[PATCH v2 00/19] ublk: add support for integrity data

[PATCH v2 00/19] ublk: add support for integrity data

[Caleb Sander Mateos]

Much work has recently gone into supporting block device integrity data
(sometimes called "metadata") in Linux. Many NVMe devices these days
support metadata transfers and/or automatic protection information
generation and verification. However, ublk devices can't yet advertise
integrity data capabilities. This patch series wires up support for
integrity data in ublk. The ublk feature is referred to as "integrity"
rather than "metadata" to match the block layer's name for it and to
avoid confusion with the existing and unrelated UBLK_IO_F_META.

To advertise support for integrity data, a ublk server fills out the
struct ublk_params's integrity field and sets UBLK_PARAM_TYPE_INTEGRITY.
The struct ublk_param_integrity flags and csum_type fields use the
existing LBMD_PI_* constants from the linux/fs.h UAPI header. The ublk
driver fills out a corresponding struct blk_integrity.

When a request with integrity data is issued to the ublk device, the
ublk driver sets UBLK_IO_F_INTEGRITY in struct ublksrv_io_desc's
op_flags field. This is necessary for a ublk server for which
bi_offload_capable() returns true to distinguish requests with integrity
data from those without.

Integrity data transfers can currently only be performed via the ublk
user copy mechanism. The overhead of zero-copy buffer registration makes
it less appealing for the small transfers typical of integrity data.
Additionally, neither io_uring NVMe passthru nor IORING_RW_ATTR_FLAG_PI
currently allow an io_uring registered buffer for the integrity data.
The ki_pos field of the struct kiocb passed to the user copy
->{read,write}_iter() callback gains a bit UBLKSRV_IO_INTEGRITY_FLAG for
a ublk server to indicate whether to access the request's data or
integrity data.

v2:
- Communicate BIP_CHECK_* flags and expected reftag seed and app tag to
  ublk server
- Add UBLK_F_INTEGRITY feature flag (Ming)
- Don't change the definition of UBLKSRV_IO_BUF_TOTAL_BITS (Ming)
- Drop patches already applied
- Add Reviewed-by tags

Caleb Sander Mateos (16):
  blk-integrity: take const pointer in blk_integrity_rq()
  ublk: move ublk flag check functions earlier
  ublk: set request integrity params in ublksrv_io_desc
  ublk: add ublk_copy_user_bvec() helper
  ublk: split out ublk_user_copy() helper
  ublk: inline ublk_check_and_get_req() into ublk_user_copy()
  ublk: move offset check out of __ublk_check_and_get_req()
  ublk: optimize ublk_user_copy() on daemon task
  selftests: ublk: display UBLK_F_INTEGRITY support
  selftests: ublk: add utility to get block device metadata size
  selftests: ublk: add kublk support for integrity params
  selftests: ublk: implement integrity user copy in kublk
  selftests: ublk: support non-O_DIRECT backing files
  selftests: ublk: add integrity data support to loop target
  selftests: ublk: add integrity params test
  selftests: ublk: add end-to-end integrity test

Stanley Zhang (3):
  ublk: support UBLK_PARAM_TYPE_INTEGRITY in device creation
  ublk: implement integrity user copy
  ublk: support UBLK_F_INTEGRITY

 drivers/block/ublk_drv.c                     | 387 ++++++++++++++-----
 include/linux/blk-integrity.h                |   6 +-
 include/uapi/linux/ublk_cmd.h                |  49 ++-
 tools/testing/selftests/ublk/Makefile        |   6 +-
 tools/testing/selftests/ublk/common.c        |   4 +-
 tools/testing/selftests/ublk/fault_inject.c  |   1 +
 tools/testing/selftests/ublk/file_backed.c   |  61 ++-
 tools/testing/selftests/ublk/kublk.c         |  90 ++++-
 tools/testing/selftests/ublk/kublk.h         |  37 +-
 tools/testing/selftests/ublk/metadata_size.c |  36 ++
 tools/testing/selftests/ublk/null.c          |   1 +
 tools/testing/selftests/ublk/stripe.c        |   6 +-
 tools/testing/selftests/ublk/test_common.sh  |  10 +
 tools/testing/selftests/ublk/test_loop_08.sh | 111 ++++++
 tools/testing/selftests/ublk/test_null_04.sh | 166 ++++++++
 15 files changed, 833 insertions(+), 138 deletions(-)
 create mode 100644 tools/testing/selftests/ublk/metadata_size.c
 create mode 100755 tools/testing/selftests/ublk/test_loop_08.sh
 create mode 100755 tools/testing/selftests/ublk/test_null_04.sh

-- 
2.45.2

[PATCH v2 01/19] blk-integrity: take const pointer in blk_integrity_rq()

[Caleb Sander Mateos]

blk_integrity_rq() doesn't modify the struct request passed in, so allow
a const pointer to be passed. Use a matching signature for the
!CONFIG_BLK_DEV_INTEGRITY version.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
---
 include/linux/blk-integrity.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/linux/blk-integrity.h b/include/linux/blk-integrity.h
index a6b84206eb94..c15b1ac62765 100644
--- a/include/linux/blk-integrity.h
+++ b/include/linux/blk-integrity.h
@@ -89,11 +89,11 @@ static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
 					       unsigned int sectors)
 {
 	return bio_integrity_intervals(bi, sectors) * bi->metadata_size;
 }
 
-static inline bool blk_integrity_rq(struct request *rq)
+static inline bool blk_integrity_rq(const struct request *rq)
 {
 	return rq->cmd_flags & REQ_INTEGRITY;
 }
 
 /*
@@ -166,13 +166,13 @@ static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
 					       unsigned int sectors)
 {
 	return 0;
 }
-static inline int blk_integrity_rq(struct request *rq)
+static inline bool blk_integrity_rq(const struct request *rq)
 {
-	return 0;
+	return false;
 }
 
 static inline struct bio_vec rq_integrity_vec(struct request *rq)
 {
 	/* the optimizer will remove all calls to this function */
-- 
2.45.2

[PATCH v2 02/19] ublk: move ublk flag check functions earlier

[Caleb Sander Mateos]

ublk_dev_support_user_copy() will be used in ublk_validate_params().
Move these functions next to ublk_{dev,queue}_is_zoned() to avoid
needing to forward-declare them.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/ublk_drv.c | 60 ++++++++++++++++++++--------------------
 1 file changed, 30 insertions(+), 30 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 837fedb02e0d..8e3da9b2b93a 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -273,10 +273,40 @@ static inline struct ublksrv_io_desc *
 ublk_get_iod(const struct ublk_queue *ubq, unsigned tag)
 {
 	return &ubq->io_cmd_buf[tag];
 }
 
+static inline bool ublk_support_zero_copy(const struct ublk_queue *ubq)
+{
+	return ubq->flags & UBLK_F_SUPPORT_ZERO_COPY;
+}
+
+static inline bool ublk_dev_support_zero_copy(const struct ublk_device *ub)
+{
+	return ub->dev_info.flags & UBLK_F_SUPPORT_ZERO_COPY;
+}
+
+static inline bool ublk_support_auto_buf_reg(const struct ublk_queue *ubq)
+{
+	return ubq->flags & UBLK_F_AUTO_BUF_REG;
+}
+
+static inline bool ublk_dev_support_auto_buf_reg(const struct ublk_device *ub)
+{
+	return ub->dev_info.flags & UBLK_F_AUTO_BUF_REG;
+}
+
+static inline bool ublk_support_user_copy(const struct ublk_queue *ubq)
+{
+	return ubq->flags & UBLK_F_USER_COPY;
+}
+
+static inline bool ublk_dev_support_user_copy(const struct ublk_device *ub)
+{
+	return ub->dev_info.flags & UBLK_F_USER_COPY;
+}
+
 static inline bool ublk_dev_is_zoned(const struct ublk_device *ub)
 {
 	return ub->dev_info.flags & UBLK_F_ZONED;
 }
 
@@ -671,40 +701,10 @@ static void ublk_apply_params(struct ublk_device *ub)
 
 	if (ub->params.types & UBLK_PARAM_TYPE_ZONED)
 		ublk_dev_param_zoned_apply(ub);
 }
 
-static inline bool ublk_support_zero_copy(const struct ublk_queue *ubq)
-{
-	return ubq->flags & UBLK_F_SUPPORT_ZERO_COPY;
-}
-
-static inline bool ublk_dev_support_zero_copy(const struct ublk_device *ub)
-{
-	return ub->dev_info.flags & UBLK_F_SUPPORT_ZERO_COPY;
-}
-
-static inline bool ublk_support_auto_buf_reg(const struct ublk_queue *ubq)
-{
-	return ubq->flags & UBLK_F_AUTO_BUF_REG;
-}
-
-static inline bool ublk_dev_support_auto_buf_reg(const struct ublk_device *ub)
-{
-	return ub->dev_info.flags & UBLK_F_AUTO_BUF_REG;
-}
-
-static inline bool ublk_support_user_copy(const struct ublk_queue *ubq)
-{
-	return ubq->flags & UBLK_F_USER_COPY;
-}
-
-static inline bool ublk_dev_support_user_copy(const struct ublk_device *ub)
-{
-	return ub->dev_info.flags & UBLK_F_USER_COPY;
-}
-
 static inline bool ublk_need_map_io(const struct ublk_queue *ubq)
 {
 	return !ublk_support_user_copy(ubq) && !ublk_support_zero_copy(ubq) &&
 		!ublk_support_auto_buf_reg(ubq);
 }
-- 
2.45.2

[PATCH v2 03/19] ublk: support UBLK_PARAM_TYPE_INTEGRITY in device creation

[Caleb Sander Mateos]

From: Stanley Zhang <stazhang@purestorage.com>

Add a feature flag UBLK_F_INTEGRITY for a ublk server to request
integrity/metadata support when creating a ublk device. The ublk server
can also check for the feature flag on the created device or the result
of UBLK_U_CMD_GET_FEATURES to tell if the ublk driver supports it.
UBLK_F_INTEGRITY requires UBLK_F_USER_COPY, as user copy is the only
data copy mode initially supported for integrity data.
Add UBLK_PARAM_TYPE_INTEGRITY and struct ublk_param_integrity to struct
ublk_params to specify the integrity params of a ublk device.
UBLK_PARAM_TYPE_INTEGRITY requires UBLK_F_INTEGRITY and a nonzero
metadata_size. The LBMD_PI_CAP_* and LBMD_PI_CSUM_* values from the
linux/fs.h UAPI header are used for the flags and csum_type fields.
If the UBLK_PARAM_TYPE_INTEGRITY flag is set, validate the integrity
parameters and apply them to the blk_integrity limits.
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: drop redundant pi_tuple_size field, use block metadata UAPI
 constants, add param validation]
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 drivers/block/ublk_drv.c      | 94 ++++++++++++++++++++++++++++++++++-
 include/uapi/linux/ublk_cmd.h | 18 +++++++
 2 files changed, 111 insertions(+), 1 deletion(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 8e3da9b2b93a..2f9316febf83 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.
@@ -628,10 +631,57 @@ 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;
@@ -690,10 +740,33 @@ 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 (!(ub->dev_info.flags & UBLK_F_INTEGRITY))
+			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)
 {
@@ -2941,10 +3014,25 @@ 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;
@@ -3131,10 +3219,14 @@ static int ublk_ctrl_add_dev(const struct ublksrv_ctrl_cmd *header)
 		if (info.flags & (UBLK_F_USER_COPY | UBLK_F_SUPPORT_ZERO_COPY |
 					UBLK_F_AUTO_BUF_REG))
 			return -EINVAL;
 	}
 
+	/* User copy is required to access integrity buffer */
+	if (info.flags & UBLK_F_INTEGRITY && !(info.flags & UBLK_F_USER_COPY))
+		return -EINVAL;
+
 	/* the created device is always owned by current user */
 	ublk_store_owner_uid_gid(&info.owner_uid, &info.owner_gid);
 
 	if (header->dev_id != info.dev_id) {
 		pr_warn("%s: dev id not match %u %u\n",
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index ec77dabba45b..a54c47832fa2 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -309,10 +309,16 @@
  * the I/O's daemon task. The q_id and tag of the registered buffer are required
  * in UBLK_U_IO_UNREGISTER_IO_BUF's ublksrv_io_cmd.
  */
 #define UBLK_F_BUF_REG_OFF_DAEMON (1ULL << 14)
 
+/*
+ * ublk device supports requests with integrity/metadata buffer.
+ * Requires UBLK_F_USER_COPY.
+ */
+#define UBLK_F_INTEGRITY (1ULL << 16)
+
 /* device state */
 #define UBLK_S_DEV_DEAD	0
 #define UBLK_S_DEV_LIVE	1
 #define UBLK_S_DEV_QUIESCED	2
 #define UBLK_S_DEV_FAIL_IO 	3
@@ -598,10 +604,20 @@ struct ublk_param_segment {
 	__u32 	max_segment_size;
 	__u16 	max_segments;
 	__u8	pad[2];
 };
 
+struct ublk_param_integrity {
+	__u32	flags; /* LBMD_PI_CAP_* from linux/fs.h */
+	__u8	interval_exp;
+	__u8	metadata_size; /* UBLK_PARAM_TYPE_INTEGRITY requires nonzero */
+	__u8	pi_offset;
+	__u8	csum_type; /* LBMD_PI_CSUM_* from linux/fs.h */
+	__u8	tag_size;
+	__u8	pad[7];
+};
+
 struct ublk_params {
 	/*
 	 * Total length of parameters, userspace has to set 'len' for both
 	 * SET_PARAMS and GET_PARAMS command, and driver may update len
 	 * if two sides use different version of 'ublk_params', same with
@@ -612,16 +628,18 @@ struct ublk_params {
 #define UBLK_PARAM_TYPE_DISCARD         (1 << 1)
 #define UBLK_PARAM_TYPE_DEVT            (1 << 2)
 #define UBLK_PARAM_TYPE_ZONED           (1 << 3)
 #define UBLK_PARAM_TYPE_DMA_ALIGN       (1 << 4)
 #define UBLK_PARAM_TYPE_SEGMENT         (1 << 5)
+#define UBLK_PARAM_TYPE_INTEGRITY       (1 << 6) /* requires UBLK_F_INTEGRITY */
 	__u32	types;			/* types of parameter included */
 
 	struct ublk_param_basic		basic;
 	struct ublk_param_discard	discard;
 	struct ublk_param_devt		devt;
 	struct ublk_param_zoned	zoned;
 	struct ublk_param_dma_align	dma;
 	struct ublk_param_segment	seg;
+	struct ublk_param_integrity	integrity;
 };
 
