scsi: libsas: add lun number check in .slave_alloc callback

hulk inclusion
category: bugfix
bugzilla: 51878
CVE: NA

-------------------------------------------------

We found that offline a sata device on hisi sas control and then
scanning the host can probe 255 non-existent devices into system.

[root@localhost ~]# 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

 1) echo "offline" > /sys/block/sdb/device/state
 2) echo "- - -" > /sys/class/scsi_host/host2/scan

Then, we can see another 255 non-existent devices in system:
  [root@localhost ~]# 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 REPORT LUN command issued to the offline device fail, it tries
to do a sequential scan and probe all devices whose lun is not 0
successfully.

To fix the problem, we try to do same things as commit 2fc62e2a
("[SCSI] libsas: disable scanning lun > 0 on ata devices"), which
will prevent the device whose lun number is not zero probe into system.
Reported-by: NWu Bo <wubo40@huawei.com>
Suggested-by: NJohn Garry <john.garry@huawei.com>
Signed-off-by: NYufen Yu <yuyufen@huawei.com>
Reviewed-by: NJason Yan <yanaijie@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/scsi/aic94xx/aic94xx_init.c

@@ -71,6 +71,7 @@ static struct scsi_host_template aic94xx_sht = {
 	.use_clustering		= ENABLE_CLUSTERING,
 	.eh_device_reset_handler	= sas_eh_device_reset_handler,
 	.eh_target_reset_handler	= sas_eh_target_reset_handler,
+	.slave_alloc		= sas_slave_alloc,
 	.target_destroy		= sas_target_destroy,
 	.ioctl			= sas_ioctl,
 	.track_queue_depth	= 1,

drivers/scsi/hisi_sas/hisi_sas_v1_hw.c

@@ -1785,6 +1785,7 @@ static struct scsi_host_template sht_v1_hw = {
 	.max_sectors		= SCSI_DEFAULT_MAX_SECTORS,
 	.eh_device_reset_handler = sas_eh_device_reset_handler,
 	.eh_target_reset_handler = sas_eh_target_reset_handler,
+	.slave_alloc		= sas_slave_alloc,
 	.target_destroy		= sas_target_destroy,
 	.ioctl			= sas_ioctl,
 	.shost_attrs		= host_attrs_v1_hw,

drivers/scsi/hisi_sas/hisi_sas_v2_hw.c

@@ -3603,6 +3603,7 @@ static struct scsi_host_template sht_v2_hw = {
 	.max_sectors		= SCSI_DEFAULT_MAX_SECTORS,
 	.eh_device_reset_handler = sas_eh_device_reset_handler,
 	.eh_target_reset_handler = sas_eh_target_reset_handler,
+	.slave_alloc		= sas_slave_alloc,
 	.target_destroy		= sas_target_destroy,
 	.ioctl			= sas_ioctl,
 	.shost_attrs		= host_attrs_v2_hw,

drivers/scsi/hisi_sas/hisi_sas_v3_hw.c

@@ -3269,6 +3269,7 @@ static struct scsi_host_template sht_v3_hw = {
 	.max_sectors		= SCSI_DEFAULT_MAX_SECTORS,
 	.eh_device_reset_handler = sas_eh_device_reset_handler,
 	.eh_target_reset_handler = sas_eh_target_reset_handler,
+	.slave_alloc		= sas_slave_alloc,
 	.target_destroy		= sas_target_destroy,
 	.ioctl			= sas_ioctl,
 	.shost_attrs		= host_attrs_v3_hw,

drivers/scsi/isci/init.c

@@ -167,6 +167,7 @@ static struct scsi_host_template isci_sht = {
 	.eh_abort_handler		= sas_eh_abort_handler,
 	.eh_device_reset_handler        = sas_eh_device_reset_handler,
 	.eh_target_reset_handler        = sas_eh_target_reset_handler,
+	.slave_alloc			= sas_slave_alloc,
 	.target_destroy			= sas_target_destroy,
 	.ioctl				= sas_ioctl,
 	.shost_attrs			= isci_host_attrs,

drivers/scsi/libsas/sas_scsi_host.c

@@ -844,6 +844,14 @@ struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
 	return found_dev;
 }
 
+int sas_slave_alloc(struct scsi_device *sdev)
+{
+	if (dev_is_sata(sdev_to_domain_dev(sdev)) && sdev->lun)
+		return -ENXIO;
+
+	return 0;
+}
+
 int sas_target_alloc(struct scsi_target *starget)
 {
 	struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
@@ -988,5 +996,6 @@ EXPORT_SYMBOL_GPL(sas_task_abort);
 EXPORT_SYMBOL_GPL(sas_phy_reset);
 EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
 EXPORT_SYMBOL_GPL(sas_eh_target_reset_handler);
+EXPORT_SYMBOL_GPL(sas_slave_alloc);
 EXPORT_SYMBOL_GPL(sas_target_destroy);
 EXPORT_SYMBOL_GPL(sas_ioctl);

drivers/scsi/mvsas/mv_init.c

@@ -49,6 +49,7 @@ static struct scsi_host_template mvs_sht = {
 	.module			= THIS_MODULE,
 	.name			= DRV_NAME,
 	.queuecommand		= sas_queuecommand,
+	.slave_alloc		= sas_slave_alloc,
 	.target_alloc		= sas_target_alloc,
 	.slave_configure	= sas_slave_configure,
 	.scan_finished		= mvs_scan_finished,

drivers/scsi/pm8001/pm8001_init.c

@@ -74,6 +74,7 @@ static struct scsi_host_template pm8001_sht = {
 	.module			= THIS_MODULE,
 	.name			= DRV_NAME,
 	.queuecommand		= sas_queuecommand,
+	.slave_alloc		= sas_slave_alloc,
 	.target_alloc		= sas_target_alloc,
 	.slave_configure	= sas_slave_configure,
 	.scan_finished		= pm8001_scan_finished,