[SCSI] qla2xxx: Explicitly tear-down vports during PCI remove_one().

During internal testing, we've seen issues (hangs) with the
'deferred' vport tear-down-processing typically accompanied with
the fc_remove_host() call.  This is due to the current
implementation's back-end vport handling being performed by the
physical-HA's DPC thread where premature shutdown could lead to
latent vport requests without a processor.

This should also address a problem reported by Gal Rosen
(http://marc.info/?l=linux-scsi&m=121731664417358&w=2) where the
driver would attempt to awaken a previously torn-down DPC thread
from interrupt context by implicitly calling wake_up_process()
rather than the driver's qla2xxx_wake_dpc() helper.  Rather, than
reshuffle the remove_one() device-removal code, during unload,
depend on the driver's timer to wake-up the DPC process, by
limiting wake-ups based on an 'unloading' flag.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

3 files changed, 12 insertions, 4 deletions

diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 6da31ba94404..94a720eabfd8 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -2237,6 +2237,7 @@ typedef struct scsi_qla_host {
 #define REGISTER_FDMI_NEEDED    26
 #define FCPORT_UPDATE_NEEDED    27
 #define VP_DPC_NEEDED           28      /* wake up for VP dpc handling */
+#define UNLOADING               29
 
         uint32_t        device_flags;
 #define DFLG_LOCAL_DEVICES              BIT_0
diff --git a/drivers/scsi/qla2xxx/qla_mbx.c b/drivers/scsi/qla2xxx/qla_mbx.c
index bc90d6b8d0a0..813bc7784c0a 100644
--- a/drivers/scsi/qla2xxx/qla_mbx.c
+++ b/drivers/scsi/qla2xxx/qla_mbx.c
@@ -2686,7 +2686,7 @@ qla24xx_report_id_acquisition(scsi_qla_host_t *ha,
                 set_bit(VP_IDX_ACQUIRED, &vha->vp_flags);
                 set_bit(VP_DPC_NEEDED, &ha->dpc_flags);
 
-                wake_up_process(ha->dpc_thread);
+                qla2xxx_wake_dpc(ha);
         }
 }
 
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index e0880ad243be..26afe44265c7 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -1775,10 +1775,15 @@ probe_out:
 static void
 qla2x00_remove_one(struct pci_dev *pdev)
 {
-        scsi_qla_host_t *ha;
+        scsi_qla_host_t *ha, *vha, *temp;
 
         ha = pci_get_drvdata(pdev);
 
+        list_for_each_entry_safe(vha, temp, &ha->vp_list, vp_list)
+                fc_vport_terminate(vha->fc_vport);
+
+        set_bit(UNLOADING, &ha->dpc_flags);
+
         qla2x00_dfs_remove(ha);
 
         qla84xx_put_chip(ha);
@@ -2450,8 +2455,10 @@ qla2x00_do_dpc(void *data)
 void
 qla2xxx_wake_dpc(scsi_qla_host_t *ha)
 {
-        if (ha->dpc_thread)
-                wake_up_process(ha->dpc_thread);
+        struct task_struct *t = ha->dpc_thread;
+
+        if (!test_bit(UNLOADING, &ha->dpc_flags) && t)
+                wake_up_process(t);
 }
 
 /*