 #endif
-- 
2.45.2

[PATCH v2 04/19] ublk: set request integrity params in ublksrv_io_desc

[Caleb Sander Mateos]

Indicate to the ublk server when an incoming request has integrity data
by setting UBLK_IO_F_INTEGRITY in the ublksrv_io_desc's op_flags field.
If the ublk device doesn't support integrity, the request will never
provide integrity data. If the ublk device supports integrity, the
request may omit the integrity buffer only if metadata_size matches the
PI tuple size determined by csum_type. In this case, the ublk server
should internally generate/verify the protection information from the
data and sector offset.
Set the UBLK_IO_F_CHECK_{GUARD,REFTAG,APPTAG} flags based on the
request's BIP_CHECK_{GUARD,REFTAG,APPTAG} flags, indicating whether to
verify the guard, reference, and app tags in the protection information.
The expected reference tag (32 or 48 bits) and app tag (16 bits) are
indicated in ublksrv_io_desc's new struct ublksrv_io_integrity integrity
field. This field is unioned with the addr field to avoid changing the
size of struct ublksrv_io_desc. UBLK_F_INTEGRITY requires
UBLK_F_USER_COPY and the addr field isn't used for UBLK_F_USER_COPY, so
the two fields aren't needed simultaneously.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 drivers/block/ublk_drv.c      | 43 +++++++++++++++++++++++++++++++----
 include/uapi/linux/ublk_cmd.h | 27 ++++++++++++++++++++--
 2 files changed, 64 insertions(+), 6 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 2f9316febf83..51469e0627ff 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -316,10 +316,36 @@ static inline bool ublk_dev_is_zoned(const struct ublk_device *ub)
 static inline bool ublk_queue_is_zoned(const struct ublk_queue *ubq)
 {
 	return ubq->flags & UBLK_F_ZONED;
 }
 
+static void ublk_setup_iod_buf(const struct ublk_queue *ubq,
+			       const struct request *req,
+			       struct ublksrv_io_desc *iod)
+{
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+	if (ubq->flags & UBLK_F_INTEGRITY) {
+		struct bio_integrity_payload *bip;
+		sector_t ref_tag_seed;
+
+		if (!blk_integrity_rq(req))
+			return;
+
+		bip = bio_integrity(req->bio);
+		ref_tag_seed = bip_get_seed(bip);
+		iod->integrity.ref_tag_lo = ref_tag_seed;
+		iod->integrity.ref_tag_hi = ref_tag_seed >> 32;
+		iod->integrity.app_tag = bip->app_tag;
+	} else
+#endif /* #ifdef CONFIG_BLK_DEV_INTEGRITY */
+	{
+		const struct ublk_io *io = &ubq->ios[req->tag];
+
+		iod->addr = io->buf.addr;
+	}
+}
+
 #ifdef CONFIG_BLK_DEV_ZONED
 
 struct ublk_zoned_report_desc {
 	__u64 sector;
 	__u32 operation;
@@ -498,11 +524,10 @@ static int ublk_report_zones(struct gendisk *disk, sector_t sector,
 
 static blk_status_t ublk_setup_iod_zoned(struct ublk_queue *ubq,
 					 struct request *req)
 {
 	struct ublksrv_io_desc *iod = ublk_get_iod(ubq, req->tag);
-	struct ublk_io *io = &ubq->ios[req->tag];
 	struct ublk_zoned_report_desc *desc;
 	u32 ublk_op;
 
 	switch (req_op(req)) {
 	case REQ_OP_ZONE_OPEN:
@@ -545,11 +570,11 @@ static blk_status_t ublk_setup_iod_zoned(struct ublk_queue *ubq,
 	}
 
 	iod->op_flags = ublk_op | ublk_req_build_flags(req);
 	iod->nr_sectors = blk_rq_sectors(req);
 	iod->start_sector = blk_rq_pos(req);
-	iod->addr = io->buf.addr;
+	ublk_setup_iod_buf(ubq, req, iod);
 
 	return BLK_STS_OK;
 }
 
 #else
@@ -1120,17 +1145,27 @@ static inline unsigned int ublk_req_build_flags(struct request *req)
 		flags |= UBLK_IO_F_NOUNMAP;
 
 	if (req->cmd_flags & REQ_SWAP)
 		flags |= UBLK_IO_F_SWAP;
 
+	if (blk_integrity_rq(req)) {
+		flags |= UBLK_IO_F_INTEGRITY;
+
+		if (bio_integrity_flagged(req->bio, BIP_CHECK_GUARD))
+			flags |= UBLK_IO_F_CHECK_GUARD;
+		if (bio_integrity_flagged(req->bio, BIP_CHECK_REFTAG))
+			flags |= UBLK_IO_F_CHECK_REFTAG;
+		if (bio_integrity_flagged(req->bio, BIP_CHECK_APPTAG))
+			flags |= UBLK_IO_F_CHECK_APPTAG;
+	}
+
 	return flags;
 }
 
 static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req)
 {
 	struct ublksrv_io_desc *iod = ublk_get_iod(ubq, req->tag);
-	struct ublk_io *io = &ubq->ios[req->tag];
 	u32 ublk_op;
 
 	switch (req_op(req)) {
 	case REQ_OP_READ:
 		ublk_op = UBLK_IO_OP_READ;
@@ -1155,11 +1190,11 @@ static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req)
 
 	/* need to translate since kernel may change */
 	iod->op_flags = ublk_op | ublk_req_build_flags(req);
 	iod->nr_sectors = blk_rq_sectors(req);
 	iod->start_sector = blk_rq_pos(req);
-	iod->addr = io->buf.addr;
+	ublk_setup_iod_buf(ubq, req, iod);
 
 	return BLK_STS_OK;
 }
 
 static inline struct ublk_uring_cmd_pdu *ublk_get_uring_cmd_pdu(
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index a54c47832fa2..a22de3fc5447 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -412,10 +412,25 @@ struct ublksrv_ctrl_dev_info {
  *
  * ublk server has to check this flag if UBLK_AUTO_BUF_REG_FALLBACK is
  * passed in.
  */
 #define		UBLK_IO_F_NEED_REG_BUF		(1U << 17)
+/* Request has an integrity data buffer */
+#define		UBLK_IO_F_INTEGRITY		(1UL << 18)
+/* Guard tag verification requested */
+#define		UBLK_IO_F_CHECK_GUARD		(1UL << 19)
+/* Reference tag verification requested */
+#define		UBLK_IO_F_CHECK_REFTAG		(1UL << 20)
+/* Application tag verification requested */
+#define		UBLK_IO_F_CHECK_APPTAG		(1UL << 21)
+
+struct ublksrv_io_integrity
+{
+	__u32 ref_tag_lo; /* low 32 bits of reference tag seed */
+	__u16 ref_tag_hi; /* high 16 bits of reference tag seed */
+	__u16 app_tag;
+};
 
 /*
  * io cmd is described by this structure, and stored in share memory, indexed
  * by request tag.
  *
@@ -432,12 +447,20 @@ struct ublksrv_io_desc {
 	};
 
 	/* start sector for this io */
 	__u64		start_sector;
 
-	/* buffer address in ublksrv daemon vm space, from ublk driver */
-	__u64		addr;
+	union {
+		/*
+		 * buffer address in ublksrv daemon vm space, from ublk driver.
+		 * Unused for UBLK_F_SUPPORT_ZERO_COPY, UBLK_F_USER_COPY, or
+		 * UBLK_F_AUTO_BUF_REG.
+		 */
+		__u64		addr;
+		/* Integrity options, for UBLK_F_INTEGRITY */
+		struct ublksrv_io_integrity integrity;
+	};
 };
 
 static inline __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod)
 {
 	return iod->op_flags & 0xff;
-- 
2.45.2

[PATCH v2 05/19] ublk: add ublk_copy_user_bvec() helper

[Caleb Sander Mateos]

Factor a helper function ublk_copy_user_bvec() out of
ublk_copy_user_pages(). It will be used for copying integrity data too.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 drivers/block/ublk_drv.c | 52 +++++++++++++++++++++++-----------------
 1 file changed, 30 insertions(+), 22 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 51469e0627ff..811a125a5b04 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -1025,10 +1025,39 @@ static const struct block_device_operations ub_fops = {
 	.open =		ublk_open,
 	.free_disk =	ublk_free_disk,
 	.report_zones =	ublk_report_zones,
 };
 
+static bool ublk_copy_user_bvec(const struct bio_vec *bv, unsigned *offset,
+				struct iov_iter *uiter, int dir, size_t *done)
+{
+	unsigned len;
+	void *bv_buf;
+	size_t copied;
+
+	if (*offset >= bv->bv_len) {
+		*offset -= bv->bv_len;
+		return true;
+	}
+
+	len = bv->bv_len - *offset;
+	bv_buf = kmap_local_page(bv->bv_page) + bv->bv_offset + *offset;
+	if (dir == ITER_DEST)
+		copied = copy_to_iter(bv_buf, len, uiter);
+	else
+		copied = copy_from_iter(bv_buf, len, uiter);
+
+	kunmap_local(bv_buf);
+
+	*done += copied;
+	if (copied < len)
+		return false;
+
+	*offset = 0;
+	return true;
+}
+
 /*
  * Copy data between request pages and io_iter, and 'offset'
  * is the start point of linear offset of request.
  */
 static size_t ublk_copy_user_pages(const struct request *req,
@@ -1037,33 +1066,12 @@ static size_t ublk_copy_user_pages(const struct request *req,
 	struct req_iterator iter;
 	struct bio_vec bv;
 	size_t done = 0;
 
 	rq_for_each_segment(bv, req, iter) {
-		unsigned len;
-		void *bv_buf;
-		size_t copied;
-
-		if (offset >= bv.bv_len) {
-			offset -= bv.bv_len;
-			continue;
-		}
-
-		len = bv.bv_len - offset;
-		bv_buf = kmap_local_page(bv.bv_page) + bv.bv_offset + offset;
-		if (dir == ITER_DEST)
-			copied = copy_to_iter(bv_buf, len, uiter);
-		else
-			copied = copy_from_iter(bv_buf, len, uiter);
-
-		kunmap_local(bv_buf);
-
-		done += copied;
-		if (copied < len)
+		if (!ublk_copy_user_bvec(&bv, &offset, uiter, dir, &done))
 			break;
-
-		offset = 0;
 	}
 	return done;
 }
 
 static inline bool ublk_need_map_req(const struct request *req)
-- 
2.45.2

[PATCH v2 06/19] ublk: split out ublk_user_copy() helper

[Caleb Sander Mateos]

ublk_ch_read_iter() and ublk_ch_write_iter() are nearly identical except
for the iter direction. Split out a helper function ublk_user_copy() to
reduce the code duplication as these functions are about to get larger.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/ublk_drv.c | 26 ++++++++++----------------
 1 file changed, 10 insertions(+), 16 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 811a125a5b04..73547ecf14cd 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -2727,42 +2727,36 @@ static struct request *ublk_check_and_get_req(struct kiocb *iocb,
 fail:
 	ublk_put_req_ref(*io, req);
 	return ERR_PTR(-EACCES);
 }
 
-static ssize_t ublk_ch_read_iter(struct kiocb *iocb, struct iov_iter *to)
+static ssize_t
+ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir)
 {
 	struct request *req;
 	struct ublk_io *io;
 	size_t buf_off;
 	size_t ret;
 
-	req = ublk_check_and_get_req(iocb, to, &buf_off, ITER_DEST, &io);
+	req = ublk_check_and_get_req(iocb, iter, &buf_off, dir, &io);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
-	ret = ublk_copy_user_pages(req, buf_off, to, ITER_DEST);
+	ret = ublk_copy_user_pages(req, buf_off, iter, dir);
 	ublk_put_req_ref(io, req);
 
 	return ret;
 }
 
-static ssize_t ublk_ch_write_iter(struct kiocb *iocb, struct iov_iter *from)
+static ssize_t ublk_ch_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-	struct request *req;
-	struct ublk_io *io;
-	size_t buf_off;
-	size_t ret;
-
-	req = ublk_check_and_get_req(iocb, from, &buf_off, ITER_SOURCE, &io);
-	if (IS_ERR(req))
-		return PTR_ERR(req);
-
-	ret = ublk_copy_user_pages(req, buf_off, from, ITER_SOURCE);
-	ublk_put_req_ref(io, req);
+	return ublk_user_copy(iocb, to, ITER_DEST);
+}
 
-	return ret;
+static ssize_t ublk_ch_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+	return ublk_user_copy(iocb, from, ITER_SOURCE);
 }
 
 static const struct file_operations ublk_ch_fops = {
 	.owner = THIS_MODULE,
 	.open = ublk_ch_open,
-- 
2.45.2

[PATCH v2 07/19] ublk: inline ublk_check_and_get_req() into ublk_user_copy()

[Caleb Sander Mateos]

ublk_check_and_get_req() has a single callsite in ublk_user_copy(). It
takes a ton of arguments in order to pass local variables from
ublk_user_copy() to ublk_check_and_get_req() and vice versa. And more
are about to be added. Combine the functions to reduce the argument
passing noise.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/ublk_drv.c | 51 ++++++++++++++--------------------------
 1 file changed, 18 insertions(+), 33 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 73547ecf14cd..a4f95a0f1223 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -2682,70 +2682,55 @@ static inline bool ublk_check_ubuf_dir(const struct request *req,
 		return true;
 
 	return false;
 }
 
-static struct request *ublk_check_and_get_req(struct kiocb *iocb,
-		struct iov_iter *iter, size_t *off, int dir,
-		struct ublk_io **io)
+static ssize_t
+ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir)
 {
 	struct ublk_device *ub = iocb->ki_filp->private_data;
 	struct ublk_queue *ubq;
 	struct request *req;
+	struct ublk_io *io;
 	size_t buf_off;
 	u16 tag, q_id;
+	ssize_t ret;
 
 	if (!user_backed_iter(iter))
-		return ERR_PTR(-EACCES);
+		return -EACCES;
 
 	if (ub->dev_info.state == UBLK_S_DEV_DEAD)
-		return ERR_PTR(-EACCES);
+		return -EACCES;
 
 	tag = ublk_pos_to_tag(iocb->ki_pos);
 	q_id = ublk_pos_to_hwq(iocb->ki_pos);
 	buf_off = ublk_pos_to_buf_off(iocb->ki_pos);
 
 	if (q_id >= ub->dev_info.nr_hw_queues)
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
 
 	ubq = ublk_get_queue(ub, q_id);
 	if (!ublk_dev_support_user_copy(ub))
-		return ERR_PTR(-EACCES);
+		return -EACCES;
 
 	if (tag >= ub->dev_info.queue_depth)
-		return ERR_PTR(-EINVAL);
+		return -EINVAL;
 
-	*io = &ubq->ios[tag];
-	req = __ublk_check_and_get_req(ub, q_id, tag, *io, buf_off);
+	io = &ubq->ios[tag];
+	req = __ublk_check_and_get_req(ub, q_id, tag, io, buf_off);
 	if (!req)
-		return ERR_PTR(-EINVAL);
-
-	if (!ublk_check_ubuf_dir(req, dir))
-		goto fail;
-
-	*off = buf_off;
-	return req;
-fail:
-	ublk_put_req_ref(*io, req);
-	return ERR_PTR(-EACCES);
-}
-
-static ssize_t
-ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir)
-{
-	struct request *req;
-	struct ublk_io *io;
-	size_t buf_off;
-	size_t ret;
+		return -EINVAL;
 
-	req = ublk_check_and_get_req(iocb, iter, &buf_off, dir, &io);
-	if (IS_ERR(req))
-		return PTR_ERR(req);
+	if (!ublk_check_ubuf_dir(req, dir)) {
+		ret = -EACCES;
+		goto out;
+	}
 
 	ret = ublk_copy_user_pages(req, buf_off, iter, dir);
-	ublk_put_req_ref(io, req);
 
+out:
+	ublk_put_req_ref(io, req);
 	return ret;
 }
 
 static ssize_t ublk_ch_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-- 
2.45.2

[PATCH v2 08/19] ublk: move offset check out of __ublk_check_and_get_req()

[Caleb Sander Mateos]

__ublk_check_and_get_req() checks that the passed in offset is within
the data length of the specified ublk request. However, only user copy
(ublk_check_and_get_req()) supports accessing ublk request data at a
nonzero offset. Zero-copy buffer registration (ublk_register_io_buf())
always passes 0 for the offset, so the check is unnecessary. Move the
check from __ublk_check_and_get_req() to ublk_check_and_get_req().

