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>

1 files changed, 171 insertions, 0 deletions

diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index e0a47f524700..5cf613544eeb 100644
--- a/drivers/target/target_core_configfs.c
+++ b/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,
 };