From: Dylan Yudaken <dylany@xxxxxx>
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@xxxxxx>
Reviewed-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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;
--
2.39.0
