_fc_adisc_handler(void *data)
  out:
         atomic_clear_mask(ZFCP_STATUS_PORT_LINK_TEST, &port->status);
         put_device(&port->sysfs_device);
-        kfree(adisc);
+        kmem_cache_free(zfcp_data.adisc_cache, adisc);
 }
 
 static int zfcp_fc_adisc(struct zfcp_port *port)
 {
         struct zfcp_fc_els_adisc *adisc;
         struct zfcp_adapter *adapter = port->adapter;
+        int ret;
 
-        adisc = kzalloc(sizeof(struct zfcp_fc_els_adisc), GFP_ATOMIC);
+        adisc = kmem_cache_alloc(zfcp_data.adisc_cache, GFP_ATOMIC);
         if (!adisc)
                 return -ENOMEM;
 
@@ -420,7 +421,11 @@ static int zfcp_fc_adisc(struct zfcp_port *port)
         hton24(adisc->adisc_req.adisc_port_id,
                fc_host_port_id(adapter->scsi_host));
 
-        return zfcp_fsf_send_els(adapter, port->d_id, &adisc->els);
+        ret = zfcp_fsf_send_els(adapter, port->d_id, &adisc->els);
+        if (ret)
+                kmem_cache_free(zfcp_data.adisc_cache, adisc);
+
+        return ret;
 }
 
 void zfcp_fc_link_test_work(struct work_struct *work)