target: simplify the target template registration API

Instead of calling target_fabric_configfs_init() +
target_fabric_configfs_register() / target_fabric_configfs_deregister()
target_fabric_configfs_free() from every target driver, rewrite the API
so that we have simple register/unregister functions that operate on
a const operations vector.

This patch also fixes a memory leak in several target drivers. Several
target drivers namely called target_fabric_configfs_deregister()
without calling target_fabric_configfs_free().

A large part of this patch is based on earlier changes from
Bart Van Assche <bart.vanassche@sandisk.com>.

(v2: Add a new TF_CIT_SETUP_DRV macro so that the core configfs code
can declare attributes as either core only or for drivers)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 49 insertions, 129 deletions

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 2114c1d2c9de..5b143d2c08f7 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -41,8 +41,7 @@
 
 #define to_tcm_loop_hba(hba)    container_of(hba, struct tcm_loop_hba, dev)
 
-/* Local pointer to allocated TCM configfs fabric module */
-static struct target_fabric_configfs *tcm_loop_fabric_configfs;
+static const struct target_core_fabric_ops loop_ops;
 
 static struct workqueue_struct *tcm_loop_workqueue;
 static struct kmem_cache *tcm_loop_cmd_cache;
@@ -1238,8 +1237,7 @@ static struct se_portal_group *tcm_loop_make_naa_tpg(
         /*
          * Register the tl_tpg as a emulated SAS TCM Target Endpoint
          */
-        ret = core_tpg_register(&tcm_loop_fabric_configfs->tf_ops,
-                        wwn, &tl_tpg->tl_se_tpg, tl_tpg,
+        ret = core_tpg_register(&loop_ops, wwn, &tl_tpg->tl_se_tpg, tl_tpg,
                         TRANSPORT_TPG_TYPE_NORMAL);
         if (ret < 0)
                 return ERR_PTR(-ENOMEM);
@@ -1387,129 +1385,51 @@ static struct configfs_attribute *tcm_loop_wwn_attrs[] = {
 
