Free struct when kref becomes 0.
Signed-off-by: Andy Grover <agrover@xxxxxxxxxx>
---
drivers/target/target_core_pr.c | 99 +++++++++++++++---------------------
include/target/target_core_base.h | 2 +-
2 files changed, 42 insertions(+), 59 deletions(-)
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 9155df0..17a4c3b 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -75,6 +75,17 @@ enum preempt_type {
PREEMPT_AND_ABORT,
};
+static void release_pr_reg(struct kref *kref)
+{
+ struct t10_pr_registration *pr_reg = container_of(kref,
+ struct t10_pr_registration, refcount);
+
+ kmem_cache_free(t10_pr_reg_cache, pr_reg);
+}
+
+#define get_pr_reg(x) kref_get(&x->refcount)
+#define put_pr_reg(x) kref_put(&x->refcount, release_pr_reg)
+
static void __core_scsi3_complete_pro_release(struct se_device *, struct se_node_acl *,
struct t10_pr_registration *, int);
@@ -109,7 +120,6 @@ target_scsi2_reservation_check(struct se_cmd *cmd)
static struct t10_pr_registration *core_scsi3_locate_pr_reg(struct se_device *,
struct se_node_acl *, struct se_session *);
-static void core_scsi3_put_pr_reg(struct t10_pr_registration *);
static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
{
@@ -144,17 +154,17 @@ static int target_check_scsi2_reservation_conflict(struct se_cmd *cmd)
* as defined in SPC-2.
*/
if (pr_reg->pr_res_holder) {
- core_scsi3_put_pr_reg(pr_reg);
+ put_pr_reg(pr_reg);
return 1;
}
if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
(pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) ||
(pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
(pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
- core_scsi3_put_pr_reg(pr_reg);
+ put_pr_reg(pr_reg);
return 1;
}
- core_scsi3_put_pr_reg(pr_reg);
+ put_pr_reg(pr_reg);
conflict = 1;
} else {
/*
@@ -611,7 +621,7 @@ static struct t10_pr_registration *__core_scsi3_do_alloc_registration(
INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
- atomic_set(&pr_reg->pr_res_holders, 0);
+ kref_init(&pr_reg->refcount);
pr_reg->pr_reg_nacl = nacl;
pr_reg->pr_reg_deve = deve;
pr_reg->pr_res_mapped_lun = deve->mapped_lun;
@@ -795,7 +805,7 @@ int core_scsi3_alloc_aptpl_registration(
INIT_LIST_HEAD(&pr_reg->pr_reg_aptpl_list);
INIT_LIST_HEAD(&pr_reg->pr_reg_atp_list);
INIT_LIST_HEAD(&pr_reg->pr_reg_atp_mem_list);
- atomic_set(&pr_reg->pr_res_holders, 0);
+ kref_init(&pr_reg->refcount);
pr_reg->pr_reg_nacl = NULL;
pr_reg->pr_reg_deve = NULL;
pr_reg->pr_res_mapped_lun = mapped_lun;
@@ -1102,8 +1112,7 @@ static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
if (dev->dev_attrib.enforce_pr_isids)
continue;
}
- atomic_inc(&pr_reg->pr_res_holders);
- smp_mb__after_atomic_inc();
+ get_pr_reg(pr_reg);
spin_unlock(&pr_tmpl->registration_lock);
return pr_reg;
}
@@ -1117,8 +1126,7 @@ static struct t10_pr_registration *__core_scsi3_locate_pr_reg(
if (strcmp(isid, pr_reg->pr_reg_isid))
continue;
- atomic_inc(&pr_reg->pr_res_holders);
- smp_mb__after_atomic_inc();
+ get_pr_reg(pr_reg);
spin_unlock(&pr_tmpl->registration_lock);
return pr_reg;
}
@@ -1145,12 +1153,6 @@ static struct t10_pr_registration *core_scsi3_locate_pr_reg(
return __core_scsi3_locate_pr_reg(dev, nacl, isid_ptr);
}
-static void core_scsi3_put_pr_reg(struct t10_pr_registration *pr_reg)
-{
- atomic_dec(&pr_reg->pr_res_holders);
- smp_mb__after_atomic_dec();
-}
-
static int core_scsi3_check_implicit_release(
struct se_device *dev,
struct t10_pr_registration *pr_reg)
@@ -1213,7 +1215,6 @@ static void __core_scsi3_free_registration(
{
struct target_core_fabric_ops *tfo =
pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
- struct t10_reservation *pr_tmpl = &dev->t10_pr;
char i_buf[PR_REG_ISID_ID_LEN];
memset(i_buf, 0, PR_REG_ISID_ID_LEN);
@@ -1227,20 +1228,7 @@ static void __core_scsi3_free_registration(
* so call core_scsi3_put_pr_reg() to decrement our reference.