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/ublk_drv.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index a4f95a0f1223..3149d705cb9a 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -253,11 +253,11 @@ struct ublk_params_header {
 
 static void ublk_io_release(void *priv);
 static void ublk_stop_dev_unlocked(struct ublk_device *ub);
 static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq);
 static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub,
-		u16 q_id, u16 tag, struct ublk_io *io, size_t offset);
+		u16 q_id, u16 tag, struct ublk_io *io);
 static inline unsigned int ublk_req_build_flags(struct request *req);
 
 static void ublk_partition_scan_work(struct work_struct *work)
 {
 	struct ublk_device *ub =
@@ -2315,11 +2315,11 @@ static int ublk_register_io_buf(struct io_uring_cmd *cmd,
 	int ret;
 
 	if (!ublk_dev_support_zero_copy(ub))
 		return -EINVAL;
 
-	req = __ublk_check_and_get_req(ub, q_id, tag, io, 0);
+	req = __ublk_check_and_get_req(ub, q_id, tag, io);
 	if (!req)
 		return -EINVAL;
 
 	ret = io_buffer_register_bvec(cmd, req, ublk_io_release, index,
 				      issue_flags);
@@ -2609,11 +2609,11 @@ static int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd,
 			__func__, cmd_op, tag, ret, io ? io->flags : 0);
 	return ret;
 }
 
 static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub,
-		u16 q_id, u16 tag, struct ublk_io *io, size_t offset)
+		u16 q_id, u16 tag, struct ublk_io *io)
 {
 	struct request *req;
 
 	/*
 	 * can't use io->req in case of concurrent UBLK_IO_COMMIT_AND_FETCH_REQ,
@@ -2630,13 +2630,10 @@ static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub,
 		goto fail_put;
 
 	if (!ublk_rq_has_data(req))
 		goto fail_put;
 
-	if (offset > blk_rq_bytes(req))
-		goto fail_put;
-
 	return req;
 fail_put:
 	ublk_put_req_ref(io, req);
 	return NULL;
 }
@@ -2714,14 +2711,19 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir)
 
 	if (tag >= ub->dev_info.queue_depth)
 		return -EINVAL;
 
 	io = &ubq->ios[tag];
-	req = __ublk_check_and_get_req(ub, q_id, tag, io, buf_off);
+	req = __ublk_check_and_get_req(ub, q_id, tag, io);
 	if (!req)
 		return -EINVAL;
 
+	if (buf_off > blk_rq_bytes(req)) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	if (!ublk_check_ubuf_dir(req, dir)) {
 		ret = -EACCES;
 		goto out;
 	}
 
-- 
2.45.2

[PATCH v2 09/19] ublk: implement integrity user copy

[Caleb Sander Mateos]

From: Stanley Zhang <stazhang@purestorage.com>

Add a function ublk_copy_user_integrity() to copy integrity information
between a request and a user iov_iter. This mirrors the existing
ublk_copy_user_pages() but operates on request integrity data instead of
regular data. Check UBLKSRV_IO_INTEGRITY_FLAG in iocb->ki_pos in
ublk_user_copy() to choose between copying data or integrity data.

Signed-off-by: Stanley Zhang <stazhang@purestorage.com>
[csander: change offset units from data bytes to integrity data bytes,
 test UBLKSRV_IO_INTEGRITY_FLAG after subtracting UBLKSRV_IO_BUF_OFFSET,
 fix CONFIG_BLK_DEV_INTEGRITY=n build,
 rebase on ublk user copy refactor]
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 drivers/block/ublk_drv.c      | 52 +++++++++++++++++++++++++++++++++--
 include/uapi/linux/ublk_cmd.h |  4 +++
 2 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 3149d705cb9a..82b193d63583 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -646,10 +646,15 @@ static inline unsigned ublk_pos_to_tag(loff_t pos)
 {
 	return ((pos - UBLKSRV_IO_BUF_OFFSET) >> UBLK_TAG_OFF) &
 		UBLK_TAG_BITS_MASK;
 }
 
+static inline bool ublk_pos_is_integrity(loff_t pos)
+{
+	return !!((pos - UBLKSRV_IO_BUF_OFFSET) & UBLKSRV_IO_INTEGRITY_FLAG);
+}
+
 static void ublk_dev_param_basic_apply(struct ublk_device *ub)
 {
 	const struct ublk_param_basic *p = &ub->params.basic;
 
 	if (p->attrs & UBLK_ATTR_READ_ONLY)
@@ -1072,10 +1077,37 @@ static size_t ublk_copy_user_pages(const struct request *req,
 			break;
 	}
 	return done;
 }
 
+#ifdef CONFIG_BLK_DEV_INTEGRITY
+static size_t ublk_copy_user_integrity(const struct request *req,
+		unsigned offset, struct iov_iter *uiter, int dir)
+{
+	size_t done = 0;
+	struct bio *bio = req->bio;
+	struct bvec_iter iter;
+	struct bio_vec iv;
+
+	if (!blk_integrity_rq(req))
+		return 0;
+
+	bio_for_each_integrity_vec(iv, bio, iter) {
+		if (!ublk_copy_user_bvec(&iv, &offset, uiter, dir, &done))
+			break;
+	}
+
+	return done;
+}
+#else /* #ifdef CONFIG_BLK_DEV_INTEGRITY */
+static size_t ublk_copy_user_integrity(const struct request *req,
+		unsigned offset, struct iov_iter *uiter, int dir)
+{
+	return 0;
+}
+#endif /* #ifdef CONFIG_BLK_DEV_INTEGRITY */
+
 static inline bool ublk_need_map_req(const struct request *req)
 {
 	return ublk_rq_has_data(req) && req_op(req) == REQ_OP_WRITE;
 }
 
@@ -2686,10 +2718,12 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir)
 {
 	struct ublk_device *ub = iocb->ki_filp->private_data;
 	struct ublk_queue *ubq;
 	struct request *req;
 	struct ublk_io *io;
+	unsigned data_len;
+	bool is_integrity;
 	size_t buf_off;
 	u16 tag, q_id;
 	ssize_t ret;
 
 	if (!user_backed_iter(iter))
@@ -2699,10 +2733,11 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir)
 		return -EACCES;
 
 	tag = ublk_pos_to_tag(iocb->ki_pos);
 	q_id = ublk_pos_to_hwq(iocb->ki_pos);
 	buf_off = ublk_pos_to_buf_off(iocb->ki_pos);
+	is_integrity = ublk_pos_is_integrity(iocb->ki_pos);
 
 	if (q_id >= ub->dev_info.nr_hw_queues)
 		return -EINVAL;
 
 	ubq = ublk_get_queue(ub, q_id);
@@ -2715,21 +2750,31 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir)
 	io = &ubq->ios[tag];
 	req = __ublk_check_and_get_req(ub, q_id, tag, io);
 	if (!req)
 		return -EINVAL;
 
-	if (buf_off > blk_rq_bytes(req)) {
+	if (is_integrity) {
+		struct blk_integrity *bi = &req->q->limits.integrity;
+
+		data_len = bio_integrity_bytes(bi, blk_rq_sectors(req));
+	} else {
+		data_len = blk_rq_bytes(req);
+	}
+	if (buf_off > data_len) {
 		ret = -EINVAL;
 		goto out;
 	}
 
 	if (!ublk_check_ubuf_dir(req, dir)) {
 		ret = -EACCES;
 		goto out;
 	}
 
-	ret = ublk_copy_user_pages(req, buf_off, iter, dir);
+	if (is_integrity)
+		ret = ublk_copy_user_integrity(req, buf_off, iter, dir);
+	else
+		ret = ublk_copy_user_pages(req, buf_off, iter, dir);
 
 out:
 	ublk_put_req_ref(io, req);
 	return ret;
 }
@@ -3963,11 +4008,12 @@ static struct miscdevice ublk_misc = {
 static int __init ublk_init(void)
 {
 	int ret;
 
 	BUILD_BUG_ON((u64)UBLKSRV_IO_BUF_OFFSET +
-			UBLKSRV_IO_BUF_TOTAL_SIZE < UBLKSRV_IO_BUF_OFFSET);
+			UBLKSRV_IO_BUF_TOTAL_SIZE +
+			UBLKSRV_IO_INTEGRITY_FLAG < UBLKSRV_IO_BUF_OFFSET);
 	BUILD_BUG_ON(sizeof(struct ublk_auto_buf_reg) != 8);
 
 	init_waitqueue_head(&ublk_idr_wq);
 
 	ret = misc_register(&ublk_misc);
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index a22de3fc5447..87262f5c054b 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -132,10 +132,14 @@
 #define UBLK_MAX_NR_QUEUES	(1U << UBLK_QID_BITS)
 
 #define UBLKSRV_IO_BUF_TOTAL_BITS	(UBLK_QID_OFF + UBLK_QID_BITS)
 #define UBLKSRV_IO_BUF_TOTAL_SIZE	(1ULL << UBLKSRV_IO_BUF_TOTAL_BITS)
 
+/* Copy to/from request integrity buffer instead of data buffer */
+#define UBLK_INTEGRITY_FLAG_OFF UBLKSRV_IO_BUF_TOTAL_BITS
+#define UBLKSRV_IO_INTEGRITY_FLAG (1ULL << UBLK_INTEGRITY_FLAG_OFF)
+
 /*
  * ublk server can register data buffers for incoming I/O requests with a sparse
  * io_uring buffer table. The request buffer can then be used as the data buffer
  * for io_uring operations via the fixed buffer index.
  * Note that the ublk server can never directly access the request data memory.
-- 
2.45.2

[PATCH v2 10/19] ublk: support UBLK_F_INTEGRITY

[Caleb Sander Mateos]

From: Stanley Zhang <stazhang@purestorage.com>

Now that all the components of the ublk integrity feature have been
implemented, add UBLK_F_INTEGRITY to UBLK_F_ALL, conditional on block
layer integrity support (CONFIG_BLK_DEV_INTEGRITY). This allows ublk
servers to create ublk devices with UBLK_F_INTEGRITY set and
UBLK_U_CMD_GET_FEATURES to report the feature as supported.

Signed-off-by: Stanley Zhang <stazhang@purestorage.com>
[csander: make feature conditional on CONFIG_BLK_DEV_INTEGRITY]
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 drivers/block/ublk_drv.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 82b193d63583..8b2466b5de07 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -73,11 +73,12 @@
 		| UBLK_F_USER_RECOVERY_FAIL_IO \
 		| UBLK_F_UPDATE_SIZE \
 		| UBLK_F_AUTO_BUF_REG \
 		| UBLK_F_QUIESCE \
 		| UBLK_F_PER_IO_DAEMON \
-		| UBLK_F_BUF_REG_OFF_DAEMON)
+		| UBLK_F_BUF_REG_OFF_DAEMON \
+		| (IS_ENABLED(CONFIG_BLK_DEV_INTEGRITY) ? UBLK_F_INTEGRITY : 0))
 
 #define UBLK_F_ALL_RECOVERY_FLAGS (UBLK_F_USER_RECOVERY \
 		| UBLK_F_USER_RECOVERY_REISSUE \
 		| UBLK_F_USER_RECOVERY_FAIL_IO)
 
