From: Stanley Zhang <[email protected]>

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 <[email protected]>
[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 <[email protected]>
---
 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


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