From b4aec40015953b65f2f114641e7fd7714c8df8e6 Mon Sep 17 00:00:00 2001 From: Dylan Yudaken Date: Tue, 22 Feb 2022 02:55:03 -0800 Subject: [PATCH] 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 Reviewed-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 18 ++++++++++++------ 1 file 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;