-- 
2.45.2

[PATCH v2 11/19] ublk: optimize ublk_user_copy() on daemon task

[Caleb Sander Mateos]

ublk user copy syscalls may be issued from any task, so they take a
reference count on the struct ublk_io to check whether it is owned by
the ublk server and prevent a concurrent UBLK_IO_COMMIT_AND_FETCH_REQ
from completing the request. However, if the user copy syscall is issued
on the io's daemon task, a concurrent UBLK_IO_COMMIT_AND_FETCH_REQ isn't
possible, so the atomic reference count dance is unnecessary. Check for
UBLK_IO_FLAG_OWNED_BY_SRV to ensure the request is dispatched to the
sever and obtain the request from ublk_io's req field instead of looking
it up on the tagset. Skip the reference count increment and decrement.
Commit 8a8fe42d765b ("ublk: optimize UBLK_IO_REGISTER_IO_BUF on daemon
task") made an analogous optimization for ublk zero copy buffer
registration.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/ublk_drv.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 8b2466b5de07..2d4f8ffda01f 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -181,11 +181,11 @@ struct ublk_io {
 	/*
 	 * The number of uses of this I/O by the ublk server
 	 * if user copy or zero copy are enabled:
 	 * - UBLK_REFCOUNT_INIT from dispatch to the server
 	 *   until UBLK_IO_COMMIT_AND_FETCH_REQ
-	 * - 1 for each inflight ublk_ch_{read,write}_iter() call
+	 * - 1 for each inflight ublk_ch_{read,write}_iter() call not on task
 	 * - 1 for each io_uring registered buffer not registered on task
 	 * The I/O can only be completed once all references are dropped.
 	 * User copy and buffer registration operations are only permitted
 	 * if the reference count is nonzero.
 	 */
@@ -2721,10 +2721,11 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir)
 	struct ublk_queue *ubq;
 	struct request *req;
 	struct ublk_io *io;
 	unsigned data_len;
 	bool is_integrity;
+	bool on_daemon;
 	size_t buf_off;
 	u16 tag, q_id;
 	ssize_t ret;
 
 	if (!user_backed_iter(iter))
@@ -2747,13 +2748,24 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir)
 
 	if (tag >= ub->dev_info.queue_depth)
 		return -EINVAL;
 
 	io = &ubq->ios[tag];
-	req = __ublk_check_and_get_req(ub, q_id, tag, io);
-	if (!req)
-		return -EINVAL;
+	on_daemon = current == READ_ONCE(io->task);
+	if (on_daemon) {
+		/* On daemon, io can't be completed concurrently, so skip ref */
+		if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV))
+			return -EINVAL;
+
+		req = io->req;
+		if (!ublk_rq_has_data(req))
+			return -EINVAL;
+	} else {
+		req = __ublk_check_and_get_req(ub, q_id, tag, io);
+		if (!req)
+			return -EINVAL;
+	}
 
 	if (is_integrity) {
 		struct blk_integrity *bi = &req->q->limits.integrity;
 
 		data_len = bio_integrity_bytes(bi, blk_rq_sectors(req));
@@ -2774,11 +2786,12 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir)
 		ret = ublk_copy_user_integrity(req, buf_off, iter, dir);
 	else
 		ret = ublk_copy_user_pages(req, buf_off, iter, dir);
 
 out:
-	ublk_put_req_ref(io, req);
+	if (!on_daemon)
+		ublk_put_req_ref(io, req);
 	return ret;
 }
 
 static ssize_t ublk_ch_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
-- 
2.45.2

[PATCH v2 12/19] selftests: ublk: display UBLK_F_INTEGRITY support

[Caleb Sander Mateos]

Add support for printing the UBLK_F_INTEGRITY feature flag in the
human-readable kublk features output.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 tools/testing/selftests/ublk/kublk.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/ublk/kublk.c b/tools/testing/selftests/ublk/kublk.c
index 185ba553686a..261095f19c93 100644
--- a/tools/testing/selftests/ublk/kublk.c
+++ b/tools/testing/selftests/ublk/kublk.c
@@ -1452,10 +1452,11 @@ static int cmd_dev_get_features(void)
 		FEAT_NAME(UBLK_F_UPDATE_SIZE),
 		FEAT_NAME(UBLK_F_AUTO_BUF_REG),
 		FEAT_NAME(UBLK_F_QUIESCE),
 		FEAT_NAME(UBLK_F_PER_IO_DAEMON),
 		FEAT_NAME(UBLK_F_BUF_REG_OFF_DAEMON),
+		FEAT_NAME(UBLK_F_INTEGRITY),
 	};
 	struct ublk_dev *dev;
 	__u64 features = 0;
 	int ret;
 
-- 
2.45.2

[PATCH v2 13/19] selftests: ublk: add utility to get block device metadata size

[Caleb Sander Mateos]

Some block device integrity parameters are available in sysfs, but
others are only accessible using the FS_IOC_GETLBMD_CAP ioctl. Add a
metadata_size utility program to print out the logical block metadata
size, PI offset, and PI size within the metadata. Example output:
$ metadata_size /dev/ublkb0
metadata_size: 64
pi_offset: 56
pi_tuple_size: 8

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 tools/testing/selftests/ublk/Makefile        |  4 +--
 tools/testing/selftests/ublk/metadata_size.c | 36 ++++++++++++++++++++
 2 files changed, 38 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/ublk/metadata_size.c

diff --git a/tools/testing/selftests/ublk/Makefile b/tools/testing/selftests/ublk/Makefile
index 06ba6fde098d..41f776bb86a6 100644
--- a/tools/testing/selftests/ublk/Makefile
+++ b/tools/testing/selftests/ublk/Makefile
@@ -47,14 +47,14 @@ TEST_PROGS += test_stress_03.sh
 TEST_PROGS += test_stress_04.sh
 TEST_PROGS += test_stress_05.sh
 TEST_PROGS += test_stress_06.sh
 TEST_PROGS += test_stress_07.sh
 
-TEST_GEN_PROGS_EXTENDED = kublk
+TEST_GEN_PROGS_EXTENDED = kublk metadata_size
 
 LOCAL_HDRS += $(wildcard *.h)
 include ../lib.mk
 
-$(TEST_GEN_PROGS_EXTENDED): $(wildcard *.c)
+$(OUTPUT)/kublk: common.c fault_inject.c file_backed.c kublk.c null.c stripe.c
 
 check:
 	shellcheck -x -f gcc *.sh
diff --git a/tools/testing/selftests/ublk/metadata_size.c b/tools/testing/selftests/ublk/metadata_size.c
new file mode 100644
index 000000000000..76ecddf04d25
--- /dev/null
+++ b/tools/testing/selftests/ublk/metadata_size.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <fcntl.h>
+#include <linux/fs.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+
+int main(int argc, char **argv)
+{
+	struct logical_block_metadata_cap cap = {};
+	const char *filename;
+	int fd;
+	int result;
+
+	if (argc != 2) {
+		fprintf(stderr, "Usage: %s BLOCK_DEVICE\n", argv[0]);
+		return 1;
+	}
+
+	filename = argv[1];
+	fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		perror(filename);
+		return 1;
+	}
+
+	result = ioctl(fd, FS_IOC_GETLBMD_CAP, &cap);
+	if (result < 0) {
+		perror("ioctl");
+		return 1;
+	}
+
+	printf("metadata_size: %u\n", cap.lbmd_size);
+	printf("pi_offset: %u\n", cap.lbmd_pi_offset);
+	printf("pi_tuple_size: %u\n", cap.lbmd_pi_size);
+	return 0;
+}
-- 
2.45.2

[PATCH v2 14/19] selftests: ublk: add kublk support for integrity params

[Caleb Sander Mateos]

Add integrity param command line arguments to kublk. Plumb these to
struct ublk_params for the null and fault_inject targets, as they don't
need to actually read or write the integrity data. Forbid the integrity
params for loop or stripe until the integrity data copy is implemented.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 tools/testing/selftests/ublk/fault_inject.c |  1 +
 tools/testing/selftests/ublk/file_backed.c  |  4 ++
 tools/testing/selftests/ublk/kublk.c        | 48 +++++++++++++++++++++
 tools/testing/selftests/ublk/kublk.h        | 21 +++++++++
 tools/testing/selftests/ublk/null.c         |  1 +
 tools/testing/selftests/ublk/stripe.c       |  4 ++
 6 files changed, 79 insertions(+)

diff --git a/tools/testing/selftests/ublk/fault_inject.c b/tools/testing/selftests/ublk/fault_inject.c
index b227bd78b252..3b897f69c014 100644
--- a/tools/testing/selftests/ublk/fault_inject.c
+++ b/tools/testing/selftests/ublk/fault_inject.c
@@ -31,10 +31,11 @@ static int ublk_fault_inject_tgt_init(const struct dev_ctx *ctx,
 			.io_min_shift		= 9,
 			.max_sectors		= info->max_io_buf_bytes >> 9,
 			.dev_sectors		= dev_size >> 9,
 		},
 	};
+	ublk_set_integrity_params(ctx, &dev->tgt.params);
 
 	dev->private_data = (void *)(unsigned long)(ctx->fault_inject.delay_us * 1000);
 	return 0;
 }
 
diff --git a/tools/testing/selftests/ublk/file_backed.c b/tools/testing/selftests/ublk/file_backed.c
index 269d5f124e06..c14ce6608696 100644
--- a/tools/testing/selftests/ublk/file_backed.c
+++ b/tools/testing/selftests/ublk/file_backed.c
@@ -156,10 +156,14 @@ static int ublk_loop_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev)
 
 	if (ctx->auto_zc_fallback) {
 		ublk_err("%s: not support auto_zc_fallback\n", __func__);
 		return -EINVAL;
 	}
+	if (ctx->metadata_size) {
+		ublk_err("%s: integrity not supported\n", __func__);
+		return -EINVAL;
+	}
 
 	ret = backing_file_tgt_init(dev);
 	if (ret)
 		return ret;
 
diff --git a/tools/testing/selftests/ublk/kublk.c b/tools/testing/selftests/ublk/kublk.c
index 261095f19c93..6ff110d0dcae 100644
--- a/tools/testing/selftests/ublk/kublk.c
+++ b/tools/testing/selftests/ublk/kublk.c
@@ -1,10 +1,12 @@
 /* SPDX-License-Identifier: MIT */
 /*
  * Description: uring_cmd based ublk
  */
 
+#include "linux/ublk_cmd.h"
+#include <linux/fs.h>
 #include "kublk.h"
 
 #define MAX_NR_TGT_ARG 	64
 
 unsigned int ublk_dbg_mask = UBLK_LOG;
@@ -1548,10 +1550,12 @@ static void __cmd_create_help(char *exe, bool recovery)
 	printf("%s %s -t [null|loop|stripe|fault_inject] [-q nr_queues] [-d depth] [-n dev_id]\n",
 			exe, recovery ? "recover" : "add");
 	printf("\t[--foreground] [--quiet] [-z] [--auto_zc] [--auto_zc_fallback] [--debug_mask mask] [-r 0|1] [-g] [-u]\n");
 	printf("\t[-e 0|1 ] [-i 0|1] [--no_ublk_fixed_fd]\n");
 	printf("\t[--nthreads threads] [--per_io_tasks]\n");
+	printf("\t[--integrity_capable] [--integrity_reftag] [--metadata_size SIZE] "
+		 "[--pi_offset OFFSET] [--csum_type ip|t10dif|nvme] [--tag_size SIZE]\n");
 	printf("\t[target options] [backfile1] [backfile2] ...\n");
 	printf("\tdefault: nr_queues=2(max 32), depth=128(max 1024), dev_id=-1(auto allocation)\n");
 	printf("\tdefault: nthreads=nr_queues");
 
 	for (i = 0; i < ARRAY_SIZE(tgt_ops_list); i++) {
@@ -1611,20 +1615,27 @@ int main(int argc, char *argv[])
 		{ "user_copy",		0,	NULL, 'u'},
 		{ "size",		1,	NULL, 's'},
 		{ "nthreads",		1,	NULL,  0 },
 		{ "per_io_tasks",	0,	NULL,  0 },
 		{ "no_ublk_fixed_fd",	0,	NULL,  0 },
+		{ "integrity_capable",	0,	NULL,  0 },
+		{ "integrity_reftag",	0,	NULL,  0 },
+		{ "metadata_size",	1,	NULL,  0 },
+		{ "pi_offset",		1,	NULL,  0 },
+		{ "csum_type",		1,	NULL,  0 },
+		{ "tag_size",		1,	NULL,  0 },
 		{ 0, 0, 0, 0 }
 	};
 	const struct ublk_tgt_ops *ops = NULL;
 	int option_idx, opt;
 	const char *cmd = argv[1];
 	struct dev_ctx ctx = {
 		.queue_depth	=	128,
 		.nr_hw_queues	=	2,
 		.dev_id		=	-1,
 		.tgt_type	=	"unknown",
+		.csum_type	=	LBMD_PI_CSUM_NONE,
 	};
 	int ret = -EINVAL, i;
 	int tgt_argc = 1;
 	char *tgt_argv[MAX_NR_TGT_ARG] = { NULL };
 	int value;
@@ -1695,10 +1706,32 @@ int main(int argc, char *argv[])
 				ctx.nthreads = strtol(optarg, NULL, 10);
 			if (!strcmp(longopts[option_idx].name, "per_io_tasks"))
 				ctx.per_io_tasks = 1;
 			if (!strcmp(longopts[option_idx].name, "no_ublk_fixed_fd"))
 				ctx.no_ublk_fixed_fd = 1;
+			if (!strcmp(longopts[option_idx].name, "integrity_capable"))
+				ctx.integrity_flags |= LBMD_PI_CAP_INTEGRITY;
+			if (!strcmp(longopts[option_idx].name, "integrity_reftag"))
+				ctx.integrity_flags |= LBMD_PI_CAP_REFTAG;
+			if (!strcmp(longopts[option_idx].name, "metadata_size"))
+				ctx.metadata_size = strtoul(optarg, NULL, 0);
+			if (!strcmp(longopts[option_idx].name, "pi_offset"))
+				ctx.pi_offset = strtoul(optarg, NULL, 0);
+			if (!strcmp(longopts[option_idx].name, "csum_type")) {
+				if (!strcmp(optarg, "ip")) {
+					ctx.csum_type = LBMD_PI_CSUM_IP;
+				} else if (!strcmp(optarg, "t10dif")) {
+					ctx.csum_type = LBMD_PI_CSUM_CRC16_T10DIF;
+				} else if (!strcmp(optarg, "nvme")) {
+					ctx.csum_type = LBMD_PI_CSUM_CRC64_NVME;
+				} else {
+					ublk_err("invalid csum_type: %s\n", optarg);
+					return -EINVAL;
+				}
+			}
+			if (!strcmp(longopts[option_idx].name, "tag_size"))
+				ctx.tag_size = strtoul(optarg, NULL, 0);
 			break;
 		case '?':
 			/*
 			 * target requires every option must have argument
 			 */
@@ -1737,10 +1770,25 @@ int main(int argc, char *argv[])
 	    ctx.auto_zc_fallback > 1) {
 		fprintf(stderr, "too many data copy modes specified\n");
 		return -EINVAL;
 	}
 
+	if (ctx.metadata_size) {
+		if (!(ctx.flags & UBLK_F_USER_COPY)) {
+			ublk_err("integrity requires user_copy\n");
+			return -EINVAL;
+		}
+
+		ctx.flags |= UBLK_F_INTEGRITY;
+	} else if (ctx.integrity_flags ||
+		   ctx.pi_offset ||
+		   ctx.csum_type != LBMD_PI_CSUM_NONE ||
+		   ctx.tag_size) {
+		ublk_err("integrity parameters require metadata_size\n");
+		return -EINVAL;
+	}
+
 	i = optind;
 	while (i < argc && ctx.nr_files < MAX_BACK_FILES) {
 		ctx.files[ctx.nr_files++] = argv[i++];
 	}
 
diff --git a/tools/testing/selftests/ublk/kublk.h b/tools/testing/selftests/ublk/kublk.h
index 8a83b90ec603..d00f2b465cdf 100644
--- a/tools/testing/selftests/ublk/kublk.h
+++ b/tools/testing/selftests/ublk/kublk.h
@@ -76,10 +76,15 @@ struct dev_ctx {
 	unsigned int	fg:1;
 	unsigned int	recovery:1;
 	unsigned int	auto_zc_fallback:1;
 	unsigned int	per_io_tasks:1;
 	unsigned int	no_ublk_fixed_fd:1;
+	__u32 integrity_flags;
+	__u8 metadata_size;
+	__u8 pi_offset;
+	__u8 csum_type;
+	__u8 tag_size;
 
 	int _evtfd;
 	int _shmid;
 
