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Commit 391e2a6d authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

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: default avatarBenjamin ESTRABAUD <ben.estrabaud@mpstor.com>
Cc: Benjamin ESTRABAUD <ben.estrabaud@mpstor.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent d5adbfcd

drivers/target/target_core_device.c

+9 −1
Original line number Diff line number Diff line
@@ -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);