Use kref to handle reference counting
Signed-off-by: Andy Grover <agrover@xxxxxxxxxx>
---
drivers/target/target_core_alua.c | 37 ++++++++++++++++++++-----------------
include/target/target_core_base.h | 2 +-
2 files changed, 21 insertions(+), 18 deletions(-)
diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index 2ac2f11..8c01ade 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -54,6 +54,16 @@ static LIST_HEAD(lu_gps_list);
struct t10_alua_lu_gp *default_lu_gp;
+static void release_alua_lu_gp(struct kref *ref)
+{
+ struct t10_alua_lu_gp *lu_gp = container_of(ref, struct t10_alua_lu_gp, refcount);
+
+ kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
+}
+
+#define get_alua_lu_gp(x) kref_get(&x->refcount)
+#define put_alua_lu_gp(x) kref_put(&x->refcount, release_alua_lu_gp)
+
/*
* REPORT_TARGET_PORT_GROUPS
*
@@ -898,8 +908,7 @@ int core_alua_do_port_transition(
local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
lu_gp = local_lu_gp_mem->lu_gp;
- atomic_inc(&lu_gp->lu_gp_ref_cnt);
- smp_mb__after_atomic_inc();
+ get_alua_lu_gp(lu_gp);
spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
/*
* For storage objects that are members of the 'default_lu_gp',
@@ -913,8 +922,8 @@ int core_alua_do_port_transition(
*/
core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
md_buf, new_state, explicit);
- atomic_dec(&lu_gp->lu_gp_ref_cnt);
- smp_mb__after_atomic_dec();
+
+ put_alua_lu_gp(lu_gp);
kfree(md_buf);
return 0;
}
@@ -985,8 +994,7 @@ int core_alua_do_port_transition(
l_tg_pt_gp->tg_pt_gp_id, (explicit) ? "explicit" : "implicit",
core_alua_dump_state(new_state));
- atomic_dec(&lu_gp->lu_gp_ref_cnt);
- smp_mb__after_atomic_dec();
+ put_alua_lu_gp(lu_gp);
kfree(md_buf);
return 0;
}
@@ -1107,7 +1115,8 @@ core_alua_allocate_lu_gp(const char *name, int def_group)
INIT_LIST_HEAD(&lu_gp->lu_gp_node);
INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
spin_lock_init(&lu_gp->lu_gp_lock);
- atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
+
+ kref_init(&lu_gp->refcount);
if (def_group) {
lu_gp->lu_gp_id = alua_lu_gps_counter++;
@@ -1200,13 +1209,7 @@ void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
list_del(&lu_gp->lu_gp_node);
alua_lu_gps_count--;
spin_unlock(&lu_gps_lock);
- /*
- * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
- * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
- * released with core_alua_put_lu_gp_from_name()
- */
- while (atomic_read(&lu_gp->lu_gp_ref_cnt))
- cpu_relax();
+
/*
* Release reference to struct t10_alua_lu_gp * from all associated
* struct se_device.
@@ -1241,7 +1244,7 @@ void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
}
spin_unlock(&lu_gp->lu_gp_lock);
- kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
+ put_alua_lu_gp(lu_gp);
}
void core_alua_free_lu_gp_mem(struct se_device *dev)
@@ -1284,7 +1287,7 @@ struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
continue;
ci = &lu_gp->lu_gp_group.cg_item;
if (!strcmp(config_item_name(ci), name)) {
- atomic_inc(&lu_gp->lu_gp_ref_cnt);
+ get_alua_lu_gp(lu_gp);
spin_unlock(&lu_gps_lock);
return lu_gp;
}
@@ -1297,7 +1300,7 @@ struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
{
spin_lock(&lu_gps_lock);
- atomic_dec(&lu_gp->lu_gp_ref_cnt);
+ put_alua_lu_gp(lu_gp);
spin_unlock(&lu_gps_lock);
}
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index d5e0da1..5bdf0d5 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -264,7 +264,7 @@ struct t10_alua_lu_gp {
u16 lu_gp_id;
int lu_gp_valid_id;
u32 lu_gp_members;
- atomic_t lu_gp_ref_cnt;
+ struct kref refcount;
spinlock_t lu_gp_lock;
struct config_group lu_gp_group;
struct list_head lu_gp_node;
--
1.7.1
--
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