 	/* built from shmem, only for ublk_dump_dev() */
@@ -200,10 +205,26 @@ struct ublk_dev {
 	void *private_data;
 };
 
 extern int ublk_queue_io_cmd(struct ublk_thread *t, struct ublk_io *io);
 
+static inline void ublk_set_integrity_params(const struct dev_ctx *ctx,
+					     struct ublk_params *params)
+{
+	if (!ctx->metadata_size)
+		return;
+
+	params->types |= UBLK_PARAM_TYPE_INTEGRITY;
+	params->integrity = (struct ublk_param_integrity) {
+		.flags = ctx->integrity_flags,
+		.interval_exp = params->basic.logical_bs_shift,
+		.metadata_size = ctx->metadata_size,
+		.pi_offset = ctx->pi_offset,
+		.csum_type = ctx->csum_type,
+		.tag_size = ctx->tag_size,
+	};
+}
 
 static inline int ublk_io_auto_zc_fallback(const struct ublksrv_io_desc *iod)
 {
 	return !!(iod->op_flags & UBLK_IO_F_NEED_REG_BUF);
 }
diff --git a/tools/testing/selftests/ublk/null.c b/tools/testing/selftests/ublk/null.c
index 280043f6b689..3aa162f08476 100644
--- a/tools/testing/selftests/ublk/null.c
+++ b/tools/testing/selftests/ublk/null.c
@@ -34,10 +34,11 @@ static int ublk_null_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev)
 			.seg_boundary_mask 	= 4095,
 			.max_segment_size 	= 32 << 10,
 			.max_segments 		= 32,
 		},
 	};
+	ublk_set_integrity_params(ctx, &dev->tgt.params);
 
 	if (info->flags & UBLK_F_SUPPORT_ZERO_COPY)
 		dev->tgt.sq_depth = dev->tgt.cq_depth = 2 * info->queue_depth;
 	return 0;
 }
diff --git a/tools/testing/selftests/ublk/stripe.c b/tools/testing/selftests/ublk/stripe.c
index fd412e1f01c0..d4aaf3351d71 100644
--- a/tools/testing/selftests/ublk/stripe.c
+++ b/tools/testing/selftests/ublk/stripe.c
@@ -296,10 +296,14 @@ static int ublk_stripe_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev)
 
 	if (ctx->auto_zc_fallback) {
 		ublk_err("%s: not support auto_zc_fallback\n", __func__);
 		return -EINVAL;
 	}
+	if (ctx->metadata_size) {
+		ublk_err("%s: integrity not supported\n", __func__);
+		return -EINVAL;
+	}
 
 	if ((chunk_size & (chunk_size - 1)) || !chunk_size) {
 		ublk_err("invalid chunk size %u\n", chunk_size);
 		return -EINVAL;
 	}
-- 
2.45.2

[PATCH v2 15/19] selftests: ublk: implement integrity user copy in kublk

[Caleb Sander Mateos]

If integrity data is enabled for kublk, allocate an integrity buffer for
each I/O. Extend ublk_user_copy() to copy the integrity data between the
ublk request and the integrity buffer if the ublksrv_io_desc indicates
that the request has integrity data.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 tools/testing/selftests/ublk/kublk.c | 41 ++++++++++++++++++++++++----
 tools/testing/selftests/ublk/kublk.h | 14 ++++++++++
 2 files changed, 50 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/ublk/kublk.c b/tools/testing/selftests/ublk/kublk.c
index 6ff110d0dcae..dfba808657b1 100644
--- a/tools/testing/selftests/ublk/kublk.c
+++ b/tools/testing/selftests/ublk/kublk.c
@@ -415,12 +415,14 @@ static void ublk_queue_deinit(struct ublk_queue *q)
 	int nr_ios = q->q_depth;
 
 	if (q->io_cmd_buf)
 		munmap(q->io_cmd_buf, ublk_queue_cmd_buf_sz(q));
 
-	for (i = 0; i < nr_ios; i++)
+	for (i = 0; i < nr_ios; i++) {
 		free(q->ios[i].buf_addr);
+		free(q->ios[i].integrity_buf);
+	}
 }
 
 static void ublk_thread_deinit(struct ublk_thread *t)
 {
 	io_uring_unregister_buffers(&t->ring);
@@ -432,23 +434,25 @@ static void ublk_thread_deinit(struct ublk_thread *t)
 		close(t->ring.ring_fd);
 		t->ring.ring_fd = -1;
 	}
 }
 
-static int ublk_queue_init(struct ublk_queue *q, unsigned long long extra_flags)
+static int ublk_queue_init(struct ublk_queue *q, unsigned long long extra_flags,
+			   __u8 metadata_size)
 {
 	struct ublk_dev *dev = q->dev;
 	int depth = dev->dev_info.queue_depth;
 	int i;
-	int cmd_buf_size, io_buf_size;
+	int cmd_buf_size, io_buf_size, integrity_size;
 	unsigned long off;
 
 	q->tgt_ops = dev->tgt.ops;
 	q->flags = 0;
 	q->q_depth = depth;
 	q->flags = dev->dev_info.flags;
 	q->flags |= extra_flags;
+	q->metadata_size = metadata_size;
 
 	/* Cache fd in queue for fast path access */
 	q->ublk_fd = dev->fds[0];
 
 	cmd_buf_size = ublk_queue_cmd_buf_sz(q);
@@ -460,15 +464,27 @@ static int ublk_queue_init(struct ublk_queue *q, unsigned long long extra_flags)
 				q->dev->dev_info.dev_id, q->q_id);
 		goto fail;
 	}
 
 	io_buf_size = dev->dev_info.max_io_buf_bytes;
+	integrity_size = ublk_integrity_len(q, io_buf_size);
 	for (i = 0; i < q->q_depth; i++) {
 		q->ios[i].buf_addr = NULL;
 		q->ios[i].flags = UBLKS_IO_NEED_FETCH_RQ | UBLKS_IO_FREE;
 		q->ios[i].tag = i;
 
+		if (integrity_size) {
+			q->ios[i].integrity_buf = malloc(integrity_size);
+			if (!q->ios[i].integrity_buf) {
+				ublk_err("ublk dev %d queue %d io %d malloc(%d) failed: %m\n",
+					 dev->dev_info.dev_id, q->q_id, i,
+					 integrity_size);
+				goto fail;
+			}
+		}
+
+
 		if (ublk_queue_no_buf(q))
 			continue;
 
 		if (posix_memalign((void **)&q->ios[i].buf_addr,
 					getpagesize(), io_buf_size)) {
@@ -607,17 +623,17 @@ static void ublk_user_copy(const struct ublk_io *io, __u8 match_ublk_op)
 	const struct ublksrv_io_desc *iod = ublk_get_iod(q, io->tag);
 	__u64 off = ublk_user_copy_offset(q->q_id, io->tag);
 	__u8 ublk_op = ublksrv_get_op(iod);
 	__u32 len = iod->nr_sectors << 9;
 	void *addr = io->buf_addr;
+	ssize_t copied;
 
 	if (ublk_op != match_ublk_op)
 		return;
 
 	while (len) {
 		__u32 copy_len = min(len, UBLK_USER_COPY_LEN);
-		ssize_t copied;
 
 		if (ublk_op == UBLK_IO_OP_WRITE)
 			copied = pread(q->ublk_fd, addr, copy_len, off);
 		else if (ublk_op == UBLK_IO_OP_READ)
 			copied = pwrite(q->ublk_fd, addr, copy_len, off);
@@ -626,10 +642,24 @@ static void ublk_user_copy(const struct ublk_io *io, __u8 match_ublk_op)
 		assert(copied == (ssize_t)copy_len);
 		addr += copy_len;
 		off += copy_len;
 		len -= copy_len;
 	}
+
+	if (!(iod->op_flags & UBLK_IO_F_INTEGRITY))
+		return;
+
+	len = ublk_integrity_len(q, iod->nr_sectors << 9);
+	off = ublk_user_copy_offset(q->q_id, io->tag);
+	off += UBLKSRV_IO_INTEGRITY_FLAG;
+	if (ublk_op == UBLK_IO_OP_WRITE)
+		copied = pread(q->ublk_fd, io->integrity_buf, len, off);
+	else if (ublk_op == UBLK_IO_OP_READ)
+		copied = pwrite(q->ublk_fd, io->integrity_buf, len, off);
+	else
+		assert(0);
+	assert(copied == (ssize_t)len);
 }
 
 int ublk_queue_io_cmd(struct ublk_thread *t, struct ublk_io *io)
 {
 	struct ublk_queue *q = ublk_io_to_queue(io);
@@ -1012,11 +1042,12 @@ static int ublk_start_daemon(const struct dev_ctx *ctx, struct ublk_dev *dev)
 
 	for (i = 0; i < dinfo->nr_hw_queues; i++) {
 		dev->q[i].dev = dev;
 		dev->q[i].q_id = i;
 
-		ret = ublk_queue_init(&dev->q[i], extra_flags);
+		ret = ublk_queue_init(&dev->q[i], extra_flags,
+				      ctx->metadata_size);
 		if (ret) {
 			ublk_err("ublk dev %d queue %d init queue failed\n",
 				 dinfo->dev_id, i);
 			goto fail;
 		}
diff --git a/tools/testing/selftests/ublk/kublk.h b/tools/testing/selftests/ublk/kublk.h
index d00f2b465cdf..830b49a7716a 100644
--- a/tools/testing/selftests/ublk/kublk.h
+++ b/tools/testing/selftests/ublk/kublk.h
@@ -110,10 +110,11 @@ struct ublk_ctrl_cmd_data {
 	__u32 len;
 };
 
 struct ublk_io {
 	char *buf_addr;
+	void *integrity_buf;
 
 #define UBLKS_IO_NEED_FETCH_RQ		(1UL << 0)
 #define UBLKS_IO_NEED_COMMIT_RQ_COMP	(1UL << 1)
 #define UBLKS_IO_FREE			(1UL << 2)
 #define UBLKS_IO_NEED_GET_DATA           (1UL << 3)
@@ -173,10 +174,11 @@ struct ublk_queue {
 /* borrow one bit of ublk uapi flags, which may never be used */
 #define UBLKS_Q_AUTO_BUF_REG_FALLBACK	(1ULL << 63)
 #define UBLKS_Q_NO_UBLK_FIXED_FD	(1ULL << 62)
 	__u64 flags;
 	int ublk_fd;	/* cached ublk char device fd */
+	__u8 metadata_size;
 	struct ublk_io ios[UBLK_QUEUE_DEPTH];
 };
 
 struct ublk_thread {
 	struct ublk_dev *dev;
@@ -222,10 +224,22 @@ static inline void ublk_set_integrity_params(const struct dev_ctx *ctx,
 		.csum_type = ctx->csum_type,
 		.tag_size = ctx->tag_size,
 	};
 }
 
+static inline size_t ublk_integrity_len(const struct ublk_queue *q, size_t len)
+{
+	/* All targets currently use interval_exp = logical_bs_shift = 9 */
+	return (len >> 9) * q->metadata_size;
+}
+
+static inline size_t
+ublk_integrity_data_len(const struct ublk_queue *q, size_t integrity_len)
+{
+	return (integrity_len / q->metadata_size) << 9;
+}
+
 static inline int ublk_io_auto_zc_fallback(const struct ublksrv_io_desc *iod)
 {
 	return !!(iod->op_flags & UBLK_IO_F_NEED_REG_BUF);
 }
 
-- 
2.45.2

[PATCH v2 16/19] selftests: ublk: support non-O_DIRECT backing files

[Caleb Sander Mateos]

A subsequent commit will add support for using a backing file to store
integrity data. Since integrity data is accessed in intervals of
metadata_size, which may be much smaller than a logical block on the
backing device, direct I/O cannot be used. Add an argument to
backing_file_tgt_init() to specify the number of files to open for
direct I/O. The remaining files will use buffered I/O. For now, continue
to request direct I/O for all the files.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 tools/testing/selftests/ublk/common.c      | 4 ++--
 tools/testing/selftests/ublk/file_backed.c | 2 +-
 tools/testing/selftests/ublk/kublk.h       | 2 +-
 tools/testing/selftests/ublk/stripe.c      | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/ublk/common.c b/tools/testing/selftests/ublk/common.c
index 01580a6f8519..d9873d4d50d0 100644
--- a/tools/testing/selftests/ublk/common.c
+++ b/tools/testing/selftests/ublk/common.c
@@ -10,11 +10,11 @@ void backing_file_tgt_deinit(struct ublk_dev *dev)
 		fsync(dev->fds[i]);
 		close(dev->fds[i]);
 	}
 }
 
-int backing_file_tgt_init(struct ublk_dev *dev)
+int backing_file_tgt_init(struct ublk_dev *dev, unsigned int nr_direct)
 {
 	int fd, i;
 
 	assert(dev->nr_fds == 1);
 
@@ -23,11 +23,11 @@ int backing_file_tgt_init(struct ublk_dev *dev)
 		unsigned long bytes;
 		struct stat st;
 
 		ublk_dbg(UBLK_DBG_DEV, "%s: file %d: %s\n", __func__, i, file);
 
-		fd = open(file, O_RDWR | O_DIRECT);
+		fd = open(file, O_RDWR | (i < nr_direct ? O_DIRECT : 0));
 		if (fd < 0) {
 			ublk_err("%s: backing file %s can't be opened: %s\n",
 					__func__, file, strerror(errno));
 			return -EBADF;
 		}
diff --git a/tools/testing/selftests/ublk/file_backed.c b/tools/testing/selftests/ublk/file_backed.c
index c14ce6608696..db4c176a4f28 100644
--- a/tools/testing/selftests/ublk/file_backed.c
+++ b/tools/testing/selftests/ublk/file_backed.c
@@ -161,11 +161,11 @@ static int ublk_loop_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev)
 	if (ctx->metadata_size) {
 		ublk_err("%s: integrity not supported\n", __func__);
 		return -EINVAL;
 	}
 