 /* End items for tcm_loop_cit */
 
-static int tcm_loop_register_configfs(void)
-{
-        struct target_fabric_configfs *fabric;
-        int ret;
-        /*
-         * Set the TCM Loop HBA counter to zero
-         */
-        tcm_loop_hba_no_cnt = 0;
-        /*
-         * Register the top level struct config_item_type with TCM core
-         */
-        fabric = target_fabric_configfs_init(THIS_MODULE, "loopback");
-        if (IS_ERR(fabric)) {
-                pr_err("tcm_loop_register_configfs() failed!\n");
-                return PTR_ERR(fabric);
-        }
-        /*
-         * Setup the fabric API of function pointers used by target_core_mod
-         */
-        fabric->tf_ops.get_fabric_name = &tcm_loop_get_fabric_name;
-        fabric->tf_ops.get_fabric_proto_ident = &tcm_loop_get_fabric_proto_ident;
-        fabric->tf_ops.tpg_get_wwn = &tcm_loop_get_endpoint_wwn;
-        fabric->tf_ops.tpg_get_tag = &tcm_loop_get_tag;
-        fabric->tf_ops.tpg_get_default_depth = &tcm_loop_get_default_depth;
-        fabric->tf_ops.tpg_get_pr_transport_id = &tcm_loop_get_pr_transport_id;
-        fabric->tf_ops.tpg_get_pr_transport_id_len =
-                                        &tcm_loop_get_pr_transport_id_len;
-        fabric->tf_ops.tpg_parse_pr_out_transport_id =
-                                        &tcm_loop_parse_pr_out_transport_id;
-        fabric->tf_ops.tpg_check_demo_mode = &tcm_loop_check_demo_mode;
-        fabric->tf_ops.tpg_check_demo_mode_cache =
-                                        &tcm_loop_check_demo_mode_cache;
-        fabric->tf_ops.tpg_check_demo_mode_write_protect =
-                                        &tcm_loop_check_demo_mode_write_protect;
-        fabric->tf_ops.tpg_check_prod_mode_write_protect =
-                                        &tcm_loop_check_prod_mode_write_protect;
-        fabric->tf_ops.tpg_check_prot_fabric_only =
-                                        &tcm_loop_check_prot_fabric_only;
-        /*
-         * The TCM loopback fabric module runs in demo-mode to a local
-         * virtual SCSI device, so fabric dependent initator ACLs are
-         * not required.
-         */
-        fabric->tf_ops.tpg_alloc_fabric_acl = &tcm_loop_tpg_alloc_fabric_acl;
-        fabric->tf_ops.tpg_release_fabric_acl =
-                                        &tcm_loop_tpg_release_fabric_acl;
-        fabric->tf_ops.tpg_get_inst_index = &tcm_loop_get_inst_index;
-        /*
-         * Used for setting up remaining TCM resources in process context
-         */
-        fabric->tf_ops.check_stop_free = &tcm_loop_check_stop_free;
-        fabric->tf_ops.release_cmd = &tcm_loop_release_cmd;
-        fabric->tf_ops.shutdown_session = &tcm_loop_shutdown_session;
-        fabric->tf_ops.close_session = &tcm_loop_close_session;
-        fabric->tf_ops.sess_get_index = &tcm_loop_sess_get_index;
-        fabric->tf_ops.sess_get_initiator_sid = NULL;
-        fabric->tf_ops.write_pending = &tcm_loop_write_pending;
-        fabric->tf_ops.write_pending_status = &tcm_loop_write_pending_status;
-        /*
-         * Not used for TCM loopback
-         */
-        fabric->tf_ops.set_default_node_attributes =
-                                        &tcm_loop_set_default_node_attributes;
-        fabric->tf_ops.get_task_tag = &tcm_loop_get_task_tag;
-        fabric->tf_ops.get_cmd_state = &tcm_loop_get_cmd_state;
-        fabric->tf_ops.queue_data_in = &tcm_loop_queue_data_in;
-        fabric->tf_ops.queue_status = &tcm_loop_queue_status;
-        fabric->tf_ops.queue_tm_rsp = &tcm_loop_queue_tm_rsp;
-        fabric->tf_ops.aborted_task = &tcm_loop_aborted_task;
-
-        /*
-         * Setup function pointers for generic logic in target_core_fabric_configfs.c
-         */
-        fabric->tf_ops.fabric_make_wwn = &tcm_loop_make_scsi_hba;
-        fabric->tf_ops.fabric_drop_wwn = &tcm_loop_drop_scsi_hba;
-        fabric->tf_ops.fabric_make_tpg = &tcm_loop_make_naa_tpg;
-        fabric->tf_ops.fabric_drop_tpg = &tcm_loop_drop_naa_tpg;
-        /*
-         * fabric_post_link() and fabric_pre_unlink() are used for
-         * registration and release of TCM Loop Virtual SCSI LUNs.
-         */
-        fabric->tf_ops.fabric_post_link = &tcm_loop_port_link;
-        fabric->tf_ops.fabric_pre_unlink = &tcm_loop_port_unlink;
-        fabric->tf_ops.fabric_make_np = NULL;
-        fabric->tf_ops.fabric_drop_np = NULL;
-        /*
-         * Setup default attribute lists for various fabric->tf_cit_tmpl
-         */
-        fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = tcm_loop_wwn_attrs;
-        fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = tcm_loop_tpg_attrs;
-        fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = tcm_loop_tpg_attrib_attrs;
