On Mon, Jan 05, 2026 at 05:57:41PM -0700, Caleb Sander Mateos wrote:
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 e44ab9981ef4..9694a4c1caa7 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -621,10 +621,15 @@ 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);
+}
It could be more readable to check UBLKSRV_IO_INTEGRITY_FLAG only.
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) @@ -1047,10 +1052,37 @@ 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; } @@ -2654,10 +2686,12 @@ 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)) @@ -2667,10 +2701,11 @@ 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);
UBLKSRV_IO_INTEGRITY_FLAG can be set for device without UBLK_F_INTEGRITY, so UBLK_F_INTEGRITY need to be checked in case of `is_integrity`.
if (q_id >= ub->dev_info.nr_hw_queues) return -EINVAL; ubq = ublk_get_queue(ub, q_id); @@ -2683,21 +2718,31 @@ 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; } @@ -3931,11 +3976,12 @@ 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);
Maybe it can be simplified as:
BUILD_BUG_ON(UBLK_INTEGRITY_FLAG_OFF >= 63); /* Must fit in loff_t */
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 c1103ad5925b..3af7e3684834 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
Thanks, Ming