From 391e2a6de9781e4906dd7e0b1cc097050bf43e11 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Sun, 23 Oct 2016 14:28:15 -0700 Subject: [PATCH] target: Don't BUG_ON during NodeACL dynamic -> explicit conversion After the v4.2+ RCU conversion to se_node_acl->lun_entry_hlist, a BUG_ON() was added in core_enable_device_list_for_node() to detect when the located orig->se_lun_acl contains an existing se_lun_acl pointer reference. However, this scenario can happen when a dynamically generated NodeACL is being converted to an explicit NodeACL, when the explicit NodeACL contains a different LUN mapping than the default provided by the WWN endpoint. So instead of triggering BUG_ON(), go ahead and fail instead following the original pre RCU conversion logic. Reported-by: Benjamin ESTRABAUD Cc: Benjamin ESTRABAUD Reviewed-by: Christoph Hellwig Cc: stable@vger.kernel.org # 4.2+ Signed-off-by: Nicholas Bellinger --- drivers/target/target_core_device.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 1ebd13ef7bd3..26929c44d703 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -352,7 +352,15 @@ int core_enable_device_list_for_node( kfree(new); return -EINVAL; } - BUG_ON(orig->se_lun_acl != NULL); + if (orig->se_lun_acl != NULL) { + pr_warn_ratelimited("Detected existing explicit" + " se_lun_acl->se_lun_group reference for %s" + " mapped_lun: %llu, failing\n", + nacl->initiatorname, mapped_lun); + mutex_unlock(&nacl->lun_entry_mutex); + kfree(new); + return -EINVAL; + } rcu_assign_pointer(new->se_lun, lun); rcu_assign_pointer(new->se_lun_acl, lun_acl);