From c9d066ebfd2fbd89173716f60578ed6e416712e4 Mon Sep 17 00:00:00 2001 From: Caleb Sander Mateos Date: Fri, 20 Jun 2025 09:10:07 -0600 Subject: [PATCH] ublk: remove ubq checks from ublk_{get,put}_req_ref() ublk_get_req_ref() and ublk_put_req_ref() currently call ublk_need_req_ref(ubq) to check whether the ublk device features require reference counting of its requests. However, all callers already know that reference counting is required: - __ublk_check_and_get_req() is only called from ublk_check_and_get_req() if user copy is enabled, and from ublk_register_io_buf() if zero copy is enabled - ublk_io_release() is only called for requests registered by ublk_register_io_buf(), which requires zero copy - ublk_ch_read_iter() and ublk_ch_write_iter() only call ublk_put_req_ref() if ublk_check_and_get_req() succeeded, which requires user copy to be enabled So drop the ublk_need_req_ref() check and the ubq argument in ublk_get_req_ref() and ublk_put_req_ref(). Signed-off-by: Caleb Sander Mateos Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20250620151008.3976463-14-csander@purestorage.com Signed-off-by: Jens Axboe --- drivers/block/ublk_drv.c | 35 +++++++++++------------------------ 1 file changed, 11 insertions(+), 24 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index c3c0601db4871..eec3abb78ce5c 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -699,24 +699,15 @@ static inline void ublk_init_req_ref(const struct ublk_queue *ubq, refcount_set(&io->ref, UBLK_REFCOUNT_INIT); } -static inline bool ublk_get_req_ref(const struct ublk_queue *ubq, - struct ublk_io *io) +static inline bool ublk_get_req_ref(struct ublk_io *io) { - if (ublk_need_req_ref(ubq)) - return refcount_inc_not_zero(&io->ref); - - return true; + return refcount_inc_not_zero(&io->ref); } -static inline void ublk_put_req_ref(const struct ublk_queue *ubq, - struct ublk_io *io, struct request *req) +static inline void ublk_put_req_ref(struct ublk_io *io, struct request *req) { - if (ublk_need_req_ref(ubq)) { - if (refcount_dec_and_test(&io->ref)) - __ublk_complete_rq(req); - } else { + if (refcount_dec_and_test(&io->ref)) __ublk_complete_rq(req); - } } static inline void ublk_sub_req_ref(struct ublk_io *io, struct request *req) @@ -2037,7 +2028,7 @@ static void ublk_io_release(void *priv) if (current == io->task && io->task_registered_buffers) io->task_registered_buffers--; else - ublk_put_req_ref(ubq, io, rq); + ublk_put_req_ref(io, rq); } static int ublk_register_io_buf(struct io_uring_cmd *cmd, @@ -2059,7 +2050,7 @@ static int ublk_register_io_buf(struct io_uring_cmd *cmd, ret = io_buffer_register_bvec(cmd, req, ublk_io_release, index, issue_flags); if (ret) { - ublk_put_req_ref(ubq, io, req); + ublk_put_req_ref(io, req); return ret; } @@ -2366,7 +2357,7 @@ static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub, if (!req) return NULL; - if (!ublk_get_req_ref(ubq, io)) + if (!ublk_get_req_ref(io)) return NULL; if (unlikely(!blk_mq_request_started(req) || req->tag != tag)) @@ -2380,7 +2371,7 @@ static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub, return req; fail_put: - ublk_put_req_ref(ubq, io, req); + ublk_put_req_ref(io, req); return NULL; } @@ -2496,13 +2487,12 @@ static struct request *ublk_check_and_get_req(struct kiocb *iocb, *off = buf_off; return req; fail: - ublk_put_req_ref(ubq, *io, req); + ublk_put_req_ref(*io, req); return ERR_PTR(-EACCES); } static ssize_t ublk_ch_read_iter(struct kiocb *iocb, struct iov_iter *to) { - struct ublk_queue *ubq; struct request *req; struct ublk_io *io; size_t buf_off; @@ -2513,15 +2503,13 @@ static ssize_t ublk_ch_read_iter(struct kiocb *iocb, struct iov_iter *to) return PTR_ERR(req); ret = ublk_copy_user_pages(req, buf_off, to, ITER_DEST); - ubq = req->mq_hctx->driver_data; - ublk_put_req_ref(ubq, io, req); + ublk_put_req_ref(io, req); return ret; } static ssize_t ublk_ch_write_iter(struct kiocb *iocb, struct iov_iter *from) { - struct ublk_queue *ubq; struct request *req; struct ublk_io *io; size_t buf_off; @@ -2532,8 +2520,7 @@ static ssize_t ublk_ch_write_iter(struct kiocb *iocb, struct iov_iter *from) return PTR_ERR(req); ret = ublk_copy_user_pages(req, buf_off, from, ITER_SOURCE); - ubq = req->mq_hctx->driver_data; - ublk_put_req_ref(ubq, io, req); + ublk_put_req_ref(io, req); return ret; } -- 2.47.2