firewire: fw-sbp2: logout and login after failed reconnect

If fw-sbp2 was too late with requesting the reconnect, the target would
reject this.  In this case, log out before attempting the reconnect.
Else several firmwares will deny the re-login because they somehow
didn't invalidate the old login.

Also, don't retry reconnects in this situation.  The retries won't
succeed either.

These changes improve chances for successful re-login and shorten the
period during which the logical unit is inaccessible.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index 914170bb50a8..80ab65161750 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -710,6 +710,11 @@ static void sbp2_login(struct work_struct *work)
         node_id       = device->node_id;
         local_node_id = device->card->node_id;
 
+        /* If this is a re-login attempt, log out, or we might be rejected. */
+        if (lu->sdev)
+                sbp2_send_management_orb(lu, device->node_id, generation,
+                                SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
+
         if (sbp2_send_management_orb(lu, node_id, generation,
                                 SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
                 if (lu->retries++ < 5)
@@ -997,9 +1002,17 @@ static void sbp2_reconnect(struct work_struct *work)
         if (sbp2_send_management_orb(lu, node_id, generation,
                                      SBP2_RECONNECT_REQUEST,
                                      lu->login_id, NULL) < 0) {
-                if (lu->retries++ >= 5) {
+                /*
+                 * If reconnect was impossible even though we are in the
+                 * current generation, fall back and try to log in again.
+                 *
+                 * We could check for "Function rejected" status, but
+                 * looking at the bus generation as simpler and more general.
+                 */
+                smp_rmb(); /* get current card generation */
+                if (generation == device->card->generation ||
+                    lu->retries++ >= 5) {
                         fw_error("%s: failed to reconnect\n", tgt->bus_id);
-                        /* Fall back and try to log in again. */
                         lu->retries = 0;
                         PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
                 }