[PATCH AUTOSEL 4.19 36/39] scsi: libsas: Add LUN number check in .slave_alloc callback

[Sasha Levin]

From: Yufen Yu <yuyufen@xxxxxxxxxx>

[ Upstream commit 49da96d77938db21864dae6b7736b71e96c1d203 ]

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@xxxxxxxxxx
Reported-by: Wu Bo <wubo40@xxxxxxxxxx>
Suggested-by: John Garry <john.garry@xxxxxxxxxx>
Reviewed-by: John Garry <john.garry@xxxxxxxxxx>
Reviewed-by: Jason Yan <yanaijie@xxxxxxxxxx>
Signed-off-by: Yufen Yu <yuyufen@xxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/scsi/aic94xx/aic94xx_init.c    | 1 +
 drivers/scsi/hisi_sas/hisi_sas_v1_hw.c | 1 +
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c | 1 +
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 1 +
 drivers/scsi/isci/init.c               | 1 +
 drivers/scsi/libsas/sas_scsi_host.c    | 9 +++++++++
 drivers/scsi/mvsas/mv_init.c           | 1 +
 drivers/scsi/pm8001/pm8001_init.c      | 1 +
 8 files changed, 16 insertions(+)

diff --git a/drivers/scsi/aic94xx/aic94xx_init.c b/drivers/scsi/aic94xx/aic94xx_init.c
index 702da909cee5..ad8a65ab489c 100644
--- a/drivers/scsi/aic94xx/aic94xx_init.c
+++ b/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,
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
index 8aa3222fe486..fea26edd505e 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
@@ -1814,6 +1814,7 @@ static struct scsi_host_template sht_v1_hw = {
 	.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,
 	.shost_attrs		= host_attrs,
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
index ebc984ffe6a2..7be943197604 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
@@ -3565,6 +3565,7 @@ static struct scsi_host_template sht_v2_hw = {
 	.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,
 	.shost_attrs		= host_attrs,
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index ce2f232b3df3..16b7ea556118 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -2115,6 +2115,7 @@ static struct scsi_host_template sht_v3_hw = {
 	.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,
 	.shost_attrs		= host_attrs,
diff --git a/drivers/scsi/isci/init.c b/drivers/scsi/isci/init.c
index dde84f744313..07de94ea3819 100644
--- a/drivers/scsi/isci/init.c
+++ b/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,
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 33229348dcb6..316a11183555 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -942,6 +942,14 @@ void sas_task_abort(struct sas_task *task)
 	}
 }
 
+int sas_slave_alloc(struct scsi_device *sdev)
+{
+	if (dev_is_sata(sdev_to_domain_dev(sdev)) && sdev->lun)
+		return -ENXIO;
+
+	return 0;
+}
+
 void sas_target_destroy(struct scsi_target *starget)
 {
 	struct domain_device *found_dev = starget->hostdata;
@@ -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);
diff --git a/drivers/scsi/mvsas/mv_init.c b/drivers/scsi/mvsas/mv_init.c
index 8c91637cd598..98d6608068ab 100644
--- a/drivers/scsi/mvsas/mv_init.c
+++ b/drivers/scsi/mvsas/mv_init.c
@@ -62,6 +62,7 @@ static struct scsi_host_template mvs_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,
 	.shost_attrs		= mvst_host_attrs,
diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index 1d59d7447a1c..9547cf516d39 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -87,6 +87,7 @@ static struct scsi_host_template pm8001_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,
 	.shost_attrs		= pm8001_host_attrs,
-- 
2.30.2