target_core_alua: Referrals configfs integration

Referrals need an LBA map, which needs to be kept
consistent across all target port groups. So
instead of tying the map to the target port groups
I've implemented a single attribute containing the
entire map.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/target_core_alua.c

@@ -1351,6 +1351,107 @@ static int core_alua_set_tg_pt_secondary_state(
 	return 0;
 }
 
+struct t10_alua_lba_map *
+core_alua_allocate_lba_map(struct list_head *list,
+			   u64 first_lba, u64 last_lba)
+{
+	struct t10_alua_lba_map *lba_map;
+
+	lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
+	if (!lba_map) {
+		pr_err("Unable to allocate struct t10_alua_lba_map\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
+	lba_map->lba_map_first_lba = first_lba;
+	lba_map->lba_map_last_lba = last_lba;
+
+	list_add_tail(&lba_map->lba_map_list, list);
+	return lba_map;
+}
+
+int
+core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
+			       int pg_id, int state)
+{
+	struct t10_alua_lba_map_member *lba_map_mem;
+
+	list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
+			    lba_map_mem_list) {
+		if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
+			pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
+			return -EINVAL;
+		}
+	}
+
+	lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
+	if (!lba_map_mem) {
+		pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
+		return -ENOMEM;
+	}
+	lba_map_mem->lba_map_mem_alua_state = state;
+	lba_map_mem->lba_map_mem_alua_pg_id = pg_id;
+
+	list_add_tail(&lba_map_mem->lba_map_mem_list,
+		      &lba_map->lba_map_mem_list);
+	return 0;
+}
+
+void
+core_alua_free_lba_map(struct list_head *lba_list)
+{
+	struct t10_alua_lba_map *lba_map, *lba_map_tmp;
+	struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;
+
+	list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
+				 lba_map_list) {
+		list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
+					 &lba_map->lba_map_mem_list,
+					 lba_map_mem_list) {
+			list_del(&lba_map_mem->lba_map_mem_list);
+			kmem_cache_free(t10_alua_lba_map_mem_cache,
+					lba_map_mem);
+		}
+		list_del(&lba_map->lba_map_list);
+		kmem_cache_free(t10_alua_lba_map_cache, lba_map);
+	}
+}
+
+void
+core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
+		      int segment_size, int segment_mult)
+{
+	struct list_head old_lba_map_list;
+	struct t10_alua_tg_pt_gp *tg_pt_gp;
+	int activate = 0, supported;
+
+	INIT_LIST_HEAD(&old_lba_map_list);
+	spin_lock(&dev->t10_alua.lba_map_lock);
+	dev->t10_alua.lba_map_segment_size = segment_size;
+	dev->t10_alua.lba_map_segment_multiplier = segment_mult;
+	list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
+	if (lba_map_list) {
+		list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
+		activate = 1;
+	}
+	spin_unlock(&dev->t10_alua.lba_map_lock);
+	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
+			    tg_pt_gp_list) {
+
+		if (!tg_pt_gp->tg_pt_gp_valid_id)
+			continue;
+		supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
+		if (activate)
+			supported |= ALUA_LBD_SUP;
+		else
+			supported &= ~ALUA_LBD_SUP;
+		tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
+	}
+	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+	core_alua_free_lba_map(&old_lba_map_list);
+}
+
 struct t10_alua_lu_gp *
 core_alua_allocate_lu_gp(const char *name, int def_group)
 {

drivers/target/target_core_alua.h

@@ -86,6 +86,8 @@ extern struct kmem_cache *t10_alua_lu_gp_cache;
 extern struct kmem_cache *t10_alua_lu_gp_mem_cache;
 extern struct kmem_cache *t10_alua_tg_pt_gp_cache;
 extern struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
+extern struct kmem_cache *t10_alua_lba_map_cache;
+extern struct kmem_cache *t10_alua_lba_map_mem_cache;
 
 extern sense_reason_t target_emulate_report_target_port_groups(struct se_cmd *);
 extern sense_reason_t target_emulate_set_target_port_groups(struct se_cmd *);
@@ -95,6 +97,12 @@ extern int core_alua_do_port_transition(struct t10_alua_tg_pt_gp *,
 				struct se_device *, struct se_port *,
 				struct se_node_acl *, int, int);
 extern char *core_alua_dump_status(int);
+extern struct t10_alua_lba_map *core_alua_allocate_lba_map(
+				struct list_head *, u64, u64);
+extern int core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *, int, int);
+extern void core_alua_free_lba_map(struct list_head *);
+extern void core_alua_set_lba_map(struct se_device *, struct list_head *,
+				int, int);
 extern struct t10_alua_lu_gp *core_alua_allocate_lu_gp(const char *, int);
 extern int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *, u16);
 extern void core_alua_free_lu_gp(struct t10_alua_lu_gp *);

drivers/target/target_core_configfs.c

@@ -1741,6 +1741,176 @@ static struct target_core_configfs_attribute target_core_attr_dev_alua_lu_gp = {
 	.store	= target_core_store_alua_lu_gp,
 };
 