-        fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
-        fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
-        /*
-         * Once fabric->tf_ops has been setup, now register the fabric for
-         * use within TCM
-         */
-        ret = target_fabric_configfs_register(fabric);
-        if (ret < 0) {
-                pr_err("target_fabric_configfs_register() for"
-                                " TCM_Loop failed!\n");
-                target_fabric_configfs_free(fabric);
-                return -1;
-        }
-        /*
-         * Setup our local pointer to *fabric.
-         */
-        tcm_loop_fabric_configfs = fabric;
-        pr_debug("TCM_LOOP[0] - Set fabric ->"
-                        " tcm_loop_fabric_configfs\n");
-        return 0;
-}
-
-static void tcm_loop_deregister_configfs(void)
-{
-        if (!tcm_loop_fabric_configfs)
-                return;
-
-        target_fabric_configfs_deregister(tcm_loop_fabric_configfs);
-        tcm_loop_fabric_configfs = NULL;
-        pr_debug("TCM_LOOP[0] - Cleared"
-                                " tcm_loop_fabric_configfs\n");
-}
+static const struct target_core_fabric_ops loop_ops = {
+        .module                         = THIS_MODULE,
+        .name                           = "loopback",
+        .get_fabric_name                = tcm_loop_get_fabric_name,
+        .get_fabric_proto_ident         = tcm_loop_get_fabric_proto_ident,
+        .tpg_get_wwn                    = tcm_loop_get_endpoint_wwn,
+        .tpg_get_tag                    = tcm_loop_get_tag,
+        .tpg_get_default_depth          = tcm_loop_get_default_depth,
+        .tpg_get_pr_transport_id        = tcm_loop_get_pr_transport_id,
+        .tpg_get_pr_transport_id_len    = tcm_loop_get_pr_transport_id_len,
+        .tpg_parse_pr_out_transport_id  = tcm_loop_parse_pr_out_transport_id,
+        .tpg_check_demo_mode            = tcm_loop_check_demo_mode,
+        .tpg_check_demo_mode_cache      = tcm_loop_check_demo_mode_cache,
+        .tpg_check_demo_mode_write_protect =
+                                tcm_loop_check_demo_mode_write_protect,
+        .tpg_check_prod_mode_write_protect =
+                                tcm_loop_check_prod_mode_write_protect,
+        .tpg_check_prot_fabric_only     = tcm_loop_check_prot_fabric_only,
+        .tpg_alloc_fabric_acl           = tcm_loop_tpg_alloc_fabric_acl,
+        .tpg_release_fabric_acl         = tcm_loop_tpg_release_fabric_acl,
+        .tpg_get_inst_index             = tcm_loop_get_inst_index,
+        .check_stop_free                = tcm_loop_check_stop_free,
+        .release_cmd                    = tcm_loop_release_cmd,
+        .shutdown_session               = tcm_loop_shutdown_session,
+        .close_session                  = tcm_loop_close_session,
+        .sess_get_index                 = tcm_loop_sess_get_index,
+        .write_pending                  = tcm_loop_write_pending,
+        .write_pending_status           = tcm_loop_write_pending_status,
+        .set_default_node_attributes    = tcm_loop_set_default_node_attributes,
+        .get_task_tag                   = tcm_loop_get_task_tag,
+        .get_cmd_state                  = tcm_loop_get_cmd_state,
+        .queue_data_in                  = tcm_loop_queue_data_in,
+        .queue_status                   = tcm_loop_queue_status,
+        .queue_tm_rsp                   = tcm_loop_queue_tm_rsp,
+        .aborted_task                   = tcm_loop_aborted_task,
+        .fabric_make_wwn                = tcm_loop_make_scsi_hba,
+        .fabric_drop_wwn                = tcm_loop_drop_scsi_hba,
+        .fabric_make_tpg                = tcm_loop_make_naa_tpg,
+        .fabric_drop_tpg                = tcm_loop_drop_naa_tpg,
+        .fabric_post_link               = tcm_loop_port_link,
+        .fabric_pre_unlink              = tcm_loop_port_unlink,
+        .tfc_wwn_attrs                  = tcm_loop_wwn_attrs,
+        .tfc_tpg_base_attrs             = tcm_loop_tpg_attrs,
+        .tfc_tpg_attrib_attrs           = tcm_loop_tpg_attrib_attrs,
+};
 
 static int __init tcm_loop_fabric_init(void)
 {
@@ -1533,7 +1453,7 @@ static int __init tcm_loop_fabric_init(void)
         if (ret)
                 goto out_destroy_cache;
 
-        ret = tcm_loop_register_configfs();
+        ret = target_register_template(&loop_ops);
         if (ret)
                 goto out_release_core_bus;
 
@@ -1551,7 +1471,7 @@ out:
 
 static void __exit tcm_loop_fabric_exit(void)
 {
-        tcm_loop_deregister_configfs();
+        target_unregister_template(&loop_ops);
         tcm_loop_release_core_bus();
         kmem_cache_destroy(tcm_loop_cmd_cache);
         destroy_workqueue(tcm_loop_workqueue);