[PATCH 3/6] io_uring: move read/write side file based prep into op handler

[Jens Axboe <axboe@xxxxxxxxx>]

In preparation for not needing req->file in on the prep side at all.

Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
 fs/io_uring.c | 73 +++++++++++++++++++++++++++++++--------------------
 1 file changed, 44 insertions(+), 29 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index c29a721114e0..ed70ac09ca18 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2030,37 +2030,19 @@ static bool io_file_supports_async(struct file *file)
 	return false;
 }
 
-static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
-		      bool force_nonblock)
+static int io_prep_rw(struct io_kiocb *req, bool force_nonblock)
 {
-	struct io_ring_ctx *ctx = req->ctx;
 	struct kiocb *kiocb = &req->rw.kiocb;
-	unsigned ioprio;
-	int ret;
 
 	if (S_ISREG(file_inode(req->file)->i_mode))
 		req->flags |= REQ_F_ISREG;
 
-	kiocb->ki_pos = READ_ONCE(sqe->off);
 	if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) {
 		req->flags |= REQ_F_CUR_POS;
 		kiocb->ki_pos = req->file->f_pos;
 	}
 	kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
-	kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
-	ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
-	if (unlikely(ret))
-		return ret;
-
-	ioprio = READ_ONCE(sqe->ioprio);
-	if (ioprio) {
-		ret = ioprio_check_cap(ioprio);
-		if (ret)
-			return ret;
-
-		kiocb->ki_ioprio = ioprio;
-	} else
-		kiocb->ki_ioprio = get_current_ioprio();
+	kiocb->ki_flags |= iocb_flags(kiocb->ki_filp);
 
 	/* don't allow async punt if RWF_NOWAIT was requested */
 	if ((kiocb->ki_flags & IOCB_NOWAIT) ||
@@ -2070,7 +2052,7 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 	if (force_nonblock)
 		kiocb->ki_flags |= IOCB_NOWAIT;
 
-	if (ctx->flags & IORING_SETUP_IOPOLL) {
+	if (req->ctx->flags & IORING_SETUP_IOPOLL) {
 		if (!(kiocb->ki_flags & IOCB_DIRECT) ||
 		    !kiocb->ki_filp->f_op->iopoll)
 			return -EOPNOTSUPP;
@@ -2084,6 +2066,31 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		kiocb->ki_complete = io_complete_rw;
 	}
 
+	return 0;
+}
+
+static int io_sqe_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+	struct kiocb *kiocb = &req->rw.kiocb;
+	unsigned ioprio;
+	int ret;
+
+	kiocb->ki_pos = READ_ONCE(sqe->off);
+	kiocb->ki_flags = 0;
+	ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
+	if (unlikely(ret))
+		return ret;
+
+	ioprio = READ_ONCE(sqe->ioprio);
+	if (ioprio) {
+		ret = ioprio_check_cap(ioprio);
+		if (ret)
+			return ret;
+
+		kiocb->ki_ioprio = ioprio;
+	} else
+		kiocb->ki_ioprio = get_current_ioprio();
+
 	req->rw.addr = READ_ONCE(sqe->addr);
 	req->rw.len = READ_ONCE(sqe->len);
 	/* we own ->private, reuse it for the buffer index  / buffer ID */
@@ -2487,13 +2494,10 @@ static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 	struct iov_iter iter;
 	ssize_t ret;
 
-	ret = io_prep_rw(req, sqe, force_nonblock);
+	ret = io_sqe_prep_rw(req, sqe);
 	if (ret)
 		return ret;
 
-	if (unlikely(!(req->file->f_mode & FMODE_READ)))
-		return -EBADF;
-
 	/* either don't need iovec imported or already have it */
 	if (!req->io || req->flags & REQ_F_NEED_CLEANUP)
 		return 0;
@@ -2518,6 +2522,13 @@ static int io_read(struct io_kiocb *req, bool force_nonblock)
 	size_t iov_count;
 	ssize_t io_size, ret;
 
+	if (unlikely(!(req->file->f_mode & FMODE_READ)))
+		return -EBADF;
+
+	ret = io_prep_rw(req, force_nonblock);
+	if (ret)
+		return ret;
+
 	ret = io_import_iovec(READ, req, &iovec, &iter, !force_nonblock);
 	if (ret < 0)
 		return ret;
@@ -2576,13 +2587,10 @@ static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 	struct iov_iter iter;
 	ssize_t ret;
 
-	ret = io_prep_rw(req, sqe, force_nonblock);
+	ret = io_sqe_prep_rw(req, sqe);
 	if (ret)
 		return ret;
 
-	if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
-		return -EBADF;
-
 	/* either don't need iovec imported or already have it */
 	if (!req->io || req->flags & REQ_F_NEED_CLEANUP)
 		return 0;
@@ -2607,6 +2615,13 @@ static int io_write(struct io_kiocb *req, bool force_nonblock)
 	size_t iov_count;
 	ssize_t ret, io_size;
 
+	if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
+		return -EBADF;
+
+	ret = io_prep_rw(req, force_nonblock);
+	if (ret)
+		return ret;
+
 	ret = io_import_iovec(WRITE, req, &iovec, &iter, !force_nonblock);
 	if (ret < 0)
 		return ret;
-- 
2.25.1