target: simplify backend driver registration
Rewrite the backend driver registration based on what we did to the fabric
drivers: introduce a read-only struct target_bakckend_ops that the driver
registers, which is then instanciate as a struct target_backend by the
core. This allows the ops vector to be smaller and allows us to mark it
const. At the same time the registration function can set up the
configfs attributes, avoiding the need to add additional boilerplate code
for that to the drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index 4a31d47..57c099d 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -51,15 +51,26 @@
#include "target_core_xcopy.h"
#define TB_CIT_SETUP(_name, _item_ops, _group_ops, _attrs) \
-static void target_core_setup_##_name##_cit(struct se_subsystem_api *sa) \
+static void target_core_setup_##_name##_cit(struct target_backend *tb) \
{ \
- struct target_backend_cits *tbc = &sa->tb_cits; \
- struct config_item_type *cit = &tbc->tb_##_name##_cit; \
+ struct config_item_type *cit = &tb->tb_##_name##_cit; \
\
cit->ct_item_ops = _item_ops; \
cit->ct_group_ops = _group_ops; \
cit->ct_attrs = _attrs; \
- cit->ct_owner = sa->owner; \
+ cit->ct_owner = tb->ops->owner; \
+ pr_debug("Setup generic %s\n", __stringify(_name)); \
+}
+
+#define TB_CIT_SETUP_DRV(_name, _item_ops, _group_ops) \
+static void target_core_setup_##_name##_cit(struct target_backend *tb) \
+{ \
+ struct config_item_type *cit = &tb->tb_##_name##_cit; \
+ \
+ cit->ct_item_ops = _item_ops; \
+ cit->ct_group_ops = _group_ops; \
+ cit->ct_attrs = tb->ops->tb_##_name##_attrs; \
+ cit->ct_owner = tb->ops->owner; \
pr_debug("Setup generic %s\n", __stringify(_name)); \
}
@@ -469,7 +480,7 @@
.store_attribute = target_core_dev_attrib_attr_store,
};
-TB_CIT_SETUP(dev_attrib, &target_core_dev_attrib_ops, NULL, NULL);
+TB_CIT_SETUP_DRV(dev_attrib, &target_core_dev_attrib_ops, NULL);
/* End functions for struct config_item_type tb_dev_attrib_cit */
@@ -1174,13 +1185,13 @@
static ssize_t target_core_show_dev_info(void *p, char *page)
{
struct se_device *dev = p;
- struct se_subsystem_api *t = dev->transport;
int bl = 0;
ssize_t read_bytes = 0;
transport_dump_dev_state(dev, page, &bl);
read_bytes += bl;
- read_bytes += t->show_configfs_dev_params(dev, page+read_bytes);
+ read_bytes += dev->transport->show_configfs_dev_params(dev,
+ page+read_bytes);
return read_bytes;
}
@@ -1198,9 +1209,8 @@
size_t count)
{
struct se_device *dev = p;
- struct se_subsystem_api *t = dev->transport;
- return t->set_configfs_dev_params(dev, page, count);
+ return dev->transport->set_configfs_dev_params(dev, page, count);
}
static struct target_core_configfs_attribute target_core_attr_dev_control = {
@@ -2477,9 +2487,9 @@
const char *name)
{
struct t10_alua_tg_pt_gp *tg_pt_gp;
- struct se_subsystem_api *t;
struct config_item *hba_ci = &group->cg_item;
struct se_hba *hba = item_to_hba(hba_ci);
+ struct target_backend *tb = hba->backend;
struct se_device *dev;
struct config_group *dev_cg = NULL, *tg_pt_gp_cg = NULL;
struct config_group *dev_stat_grp = NULL;
@@ -2488,10 +2498,6 @@
ret = mutex_lock_interruptible(&hba->hba_access_mutex);
if (ret)
return ERR_PTR(ret);
- /*
- * Locate the struct se_subsystem_api from parent's struct se_hba.