-	ret = backing_file_tgt_init(dev);
+	ret = backing_file_tgt_init(dev, 1);
 	if (ret)
 		return ret;
 
 	if (dev->tgt.nr_backing_files != 1)
 		return -EINVAL;
diff --git a/tools/testing/selftests/ublk/kublk.h b/tools/testing/selftests/ublk/kublk.h
index 830b49a7716a..96c66b337bc0 100644
--- a/tools/testing/selftests/ublk/kublk.h
+++ b/tools/testing/selftests/ublk/kublk.h
@@ -460,8 +460,8 @@ extern const struct ublk_tgt_ops null_tgt_ops;
 extern const struct ublk_tgt_ops loop_tgt_ops;
 extern const struct ublk_tgt_ops stripe_tgt_ops;
 extern const struct ublk_tgt_ops fault_inject_tgt_ops;
 
 void backing_file_tgt_deinit(struct ublk_dev *dev);
-int backing_file_tgt_init(struct ublk_dev *dev);
+int backing_file_tgt_init(struct ublk_dev *dev, unsigned int nr_direct);
 
 #endif
diff --git a/tools/testing/selftests/ublk/stripe.c b/tools/testing/selftests/ublk/stripe.c
index d4aaf3351d71..2be1c36438e7 100644
--- a/tools/testing/selftests/ublk/stripe.c
+++ b/tools/testing/selftests/ublk/stripe.c
@@ -313,11 +313,11 @@ static int ublk_stripe_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev)
 		return -EINVAL;
 	}
 
 	chunk_shift = ilog2(chunk_size);
 
-	ret = backing_file_tgt_init(dev);
+	ret = backing_file_tgt_init(dev, dev->tgt.nr_backing_files);
 	if (ret)
 		return ret;
 
 	if (!dev->tgt.nr_backing_files || dev->tgt.nr_backing_files > NR_STRIPE)
 		return -EINVAL;
-- 
2.45.2

[PATCH v2 17/19] selftests: ublk: add integrity data support to loop target

[Caleb Sander Mateos]

To perform and end-to-end test of integrity information through a ublk
device, we need to actually store it somewhere and retrieve it. Add this
support to kublk's loop target. It uses a second backing file for the
integrity data corresponding to the data stored in the first file.
The integrity file is opened without O_DIRECT since it will be accessed
at sub-block granularity. Each incoming read/write results in a pair of
reads/writes, one to the data file, and one to the integrity file. If
either backing I/O fails, the error is propagated to the ublk request.
If both backing I/Os read/write some bytes, the ublk request is
completed with the smaller of the number of blocks accessed by each I/O.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 tools/testing/selftests/ublk/file_backed.c | 63 +++++++++++++++-------
 1 file changed, 45 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/ublk/file_backed.c b/tools/testing/selftests/ublk/file_backed.c
index db4c176a4f28..b8aacaa928a4 100644
--- a/tools/testing/selftests/ublk/file_backed.c
+++ b/tools/testing/selftests/ublk/file_backed.c
@@ -33,48 +33,62 @@ static int loop_queue_tgt_rw_io(struct ublk_thread *t, struct ublk_queue *q,
 	unsigned ublk_op = ublksrv_get_op(iod);
 	unsigned zc = ublk_queue_use_zc(q);
 	unsigned auto_zc = ublk_queue_use_auto_zc(q);
 	enum io_uring_op op = ublk_to_uring_op(iod, zc | auto_zc);
 	struct ublk_io *io = ublk_get_io(q, tag);
+	__u64 offset = iod->start_sector << 9;
+	__u32 len = iod->nr_sectors << 9;
 	struct io_uring_sqe *sqe[3];
 	void *addr = io->buf_addr;
 
+	if (iod->op_flags & UBLK_IO_F_INTEGRITY) {
+		ublk_io_alloc_sqes(t, sqe, 1);
+		/* Use second backing file for integrity data */
+		io_uring_prep_rw(op, sqe[0], ublk_get_registered_fd(q, 2),
+				 io->integrity_buf,
+				 ublk_integrity_len(q, len),
+				 ublk_integrity_len(q, offset));
+		sqe[0]->flags = IOSQE_FIXED_FILE;
+		/* tgt_data = 1 indicates integrity I/O */
+		sqe[0]->user_data = build_user_data(tag, ublk_op, 1, q->q_id, 1);
+	}
+
 	if (!zc || auto_zc) {
 		ublk_io_alloc_sqes(t, sqe, 1);
 		if (!sqe[0])
 			return -ENOMEM;
 
 		io_uring_prep_rw(op, sqe[0], ublk_get_registered_fd(q, 1) /*fds[1]*/,
 				addr,
-				iod->nr_sectors << 9,
-				iod->start_sector << 9);
+				len,
+				offset);
 		if (auto_zc)
 			sqe[0]->buf_index = tag;
 		io_uring_sqe_set_flags(sqe[0], IOSQE_FIXED_FILE);
 		/* bit63 marks us as tgt io */
 		sqe[0]->user_data = build_user_data(tag, ublk_op, 0, q->q_id, 1);
-		return 1;
+		return !!(iod->op_flags & UBLK_IO_F_INTEGRITY) + 1;
 	}
 
 	ublk_io_alloc_sqes(t, sqe, 3);
 
 	io_uring_prep_buf_register(sqe[0], q, tag, q->q_id, io->buf_index);
 	sqe[0]->flags |= IOSQE_CQE_SKIP_SUCCESS | IOSQE_IO_HARDLINK;
 	sqe[0]->user_data = build_user_data(tag,
 			ublk_cmd_op_nr(sqe[0]->cmd_op), 0, q->q_id, 1);
 
 	io_uring_prep_rw(op, sqe[1], ublk_get_registered_fd(q, 1) /*fds[1]*/, 0,
-		iod->nr_sectors << 9,
-		iod->start_sector << 9);
+			len,
+			offset);
 	sqe[1]->buf_index = tag;
 	sqe[1]->flags |= IOSQE_FIXED_FILE | IOSQE_IO_HARDLINK;
 	sqe[1]->user_data = build_user_data(tag, ublk_op, 0, q->q_id, 1);
 
 	io_uring_prep_buf_unregister(sqe[2], q, tag, q->q_id, io->buf_index);
 	sqe[2]->user_data = build_user_data(tag, ublk_cmd_op_nr(sqe[2]->cmd_op), 0, q->q_id, 1);
 
-	return 2;
+	return !!(iod->op_flags & UBLK_IO_F_INTEGRITY) + 2;
 }
 
 static int loop_queue_tgt_io(struct ublk_thread *t, struct ublk_queue *q, int tag)
 {
 	const struct ublksrv_io_desc *iod = ublk_get_iod(q, tag);
@@ -117,16 +131,21 @@ static void ublk_loop_io_done(struct ublk_thread *t, struct ublk_queue *q,
 {
 	unsigned tag = user_data_to_tag(cqe->user_data);
 	unsigned op = user_data_to_op(cqe->user_data);
 	struct ublk_io *io = ublk_get_io(q, tag);
 
-	if (cqe->res < 0 || op != ublk_cmd_op_nr(UBLK_U_IO_UNREGISTER_IO_BUF)) {
-		if (!io->result)
-			io->result = cqe->res;
-		if (cqe->res < 0)
-			ublk_err("%s: io failed op %x user_data %lx\n",
-					__func__, op, cqe->user_data);
+	if (cqe->res < 0) {
+		io->result = cqe->res;
+		ublk_err("%s: io failed op %x user_data %lx\n",
+				__func__, op, cqe->user_data);
+	} else if (op != ublk_cmd_op_nr(UBLK_U_IO_UNREGISTER_IO_BUF)) {
+		__s32 data_len = user_data_to_tgt_data(cqe->user_data)
+			? ublk_integrity_data_len(q, cqe->res)
+			: cqe->res;
+
+		if (!io->result || data_len < io->result)
+			io->result = data_len;
 	}
 
 	/* buffer register op is IOSQE_CQE_SKIP_SUCCESS */
 	if (op == ublk_cmd_op_nr(UBLK_U_IO_REGISTER_IO_BUF))
 		io->tgt_ios += 1;
@@ -136,10 +155,11 @@ static void ublk_loop_io_done(struct ublk_thread *t, struct ublk_queue *q,
 }
 
 static int ublk_loop_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev)
 {
 	unsigned long long bytes;
+	unsigned long blocks;
 	int ret;
 	struct ublk_params p = {
 		.types = UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DMA_ALIGN,
 		.basic = {
 			.attrs = UBLK_ATTR_VOLATILE_CACHE,
@@ -152,27 +172,34 @@ static int ublk_loop_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev)
 		.dma = {
 			.alignment = 511,
 		},
 	};
 
+	ublk_set_integrity_params(ctx, &p);
 	if (ctx->auto_zc_fallback) {
 		ublk_err("%s: not support auto_zc_fallback\n", __func__);
 		return -EINVAL;
 	}
-	if (ctx->metadata_size) {
-		ublk_err("%s: integrity not supported\n", __func__);
-		return -EINVAL;
-	}
 
+	/* Use O_DIRECT only for data file */
 	ret = backing_file_tgt_init(dev, 1);
 	if (ret)
 		return ret;
 
-	if (dev->tgt.nr_backing_files != 1)
+	/* Expect a second file for integrity data */
+	if (dev->tgt.nr_backing_files != 1 + !!ctx->metadata_size)
 		return -EINVAL;
 
-	bytes = dev->tgt.backing_file_size[0];
+	blocks = dev->tgt.backing_file_size[0] >> p.basic.logical_bs_shift;
+	if (ctx->metadata_size) {
+		unsigned long metadata_blocks =
+			dev->tgt.backing_file_size[1] / ctx->metadata_size;
+
+		/* Ensure both data and integrity data fit in backing files */
+		blocks = min(blocks, metadata_blocks);
+	}
+	bytes = blocks << p.basic.logical_bs_shift;
 	dev->tgt.dev_size = bytes;
 	p.basic.dev_sectors = bytes >> 9;
 	dev->tgt.params = p;
 
 	return 0;
-- 
2.45.2

[PATCH v2 18/19] selftests: ublk: add integrity params test

[Caleb Sander Mateos]

Add test case null_04 to exercise all the different integrity params. It
creates 4 different ublk devices with different combinations of
integrity arguments and verifies their integrity limits via sysfs and
the metadata_size utility.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 tools/testing/selftests/ublk/Makefile        |   1 +
 tools/testing/selftests/ublk/test_common.sh  |  10 ++
 tools/testing/selftests/ublk/test_null_04.sh | 166 +++++++++++++++++++
 3 files changed, 177 insertions(+)
 create mode 100755 tools/testing/selftests/ublk/test_null_04.sh

diff --git a/tools/testing/selftests/ublk/Makefile b/tools/testing/selftests/ublk/Makefile
index 41f776bb86a6..bfd68ae64142 100644
--- a/tools/testing/selftests/ublk/Makefile
+++ b/tools/testing/selftests/ublk/Makefile
@@ -25,10 +25,11 @@ TEST_PROGS += test_generic_14.sh
 TEST_PROGS += test_generic_15.sh
 
 TEST_PROGS += test_null_01.sh
 TEST_PROGS += test_null_02.sh
 TEST_PROGS += test_null_03.sh
+TEST_PROGS += test_null_04.sh
 TEST_PROGS += test_loop_01.sh
 TEST_PROGS += test_loop_02.sh
 TEST_PROGS += test_loop_03.sh
 TEST_PROGS += test_loop_04.sh
 TEST_PROGS += test_loop_05.sh
diff --git a/tools/testing/selftests/ublk/test_common.sh b/tools/testing/selftests/ublk/test_common.sh
index ea9a5f3eb70a..7ff6ce79d62c 100755
--- a/tools/testing/selftests/ublk/test_common.sh
+++ b/tools/testing/selftests/ublk/test_common.sh
@@ -382,10 +382,20 @@ run_io_and_recover()
 _ublk_test_top_dir()
 {
 	cd "$(dirname "$0")" && pwd
 }
 
