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ublk: decouple zero copy from user copy

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UBLK_F_USER_COPY and UBLK_F_SUPPORT_ZERO_COPY are two different
features, and shouldn't be coupled together.

Commit 1f6540e2aa ("ublk: zc register/unregister bvec") enables
user copy automatically in case of UBLK_F_SUPPORT_ZERO_COPY, this way
isn't correct.

So decouple zero copy from user copy, and use independent helper to
check each one.

Fixes: 1f6540e2aa ("ublk: zc register/unregister bvec")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250429022941.1718671-3-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Ming Lei
2025-04-29 10:29:37 +08:00
committed by Jens Axboe
parent 730d837979
commit 69edf98be8
1 changed files with 23 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/block/ublk_drv.c
+23 -12
View File
@@ -205,11 +205,6 @@ static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub,
static inline unsigned int ublk_req_build_flags(struct request *req);
static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq,
int tag);
static inline bool ublk_dev_is_user_copy(const struct ublk_device *ub)
{
return ub->dev_info.flags & (UBLK_F_USER_COPY | UBLK_F_SUPPORT_ZERO_COPY);
}
static inline bool ublk_dev_is_zoned(const struct ublk_device *ub)
{
return ub->dev_info.flags & UBLK_F_ZONED;
@@ -609,14 +604,19 @@ static void ublk_apply_params(struct ublk_device *ub)
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_support_user_copy(const struct ublk_queue *ubq)
{
return ubq->flags & (UBLK_F_USER_COPY | UBLK_F_SUPPORT_ZERO_COPY);
return ubq->flags & UBLK_F_USER_COPY;
}
static inline bool ublk_need_map_io(const struct ublk_queue *ubq)
{
return !ublk_support_user_copy(ubq);
return !ublk_support_user_copy(ubq) && !ublk_support_zero_copy(ubq);
}
static inline bool ublk_need_req_ref(const struct ublk_queue *ubq)
@@ -624,8 +624,11 @@ static inline bool ublk_need_req_ref(const struct ublk_queue *ubq)
/*
* read()/write() is involved in user copy, so request reference
* has to be grabbed
*
* for zero copy, request buffer need to be registered to io_uring
* buffer table, so reference is needed
*/
return ublk_support_user_copy(ubq);
return ublk_support_user_copy(ubq) || ublk_support_zero_copy(ubq);
}
static inline void ublk_init_req_ref(const struct ublk_queue *ubq,
@@ -2245,6 +2248,9 @@ static struct request *ublk_check_and_get_req(struct kiocb *iocb,
if (!ubq)
return ERR_PTR(-EINVAL);
if (!ublk_support_user_copy(ubq))
return ERR_PTR(-EACCES);
if (tag >= ubq->q_depth)
return ERR_PTR(-EINVAL);
@@ -2783,13 +2789,18 @@ static int ublk_ctrl_add_dev(const struct ublksrv_ctrl_cmd *header)
ub->dev_info.flags |= UBLK_F_CMD_IOCTL_ENCODE |
UBLK_F_URING_CMD_COMP_IN_TASK;
/* GET_DATA isn't needed any more with USER_COPY */
if (ublk_dev_is_user_copy(ub))
/* GET_DATA isn't needed any more with USER_COPY or ZERO COPY */
if (ub->dev_info.flags & (UBLK_F_USER_COPY | UBLK_F_SUPPORT_ZERO_COPY))
ub->dev_info.flags &= ~UBLK_F_NEED_GET_DATA;
/* Zoned storage support requires user copy feature */
/*
* Zoned storage support requires reuse `ublksrv_io_cmd->addr` for
* returning write_append_lba, which is only allowed in case of
* user copy or zero copy
*/
if (ublk_dev_is_zoned(ub) &&
(!IS_ENABLED(CONFIG_BLK_DEV_ZONED) || !ublk_dev_is_user_copy(ub))) {
(!IS_ENABLED(CONFIG_BLK_DEV_ZONED) || !(ub->dev_info.flags &
(UBLK_F_USER_COPY | UBLK_F_SUPPORT_ZERO_COPY)))) {
ret = -EINVAL;
goto out_free_dev_number;
}