Do not accept new sessions after core_tpg_del_initiator_node_acl()
has set acl_stop. Ensure that core_tpg_del_initiator_node_acl()
waits until all sessions have dropped their reference on the
associated struct se_node_acl object by removing the sess_tearing_down
test. Modify all target drivers such that these test the return
value of transport_register_session().
This patch avoids that e.g. stopping the ib_srpt driver can hang as
follows:
INFO: task rmdir:4473 blocked for more than 120 seconds.
rmdir
Call Trace:
[<ffffffff81517132>] schedule+0x42/0x90
[<ffffffff8151b27f>] schedule_timeout+0x17f/0x1d0
[<ffffffff815181b5>] wait_for_completion+0xe5/0x120
[<ffffffffa04aa401>] core_tpg_del_initiator_node_acl+0x171/0x220 [target_core_mod]
[<ffffffffa049dcaf>] target_fabric_nacl_base_release+0x4f/0x60 [target_core_mod]
[<ffffffffa0482bef>] config_item_release+0x6f/0xc0 [configfs]
[<ffffffffa0482c5b>] config_item_put+0x1b/0x20 [configfs]
[<ffffffffa0481f88>] configfs_rmdir+0x1e8/0x2e0 [configfs]
[<ffffffff81183461>] vfs_rmdir+0x81/0x120
[<ffffffff81187246>] do_rmdir+0x146/0x190
[<ffffffff811872d1>] SyS_rmdir+0x11/0x20
[<ffffffff8151c857>] entry_SYSCALL_64_fastpath+0x12/0x6f
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Cc: Andy Grover <agrover@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
---
drivers/target/target_core_tpg.c | 3 ---
drivers/target/target_core_transport.c | 32 +++++++++++++++++++++++---------
2 files changed, 23 insertions(+), 12 deletions(-)
diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c
index 62103a8..ef99cc7 100644
--- a/drivers/target/target_core_tpg.c
+++ b/drivers/target/target_core_tpg.c
@@ -324,9 +324,6 @@ void core_tpg_del_initiator_node_acl(struct se_node_acl *acl)
list_for_each_entry_safe(sess, sess_tmp, &acl->acl_sess_list,
sess_acl_list) {
- if (sess->sess_tearing_down != 0)
- continue;
-
target_get_session(sess);
list_move(&sess->sess_acl_list, &sess_list);
}
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 1b5525f..8e1bf50 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -332,14 +332,22 @@ static int __transport_register_session_with_nacl(struct se_node_acl *se_nacl,
kref_get(&se_nacl->acl_kref);
spin_lock_irq(&se_nacl->nacl_sess_lock);
- /*
- * The se_nacl->nacl_sess pointer will be set to the
- * last active I_T Nexus for each struct se_node_acl.
- */
- se_nacl->nacl_sess = se_sess;
- list_add_tail(&se_sess->sess_acl_list, &se_nacl->acl_sess_list);
+ if (!se_nacl->acl_stop) {
+ /*
+ * The se_nacl->nacl_sess pointer will be set to the
+ * last active I_T Nexus for each struct se_node_acl.
+ */
+ se_nacl->nacl_sess = se_sess;
+ list_add_tail(&se_sess->sess_acl_list,
+ &se_nacl->acl_sess_list);
+ } else {
+ ret = -ENOENT;
+ }
spin_unlock_irq(&se_nacl->nacl_sess_lock);
+ if (ret < 0)
+ target_put_nacl(se_nacl);
+
return ret;
}
@@ -362,12 +370,17 @@ int __transport_register_session(struct se_portal_group *se_tpg,
* eg: *NOT* discovery sessions.
*/
if (se_nacl)
- __transport_register_session_with_nacl(se_nacl, se_sess);
+ ret = __transport_register_session_with_nacl(se_nacl, se_sess);
+
+ if (ret < 0)
+ goto out;
+
list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
+out:
return ret;
}
EXPORT_SYMBOL(__transport_register_session);
@@ -378,10 +391,11 @@ int transport_register_session(struct se_portal_group *se_tpg,
void *fabric_sess_ptr)
{
unsigned long flags;
- int ret = 0;
+ int ret;
spin_lock_irqsave(&se_tpg->session_lock, flags);
- __transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
+ ret = __transport_register_session(se_tpg, se_nacl, se_sess,
+ fabric_sess_ptr);
spin_unlock_irqrestore(&se_tpg->session_lock, flags);
return ret;
--
2.1.4
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