+static ssize_t target_core_show_dev_lba_map(void *p, char *page)
+{
+	struct se_device *dev = p;
+	struct t10_alua_lba_map *map;
+	struct t10_alua_lba_map_member *mem;
+	char *b = page;
+	int bl = 0;
+	char state;
+
+	spin_lock(&dev->t10_alua.lba_map_lock);
+	if (!list_empty(&dev->t10_alua.lba_map_list))
+	    bl += sprintf(b + bl, "%u %u\n",
+			  dev->t10_alua.lba_map_segment_size,
+			  dev->t10_alua.lba_map_segment_multiplier);
+	list_for_each_entry(map, &dev->t10_alua.lba_map_list, lba_map_list) {
+		bl += sprintf(b + bl, "%llu %llu",
+			      map->lba_map_first_lba, map->lba_map_last_lba);
+		list_for_each_entry(mem, &map->lba_map_mem_list,
+				    lba_map_mem_list) {
+			switch (mem->lba_map_mem_alua_state) {
+			case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
+				state = 'O';
+				break;
+			case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
+				state = 'A';
+				break;
+			case ALUA_ACCESS_STATE_STANDBY:
+				state = 'S';
+				break;
+			case ALUA_ACCESS_STATE_UNAVAILABLE:
+				state = 'U';
+				break;
+			default:
+				state = '.';
+				break;
+			}
+			bl += sprintf(b + bl, " %d:%c",
+				      mem->lba_map_mem_alua_pg_id, state);
+		}
+		bl += sprintf(b + bl, "\n");
+	}
+	spin_unlock(&dev->t10_alua.lba_map_lock);
+	return bl;
+}
+
+static ssize_t target_core_store_dev_lba_map(
+	void *p,
+	const char *page,
+	size_t count)
+{
+	struct se_device *dev = p;
+	struct t10_alua_lba_map *lba_map = NULL;
+	struct list_head lba_list;
+	char *map_entries, *ptr;
+	char state;
+	int pg_num = -1, pg;
+	int ret = 0, num = 0, pg_id, alua_state;
+	unsigned long start_lba = -1, end_lba = -1;
+	unsigned long segment_size = -1, segment_mult = -1;
+
+	map_entries = kstrdup(page, GFP_KERNEL);
+	if (!map_entries)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&lba_list);
+	while ((ptr = strsep(&map_entries, "\n")) != NULL) {
+		if (!*ptr)
+			continue;
+
+		if (num == 0) {
+			if (sscanf(ptr, "%lu %lu\n",
+				   &segment_size, &segment_mult) != 2) {
+				pr_err("Invalid line %d\n", num);
+				ret = -EINVAL;
+				break;
+			}
+			num++;
+			continue;
+		}
+		if (sscanf(ptr, "%lu %lu", &start_lba, &end_lba) != 2) {
+			pr_err("Invalid line %d\n", num);
+			ret = -EINVAL;
+			break;
+		}
+		ptr = strchr(ptr, ' ');
+		if (!ptr) {
+			pr_err("Invalid line %d, missing end lba\n", num);
+			ret = -EINVAL;
+			break;
+		}
+		ptr++;
+		ptr = strchr(ptr, ' ');
+		if (!ptr) {
+			pr_err("Invalid line %d, missing state definitions\n",
+			       num);
+			ret = -EINVAL;
+			break;
+		}
+		ptr++;
+		lba_map = core_alua_allocate_lba_map(&lba_list,
+						     start_lba, end_lba);
+		if (IS_ERR(lba_map)) {
+			ret = PTR_ERR(lba_map);
+			break;
+		}
+		pg = 0;
+		while (sscanf(ptr, "%d:%c", &pg_id, &state) == 2) {
+			switch (state) {
+			case 'O':
+				alua_state = ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED;
+				break;
+			case 'A':
+				alua_state = ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED;
+				break;
+			case 'S':
+				alua_state = ALUA_ACCESS_STATE_STANDBY;
+				break;
+			case 'U':
+				alua_state = ALUA_ACCESS_STATE_UNAVAILABLE;
+				break;
+			default:
+				pr_err("Invalid ALUA state '%c'\n", state);
+				ret = -EINVAL;
+				goto out;
+			}
+
+			ret = core_alua_allocate_lba_map_mem(lba_map,
+							     pg_id, alua_state);
+			if (ret) {
+				pr_err("Invalid target descriptor %d:%c "
+				       "at line %d\n",
+				       pg_id, state, num);
+				break;
+			}
+			pg++;
+			ptr = strchr(ptr, ' ');
+			if (ptr)
+				ptr++;
+			else
+				break;
+		}
+		if (pg_num == -1)
+		    pg_num = pg;
+		else if (pg != pg_num) {
+			pr_err("Only %d from %d port groups definitions "
+			       "at line %d\n", pg, pg_num, num);
+			ret = -EINVAL;
+			break;
+		}
+		num++;
+	}
+out:
+	if (ret) {
+		core_alua_free_lba_map(&lba_list);
+		count = ret;
+	} else
+		core_alua_set_lba_map(dev, &lba_list,
+				      segment_size, segment_mult);
+	kfree(map_entries);
+	return count;
+}
+
+static struct target_core_configfs_attribute target_core_attr_dev_lba_map = {
+	.attr	= { .ca_owner = THIS_MODULE,
+		    .ca_name = "lba_map",
+		    .ca_mode = S_IRUGO | S_IWUSR },
+	.show	= target_core_show_dev_lba_map,
+	.store	= target_core_store_dev_lba_map,
+};
+
 static struct configfs_attribute *lio_core_dev_attrs[] = {
 	&target_core_attr_dev_info.attr,
 	&target_core_attr_dev_control.attr,
@@ -1748,6 +1918,7 @@ static struct configfs_attribute *lio_core_dev_attrs[] = {
 	&target_core_attr_dev_udev_path.attr,
 	&target_core_attr_dev_enable.attr,
 	&target_core_attr_dev_alua_lu_gp.attr,
+	&target_core_attr_dev_lba_map.attr,
 	NULL,
 };
 

