UPSTREAM: io_uring: io_kiocb_update_pos() should not touch file for non -1 offset
commit 6f83ab22adcb77a5824d2c274dace0d99e21319f upstream.
-1 tells use to use the current position, but we check if the file is
a stream regardless of that. Fix up io_kiocb_update_pos() to only
dip into file if we need to. This is both more efficient and also drops
12 bytes of text on aarch64 and 64 bytes on x86-64.
Fixes: b4aec4001595 ("io_uring: do not recalculate ppos unnecessarily")
Change-Id: I5c22ce8122b0e1f0ad423a5b3aa520ee416feff1
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Bug: 268174392
(cherry picked from commit 89a77271d254752d83507fc347dc2d675885fe07)
Signed-off-by: Greg Kroah-Hartman <[email protected]>
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 06267fb..d758427 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -3021,19 +3021,18 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
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 (!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;
- }
+ if (kiocb->ki_pos != -1)
+ return &kiocb->ki_pos;
+
+ if (!(req->file->f_mode & FMODE_STREAM)) {
+ req->flags |= REQ_F_CUR_POS;
+ kiocb->ki_pos = req->file->f_pos;
+ return &kiocb->ki_pos;
}
- return is_stream ? NULL : &kiocb->ki_pos;
+
+ kiocb->ki_pos = 0;
+ return NULL;
}
static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
