[PATCH 2/3] io_uring: add a helper for async rw iovec prep

Pavel Begunkov
2020-07-13T20:01:24Z

Preparing reads/writes for async is a bit tricky. Extract a helper to
not repeat it twice.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
fs/io_uring.c | 46 ++++++++++++++++++++--------------------------
1 file changed, 20 insertions(+), 26 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index d9c10070dcba..217dbb6563e7 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2871,11 +2871,27 @@ static int io_setup_async_rw(struct io_kiocb *req, ssize_t io_size,
return 0;
}

+static inline int io_rw_prep_async(struct io_kiocb *req, int rw,
+ bool force_nonblock)
+{
+ struct io_async_ctx *io = req->io;
+ struct iov_iter iter;
+ ssize_t ret;
+
+ io->rw.iov = io->rw.fast_iov;
+ req->io = NULL;
+ ret = io_import_iovec(rw, req, &io->rw.iov, &iter, !force_nonblock);
+ req->io = io;
+ if (unlikely(ret < 0))
+ return ret;
+
+ io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter);
+ return 0;
+}
+
static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
bool force_nonblock)
{
- struct io_async_ctx *io;
- struct iov_iter iter;
ssize_t ret;

ret = io_prep_rw(req, sqe, force_nonblock);
@@ -2888,17 +2904,7 @@ static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
/* either don't need iovec imported or already have it */
if (!req->io || req->flags & REQ_F_NEED_CLEANUP)
return 0;
-
- io = req->io;
- io->rw.iov = io->rw.fast_iov;
- req->io = NULL;
- ret = io_import_iovec(READ, req, &io->rw.iov, &iter, !force_nonblock);
- req->io = io;
- if (ret < 0)
- return ret;
-
- io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter);
- return 0;
+ return io_rw_prep_async(req, READ, force_nonblock);
}

static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
@@ -3042,8 +3048,6 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
bool force_nonblock)
{
- struct io_async_ctx *io;
- struct iov_iter iter;
ssize_t ret;

ret = io_prep_rw(req, sqe, force_nonblock);
@@ -3058,17 +3062,7 @@ static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
/* either don't need iovec imported or already have it */
if (!req->io || req->flags & REQ_F_NEED_CLEANUP)
return 0;
-
- io = req->io;
- io->rw.iov = io->rw.fast_iov;
- req->io = NULL;
- ret = io_import_iovec(WRITE, req, &io->rw.iov, &iter, !force_nonblock);
- req->io = io;
- if (ret < 0)
- return ret;
-
- io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter);
- return 0;
+ return io_rw_prep_async(req, WRITE, force_nonblock);
}

static int io_write(struct io_kiocb *req, bool force_nonblock,
--
2.24.0