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ublk: remove ubq checks from ublk_{get,put}_req_ref()

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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 <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250620151008.3976463-14-csander@purestorage.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Caleb Sander Mateos 2025-06-20 09:10:07 -06:00 committed by Jens Axboe
parent 1ceeedb597
commit c9d066ebfd
1 changed files with 11 additions and 24 deletions
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35
drivers/block/ublk_drv.c
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@ -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;
}