ublk: convert to refcount_t

Convert to refcount_t and prepare for supporting to register bvec buffer
automatically, which needs to initialize reference counter as 2, and
kref doesn't provide this interface, so convert to refcount_t.

Reviewed-by: Caleb Sander Mateos <csander@purestorage.com>
Suggested-by: Caleb Sander Mateos <csander@purestorage.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250520045455.515691-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index cb612151e9a1de7630c49a2b78d278e005d52856..ae2f47dc82247a2b17ac72a6c37bd9b2f536276c 100644 (file)
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -79,7 +79,7 @@
         UBLK_PARAM_TYPE_DMA_ALIGN | UBLK_PARAM_TYPE_SEGMENT)
 
 struct ublk_rq_data {
-       struct kref ref;
+       refcount_t ref;
 };
 
 struct ublk_uring_cmd_pdu {
@@ -488,7 +488,6 @@ static blk_status_t ublk_setup_iod_zoned(struct ublk_queue *ubq,
 #endif
 
 static inline void __ublk_complete_rq(struct request *req);
-static void ublk_complete_rq(struct kref *ref);
 
 static dev_t ublk_chr_devt;
 static const struct class ublk_chr_class = {
@@ -648,7 +647,7 @@ static inline void ublk_init_req_ref(const struct ublk_queue *ubq,
        if (ublk_need_req_ref(ubq)) {
                struct ublk_rq_data *data = blk_mq_rq_to_pdu(req);
 
-               kref_init(&data->ref);
+               refcount_set(&data->ref, 1);
        }
 }
 
@@ -658,7 +657,7 @@ static inline bool ublk_get_req_ref(const struct ublk_queue *ubq,
        if (ublk_need_req_ref(ubq)) {
                struct ublk_rq_data *data = blk_mq_rq_to_pdu(req);
 
-               return kref_get_unless_zero(&data->ref);
+               return refcount_inc_not_zero(&data->ref);
        }
 
        return true;
@@ -670,7 +669,8 @@ static inline void ublk_put_req_ref(const struct ublk_queue *ubq,
        if (ublk_need_req_ref(ubq)) {
                struct ublk_rq_data *data = blk_mq_rq_to_pdu(req);
 
-               kref_put(&data->ref, ublk_complete_rq);
+               if (refcount_dec_and_test(&data->ref))
+                       __ublk_complete_rq(req);
        } else {
                __ublk_complete_rq(req);
        }
@@ -1122,15 +1122,6 @@ exit:
        blk_mq_end_request(req, res);
 }
 
-static void ublk_complete_rq(struct kref *ref)
-{
-       struct ublk_rq_data *data = container_of(ref, struct ublk_rq_data,
-                       ref);
-       struct request *req = blk_mq_rq_from_pdu(data);
-
-       __ublk_complete_rq(req);
-}
-
 static void ublk_complete_io_cmd(struct ublk_io *io, struct request *req,
                                 int res, unsigned issue_flags)
 {