[PATCH 06/20] ublk: support UBLK_PARAM_TYPE_INTEGRITY in device creation

Caleb Sander Mateos
2025-12-17T05:35:13Z

From: Stanley Zhang <stazhang@purestorage.com>

If the UBLK_PARAM_TYPE_INTEGRITY flag is set, validate the integrity
parameters and apply them to the blk_integrity limits.
UBLK_PARAM_TYPE_INTEGRITY requires CONFIG_BLK_DEV_INTEGRITY=y,
UBLK_F_USER_COPY, and metadata_size > 0. Reuse the block metadata ioctl
LBMD_PI_CAP_* and LBMD_PI_CSUM_* constants from the linux/fs.h UAPI
header for the flags and csum_type field values.
The struct ublk_param_integrity validations are based on the checks in
blk_validate_integrity_limits(). Any invalid parameters should be
rejected before being applied to struct blk_integrity.

Signed-off-by: Stanley Zhang <stazhang@purestorage.com>
[csander: add param validation]
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
drivers/block/ublk_drv.c | 92 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 91 insertions(+), 1 deletion(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 4da5d8ff1e1d..2893a9172220 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -42,10 +42,12 @@
#include <linux/mm.h>
#include <asm/page.h>
#include <linux/task_work.h>
#include <linux/namei.h>
#include <linux/kref.h>
+#include <linux/blk-integrity.h>
+#include <uapi/linux/fs.h>
#include <uapi/linux/ublk_cmd.h>

#define UBLK_MINORS (1U << MINORBITS)

#define UBLK_INVALID_BUF_IDX ((u16)-1)
@@ -81,11 +83,12 @@

/* All UBLK_PARAM_TYPE_* should be included here */
#define UBLK_PARAM_TYPE_ALL \
(UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD | \
UBLK_PARAM_TYPE_DEVT | UBLK_PARAM_TYPE_ZONED | \
- UBLK_PARAM_TYPE_DMA_ALIGN | UBLK_PARAM_TYPE_SEGMENT)
+ UBLK_PARAM_TYPE_DMA_ALIGN | UBLK_PARAM_TYPE_SEGMENT | \
+ UBLK_PARAM_TYPE_INTEGRITY)

struct ublk_uring_cmd_pdu {
/*
* Store requests in same batch temporarily for queuing them to
* daemon context.
@@ -613,10 +616,57 @@ static void ublk_dev_param_basic_apply(struct ublk_device *ub)
set_disk_ro(ub->ub_disk, true);

set_capacity(ub->ub_disk, p->dev_sectors);
}

+static int ublk_integrity_flags(u32 flags)
+{
+ int ret_flags = 0;
+
+ if (flags & LBMD_PI_CAP_INTEGRITY) {
+ flags &= ~LBMD_PI_CAP_INTEGRITY;
+ ret_flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
+ }
+ if (flags & LBMD_PI_CAP_REFTAG) {
+ flags &= ~LBMD_PI_CAP_REFTAG;
+ ret_flags |= BLK_INTEGRITY_REF_TAG;
+ }
+ return flags ? -EINVAL : ret_flags;
+}
+
+static int ublk_integrity_pi_tuple_size(u8 csum_type)
+{
+ switch (csum_type) {
+ case LBMD_PI_CSUM_NONE:
+ return 0;
+ case LBMD_PI_CSUM_IP:
+ case LBMD_PI_CSUM_CRC16_T10DIF:
+ return 8;
+ case LBMD_PI_CSUM_CRC64_NVME:
+ return 16;
+ default:
+ return -EINVAL;
+ }
+}
+
+static enum blk_integrity_checksum ublk_integrity_csum_type(u8 csum_type)
+{
+ switch (csum_type) {
+ case LBMD_PI_CSUM_NONE:
+ return BLK_INTEGRITY_CSUM_NONE;
+ case LBMD_PI_CSUM_IP:
+ return BLK_INTEGRITY_CSUM_IP;
+ case LBMD_PI_CSUM_CRC16_T10DIF:
+ return BLK_INTEGRITY_CSUM_CRC;
+ case LBMD_PI_CSUM_CRC64_NVME:
+ return BLK_INTEGRITY_CSUM_CRC64;
+ default:
+ WARN_ON_ONCE(1);
+ return BLK_INTEGRITY_CSUM_NONE;
+ }
+}
+
static int ublk_validate_params(const struct ublk_device *ub)
{
/* basic param is the only one which must be set */
if (ub->params.types & UBLK_PARAM_TYPE_BASIC) {
const struct ublk_param_basic *p = &ub->params.basic;
@@ -675,10 +725,35 @@ static int ublk_validate_params(const struct ublk_device *ub)
return -EINVAL;
if (p->max_segment_size < UBLK_MIN_SEGMENT_SIZE)
return -EINVAL;
}

+ if (ub->params.types & UBLK_PARAM_TYPE_INTEGRITY) {
+ const struct ublk_param_integrity *p = &ub->params.integrity;
+ int pi_tuple_size = ublk_integrity_pi_tuple_size(p->csum_type);
+ int flags = ublk_integrity_flags(p->flags);
+
+ if (!IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY))
+ return -EINVAL;
+ if (!ublk_dev_support_user_copy(ub))
+ return -EINVAL;
+ if (flags < 0)
+ return flags;
+ if (pi_tuple_size < 0)
+ return pi_tuple_size;
+ if (!p->metadata_size)
+ return -EINVAL;
+ if (p->csum_type == LBMD_PI_CSUM_NONE &&
+ (p->flags & LBMD_PI_CAP_REFTAG))
+ return -EINVAL;
+ if (p->pi_offset + pi_tuple_size > p->metadata_size)
+ return -EINVAL;
+ if (p->interval_exp < SECTOR_SHIFT ||
+ p->interval_exp > ub->params.basic.logical_bs_shift)
+ return -EINVAL;
+ }
+
return 0;
}

static void ublk_apply_params(struct ublk_device *ub)
{
@@ -2901,10 +2976,25 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub,
lim.seg_boundary_mask = ub->params.seg.seg_boundary_mask;
lim.max_segment_size = ub->params.seg.max_segment_size;
lim.max_segments = ub->params.seg.max_segments;
}

+ if (ub->params.types & UBLK_PARAM_TYPE_INTEGRITY) {
+ const struct ublk_param_integrity *p = &ub->params.integrity;
+ int pi_tuple_size = ublk_integrity_pi_tuple_size(p->csum_type);
+
+ lim.integrity = (struct blk_integrity) {
+ .flags = ublk_integrity_flags(p->flags),
+ .csum_type = ublk_integrity_csum_type(p->csum_type),
+ .metadata_size = p->metadata_size,
+ .pi_offset = p->pi_offset,
+ .interval_exp = p->interval_exp,
+ .tag_size = p->tag_size,
+ .pi_tuple_size = pi_tuple_size,
+ };
+ }
+
if (wait_for_completion_interruptible(&ub->completion) != 0)
return -EINTR;

if (ub->ublksrv_tgid != ublksrv_pid)
return -EINVAL;
--
2.45.2