| From 391e2a6de9781e4906dd7e0b1cc097050bf43e11 Mon Sep 17 00:00:00 2001 |
| From: Nicholas Bellinger <nab@linux-iscsi.org> |
| Date: Sun, 23 Oct 2016 14:28:15 -0700 |
| Subject: target: Don't BUG_ON during NodeACL dynamic -> explicit conversion |
| |
| From: Nicholas Bellinger <nab@linux-iscsi.org> |
| |
| 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 <ben.estrabaud@mpstor.com> |
| Cc: Benjamin ESTRABAUD <ben.estrabaud@mpstor.com> |
| Reviewed-by: Christoph Hellwig <hch@lst.de> |
| Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/target/target_core_device.c | 10 +++++++++- |
| 1 file changed, 9 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/target/target_core_device.c |
| +++ b/drivers/target/target_core_device.c |
| @@ -362,7 +362,15 @@ 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); |