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authorDylan Yudaken <dylany@fb.com>2022-02-22 02:55:03 -0800
committerJens Axboe <axboe@kernel.dk>2022-03-10 06:32:49 -0700
commitb4aec40015953b65f2f114641e7fd7714c8df8e6 (patch)
treea8d536ef9a42db0804c9d0df40e5aa3e649d3f6f
parentd34e1e5b396a0dbaa4a29b7138df662cfb9d8e8e (diff)
io_uring: do not recalculate ppos unnecessarily
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>
-rw-r--r--fs/io_uring.c18
1 files changed, 12 insertions, 6 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index d0f3e084da16..c9efb1d32fd2 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3086,18 +3086,22 @@ 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 io_kiocb *req, ssize_t ret,
@@ -3658,6 +3662,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
struct io_async_rw *rw;
ssize_t ret, ret2;
+ loff_t *ppos;
if (!req_has_async_data(req)) {
ret = io_import_iovec(READ, req, &iovec, s, issue_flags);
@@ -3688,9 +3693,9 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
kiocb->ki_flags &= ~IOCB_NOWAIT;
}
- 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;
@@ -3789,6 +3794,7 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
struct kiocb *kiocb = &req->rw.kiocb;
bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
ssize_t ret, ret2;
+ loff_t *ppos;
if (!req_has_async_data(req)) {
ret = io_import_iovec(WRITE, req, &iovec, s, issue_flags);
@@ -3819,9 +3825,9 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags)
kiocb->ki_flags &= ~IOCB_NOWAIT;
}
- 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;