From: Nicholas Bellinger Date: Sun, 23 Oct 2016 21:28:15 +0000 (-0700) Subject: target: Don't BUG_ON during NodeACL dynamic -> explicit conversion X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=eb49824ca9c9fb1030cf9a6e51a89fa2471422fa;p=linux-beck.git target: Don't BUG_ON during NodeACL dynamic -> explicit conversion commit 391e2a6de9781e4906dd7e0b1cc097050bf43e11 upstream. 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 Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index 6b423485c5d6..ea9617c7b403 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -351,7 +351,15 @@ 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);