- */
- t = hba->transport;
dev = target_alloc_device(hba, name);
if (!dev)
@@ -2504,17 +2510,17 @@
if (!dev_cg->default_groups)
goto out_free_device;
- config_group_init_type_name(dev_cg, name, &t->tb_cits.tb_dev_cit);
+ config_group_init_type_name(dev_cg, name, &tb->tb_dev_cit);
config_group_init_type_name(&dev->dev_attrib.da_group, "attrib",
- &t->tb_cits.tb_dev_attrib_cit);
+ &tb->tb_dev_attrib_cit);
config_group_init_type_name(&dev->dev_pr_group, "pr",
- &t->tb_cits.tb_dev_pr_cit);
+ &tb->tb_dev_pr_cit);
config_group_init_type_name(&dev->t10_wwn.t10_wwn_group, "wwn",
- &t->tb_cits.tb_dev_wwn_cit);
+ &tb->tb_dev_wwn_cit);
config_group_init_type_name(&dev->t10_alua.alua_tg_pt_gps_group,
- "alua", &t->tb_cits.tb_dev_alua_tg_pt_gps_cit);
+ "alua", &tb->tb_dev_alua_tg_pt_gps_cit);
config_group_init_type_name(&dev->dev_stat_grps.stat_group,
- "statistics", &t->tb_cits.tb_dev_stat_cit);
+ "statistics", &tb->tb_dev_stat_cit);
dev_cg->default_groups[0] = &dev->dev_attrib.da_group;
dev_cg->default_groups[1] = &dev->dev_pr_group;
@@ -2644,7 +2650,7 @@
char *page)
{
return sprintf(page, "HBA Index: %d plugin: %s version: %s\n",
- hba->hba_id, hba->transport->name,
+ hba->hba_id, hba->backend->ops->name,
TARGET_CORE_CONFIGFS_VERSION);
}
@@ -2664,11 +2670,10 @@
static ssize_t target_core_hba_store_attr_hba_mode(struct se_hba *hba,
const char *page, size_t count)
{
- struct se_subsystem_api *transport = hba->transport;
unsigned long mode_flag;
int ret;
- if (transport->pmode_enable_hba == NULL)
+ if (hba->backend->ops->pmode_enable_hba == NULL)
return -EINVAL;
ret = kstrtoul(page, 0, &mode_flag);
@@ -2682,7 +2687,7 @@
return -EINVAL;
}
- ret = transport->pmode_enable_hba(hba, mode_flag);
+ ret = hba->backend->ops->pmode_enable_hba(hba, mode_flag);
if (ret < 0)
return -EINVAL;
if (ret > 0)
@@ -2808,16 +2813,15 @@
/* Stop functions for struct config_item_type target_core_hba_cit */
-void target_core_setup_sub_cits(struct se_subsystem_api *sa)
+void target_setup_backend_cits(struct target_backend *tb)
{
- target_core_setup_dev_cit(sa);
- target_core_setup_dev_attrib_cit(sa);
- target_core_setup_dev_pr_cit(sa);
- target_core_setup_dev_wwn_cit(sa);
- target_core_setup_dev_alua_tg_pt_gps_cit(sa);
- target_core_setup_dev_stat_cit(sa);
+ target_core_setup_dev_cit(tb);
+ target_core_setup_dev_attrib_cit(tb);
+ target_core_setup_dev_pr_cit(tb);
+ target_core_setup_dev_wwn_cit(tb);
+ target_core_setup_dev_alua_tg_pt_gps_cit(tb);
+ target_core_setup_dev_stat_cit(tb);
}
-EXPORT_SYMBOL(target_core_setup_sub_cits);
static int __init target_core_init_configfs(void)
{
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 47a7360..af906f1c 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -1367,13 +1367,13 @@
struct se_device *dev;
struct se_lun *xcopy_lun;
- dev = hba->transport->alloc_device(hba, name);
+ dev = hba->backend->ops->alloc_device(hba, name);
if (!dev)
return NULL;
dev->dev_link_magic = SE_DEV_LINK_MAGIC;
dev->se_hba = hba;
- dev->transport = hba->transport;
