Offlining a SATA device connected to a hisi SAS controller and then
scanning the host will result in detecting 255 non-existent devices:
# lsscsi
[2:0:0:0] disk ATA Samsung SSD 860 2B6Q /dev/sda
[2:0:1:0] disk ATA WDC WD2003FYYS-3 1D01 /dev/sdb
[2:0:2:0] disk SEAGATE ST600MM0006 B001 /dev/sdc
# echo "offline" > /sys/block/sdb/device/state
# echo "- - -" > /sys/class/scsi_host/host2/scan
# lsscsi
[2:0:0:0] disk ATA Samsung SSD 860 2B6Q /dev/sda
[2:0:1:0] disk ATA WDC WD2003FYYS-3 1D01 /dev/sdb
[2:0:1:1] disk ATA WDC WD2003FYYS-3 1D01 /dev/sdh
...
[2:0:1:255] disk ATA WDC WD2003FYYS-3 1D01 /dev/sdjb
After a REPORT LUN command issued to the offline device fails, the SCSI
midlayer tries to do a sequential scan of all devices whose LUN number is
not 0. However, SATA does not support LUN numbers at all.
Introduce a generic sas_slave_alloc() handler which will return -ENXIO for
SATA devices if the requested LUN number is larger than 0 and make libsas
drivers use this function as their .slave_alloc callback.
Link: https://lore.kernel.org/r/20210622034037.1467088-1-yuyufen@huawei.com
Reported-by: Wu Bo <wubo40@huawei.com>
Suggested-by: John Garry <john.garry@huawei.com>
Reviewed-by: John Garry <john.garry@huawei.com>
Reviewed-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
49da96d779