+METADATA_SIZE_PROG="$(_ublk_test_top_dir)/metadata_size"
+
+_get_metadata_size()
+{
+	local dev_id=$1
+	local field=$2
+
+	"$METADATA_SIZE_PROG" "/dev/ublkb$dev_id" | grep "$field" | grep -o "[0-9]*"
+}
+
 UBLK_PROG=$(_ublk_test_top_dir)/kublk
 UBLK_TEST_QUIET=1
 UBLK_TEST_SHOW_RESULT=1
 UBLK_BACKFILES=()
 export UBLK_PROG
diff --git a/tools/testing/selftests/ublk/test_null_04.sh b/tools/testing/selftests/ublk/test_null_04.sh
new file mode 100755
index 000000000000..0b0719ea33a3
--- /dev/null
+++ b/tools/testing/selftests/ublk/test_null_04.sh
@@ -0,0 +1,166 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+. "$(cd "$(dirname "$0")" && pwd)"/test_common.sh
+
+TID=null_04
+
+_prep_test "null" "integrity params"
+
+dev_id=$(_add_ublk_dev -t null -u --metadata_size 8)
+_check_add_dev $TID $?
+metadata_size=$(_get_metadata_size "$dev_id" metadata_size)
+if [ "$metadata_size" != 8 ]; then
+	echo "metadata_size $metadata_size != 8"
+	_show_result $TID 255
+fi
+pi_offset=$(_get_metadata_size "$dev_id" pi_offset)
+if [ "$pi_offset" != 0 ]; then
+	echo "pi_offset $pi_offset != 0"
+	_show_result $TID 255
+fi
+pi_tuple_size=$(_get_metadata_size "$dev_id" pi_tuple_size)
+if [ "$pi_tuple_size" != 0 ]; then
+	echo "pi_tuple_size $pi_tuple_size != 0"
+	_show_result $TID 255
+fi
+capable=$(cat "/sys/block/ublkb$dev_id/integrity/device_is_integrity_capable")
+if [ "$capable" != 0 ]; then
+	echo "device_is_integrity_capable $capable != 0"
+	_show_result $TID 255
+fi
+format=$(cat "/sys/block/ublkb$dev_id/integrity/format")
+if [ "$format" != nop ]; then
+	echo "format $format != nop"
+	_show_result $TID 255
+fi
+protection_interval_bytes=$(cat "/sys/block/ublkb$dev_id/integrity/protection_interval_bytes")
+if [ "$protection_interval_bytes" != 512 ]; then
+	echo "protection_interval_bytes $protection_interval_bytes != 512"
+	_show_result $TID 255
+fi
+tag_size=$(cat "/sys/block/ublkb$dev_id/integrity/tag_size")
+if [ "$tag_size" != 0 ]; then
+	echo "tag_size $tag_size != 0"
+	_show_result $TID 255
+fi
+_cleanup_test
+
+dev_id=$(_add_ublk_dev -t null -u --integrity_capable --metadata_size 64 --pi_offset 56 --csum_type ip)
+_check_add_dev $TID $?
+metadata_size=$(_get_metadata_size "$dev_id" metadata_size)
+if [ "$metadata_size" != 64 ]; then
+	echo "metadata_size $metadata_size != 64"
+	_show_result $TID 255
+fi
+pi_offset=$(_get_metadata_size "$dev_id" pi_offset)
+if [ "$pi_offset" != 56 ]; then
+	echo "pi_offset $pi_offset != 56"
+	_show_result $TID 255
+fi
+pi_tuple_size=$(_get_metadata_size "$dev_id" pi_tuple_size)
+if [ "$pi_tuple_size" != 8 ]; then
+	echo "pi_tuple_size $pi_tuple_size != 8"
+	_show_result $TID 255
+fi
+capable=$(cat "/sys/block/ublkb$dev_id/integrity/device_is_integrity_capable")
+if [ "$capable" != 1 ]; then
+	echo "device_is_integrity_capable $capable != 1"
+	_show_result $TID 255
+fi
+format=$(cat "/sys/block/ublkb$dev_id/integrity/format")
+if [ "$format" != T10-DIF-TYPE3-IP ]; then
+	echo "format $format != T10-DIF-TYPE3-IP"
+	_show_result $TID 255
+fi
+protection_interval_bytes=$(cat "/sys/block/ublkb$dev_id/integrity/protection_interval_bytes")
+if [ "$protection_interval_bytes" != 512 ]; then
+	echo "protection_interval_bytes $protection_interval_bytes != 512"
+	_show_result $TID 255
+fi
+tag_size=$(cat "/sys/block/ublkb$dev_id/integrity/tag_size")
+if [ "$tag_size" != 0 ]; then
+	echo "tag_size $tag_size != 0"
+	_show_result $TID 255
+fi
+_cleanup_test
+
+dev_id=$(_add_ublk_dev -t null -u --integrity_reftag --metadata_size 8 --csum_type t10dif)
+_check_add_dev $TID $?
+metadata_size=$(_get_metadata_size "$dev_id" metadata_size)
+if [ "$metadata_size" != 8 ]; then
+	echo "metadata_size $metadata_size != 8"
+	_show_result $TID 255
+fi
+pi_offset=$(_get_metadata_size "$dev_id" pi_offset)
+if [ "$pi_offset" != 0 ]; then
+	echo "pi_offset $pi_offset != 0"
+	_show_result $TID 255
+fi
+pi_tuple_size=$(_get_metadata_size "$dev_id" pi_tuple_size)
+if [ "$pi_tuple_size" != 8 ]; then
+	echo "pi_tuple_size $pi_tuple_size != 8"
+	_show_result $TID 255
+fi
+capable=$(cat "/sys/block/ublkb$dev_id/integrity/device_is_integrity_capable")
+if [ "$capable" != 0 ]; then
+	echo "device_is_integrity_capable $capable != 0"
+	_show_result $TID 255
+fi
+format=$(cat "/sys/block/ublkb$dev_id/integrity/format")
+if [ "$format" != T10-DIF-TYPE1-CRC ]; then
+	echo "format $format != T10-DIF-TYPE1-CRC"
+	_show_result $TID 255
+fi
+protection_interval_bytes=$(cat "/sys/block/ublkb$dev_id/integrity/protection_interval_bytes")
+if [ "$protection_interval_bytes" != 512 ]; then
+	echo "protection_interval_bytes $protection_interval_bytes != 512"
+	_show_result $TID 255
+fi
+tag_size=$(cat "/sys/block/ublkb$dev_id/integrity/tag_size")
+if [ "$tag_size" != 0 ]; then
+	echo "tag_size $tag_size != 0"
+	_show_result $TID 255
+fi
+_cleanup_test
+
+dev_id=$(_add_ublk_dev -t null -u --metadata_size 16 --csum_type nvme --tag_size 8)
+_check_add_dev $TID $?
+metadata_size=$(_get_metadata_size "$dev_id" metadata_size)
+if [ "$metadata_size" != 16 ]; then
+	echo "metadata_size $metadata_size != 16"
+	_show_result $TID 255
+fi
+pi_offset=$(_get_metadata_size "$dev_id" pi_offset)
+if [ "$pi_offset" != 0 ]; then
+	echo "pi_offset $pi_offset != 0"
+	_show_result $TID 255
+fi
+pi_tuple_size=$(_get_metadata_size "$dev_id" pi_tuple_size)
+if [ "$pi_tuple_size" != 16 ]; then
+	echo "pi_tuple_size $pi_tuple_size != 16"
+	_show_result $TID 255
+fi
+capable=$(cat "/sys/block/ublkb$dev_id/integrity/device_is_integrity_capable")
+if [ "$capable" != 0 ]; then
+	echo "device_is_integrity_capable $capable != 0"
+	_show_result $TID 255
+fi
+format=$(cat "/sys/block/ublkb$dev_id/integrity/format")
+if [ "$format" != EXT-DIF-TYPE3-CRC64 ]; then
+	echo "format $format != EXT-DIF-TYPE3-CRC64"
+	_show_result $TID 255
+fi
+protection_interval_bytes=$(cat "/sys/block/ublkb$dev_id/integrity/protection_interval_bytes")
+if [ "$protection_interval_bytes" != 512 ]; then
+	echo "protection_interval_bytes $protection_interval_bytes != 512"
+	_show_result $TID 255
+fi
+tag_size=$(cat "/sys/block/ublkb$dev_id/integrity/tag_size")
+if [ "$tag_size" != 8 ]; then
+	echo "tag_size $tag_size != 8"
+	_show_result $TID 255
+fi
+_cleanup_test
+
+_show_result $TID 0
-- 
2.45.2

[PATCH v2 19/19] selftests: ublk: add end-to-end integrity test

[Caleb Sander Mateos]

Add test case loop_08 to verify the ublk integrity data flow. It uses
the kublk loop target to create a ublk device with integrity on top of
backing data and integrity files. It then writes to the whole device
with fio configured to generate integrity data. Then it reads back the
whole device with fio configured to verify the integrity data.
It also verifies that injected guard, reftag, and apptag corruptions are
correctly detected.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 tools/testing/selftests/ublk/Makefile        |   1 +
 tools/testing/selftests/ublk/test_loop_08.sh | 111 +++++++++++++++++++
 2 files changed, 112 insertions(+)
 create mode 100755 tools/testing/selftests/ublk/test_loop_08.sh

diff --git a/tools/testing/selftests/ublk/Makefile b/tools/testing/selftests/ublk/Makefile
index bfd68ae64142..ab745443fd58 100644
--- a/tools/testing/selftests/ublk/Makefile
+++ b/tools/testing/selftests/ublk/Makefile
@@ -33,10 +33,11 @@ TEST_PROGS += test_loop_02.sh
 TEST_PROGS += test_loop_03.sh
 TEST_PROGS += test_loop_04.sh
 TEST_PROGS += test_loop_05.sh
 TEST_PROGS += test_loop_06.sh
 TEST_PROGS += test_loop_07.sh
+TEST_PROGS += test_loop_08.sh
 TEST_PROGS += test_stripe_01.sh
 TEST_PROGS += test_stripe_02.sh
 TEST_PROGS += test_stripe_03.sh
 TEST_PROGS += test_stripe_04.sh
 TEST_PROGS += test_stripe_05.sh
diff --git a/tools/testing/selftests/ublk/test_loop_08.sh b/tools/testing/selftests/ublk/test_loop_08.sh
new file mode 100755
index 000000000000..ca289cfb2ad4
--- /dev/null
+++ b/tools/testing/selftests/ublk/test_loop_08.sh
@@ -0,0 +1,111 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+. "$(cd "$(dirname "$0")" && pwd)"/test_common.sh
+
+if ! _have_program fio; then
+	exit $UBLK_SKIP_CODE
+fi
+
+fio_version=$(fio --version)
+if [[ "$fio_version" =~ fio-[0-9]+\.[0-9]+$ ]]; then
+	echo "Requires development fio version with https://github.com/axboe/fio/pull/1992"
+	exit $UBLK_SKIP_CODE
+fi
+
+TID=loop_08
+
+_prep_test "loop" "end-to-end integrity"
+
+_create_backfile 0 256M
+_create_backfile 1 32M # 256M * (64 integrity bytes / 512 data bytes)
+integrity_params="--integrity_capable --integrity_reftag
+                  --metadata_size 64 --pi_offset 56 --csum_type t10dif"
+dev_id=$(_add_ublk_dev -t loop -u $integrity_params "${UBLK_BACKFILES[@]}")
+_check_add_dev $TID $?
+
+# 1M * (64 integrity bytes / 512 data bytes) = 128K
+fio_args="--ioengine io_uring --direct 1 --bsrange 512-1M --iodepth 32
+          --md_per_io_size 128K --pi_act 0 --pi_chk GUARD,REFTAG,APPTAG
+          --filename /dev/ublkb$dev_id"
+fio --name fill --rw randwrite $fio_args > /dev/null
+err=$?
+if [ $err != 0 ]; then
+	echo "fio fill failed"
+	_show_result $TID $err
+fi
+
+fio --name verify --rw randread $fio_args > /dev/null
+err=$?
+if [ $err != 0 ]; then
+	echo "fio verify failed"
+	_show_result $TID $err
+fi
+
+fio_err=$(mktemp fio_err_XXXXX)
+
+# Overwrite 4-byte reftag at offset 56 + 4 = 60
+dd_reftag_args="bs=1 seek=60 count=4 oflag=dsync conv=notrunc status=none"
+dd if=/dev/urandom "of=${UBLK_BACKFILES[1]}" $dd_reftag_args
+err=$?
+if [ $err != 0 ]; then
+	echo "dd corrupted_reftag failed"
+	rm -f "$fio_err"
+	_show_result $TID $err
+fi
+if fio --name corrupted_reftag --rw randread $fio_args > /dev/null 2> "$fio_err"; then
+	echo "fio corrupted_reftag unexpectedly succeeded"
+	rm -f "$fio_err"
+	_show_result $TID 255
+fi
+expected_err="REFTAG compare error: LBA: 0 Expected=0, Actual="
+if ! grep -q "$expected_err" "$fio_err"; then
+	echo "fio corrupted_reftag message not found: $expected_err"
+	rm -f "$fio_err"
+	_show_result $TID 255
+fi
+# Reset to 0
+dd if=/dev/zero "of=${UBLK_BACKFILES[1]}" $dd_reftag_args
+err=$?
+if [ $err != 0 ]; then
+	echo "dd restore corrupted_reftag failed"
+	rm -f "$fio_err"
+	_show_result $TID $err
+fi
+
+dd_data_args="bs=512 count=1 oflag=direct,dsync conv=notrunc status=none"
+dd if=/dev/zero "of=${UBLK_BACKFILES[0]}" $dd_data_args
+err=$?
+if [ $err != 0 ]; then
+	echo "dd corrupted_data failed"
+	rm -f "$fio_err"
+	_show_result $TID $err
+fi
+if fio --name corrupted_data --rw randread $fio_args > /dev/null 2> "$fio_err"; then
+	echo "fio corrupted_data unexpectedly succeeded"
+	rm -f "$fio_err"
+	_show_result $TID 255
+fi
+expected_err="Guard compare error: LBA: 0 Expected=0, Actual="
+if ! grep -q "$expected_err" "$fio_err"; then
+	echo "fio corrupted_data message not found: $expected_err"
+	rm -f "$fio_err"
+	_show_result $TID 255
+fi
+
+if fio --name bad_apptag --rw randread $fio_args --apptag 0x4321 > /dev/null 2> "$fio_err"; then
+	echo "fio bad_apptag unexpectedly succeeded"
+	rm -f "$fio_err"
+	_show_result $TID 255
+fi
+expected_err="APPTAG compare error: LBA: [0-9]* Expected=4321, Actual=1234"
+if ! grep -q "$expected_err" "$fio_err"; then
+	echo "fio bad_apptag message not found: $expected_err"
+	rm -f "$fio_err"
+	_show_result $TID 255
+fi
+
+rm -f "$fio_err"
+
+_cleanup_test
+_show_result $TID 0
-- 
2.45.2

Re: [PATCH v2 04/19] ublk: set request integrity params in ublksrv_io_desc

[Ming Lei]

On Fri, Jan 02, 2026 at 05:45:14PM -0700, Caleb Sander Mateos wrote:
> Indicate to the ublk server when an incoming request has integrity data
> by setting UBLK_IO_F_INTEGRITY in the ublksrv_io_desc's op_flags field.
> If the ublk device doesn't support integrity, the request will never
> provide integrity data. If the ublk device supports integrity, the
> request may omit the integrity buffer only if metadata_size matches the
> PI tuple size determined by csum_type. In this case, the ublk server
> should internally generate/verify the protection information from the
> data and sector offset.
> Set the UBLK_IO_F_CHECK_{GUARD,REFTAG,APPTAG} flags based on the
> request's BIP_CHECK_{GUARD,REFTAG,APPTAG} flags, indicating whether to
> verify the guard, reference, and app tags in the protection information.
> The expected reference tag (32 or 48 bits) and app tag (16 bits) are
> indicated in ublksrv_io_desc's new struct ublksrv_io_integrity integrity
> field. This field is unioned with the addr field to avoid changing the

It might be fine to set per-rq app_tag, but bios in one request might have
different app_tag in case of io merge actually.

Also block layer builds ref_tag for each internal, please see
t10_pi_generate() and ext_pi_crc64_generate().

So looks this way is wrong.

More importantly reusing iod->addr for other purpose not related with IO
buffer is very unfriendly for adding new features, and one lesson is for ZONED support
by reusing ublksrv_io_cmd->addr for zoned's append lba.

For example, there is chance to support dma-buf based zero copy for ublk, and
please see the io-uring dma-buf support[1], and iod->addr might carry IO buffer info
in dma-buf format in future.