*/
if (dec_holders)
- core_scsi3_put_pr_reg(pr_reg);
- /*
- * Wait until all reference from any other I_T nexuses for this
- * *pr_reg have been released. Because list_del() is called above,
- * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
- * count back to zero, and we release *pr_reg.
- */
- while (atomic_read(&pr_reg->pr_res_holders) != 0) {
- spin_unlock(&pr_tmpl->registration_lock);
- pr_debug("SPC-3 PR [%s] waiting for pr_res_holders\n",
- tfo->get_fabric_name());
- cpu_relax();
- spin_lock(&pr_tmpl->registration_lock);
- }
+ put_pr_reg(pr_reg);
pr_debug("SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
" Node: %s%s\n", tfo->get_fabric_name(),
@@ -1254,17 +1242,14 @@ static void __core_scsi3_free_registration(
" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
pr_reg->pr_res_generation);
- if (!preempt_and_abort_list) {
- pr_reg->pr_reg_deve = NULL;
- pr_reg->pr_reg_nacl = NULL;
- kmem_cache_free(t10_pr_reg_cache, pr_reg);
- return;
- }
/*
* For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
* are released once the ABORT_TASK_SET has completed..
*/
- list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
+ if (preempt_and_abort_list)
+ list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
+ else
+ put_pr_reg(pr_reg);
}
void core_scsi3_free_pr_reg_from_nacl(
@@ -1653,7 +1638,7 @@ core_scsi3_decode_spec_i_port(
pr_reg_e = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
iport_ptr);
if (pr_reg_e) {
- core_scsi3_put_pr_reg(pr_reg_e);
+ put_pr_reg(pr_reg_e);
core_scsi3_lunacl_undepend_item(dest_se_deve);
core_scsi3_nodeacl_undepend_item(dest_node_acl);
core_scsi3_tpg_undepend_item(dest_tpg);
@@ -2181,7 +2166,7 @@ core_scsi3_emulate_pro_register(struct se_cmd *cmd, u64 res_key, u64 sa_res_key,
ret = core_scsi3_update_and_write_aptpl(dev, aptpl);
out:
- core_scsi3_put_pr_reg(pr_reg);
+ put_pr_reg(pr_reg);
return ret;
}
@@ -2359,7 +2344,7 @@ core_scsi3_pro_reserve(struct se_cmd *cmd, int type, int scope, u64 res_key)
ret = 0;
out_put_pr_reg:
- core_scsi3_put_pr_reg(pr_reg);
+ put_pr_reg(pr_reg);
return ret;
}
@@ -2573,7 +2558,7 @@ write_aptpl:
core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
out_put_pr_reg:
- core_scsi3_put_pr_reg(pr_reg);
+ put_pr_reg(pr_reg);
return ret;
}
@@ -2613,7 +2598,7 @@ core_scsi3_emulate_pro_clear(struct se_cmd *cmd, u64 res_key)
" res_key: 0x%016Lx does not match"
" existing SA REGISTER res_key:"
" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
- core_scsi3_put_pr_reg(pr_reg_n);
+ put_pr_reg(pr_reg_n);
return TCM_RESERVATION_CONFLICT;
}
/*
@@ -2757,12 +2742,12 @@ core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
return TCM_RESERVATION_CONFLICT;
}
if (pr_reg_n->pr_res_key != res_key) {
- core_scsi3_put_pr_reg(pr_reg_n);
+ put_pr_reg(pr_reg_n);
return TCM_RESERVATION_CONFLICT;
}
if (scope != PR_SCOPE_LU_SCOPE) {
pr_err("SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
- core_scsi3_put_pr_reg(pr_reg_n);
+ put_pr_reg(pr_reg_n);
