From: Dylan Yudaken dylany@fb.com
commit b4aec40015953b65f2f114641e7fd7714c8df8e6 upstream.
There is a slight optimisation to be had by calculating the correct pos pointer inside io_kiocb_update_pos and then using that later.
It seems code size drops by a bit: 000000000000a1b0 0000000000000400 t io_read 000000000000a5b0 0000000000000319 t io_write
vs 000000000000a1b0 00000000000003f6 t io_read 000000000000a5b0 0000000000000310 t io_write
Signed-off-by: Dylan Yudaken dylany@fb.com Reviewed-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- io_uring/io_uring.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index eaf8463c9b14..d4e017b07371 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -3000,18 +3000,22 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) } }
-static inline void io_kiocb_update_pos(struct io_kiocb *req) +static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req) { struct kiocb *kiocb = &req->rw.kiocb; + bool is_stream = req->file->f_mode & FMODE_STREAM;
if (kiocb->ki_pos == -1) { - if (!(req->file->f_mode & FMODE_STREAM)) { + if (!is_stream) { req->flags |= REQ_F_CUR_POS; kiocb->ki_pos = req->file->f_pos; + return &kiocb->ki_pos; } else { kiocb->ki_pos = 0; + return NULL; } } + return is_stream ? NULL : &kiocb->ki_pos; }
static void kiocb_done(struct kiocb *kiocb, ssize_t ret, @@ -3537,6 +3541,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags) bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; struct iov_iter_state __state, *state; ssize_t ret, ret2; + loff_t *ppos;
if (rw) { iter = &rw->iter; @@ -3569,9 +3574,9 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags) return ret ?: -EAGAIN; }
- io_kiocb_update_pos(req); + ppos = io_kiocb_update_pos(req);
- ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), req->result); + ret = rw_verify_area(READ, req->file, ppos, req->result); if (unlikely(ret)) { kfree(iovec); return ret; @@ -3675,6 +3680,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags) bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK; struct iov_iter_state __state, *state; ssize_t ret, ret2; + loff_t *ppos;
if (rw) { iter = &rw->iter; @@ -3705,9 +3711,9 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags) (req->flags & REQ_F_ISREG)) goto copy_iov;
- io_kiocb_update_pos(req); + ppos = io_kiocb_update_pos(req);
- ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), req->result); + ret = rw_verify_area(WRITE, req->file, ppos, req->result); if (unlikely(ret)) goto out_free;