We now allow multiple tasks to operate on I/Os belonging to the same
queue concurrently. This means that any writes to ublk_queue in the I/O
path are potential sources of data races. Try to prevent these by
marking ublk_queue pointers as const in ublk_register_io_buf.
Suggested-by: Ming Lei <ming.lei@xxxxxxxxxx>
Signed-off-by: Uday Shankar <ushankar@xxxxxxxxxxxxxxx>
Reviewed-by: Caleb Sander Mateos <csander@xxxxxxxxxxxxxxx>
---
drivers/block/ublk_drv.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index b44cbcbcc9d1735c398dc9ac7e93f4c8736b9201..215ab45b00e10150e58d7f5ea5b5d13e40a1aa79 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -211,7 +211,7 @@ struct ublk_params_header {
static bool ublk_abort_requests(struct ublk_device *ub, struct ublk_queue *ubq);
static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub,
- struct ublk_queue *ubq, int tag, size_t offset);
+ const struct ublk_queue *ubq, int tag, size_t offset);
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);
@@ -1867,7 +1867,7 @@ static void ublk_io_release(void *priv)
}
static int ublk_register_io_buf(struct io_uring_cmd *cmd,
- struct ublk_queue *ubq, unsigned int tag,
+ const struct ublk_queue *ubq, unsigned int tag,
unsigned int index, unsigned int issue_flags)
{
struct ublk_device *ub = cmd->file->private_data;
@@ -2044,7 +2044,7 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
}
static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub,
- struct ublk_queue *ubq, int tag, size_t offset)
+ const struct ublk_queue *ubq, int tag, size_t offset)
{
struct request *req;
--
2.34.1
