> -----Original Message-----
> From: David Laight
> Sent: 31 March 2020 14:52
> To: Linux Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>
> Subject: [RFC PATCH 02/12] fs/io_uring Don't use the return value from import_iovec().
>
> This is the only code that relies on import_iovec() returning
> iter.count on success.
> Not using the value actually saves passing it through to functions
> that are also passed the 'iter'.
> This allows a better interface to import_iovec().
>
> Signed-off-by: David Laight <david.laight@xxxxxxxxxx>
> ---
> fs/io_uring.c | 34 ++++++++++++++--------------------
> 1 file changed, 14 insertions(+), 20 deletions(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 3affd96..d8dc2e2 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -2153,12 +2153,11 @@ static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb,
> return ret;
> }
>
> -static void io_req_map_rw(struct io_kiocb *req, ssize_t io_size,
> - struct iovec *iovec, struct iovec *fast_iov,
> - struct iov_iter *iter)
> +static void io_req_map_rw(struct io_kiocb *req, struct iovec *iovec,
> + struct iovec *fast_iov, struct iov_iter *iter)
> {
> req->io->rw.nr_segs = iter->nr_segs;
> - req->io->rw.size = io_size;
> + req->io->rw.size = iter->count;
> req->io->rw.iov = iovec;
> if (!req->io->rw.iov) {
> req->io->rw.iov = req->io->rw.fast_iov;
> @@ -2177,9 +2176,8 @@ static int io_alloc_async_ctx(struct io_kiocb *req)
> return req->io == NULL;
> }
>
> -static int io_setup_async_rw(struct io_kiocb *req, ssize_t io_size,
> - struct iovec *iovec, struct iovec *fast_iov,
> - struct iov_iter *iter)
> +static int io_setup_async_rw(struct io_kiocb *req, struct iovec *iovec,
> + struct iovec *fast_iov, struct iov_iter *iter)
> {
> if (!io_op_defs[req->opcode].async_ctx)
> return 0;
> @@ -2187,7 +2185,7 @@ static int io_setup_async_rw(struct io_kiocb *req, ssize_t io_size,
> if (io_alloc_async_ctx(req))
> return -ENOMEM;
>
> - io_req_map_rw(req, io_size, iovec, fast_iov, iter);
> + io_req_map_rw(req, iovec, fast_iov, iter);
> }
> return 0;
> }
> @@ -2218,7 +2216,7 @@ static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
> if (ret < 0)
> return ret;
>
> - io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter);
> + io_req_map_rw(req, io->rw.iov, io->rw.fast_iov, &iter);
> return 0;
> }
>
> @@ -2229,7 +2227,7 @@ static int io_read(struct io_kiocb *req, struct io_kiocb **nxt,
> struct kiocb *kiocb = &req->rw.kiocb;
> struct iov_iter iter;
> size_t iov_count;
> - ssize_t io_size, ret;
> + ssize_t ret;
>
> ret = io_import_iovec(READ, req, &iovec, &iter);
> if (ret < 0)
> @@ -2240,9 +2238,8 @@ static int io_read(struct io_kiocb *req, struct io_kiocb **nxt,
> req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT;
>
> req->result = 0;
> - io_size = ret;
> if (req->flags & REQ_F_LINK)
> - req->result = io_size;
> + req->result = iter.count;
>
> /*
> * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so
> @@ -2268,8 +2265,7 @@ static int io_read(struct io_kiocb *req, struct io_kiocb **nxt,
> kiocb_done(kiocb, ret2, nxt, req->in_async);
> } else {
> copy_iov:
> - ret = io_setup_async_rw(req, io_size, iovec,
> - inline_vecs, &iter);
> + ret = io_setup_async_rw(req, iovec, inline_vecs, &iter);
> if (ret)
> goto out_free;
> return -EAGAIN;
> @@ -2307,7 +2303,7 @@ static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
> if (ret < 0)
> return ret;
>
> - io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter);
> + io_req_map_rw(req, io->rw.iov, io->rw.fast_iov, &iter);
> return 0;
> }
>
> @@ -2318,7 +2314,7 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt,
> struct kiocb *kiocb = &req->rw.kiocb;
> struct iov_iter iter;
> size_t iov_count;
> - ssize_t ret, io_size;
> + ssize_t ret;
>
> ret = io_import_iovec(WRITE, req, &iovec, &iter);
> if (ret < 0)
> @@ -2329,9 +2325,8 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt,
> req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT;
>
> req->result = 0;
> - io_size = ret;
> if (req->flags & REQ_F_LINK)
> - req->result = io_size;
> + req->result = iter.count;
>
> /*
> * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so
> @@ -2381,8 +2376,7 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt,
> kiocb_done(kiocb, ret2, nxt, req->in_async);
> } else {
> copy_iov:
> - ret = io_setup_async_rw(req, io_size, iovec,
> - inline_vecs, &iter);
> + ret = io_setup_async_rw(req, iovec, inline_vecs, &iter);
> if (ret)
> goto out_free;
> return -EAGAIN;
> --
> 1.8.1.2
-
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