+ dev->transport = hba->backend->ops;
dev->prot_length = sizeof(struct se_dif_v1_tuple);
INIT_LIST_HEAD(&dev->dev_list);
@@ -1571,7 +1571,7 @@
goto out_free_hba;
}
- hba->transport->set_configfs_dev_params(dev, buf, sizeof(buf));
+ hba->backend->ops->set_configfs_dev_params(dev, buf, sizeof(buf));
ret = target_configure_device(dev);
if (ret)
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index e865885..7c5b1ef 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -46,10 +46,6 @@
return container_of(dev, struct fd_dev, dev);
}
-/* fd_attach_hba(): (Part of se_subsystem_api_t template)
- *
- *
- */
static int fd_attach_hba(struct se_hba *hba, u32 host_id)
{
struct fd_host *fd_host;
@@ -881,7 +877,7 @@
NULL,
};
-static struct se_subsystem_api fileio_template = {
+static const struct target_backend_ops fileio_ops = {
.name = "fileio",
.inquiry_prod = "FILEIO",
.inquiry_rev = FD_VERSION,
@@ -899,21 +895,17 @@
.init_prot = fd_init_prot,
.format_prot = fd_format_prot,
.free_prot = fd_free_prot,
+ .tb_dev_attrib_attrs = fileio_backend_dev_attrs,
};
static int __init fileio_module_init(void)
{
- struct target_backend_cits *tbc = &fileio_template.tb_cits;
-
- target_core_setup_sub_cits(&fileio_template);
- tbc->tb_dev_attrib_cit.ct_attrs = fileio_backend_dev_attrs;
-
- return transport_subsystem_register(&fileio_template);
+ return transport_backend_register(&fileio_ops);
}
static void __exit fileio_module_exit(void)
{
- transport_subsystem_release(&fileio_template);
+ target_backend_unregister(&fileio_ops);
}
MODULE_DESCRIPTION("TCM FILEIO subsystem plugin");
diff --git a/drivers/target/target_core_hba.c b/drivers/target/target_core_hba.c
index e6e496f..62ea4e8 100644
--- a/drivers/target/target_core_hba.c
+++ b/drivers/target/target_core_hba.c
@@ -39,63 +39,75 @@
#include "target_core_internal.h"
-static LIST_HEAD(subsystem_list);
-static DEFINE_MUTEX(subsystem_mutex);
+static LIST_HEAD(backend_list);
+static DEFINE_MUTEX(backend_mutex);
static u32 hba_id_counter;
static DEFINE_SPINLOCK(hba_lock);
static LIST_HEAD(hba_list);
-int transport_subsystem_register(struct se_subsystem_api *sub_api)
+
+int transport_backend_register(const struct target_backend_ops *ops)
{
- struct se_subsystem_api *s;
+ struct target_backend *tb, *old;
- INIT_LIST_HEAD(&sub_api->sub_api_list);
+ tb = kzalloc(sizeof(*tb), GFP_KERNEL);
+ if (!tb)
+ return -ENOMEM;
+ tb->ops = ops;
- mutex_lock(&subsystem_mutex);
- list_for_each_entry(s, &subsystem_list, sub_api_list) {
- if (!strcmp(s->name, sub_api->name)) {
- pr_err("%p is already registered with"
- " duplicate name %s, unable to process"
- " request\n", s, s->name);
- mutex_unlock(&subsystem_mutex);
+ mutex_lock(&backend_mutex);
+ list_for_each_entry(old, &backend_list, list) {
+ if (!strcmp(old->ops->name, ops->name)) {
+ pr_err("backend %s already registered.\n", ops->name);
+ mutex_unlock(&backend_mutex);
+ kfree(tb);
return -EEXIST;
}
}
- list_add_tail(&sub_api->sub_api_list, &subsystem_list);
- mutex_unlock(&subsystem_mutex);
