io_uring: add a helper for async rw iovec prep

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>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 3b8465d..31466bc 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2872,11 +2872,27 @@ 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);
@@ -2889,17 +2905,7 @@ 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,
@@ -3043,8 +3049,6 @@ out_free:
 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);
@@ -3059,17 +3063,7 @@ 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,