firewire: fw-sbp2: don't retry login or reconnect after unplug

If a device is being unplugged while fw-sbp2 had a login or reconnect on
schedule, it would take about half a minute to shut the fw_unit down:

    Jan 27 18:34:54 stein firewire_sbp2: logged in to fw2.0 LUN 0000 (0 retries)
    <unplug>
    Jan 27 18:34:59 stein firewire_sbp2: sbp2_scsi_abort
    Jan 27 18:34:59 stein scsi 25:0:0:0: Device offlined - not ready after error recovery
    Jan 27 18:35:01 stein firewire_sbp2: orb reply timed out, rcode=0x11
    Jan 27 18:35:06 stein firewire_sbp2: orb reply timed out, rcode=0x11
    Jan 27 18:35:12 stein firewire_sbp2: orb reply timed out, rcode=0x11
    Jan 27 18:35:17 stein firewire_sbp2: orb reply timed out, rcode=0x11
    Jan 27 18:35:22 stein firewire_sbp2: orb reply timed out, rcode=0x11
    Jan 27 18:35:27 stein firewire_sbp2: orb reply timed out, rcode=0x11
    Jan 27 18:35:32 stein firewire_sbp2: orb reply timed out, rcode=0x11
    Jan 27 18:35:32 stein firewire_sbp2: failed to login to fw2.0 LUN 0000
    Jan 27 18:35:32 stein firewire_sbp2: released fw2.0

After this patch, typically only a few seconds spent in __scsi_add_device
remain:

    Jan 27 19:05:50 stein firewire_sbp2: logged in to fw2.0 LUN 0000 (0 retries)
    <unplug>
    Jan 27 19:05:56 stein firewire_sbp2: sbp2_scsi_abort
    Jan 27 19:05:56 stein scsi 33:0:0:0: Device offlined - not ready after error recovery
    Jan 27 19:05:56 stein firewire_sbp2: released fw2.0

The benefit of this is less noise in the syslog.  It furthermore avoids
a few wasted CPU cycles and needlessly prolonged lifetime of a few
driver objects.

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

1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index a15e3c7d21d3..72fddf5a12a3 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -499,6 +499,9 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
         unsigned int timeout;
         int retval = -ENOMEM;
 
+        if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
+                return 0;
+
         orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
         if (orb == NULL)
                 return -ENOMEM;
@@ -619,16 +622,13 @@ static void sbp2_release_target(struct kref *kref)
         struct sbp2_logical_unit *lu, *next;
         struct Scsi_Host *shost =
                 container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
-        struct fw_device *device = fw_device(tgt->unit->device.parent);
 
         list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
                 if (lu->sdev)
                         scsi_remove_device(lu->sdev);
 
-                if (!fw_device_is_shutdown(device))
-                        sbp2_send_management_orb(lu, tgt->node_id,
-                                        lu->generation, SBP2_LOGOUT_REQUEST,
-                                        lu->login_id, NULL);
+                sbp2_send_management_orb(lu, tgt->node_id, lu->generation,
+                                SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 
                 fw_core_remove_address_handler(&lu->address_handler);
                 list_del(&lu->link);
@@ -673,6 +673,9 @@ static void sbp2_login(struct work_struct *work)
         struct sbp2_login_response response;
         int generation, node_id, local_node_id;
 
+        if (fw_device_is_shutdown(device))
+                goto out;
+
         generation    = device->generation;
         smp_rmb();    /* node_id must not be older than generation */
         node_id       = device->node_id;
@@ -944,6 +947,9 @@ static void sbp2_reconnect(struct work_struct *work)
         struct fw_device *device = fw_device(unit->device.parent);
         int generation, node_id, local_node_id;
 
+        if (fw_device_is_shutdown(device))
+                goto out;
+
         generation    = device->generation;
         smp_rmb();    /* node_id must not be older than generation */
         node_id       = device->node_id;