+ target_setup_backend_cits(tb);
+ list_add_tail(&tb->list, &backend_list);
+ mutex_unlock(&backend_mutex);
- pr_debug("TCM: Registered subsystem plugin: %s struct module:"
- " %p\n", sub_api->name, sub_api->owner);
+ pr_debug("TCM: Registered subsystem plugin: %s struct module: %p\n",
+ ops->name, ops->owner);
return 0;
}
-EXPORT_SYMBOL(transport_subsystem_register);
+EXPORT_SYMBOL(transport_backend_register);
-void transport_subsystem_release(struct se_subsystem_api *sub_api)
+void target_backend_unregister(const struct target_backend_ops *ops)
{
- mutex_lock(&subsystem_mutex);
- list_del(&sub_api->sub_api_list);
- mutex_unlock(&subsystem_mutex);
+ struct target_backend *tb;
+
+ mutex_lock(&backend_mutex);
+ list_for_each_entry(tb, &backend_list, list) {
+ if (tb->ops == ops) {
+ list_del(&tb->list);
+ kfree(tb);
+ break;
+ }
+ }
+ mutex_unlock(&backend_mutex);
}
-EXPORT_SYMBOL(transport_subsystem_release);
+EXPORT_SYMBOL(target_backend_unregister);
-static struct se_subsystem_api *core_get_backend(const char *sub_name)
+static struct target_backend *core_get_backend(const char *name)
{
- struct se_subsystem_api *s;
+ struct target_backend *tb;
- mutex_lock(&subsystem_mutex);
- list_for_each_entry(s, &subsystem_list, sub_api_list) {
- if (!strcmp(s->name, sub_name))
+ mutex_lock(&backend_mutex);
+ list_for_each_entry(tb, &backend_list, list) {
+ if (!strcmp(tb->ops->name, name))
goto found;
}
- mutex_unlock(&subsystem_mutex);
+ mutex_unlock(&backend_mutex);
return NULL;
found:
- if (s->owner && !try_module_get(s->owner))
- s = NULL;
- mutex_unlock(&subsystem_mutex);
- return s;
+ if (tb->ops->owner && !try_module_get(tb->ops->owner))
+ tb = NULL;
+ mutex_unlock(&backend_mutex);
+ return tb;
}
struct se_hba *
@@ -116,13 +128,13 @@
hba->hba_index = scsi_get_new_index(SCSI_INST_INDEX);
hba->hba_flags |= hba_flags;
- hba->transport = core_get_backend(plugin_name);
- if (!hba->transport) {
+ hba->backend = core_get_backend(plugin_name);
+ if (!hba->backend) {
ret = -EINVAL;
goto out_free_hba;
}
- ret = hba->transport->attach_hba(hba, plugin_dep_id);
+ ret = hba->backend->ops->attach_hba(hba, plugin_dep_id);
if (ret < 0)
goto out_module_put;
@@ -137,8 +149,8 @@
return hba;
out_module_put:
- module_put(hba->transport->owner);
- hba->transport = NULL;
+ module_put(hba->backend->ops->owner);
+ hba->backend = NULL;
out_free_hba:
kfree(hba);
return ERR_PTR(ret);
@@ -149,7 +161,7 @@
{
WARN_ON(hba->dev_count);
- hba->transport->detach_hba(hba);
+ hba->backend->ops->detach_hba(hba);
spin_lock(&hba_lock);
list_del(&hba->hba_node);
@@ -158,9 +170,9 @@
pr_debug("CORE_HBA[%d] - Detached HBA from Generic Target"
" Core\n", hba->hba_id);
- module_put(hba->transport->owner);
+ module_put(hba->backend->ops->owner);
- hba->transport = NULL;
+ hba->backend = NULL;
kfree(hba);
return 0;
}
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 8c96568..79f651f 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -54,12 +54,6 @@
}
-static struct se_subsystem_api iblock_template;
-
