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 | 101 +++++++++++++++++++++++++++++++++-
include/uapi/linux/ublk_cmd.h | 19 +++++++
2 files changed, 119 insertions(+), 1 deletion(-)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 8e3da9b2b93a..b91b2111f280 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.
@@ -313,10 +316,15 @@ 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 inline bool ublk_dev_support_integrity(const struct ublk_device *ub)
+{
+ return ub->dev_info.flags & UBLK_F_INTEGRITY;
+}
+
#ifdef CONFIG_BLK_DEV_ZONED
struct ublk_zoned_report_desc {
__u64 sector;
__u32 operation;
@@ -628,10 +636,57 @@ 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 +745,33 @@ 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 (!ublk_dev_support_integrity(ub))
+ return -EINVAL;
+ if (flags < 0)
+ return flags;
+ if (pi_tuple_size < 0)
+ return pi_tuple_size;
+ if (!p->metadata_size)
+ return -EINVAL;
+ if (p->csum_type == LBMD_PI_CSUM_NONE &&
+ p->flags & LBMD_PI_CAP_REFTAG)
+ return -EINVAL;
+ if (p->pi_offset + pi_tuple_size > p->metadata_size)
+ return -EINVAL;
+ if (p->interval_exp < SECTOR_SHIFT ||
+ p->interval_exp > ub->params.basic.logical_bs_shift)
+ return -EINVAL;
+ }
+
return 0;
}
static void ublk_apply_params(struct ublk_device *ub)
{
@@ -2941,10 +3019,27 @@ 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.max_integrity_segments =
+ p->max_integrity_segments ?: USHRT_MAX;
+ 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 +3226,14 @@ 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..4c141d7e4710 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 +604,21 @@ 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 */
+ __u16 max_integrity_segments; /* 0 means no limit */
+ __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[5];
+};
+
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 +629,18 @@ 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