[SCSI] iscsi class, iscsi_tcp, iser, qla4xxx: add netdevname sysfs attr

iSCSI must support software iscsi (iscsi_tcp, iser), hardware iscsi (qla4xxx),
and partial offload (broadcom). To be able to allow each stack or driver
or port (virtual or physical) to be able to log into the same target portal
we use the initiator tuple [[HWADDRESS | NETDEVNAME], INITIATOR_NAME] and
the target tuple [TARGETNAME, CONN_ADDRESS, CONN_PORT] to id a session.
This patch adds the netdev name, which is used by software iscsi when
it binds a session to a netdevice using the SO_BINDTODEVICE sock opt.
It cannot use HWADDRESS because if someone did vlans then the same netdevice
will have the same mac and the initiator,target id will not be unique.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: David C Somayajulu <david.somayajulu@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 1632866f52cc..865dd5739f0e 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -1483,6 +1483,7 @@ void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
         kfree(session->username);
         kfree(session->username_in);
         kfree(session->targetname);
+        kfree(session->netdev);
         kfree(session->hwaddress);
         kfree(session->initiatorname);
 
@@ -2040,6 +2041,12 @@ int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
         int len;
 
         switch (param) {
+        case ISCSI_HOST_PARAM_NETDEV_NAME:
+                if (!session->netdev)
+                        len = sprintf(buf, "%s\n", "default");
+                else
+                        len = sprintf(buf, "%s\n", session->netdev);
+                break;
         case ISCSI_HOST_PARAM_HWADDRESS:
                 if (!session->hwaddress)
                         len = sprintf(buf, "%s\n", "default");
@@ -2067,6 +2074,10 @@ int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
         struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
 
         switch (param) {
+        case ISCSI_HOST_PARAM_NETDEV_NAME:
+                if (!session->netdev)
+                        session->netdev = kstrdup(buf, GFP_KERNEL);
+                break;
         case ISCSI_HOST_PARAM_HWADDRESS:
                 if (!session->hwaddress)
                         session->hwaddress = kstrdup(buf, GFP_KERNEL);