From 5ea5dd45844d1b727ab2a76f47d6e9aa65d1e921 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 4 Feb 2021 13:52:03 +0000 Subject: [PATCH] io_uring: inline io_read()'s iovec freeing io_read() has not the simpliest control flow with a lot of jumps and it's hard to read. One of those is a out_free: label, which frees iovec. However, from the middle of io_read() iovec is NULL'ed and so kfree(iovec) is no-op, it leaves us with two place where we can inline it and further clean up the code. Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 31 +++++++++++++------------------ 1 file changed, 13 insertions(+), 18 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 25fffff..35ad889 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3530,14 +3530,18 @@ static int io_read(struct io_kiocb *req, bool force_nonblock, } ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), io_size); - if (unlikely(ret)) - goto out_free; + if (unlikely(ret)) { + kfree(iovec); + return ret; + } ret = io_iter_do_read(req, iter); if (ret == -EIOCBQUEUED) { - ret = 0; - goto out_free; + /* it's faster to check here then delegate to kfree */ + if (iovec) + kfree(iovec); + return 0; } else if (ret == -EAGAIN) { /* IOPOLL retry should happen for io-wq threads */ if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL)) @@ -3560,8 +3564,6 @@ static int io_read(struct io_kiocb *req, bool force_nonblock, return ret2; rw = req->async_data; - /* it's copied and will be cleaned with ->io */ - iovec = NULL; /* now use our persistent iterator, if we aren't already */ iter = &rw->iter; retry: @@ -3580,21 +3582,14 @@ retry: * do, then just retry at the new offset. */ ret = io_iter_do_read(req, iter); - if (ret == -EIOCBQUEUED) { - ret = 0; - goto out_free; - } else if (ret > 0 && ret < io_size) { - /* we got some bytes, but not all. retry. */ + if (ret == -EIOCBQUEUED) + return 0; + /* we got some bytes, but not all. retry. */ + if (ret > 0 && ret < io_size) goto retry; - } done: kiocb_done(kiocb, ret, cs); - ret = 0; -out_free: - /* it's reportedly faster than delegating the null check to kfree() */ - if (iovec) - kfree(iovec); - return ret; + return 0; } static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) -- 2.7.4