[1] https://lore.kernel.org/io-uring/cover.1763725387.git.asml.silence@gmail.com/#t


> size of struct ublksrv_io_desc. UBLK_F_INTEGRITY requires
> UBLK_F_USER_COPY and the addr field isn't used for UBLK_F_USER_COPY, so
> the two fields aren't needed simultaneously.
> 
> Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
> ---
>  drivers/block/ublk_drv.c      | 43 +++++++++++++++++++++++++++++++----
>  include/uapi/linux/ublk_cmd.h | 27 ++++++++++++++++++++--
>  2 files changed, 64 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> index 2f9316febf83..51469e0627ff 100644
> --- a/drivers/block/ublk_drv.c
> +++ b/drivers/block/ublk_drv.c
> @@ -316,10 +316,36 @@ static inline bool ublk_dev_is_zoned(const struct ublk_device *ub)
>  static inline bool ublk_queue_is_zoned(const struct ublk_queue *ubq)
>  {
>  	return ubq->flags & UBLK_F_ZONED;
>  }
>  
> +static void ublk_setup_iod_buf(const struct ublk_queue *ubq,
> +			       const struct request *req,
> +			       struct ublksrv_io_desc *iod)
> +{
> +#ifdef CONFIG_BLK_DEV_INTEGRITY
> +	if (ubq->flags & UBLK_F_INTEGRITY) {
> +		struct bio_integrity_payload *bip;
> +		sector_t ref_tag_seed;
> +
> +		if (!blk_integrity_rq(req))
> +			return;
> +
> +		bip = bio_integrity(req->bio);
> +		ref_tag_seed = bip_get_seed(bip);

As mentioned, t10_pi_generate() and ext_pi_crc64_generate() builds
per-internal ref tag.


> +		iod->integrity.ref_tag_lo = ref_tag_seed;
> +		iod->integrity.ref_tag_hi = ref_tag_seed >> 32;
> +		iod->integrity.app_tag = bip->app_tag;

In case of io merge, each bio may have different ->app_tag.

Given you have to copy meta data via user copy, I suggest to follow the PI
standard and make it per-internal.

Thanks, 
Ming

Re: [PATCH v2 01/19] blk-integrity: take const pointer in blk_integrity_rq()

[Martin K. Petersen]

Caleb,

> blk_integrity_rq() doesn't modify the struct request passed in, so allow
> a const pointer to be passed. Use a matching signature for the
> !CONFIG_BLK_DEV_INTEGRITY version.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

-- 
Martin K. Petersen

Re: [PATCH v2 04/19] ublk: set request integrity params in ublksrv_io_desc

[Caleb Sander Mateos]

On Sat, Jan 3, 2026 at 6:14 AM Ming Lei <ming.lei@redhat.com> wrote:
>
> On Fri, Jan 02, 2026 at 05:45:14PM -0700, Caleb Sander Mateos wrote:
> > Indicate to the ublk server when an incoming request has integrity data
> > by setting UBLK_IO_F_INTEGRITY in the ublksrv_io_desc's op_flags field.
> > If the ublk device doesn't support integrity, the request will never
> > provide integrity data. If the ublk device supports integrity, the
> > request may omit the integrity buffer only if metadata_size matches the
> > PI tuple size determined by csum_type. In this case, the ublk server
> > should internally generate/verify the protection information from the
> > data and sector offset.
> > Set the UBLK_IO_F_CHECK_{GUARD,REFTAG,APPTAG} flags based on the
> > request's BIP_CHECK_{GUARD,REFTAG,APPTAG} flags, indicating whether to
> > verify the guard, reference, and app tags in the protection information.
> > The expected reference tag (32 or 48 bits) and app tag (16 bits) are
> > indicated in ublksrv_io_desc's new struct ublksrv_io_integrity integrity
> > field. This field is unioned with the addr field to avoid changing the
>
> It might be fine to set per-rq app_tag, but bios in one request might have
> different app_tag in case of io merge actually.

I based this logic largely on the code under if (ns->head->ms) in
nvme_setup_rw(). That also assumes a single app_tag for the request.
Sounds like an existing bug if bios with different app_tags can be
merged together?

>
> Also block layer builds ref_tag for each internal, please see

What do you mean by "internal"? "interval"?

> t10_pi_generate() and ext_pi_crc64_generate().

Yes, the reftag increases by 1 for each integrity interval. That's why
it suffices for an NVMe command reading multiple blocks to specify
only the expected reftag for the first block; the reftags for
subsequent blocks are incremented accordingly.

Actually, I think we probably don't need to communicate the reftag
seed to the ublk server. NVMe doesn't use the reftag seed (which can
be overridden by struct uio_meta's seed field). Instead,
nvme_set_ref_tag() always uses the offset into the block device
divided by the integrity interval size, as required by all the
existing csum_type formats the kernel supports. So a ublk server could
just use the start_sector field of struct ublksrv_io_desc to compute
the expected reftags. And using start_sector as the reftag also means
merging requests would preserve their expected reftags.

>
> So looks this way is wrong.
>
> More importantly reusing iod->addr for other purpose not related with IO
> buffer is very unfriendly for adding new features, and one lesson is for ZONED support
> by reusing ublksrv_io_cmd->addr for zoned's append lba.

That's a fair point.

>
> For example, there is chance to support dma-buf based zero copy for ublk, and
> please see the io-uring dma-buf support[1], and iod->addr might carry IO buffer info
> in dma-buf format in future.
>
> [1] https://lore.kernel.org/io-uring/cover.1763725387.git.asml.silence@gmail.com/#t
>
>
> > size of struct ublksrv_io_desc. UBLK_F_INTEGRITY requires
> > UBLK_F_USER_COPY and the addr field isn't used for UBLK_F_USER_COPY, so
> > the two fields aren't needed simultaneously.
> >
> > Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
> > ---
> >  drivers/block/ublk_drv.c      | 43 +++++++++++++++++++++++++++++++----
> >  include/uapi/linux/ublk_cmd.h | 27 ++++++++++++++++++++--
> >  2 files changed, 64 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> > index 2f9316febf83..51469e0627ff 100644
> > --- a/drivers/block/ublk_drv.c
> > +++ b/drivers/block/ublk_drv.c
> > @@ -316,10 +316,36 @@ static inline bool ublk_dev_is_zoned(const struct ublk_device *ub)
> >  static inline bool ublk_queue_is_zoned(const struct ublk_queue *ubq)
> >  {
> >       return ubq->flags & UBLK_F_ZONED;
> >  }
> >
> > +static void ublk_setup_iod_buf(const struct ublk_queue *ubq,
> > +                            const struct request *req,
> > +                            struct ublksrv_io_desc *iod)
> > +{
> > +#ifdef CONFIG_BLK_DEV_INTEGRITY
> > +     if (ubq->flags & UBLK_F_INTEGRITY) {
> > +             struct bio_integrity_payload *bip;
> > +             sector_t ref_tag_seed;
> > +
> > +             if (!blk_integrity_rq(req))
> > +                     return;
> > +
> > +             bip = bio_integrity(req->bio);
> > +             ref_tag_seed = bip_get_seed(bip);
>
> As mentioned, t10_pi_generate() and ext_pi_crc64_generate() builds
> per-internal ref tag.

As mentioned, the reftags for subsequent intervals can be computed by
simply incrementing the seed. If the seed is assumed to always be
start_sector >> (interval_exp - SECTOR_SHIFT), then it may not be
necessary to communicate ref_tag_seed at all.

>
>
> > +             iod->integrity.ref_tag_lo = ref_tag_seed;
> > +             iod->integrity.ref_tag_hi = ref_tag_seed >> 32;
> > +             iod->integrity.app_tag = bip->app_tag;
>
> In case of io merge, each bio may have different ->app_tag.

It seems like it would make more sense to prevent merging bios with
different app_tags. In the common case where a request contains a
single bio, which has a single app_tag, it would be much more
efficient to communicate only the 1 app_tag instead of having to pass
a separate app_tag for every logical block/integrity interval.

>
> Given you have to copy meta data via user copy, I suggest to follow the PI
> standard and make it per-internal.

How are you suggesting the ublk server access bip->app_tag and
bip_get_seed(bip) (if overriding the reftag seed is supported)? Would
the ublk server need to make another user copy syscall?

Or would you prefer I drop the BIP_CHECK_* flag support from this
patch set for now?

Thanks,
Caleb

Re: [PATCH v2 04/19] ublk: set request integrity params in ublksrv_io_desc

[Ming Lei]

On Mon, Jan 05, 2026 at 08:44:48AM -0800, Caleb Sander Mateos wrote:
> On Sat, Jan 3, 2026 at 6:14 AM Ming Lei <ming.lei@redhat.com> wrote:
> >
> > On Fri, Jan 02, 2026 at 05:45:14PM -0700, Caleb Sander Mateos wrote:
> > > Indicate to the ublk server when an incoming request has integrity data
> > > by setting UBLK_IO_F_INTEGRITY in the ublksrv_io_desc's op_flags field.
> > > If the ublk device doesn't support integrity, the request will never
> > > provide integrity data. If the ublk device supports integrity, the
> > > request may omit the integrity buffer only if metadata_size matches the
> > > PI tuple size determined by csum_type. In this case, the ublk server
> > > should internally generate/verify the protection information from the
> > > data and sector offset.
> > > Set the UBLK_IO_F_CHECK_{GUARD,REFTAG,APPTAG} flags based on the
> > > request's BIP_CHECK_{GUARD,REFTAG,APPTAG} flags, indicating whether to
> > > verify the guard, reference, and app tags in the protection information.
> > > The expected reference tag (32 or 48 bits) and app tag (16 bits) are
> > > indicated in ublksrv_io_desc's new struct ublksrv_io_integrity integrity
> > > field. This field is unioned with the addr field to avoid changing the
> >
> > It might be fine to set per-rq app_tag, but bios in one request might have
> > different app_tag in case of io merge actually.
> 
> I based this logic largely on the code under if (ns->head->ms) in
> nvme_setup_rw(). That also assumes a single app_tag for the request.
> Sounds like an existing bug if bios with different app_tags can be
> merged together?

Looks it is true.

> 
> >
> > Also block layer builds ref_tag for each internal, please see
> 
> What do you mean by "internal"? "interval"?
> 
> > t10_pi_generate() and ext_pi_crc64_generate().
> 
> Yes, the reftag increases by 1 for each integrity interval. That's why
> it suffices for an NVMe command reading multiple blocks to specify
> only the expected reftag for the first block; the reftags for
> subsequent blocks are incremented accordingly.
> 
> Actually, I think we probably don't need to communicate the reftag
> seed to the ublk server. NVMe doesn't use the reftag seed (which can
> be overridden by struct uio_meta's seed field). Instead,
> nvme_set_ref_tag() always uses the offset into the block device
> divided by the integrity interval size, as required by all the
> existing csum_type formats the kernel supports. So a ublk server could
> just use the start_sector field of struct ublksrv_io_desc to compute
> the expected reftags. And using start_sector as the reftag also means
> merging requests would preserve their expected reftags.

IMO, this way looks fine from user viewpoint, especially aligning with NVMe. 

> 
> >
> > So looks this way is wrong.
> >
> > More importantly reusing iod->addr for other purpose not related with IO
> > buffer is very unfriendly for adding new features, and one lesson is for ZONED support
> > by reusing ublksrv_io_cmd->addr for zoned's append lba.
> 
> That's a fair point.

One candidate is add per-IO mmaped meta area, which can be flexible to
cover more use cases. 

> 
> >
> > For example, there is chance to support dma-buf based zero copy for ublk, and
> > please see the io-uring dma-buf support[1], and iod->addr might carry IO buffer info
> > in dma-buf format in future.
> >
> > [1] https://lore.kernel.org/io-uring/cover.1763725387.git.asml.silence@gmail.com/#t

BTW, PI data size is often small, and it belongs to kernel, there could be
chance to define PI data as pre-mapped DMA-BUF, then almost all drivers can
benefit from avoiding the runtime dma mapping for meta. But that may be one
bigger thing.

> >
> >
> > > size of struct ublksrv_io_desc. UBLK_F_INTEGRITY requires
> > > UBLK_F_USER_COPY and the addr field isn't used for UBLK_F_USER_COPY, so
> > > the two fields aren't needed simultaneously.
> > >
> > > Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
> > > ---
> > >  drivers/block/ublk_drv.c      | 43 +++++++++++++++++++++++++++++++----
> > >  include/uapi/linux/ublk_cmd.h | 27 ++++++++++++++++++++--
> > >  2 files changed, 64 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> > > index 2f9316febf83..51469e0627ff 100644
> > > --- a/drivers/block/ublk_drv.c
> > > +++ b/drivers/block/ublk_drv.c
> > > @@ -316,10 +316,36 @@ static inline bool ublk_dev_is_zoned(const struct ublk_device *ub)
> > >  static inline bool ublk_queue_is_zoned(const struct ublk_queue *ubq)
> > >  {
> > >       return ubq->flags & UBLK_F_ZONED;
> > >  }
> > >
> > > +static void ublk_setup_iod_buf(const struct ublk_queue *ubq,
> > > +                            const struct request *req,
> > > +                            struct ublksrv_io_desc *iod)
> > > +{
> > > +#ifdef CONFIG_BLK_DEV_INTEGRITY
> > > +     if (ubq->flags & UBLK_F_INTEGRITY) {
> > > +             struct bio_integrity_payload *bip;
> > > +             sector_t ref_tag_seed;
> > > +
> > > +             if (!blk_integrity_rq(req))
> > > +                     return;
> > > +
> > > +             bip = bio_integrity(req->bio);
> > > +             ref_tag_seed = bip_get_seed(bip);
> >
> > As mentioned, t10_pi_generate() and ext_pi_crc64_generate() builds
> > per-internal ref tag.
> 
> As mentioned, the reftags for subsequent intervals can be computed by
> simply incrementing the seed. If the seed is assumed to always be
> start_sector >> (interval_exp - SECTOR_SHIFT), then it may not be
> necessary to communicate ref_tag_seed at all.

Fair enough, but this should be documented in UAPI interface.

> 
> >
> >
> > > +             iod->integrity.ref_tag_lo = ref_tag_seed;
> > > +             iod->integrity.ref_tag_hi = ref_tag_seed >> 32;
> > > +             iod->integrity.app_tag = bip->app_tag;
> >
> > In case of io merge, each bio may have different ->app_tag.
> 
> It seems like it would make more sense to prevent merging bios with
> different app_tags. In the common case where a request contains a
> single bio, which has a single app_tag, it would be much more
> efficient to communicate only the 1 app_tag instead of having to pass
> a separate app_tag for every logical block/integrity interval.

OK.

> 
> >
> > Given you have to copy meta data via user copy, I suggest to follow the PI
> > standard and make it per-internal.
> 
> How are you suggesting the ublk server access bip->app_tag and
> bip_get_seed(bip) (if overriding the reftag seed is supported)? Would
> the ublk server need to make another user copy syscall?
> 
> Or would you prefer I drop the BIP_CHECK_* flag support from this
> patch set for now?

I can understand the motivation, and extra syscall should be avoided for
communicating reftag & apptag only, given you have explained both can be
per-request instead of per-interval.

But iod->addr should be avoided for this purpose, otherwise, new feature
can conflict with this usage easily.

But per-io mmapped area can solve this issue, the meta size can be one parameter
of `ublksrv_ctrl_dev_info` with feature flag of UBLK_F_MMAPED_IO_META, what
do you think of this way?


Thanks,
Ming