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, 101 insertions, 0 deletions

diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index 0843c8f4b94e..e73edcad7930 100644
--- a/drivers/target/target_core_alua.c
+++ b/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)
 {