drivers/target/target_core_device.c

@@ -1585,6 +1585,7 @@ void target_free_device(struct se_device *dev)
 	}
 
 	core_alua_free_lu_gp_mem(dev);
+	core_alua_set_lba_map(dev, NULL, 0, 0);
 	core_scsi3_free_all_registrations(dev);
 	se_release_vpd_for_dev(dev);
 

drivers/target/target_core_transport.c

@@ -62,6 +62,8 @@ struct kmem_cache *t10_alua_lu_gp_cache;
 struct kmem_cache *t10_alua_lu_gp_mem_cache;
 struct kmem_cache *t10_alua_tg_pt_gp_cache;
 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
+struct kmem_cache *t10_alua_lba_map_cache;
+struct kmem_cache *t10_alua_lba_map_mem_cache;
 
 static void transport_complete_task_attr(struct se_cmd *cmd);
 static void transport_handle_queue_full(struct se_cmd *cmd,
@@ -128,14 +130,36 @@ int init_se_kmem_caches(void)
 				"mem_t failed\n");
 		goto out_free_tg_pt_gp_cache;
 	}
+	t10_alua_lba_map_cache = kmem_cache_create(
+			"t10_alua_lba_map_cache",
+			sizeof(struct t10_alua_lba_map),
+			__alignof__(struct t10_alua_lba_map), 0, NULL);
+	if (!t10_alua_lba_map_cache) {
+		pr_err("kmem_cache_create() for t10_alua_lba_map_"
+				"cache failed\n");
+		goto out_free_tg_pt_gp_mem_cache;
+	}
+	t10_alua_lba_map_mem_cache = kmem_cache_create(
+			"t10_alua_lba_map_mem_cache",
+			sizeof(struct t10_alua_lba_map_member),
+			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
+	if (!t10_alua_lba_map_mem_cache) {
+		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
+				"cache failed\n");
+		goto out_free_lba_map_cache;
+	}
 
 	target_completion_wq = alloc_workqueue("target_completion",
 					       WQ_MEM_RECLAIM, 0);
 	if (!target_completion_wq)
-		goto out_free_tg_pt_gp_mem_cache;
+		goto out_free_lba_map_mem_cache;
 
 	return 0;
 
+out_free_lba_map_mem_cache:
+	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
+out_free_lba_map_cache:
+	kmem_cache_destroy(t10_alua_lba_map_cache);
 out_free_tg_pt_gp_mem_cache:
 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
 out_free_tg_pt_gp_cache:
@@ -164,6 +188,8 @@ void release_se_kmem_caches(void)
 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
+	kmem_cache_destroy(t10_alua_lba_map_cache);
+	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
 }
 
 /* This code ensures unique mib indexes are handed out. */