[PATCH v3 3/5] scsi: libsas: always unregister the old device if going to discover new

From: Jason Yan
Date: Mon Sep 24 2018 - 22:43:32 EST


If we went into sas_rediscover_dev() the attached_sas_addr was already
insured not to be zero. So it's unnecessary to check if the
attached_sas_addr is zero.

And although if the sas address is not changed, we always have to
unregister the old device when we are going to register a new one. We
cannot just leave the device there and bring up the new.

Signed-off-by: Jason Yan <yanaijie@xxxxxxxxxx>
CC: chenxiang <chenxiang66@xxxxxxxxxxxxx>
CC: John Garry <john.garry@xxxxxxxxxx>
CC: Johannes Thumshirn <jthumshirn@xxxxxxx>
CC: Ewan Milne <emilne@xxxxxxxxxx>
CC: Christoph Hellwig <hch@xxxxxx>
CC: Tomas Henzl <thenzl@xxxxxxxxxx>
CC: Dan Williams <dan.j.williams@xxxxxxxxx>
CC: Hannes Reinecke <hare@xxxxxxxx>
Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
---
drivers/scsi/libsas/sas_expander.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index fadc99cb60df..52222940d398 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -2054,14 +2054,11 @@ static int sas_rediscover_dev(struct domain_device *dev, int phy_id, bool last)
return res;
}

- /* delete the old link */
- if (SAS_ADDR(phy->attached_sas_addr) &&
- SAS_ADDR(sas_addr) != SAS_ADDR(phy->attached_sas_addr)) {
- SAS_DPRINTK("ex %016llx phy 0x%x replace %016llx\n",
- SAS_ADDR(dev->sas_addr), phy_id,
- SAS_ADDR(phy->attached_sas_addr));
- sas_unregister_devs_sas_addr(dev, phy_id, last);
- }
+ /* we always have to delete the old device when we went here */
+ SAS_DPRINTK("ex %016llx phy 0x%x replace %016llx\n",
+ SAS_ADDR(dev->sas_addr), phy_id,
+ SAS_ADDR(phy->attached_sas_addr));
+ sas_unregister_devs_sas_addr(dev, phy_id, last);

return sas_discover_new(dev, phy_id);
}
--
2.14.4