-/* iblock_attach_hba(): (Part of se_subsystem_api_t template)
- *
- *
- */
static int iblock_attach_hba(struct se_hba *hba, u32 host_id)
{
pr_debug("CORE_HBA[%d] - TCM iBlock HBA Driver %s on"
@@ -899,7 +893,7 @@
NULL,
};
-static struct se_subsystem_api iblock_template = {
+static const struct target_backend_ops iblock_ops = {
.name = "iblock",
.inquiry_prod = "IBLOCK",
.inquiry_rev = IBLOCK_VERSION,
@@ -919,21 +913,17 @@
.get_io_min = iblock_get_io_min,
.get_io_opt = iblock_get_io_opt,
.get_write_cache = iblock_get_write_cache,
+ .tb_dev_attrib_attrs = iblock_backend_dev_attrs,
};
static int __init iblock_module_init(void)
{
- struct target_backend_cits *tbc = &iblock_template.tb_cits;
-
- target_core_setup_sub_cits(&iblock_template);
- tbc->tb_dev_attrib_cit.ct_attrs = iblock_backend_dev_attrs;
-
- return transport_subsystem_register(&iblock_template);
+ return transport_backend_register(&iblock_ops);
}
static void __exit iblock_module_exit(void)
{
- transport_subsystem_release(&iblock_template);
+ target_backend_unregister(&iblock_ops);
}
MODULE_DESCRIPTION("TCM IBLOCK subsystem plugin");
diff --git a/drivers/target/target_core_internal.h b/drivers/target/target_core_internal.h
index ce80ca7..01181ae 100644
--- a/drivers/target/target_core_internal.h
+++ b/drivers/target/target_core_internal.h
@@ -1,6 +1,19 @@
#ifndef TARGET_CORE_INTERNAL_H
#define TARGET_CORE_INTERNAL_H
+struct target_backend {
+ struct list_head list;
+
+ const struct target_backend_ops *ops;
+
+ struct config_item_type tb_dev_cit;
+ struct config_item_type tb_dev_attrib_cit;
+ struct config_item_type tb_dev_pr_cit;
+ struct config_item_type tb_dev_wwn_cit;
+ struct config_item_type tb_dev_alua_tg_pt_gps_cit;
+ struct config_item_type tb_dev_stat_cit;
+};
+
/* target_core_alua.c */
extern struct t10_alua_lu_gp *default_lu_gp;
@@ -40,6 +53,9 @@
int target_configure_device(struct se_device *dev);
void target_free_device(struct se_device *);
+/* target_core_configfs.c */
+void target_setup_backend_cits(struct target_backend *);
+
/* target_core_fabric_lib.c */
int target_get_pr_transport_id_len(struct se_node_acl *nacl,
struct t10_pr_registration *pr_reg, int *format_code);
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 21db991..2e3a0b0 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -57,8 +57,6 @@
return container_of(dev, struct pscsi_dev_virt, dev);
}
-static struct se_subsystem_api pscsi_template;
-
static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
static void pscsi_req_done(struct request *, int);
@@ -1141,7 +1139,7 @@
NULL,
};
-static struct se_subsystem_api pscsi_template = {
+static const struct target_backend_ops pscsi_ops = {
.name = "pscsi",
.owner = THIS_MODULE,
.transport_flags = TRANSPORT_FLAG_PASSTHROUGH,
@@ -1157,21 +1155,17 @@
.show_configfs_dev_params = pscsi_show_configfs_dev_params,
.get_device_type = pscsi_get_device_type,
.get_blocks = pscsi_get_blocks,
+ .tb_dev_attrib_attrs = pscsi_backend_dev_attrs,
};
static int __init pscsi_module_init(void)
