@@ -1889,7 +1889,8 @@ static void lio_tpg_release_fabric_acl(
}
/*
- * Called with spin_lock_bh(struct se_portal_group->session_lock) held..
+ * Called with spin_lock_irq(struct se_portal_group->session_lock) held
+ * or not held.
*
* Also, this function calls iscsit_inc_session_usage_count() on the
* struct iscsi_session in question.
@@ -1897,19 +1898,32 @@ static void lio_tpg_release_fabric_acl(
static int lio_tpg_shutdown_session(struct se_session *se_sess)
{
struct iscsi_session *sess = se_sess->fabric_sess_ptr;
+ struct se_portal_group *se_tpg = se_sess->se_tpg;
+ bool local_lock = false;
+
+ if (!spin_is_locked(&se_tpg->session_lock)) {
+ spin_lock_irq(&se_tpg->session_lock);
+ local_lock = true;
+ }
spin_lock(&sess->conn_lock);
if (atomic_read(&sess->session_fall_back_to_erl0) ||
atomic_read(&sess->session_logout) ||
(sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
spin_unlock(&sess->conn_lock);
+ if (local_lock)
+ spin_unlock_irq(&sess->conn_lock);
return 0;
}
atomic_set(&sess->session_reinstatement, 1);
spin_unlock(&sess->conn_lock);
iscsit_stop_time2retain_timer(sess);
+ spin_unlock_irq(&se_tpg->session_lock);
+
iscsit_stop_session(sess, 1, 1);
+ if (!local_lock)
+ spin_lock_irq(&se_tpg->session_lock);
return 1;
}
This is a note to let you know that I have just added a patch titled iscsi-target: Fix potential dead-lock during node acl delete to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt24. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ---8<------------------------------------------------------------ From 035d3e188204b453ac84c9a3601ef8357ffd3881 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger <nab@linux-iscsi.org> Date: Tue, 19 Jan 2016 16:15:27 -0800 Subject: iscsi-target: Fix potential dead-lock during node acl delete commit 26a99c19f810b2593410899a5b304b21b47428a6 upstream. This patch is a iscsi-target specific bug-fix for a dead-lock that can occur during explicit struct se_node_acl->acl_group se_session deletion via configfs rmdir(2), when iscsi-target time2retain timer is still active. It changes iscsi-target to obtain se_portal_group->session_lock internally using spin_in_locked() to check for the specific se_node_acl configfs shutdown rmdir(2) case. Note this patch is intended for stable, and the subsequent v4.5-rc patch converts target_core_tpg.c to use proper se_sess->sess_kref reference counting for both se_node_acl deletion + se_node_acl->queue_depth se_session restart. Reported-by:: Sagi Grimberg <sagig@mellanox.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Andy Grover <agrover@redhat.com> Cc: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/target/iscsi/iscsi_target_configfs.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)