[SCSI] iscsi: fix session refcouting

iscsi_tcp and iser cannot be rmmod from the kernel when sessions
are running because session removal is driven from userspace. For
those modules we get a module reference when a session is
created then drop it when the session is removed.

For qla4xxx, they can jsut remove the sessions from the pci remove
function like normal HW drivers, so this patch moves the module
reference from the transport class functions shared by all
drivers to the libiscsi functions only used be software iscsi
modules.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 7c76a989b21875306500d7b5b59981f6e8d103fb..7e6e031cc41bf0a09541d55bc6f6bb6f9850178c 100644 (file)
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -1287,13 +1287,18 @@ iscsi_session_setup(struct iscsi_transport *iscsit,
        if (scsi_add_host(shost, NULL))
                goto add_host_fail;
 
+       if (!try_module_get(iscsit->owner))
+               goto cls_session_fail;
+
        cls_session = iscsi_create_session(shost, iscsit, 0);
        if (!cls_session)
-               goto cls_session_fail;
+               goto module_put;
        *(unsigned long*)shost->hostdata = (unsigned long)cls_session;
 
        return cls_session;
 
+module_put:
+       module_put(iscsit->owner);
 cls_session_fail:
        scsi_remove_host(shost);
 add_host_fail:
@@ -1325,6 +1330,7 @@ void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
 
        iscsi_destroy_session(cls_session);
        scsi_host_put(shost);
+       module_put(cls_session->transport->owner);
 }
 EXPORT_SYMBOL_GPL(iscsi_session_teardown);
 

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 147c854e1d4dbb15404d4604d0927597d9a05d23..8717ff51ba4b9c70dcb23e7636b087a3bfe59725 100644 (file)
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -228,13 +228,11 @@ static struct iscsi_cls_conn *iscsi_conn_lookup(uint32_t sid, uint32_t cid)
 static void iscsi_session_release(struct device *dev)
 {
        struct iscsi_cls_session *session = iscsi_dev_to_session(dev);
-       struct iscsi_transport *transport = session->transport;
        struct Scsi_Host *shost;
 
        shost = iscsi_session_to_shost(session);
        scsi_host_put(shost);
        kfree(session);
-       module_put(transport->owner);
 }
 
 static int iscsi_is_session_dev(const struct device *dev)
@@ -305,13 +303,11 @@ iscsi_create_session(struct Scsi_Host *shost,
        struct iscsi_cls_session *session;
        int err;
 
-       if (!try_module_get(transport->owner))
-               return NULL;
-
        session = kzalloc(sizeof(*session) + transport->sessiondata_size,
                          GFP_KERNEL);
        if (!session)
-               goto module_put;
+               return NULL;
+
        session->transport = transport;
        session->recovery_tmo = 120;
        INIT_WORK(&session->recovery_work, session_recovery_timedout, session);
@@ -349,8 +345,6 @@ iscsi_create_session(struct Scsi_Host *shost,
 
 free_session:
        kfree(session);
-module_put:
-       module_put(transport->owner);
        return NULL;
 }