[PATCH 14/16] qla2xxx: Fix duplicate switch's Nport ID entries

[Himanshu Madhani]

From: Quinn Tran <quinn.t...@cavium.com>

Current code relies on switch to provide a unique combination
of WWPN + NPORTID to tract an FC port.  This patch tries to detect
a case where switch data base can get corrupted where multiple WWPNs
can have the same Nport ID.  The 1st Nport ID on the list will be
kept while the duplicate Nport ID will be discard.

Signed-off-by: Quinn Tran <quinn.t...@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madh...@cavium.com>
---
 drivers/scsi/qla2xxx/qla_gs.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/qla2xxx/qla_gs.c b/drivers/scsi/qla2xxx/qla_gs.c
index 56a80c6e50e3..84e234c1f302 100644
--- a/drivers/scsi/qla2xxx/qla_gs.c
+++ b/drivers/scsi/qla2xxx/qla_gs.c
@@ -3619,9 +3619,10 @@ void qla24xx_async_gnnft_done(scsi_qla_host_t *vha, 
srb_t *sp)
        fc_port_t *fcport;
        u32 i, rc;
        bool found;
-       struct fab_scan_rp *rp;
+       struct fab_scan_rp *rp, *trp;
        unsigned long flags;
        u8 recheck = 0;
+       u16 dup = 0, dup_cnt = 0;
 
        ql_dbg(ql_dbg_disc, vha, 0xffff,
            "%s enter\n", __func__);
@@ -3652,6 +3653,7 @@ void qla24xx_async_gnnft_done(scsi_qla_host_t *vha, srb_t 
*sp)
 
        for (i = 0; i < vha->hw->max_fibre_devices; i++) {
                u64 wwn;
+               int k;
 
                rp = &vha->scan.l[i];
                found = false;
@@ -3660,6 +3662,20 @@ void qla24xx_async_gnnft_done(scsi_qla_host_t *vha, 
srb_t *sp)
                if (wwn == 0)
                        continue;
 
+               /* Remove duplicate NPORT ID entries from switch data base */
+               for (k = i + 1; k < vha->hw->max_fibre_devices; k++) {
+                       trp = &vha->scan.l[k];
+                       if (rp->id.b24 == trp->id.b24) {
+                               dup = 1;
+                               dup_cnt++;
+                               ql_dbg(ql_dbg_disc + ql_dbg_verbose,
+                                   vha, 0xffff,
+                                   "Detected duplicate NPORT ID from switch 
data base: ID %06x WWN %8phN WWN %8phN\n",
+                                   rp->id.b24, rp->port_name, trp->port_name);
+                               memset(trp, 0, sizeof(*trp));
+                       }
+               }
+
                if (!memcmp(rp->port_name, vha->port_name, WWN_SIZE))
                        continue;
 
@@ -3699,6 +3715,12 @@ void qla24xx_async_gnnft_done(scsi_qla_host_t *vha, 
srb_t *sp)
                }
        }
 
+       if (dup) {
+               ql_log(ql_log_warn, vha, 0xffff,
+                   "Detected %d duplicate NPORT ID(s) from switch data base\n",
+                   dup_cnt);
+       }
+
        /*
         * Logout all previous fabric dev marked lost, except FCP2 devices.
         */
-- 
2.12.0