return TCM_INVALID_PARAMETER_LIST;
}
@@ -2775,7 +2760,7 @@ core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
if (!all_reg && !sa_res_key) {
spin_unlock(&dev->dev_reservation_lock);
- core_scsi3_put_pr_reg(pr_reg_n);
+ put_pr_reg(pr_reg_n);
return TCM_INVALID_PARAMETER_LIST;
}
/*
@@ -2869,7 +2854,7 @@ core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
*/
if (!released_regs) {
spin_unlock(&dev->dev_reservation_lock);
- core_scsi3_put_pr_reg(pr_reg_n);
+ put_pr_reg(pr_reg_n);
return TCM_RESERVATION_CONFLICT;
}
/*
@@ -2891,7 +2876,7 @@ core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
if (pr_tmpl->pr_aptpl_active)
core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
- core_scsi3_put_pr_reg(pr_reg_n);
+ put_pr_reg(pr_reg_n);
core_scsi3_pr_generation(cmd->se_dev);
return 0;
}
@@ -3020,7 +3005,7 @@ core_scsi3_pro_preempt(struct se_cmd *cmd, int type, int scope, u64 res_key,
if (pr_tmpl->pr_aptpl_active)
core_scsi3_update_and_write_aptpl(cmd->se_dev, true);
- core_scsi3_put_pr_reg(pr_reg_n);
+ put_pr_reg(pr_reg_n);
core_scsi3_pr_generation(cmd->se_dev);
return 0;
}
@@ -3442,13 +3427,13 @@ after_iport_check:
__core_scsi3_free_registration(dev, pr_reg, NULL, 1);
spin_unlock(&pr_tmpl->registration_lock);
} else
- core_scsi3_put_pr_reg(pr_reg);
+ put_pr_reg(pr_reg);
core_scsi3_update_and_write_aptpl(cmd->se_dev, aptpl);
transport_kunmap_data_sg(cmd);
- core_scsi3_put_pr_reg(dest_pr_reg);
+ put_pr_reg(dest_pr_reg);
return 0;
out:
if (buf)
@@ -3460,7 +3445,7 @@ out:
core_scsi3_tpg_undepend_item(dest_se_tpg);
out_put_pr_reg:
- core_scsi3_put_pr_reg(pr_reg);
+ put_pr_reg(pr_reg);
return ret;
}
@@ -3862,8 +3847,7 @@ core_scsi3_pri_read_full_status(struct se_cmd *cmd)
se_tpg = pr_reg->pr_reg_nacl->se_tpg;
add_desc_len = 0;
- atomic_inc(&pr_reg->pr_res_holders);
- smp_mb__after_atomic_inc();
+ get_pr_reg(pr_reg);
spin_unlock(&pr_tmpl->registration_lock);
/*
* Determine expected length of $FABRIC_MOD specific
@@ -3876,8 +3860,7 @@ core_scsi3_pri_read_full_status(struct se_cmd *cmd)
pr_warn("SPC-3 PRIN READ_FULL_STATUS ran"
" out of buffer: %d\n", cmd->data_length);
spin_lock(&pr_tmpl->registration_lock);
- atomic_dec(&pr_reg->pr_res_holders);
- smp_mb__after_atomic_dec();
+ put_pr_reg(pr_reg);
break;
}
/*
@@ -3938,8 +3921,8 @@ core_scsi3_pri_read_full_status(struct se_cmd *cmd)
se_nacl, pr_reg, &format_code, &buf[off+4]);
spin_lock(&pr_tmpl->registration_lock);
- atomic_dec(&pr_reg->pr_res_holders);
- smp_mb__after_atomic_dec();
+ put_pr_reg(pr_reg);
+
/*
* Set the ADDITIONAL DESCRIPTOR LENGTH
*/
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 6bf1da9..513429a 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -363,7 +363,7 @@ struct t10_pr_registration {
u32 pr_res_generation;
u64 pr_reg_bin_isid;
u64 pr_res_key;
- atomic_t pr_res_holders;
+ struct kref refcount;
struct se_node_acl *pr_reg_nacl;
struct se_dev_entry *pr_reg_deve;
struct se_lun *pr_reg_tg_pt_lun;
--
1.7.1
--
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