[PATCH v4 06/15] scsi: core: Query the Block Limits Extension VPD page

Bart Van Assche
2023-11-14T21:42:21Z

Parse the Reduced Stream Control Supported (RSCS) bit from the block
limits extension VPD page. The RSCS bit is defined in SBC-5 r05
(https://www.t10.org/cgi-bin/ac.pl?t=f&f=sbc5r05.pdf).

Reviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/scsi/scsi.c | 2 ++
drivers/scsi/scsi_sysfs.c | 10 ++++++++++
drivers/scsi/sd.c | 13 +++++++++++++
drivers/scsi/sd.h | 1 +
include/scsi/scsi_device.h | 1 +
5 files changed, 27 insertions(+)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 76d369343c7a..74cc3369dd8d 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -499,6 +499,8 @@ void scsi_attach_vpd(struct scsi_device *sdev)
scsi_update_vpd_page(sdev, 0xb1, &sdev->vpd_pgb1);
if (vpd_buf->data[i] == 0xb2)
scsi_update_vpd_page(sdev, 0xb2, &sdev->vpd_pgb2);
+ if (vpd_buf->data[i] == 0xb7)
+ scsi_update_vpd_page(sdev, 0xb7, &sdev->vpd_pgb7);
}
kfree(vpd_buf);
}
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 24f6eefb6803..93652a786a46 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -449,6 +449,7 @@ static void scsi_device_dev_release(struct device *dev)
struct scsi_vpd *vpd_pg80 = NULL, *vpd_pg83 = NULL;
struct scsi_vpd *vpd_pg0 = NULL, *vpd_pg89 = NULL;
struct scsi_vpd *vpd_pgb0 = NULL, *vpd_pgb1 = NULL, *vpd_pgb2 = NULL;
+ struct scsi_vpd *vpd_pgb7 = NULL;
unsigned long flags;

might_sleep();
@@ -494,6 +495,8 @@ static void scsi_device_dev_release(struct device *dev)
lockdep_is_held(&sdev->inquiry_mutex));
vpd_pgb2 = rcu_replace_pointer(sdev->vpd_pgb2, vpd_pgb2,
lockdep_is_held(&sdev->inquiry_mutex));
+ vpd_pgb7 = rcu_replace_pointer(sdev->vpd_pgb7, vpd_pgb7,
+ lockdep_is_held(&sdev->inquiry_mutex));
mutex_unlock(&sdev->inquiry_mutex);

if (vpd_pg0)
@@ -510,6 +513,8 @@ static void scsi_device_dev_release(struct device *dev)
kfree_rcu(vpd_pgb1, rcu);
if (vpd_pgb2)
kfree_rcu(vpd_pgb2, rcu);
+ if (vpd_pgb7)
+ kfree_rcu(vpd_pgb7, rcu);
kfree(sdev->inquiry);
kfree(sdev);

@@ -921,6 +926,7 @@ sdev_vpd_pg_attr(pg89);
sdev_vpd_pg_attr(pgb0);
sdev_vpd_pg_attr(pgb1);
sdev_vpd_pg_attr(pgb2);
+sdev_vpd_pg_attr(pgb7);
sdev_vpd_pg_attr(pg0);

static ssize_t show_inquiry(struct file *filep, struct kobject *kobj,
@@ -1295,6 +1301,9 @@ static umode_t scsi_sdev_bin_attr_is_visible(struct kobject *kobj,
if (attr == &dev_attr_vpd_pgb2 && !sdev->vpd_pgb2)
return 0;

+ if (attr == &dev_attr_vpd_pgb7 && !sdev->vpd_pgb7)
+ return 0;
+
return S_IRUGO;
}

@@ -1347,6 +1356,7 @@ static struct bin_attribute *scsi_sdev_bin_attrs[] = {
&dev_attr_vpd_pgb0,
&dev_attr_vpd_pgb1,
&dev_attr_vpd_pgb2,
+ &dev_attr_vpd_pgb7,
&dev_attr_inquiry,
NULL
};
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 530918cbfce2..56c4310a741b 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3103,6 +3103,18 @@ static void sd_read_block_limits(struct scsi_disk *sdkp)
rcu_read_unlock();
}

+/* Parse the Block Limits Extension VPD page (0xb7) */
+static void sd_read_block_limits_ext(struct scsi_disk *sdkp)
+{
+ struct scsi_vpd *vpd;
+
+ rcu_read_lock();
+ vpd = rcu_dereference(sdkp->device->vpd_pgb7);
+ if (vpd && vpd->len >= 2)
+ sdkp->rscs = vpd->data[5] & 1;
+ rcu_read_unlock();
+}
+
/**
* sd_read_block_characteristics - Query block dev. characteristics
* @sdkp: disk to query
@@ -3457,6 +3469,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
if (scsi_device_supports_vpd(sdp)) {
sd_read_block_provisioning(sdkp);
sd_read_block_limits(sdkp);
+ sd_read_block_limits_ext(sdkp);
sd_read_block_characteristics(sdkp);
sd_zbc_read_zones(sdkp, buffer);
sd_read_cpr(sdkp);
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 409dda5350d1..e4539122f2a2 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -151,6 +151,7 @@ struct scsi_disk {
unsigned urswrz : 1;
unsigned security : 1;
unsigned ignore_medium_access_errors : 1;
+ bool rscs : 1; /* reduced stream control support */
};
#define to_scsi_disk(obj) container_of(obj, struct scsi_disk, disk_dev)

diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 10480eb582b2..a1588f3965f9 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -153,6 +153,7 @@ struct scsi_device {
struct scsi_vpd __rcu *vpd_pgb0;
struct scsi_vpd __rcu *vpd_pgb1;
struct scsi_vpd __rcu *vpd_pgb2;
+ struct scsi_vpd __rcu *vpd_pgb7;

struct scsi_target *sdev_target;