{
- struct target_backend_cits *tbc = &pscsi_template.tb_cits;
-
- target_core_setup_sub_cits(&pscsi_template);
- tbc->tb_dev_attrib_cit.ct_attrs = pscsi_backend_dev_attrs;
-
- return transport_subsystem_register(&pscsi_template);
+ return transport_backend_register(&pscsi_ops);
}
static void __exit pscsi_module_exit(void)
{
- transport_subsystem_release(&pscsi_template);
+ target_backend_unregister(&pscsi_ops);
}
MODULE_DESCRIPTION("TCM PSCSI subsystem plugin");
diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
index 55315fd..cf443a8 100644
--- a/drivers/target/target_core_rd.c
+++ b/drivers/target/target_core_rd.c
@@ -43,10 +43,6 @@
return container_of(dev, struct rd_dev, dev);
}
-/* rd_attach_hba(): (Part of se_subsystem_api_t template)
- *
- *
- */
static int rd_attach_hba(struct se_hba *hba, u32 host_id)
{
struct rd_host *rd_host;
@@ -735,7 +731,7 @@
NULL,
};
-static struct se_subsystem_api rd_mcp_template = {
+static const struct target_backend_ops rd_mcp_ops = {
.name = "rd_mcp",
.inquiry_prod = "RAMDISK-MCP",
.inquiry_rev = RD_MCP_VERSION,
@@ -751,25 +747,15 @@
.get_blocks = rd_get_blocks,
.init_prot = rd_init_prot,
.free_prot = rd_free_prot,
+ .tb_dev_attrib_attrs = rd_mcp_backend_dev_attrs,
};
int __init rd_module_init(void)
{
- struct target_backend_cits *tbc = &rd_mcp_template.tb_cits;
- int ret;
-
- target_core_setup_sub_cits(&rd_mcp_template);
- tbc->tb_dev_attrib_cit.ct_attrs = rd_mcp_backend_dev_attrs;
-
- ret = transport_subsystem_register(&rd_mcp_template);
- if (ret < 0) {
- return ret;
- }
-
- return 0;
+ return transport_backend_register(&rd_mcp_ops);
}
void rd_module_exit(void)
{
- transport_subsystem_release(&rd_mcp_template);
+ target_backend_unregister(&rd_mcp_ops);
}
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 60330e00..fb67e31 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -1115,7 +1115,7 @@
NULL,
};
-static struct se_subsystem_api tcmu_template = {
+static const struct target_backend_ops tcmu_ops = {
.name = "user",
.inquiry_prod = "USER",
.inquiry_rev = TCMU_VERSION,
@@ -1131,11 +1131,11 @@
.show_configfs_dev_params = tcmu_show_configfs_dev_params,
.get_device_type = sbc_get_device_type,
.get_blocks = tcmu_get_blocks,
+ .tb_dev_attrib_attrs = tcmu_backend_dev_attrs,
};
static int __init tcmu_module_init(void)
{
- struct target_backend_cits *tbc = &tcmu_template.tb_cits;
int ret;
BUILD_BUG_ON((sizeof(struct tcmu_cmd_entry) % TCMU_OP_ALIGN_SIZE) != 0);
@@ -1158,10 +1158,7 @@
goto out_unreg_device;
}
- target_core_setup_sub_cits(&tcmu_template);
- tbc->tb_dev_attrib_cit.ct_attrs = tcmu_backend_dev_attrs;
-
- ret = transport_subsystem_register(&tcmu_template);
+ ret = transport_backend_register(&tcmu_ops);
if (ret)
goto out_unreg_genl;
@@ -1179,7 +1176,7 @@
static void __exit tcmu_module_exit(void)
{
- transport_subsystem_release(&tcmu_template);
+ target_backend_unregister(&tcmu_ops);
genl_unregister_family(&tcmu_genl_family);
root_device_unregister(tcmu_root_device);
kmem_cache_destroy(tcmu_cmd_cache);
