[PATCH AUTOSEL 5.15 09/19] io_uring: assign non-fixed early for async work

[PATCH AUTOSEL 5.15 09/19] io_uring: assign non-fixed early for async work

[Sasha Levin]

From: Jens Axboe <axboe@kernel.dk>

[ Upstream commit a196c78b5443fc61af2c0490213b9d125482cbd1 ]

We defer file assignment to ensure that fixed files work with links
between a direct accept/open and the links that follow it. But this has
the side effect that normal file assignment is then not complete by the
time that request submission has been done.

For deferred execution, if the file is a regular file, assign it when
we do the async prep anyway.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/io_uring.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 7aad4bde92e9..2f7ac8df9a0c 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -6506,7 +6506,12 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 
 static int io_req_prep_async(struct io_kiocb *req)
 {
-	if (!io_op_defs[req->opcode].needs_async_setup)
+	const struct io_op_def *def = &io_op_defs[req->opcode];
+
+	/* assign early for deferred execution for non-fixed file */
+	if (def->needs_file && !(req->flags & REQ_F_FIXED_FILE))
+		req->file = io_file_get_normal(req, req->fd);
+	if (!def->needs_async_setup)
 		return 0;
 	if (WARN_ON_ONCE(req->async_data))
 		return -EFAULT;
-- 
2.35.1

Re: [PATCH AUTOSEL 5.15 09/19] io_uring: assign non-fixed early for async work

[Jens Axboe]

On 5/10/22 9:44 AM, Sasha Levin wrote:
> From: Jens Axboe <axboe@kernel.dk>
> 
> [ Upstream commit a196c78b5443fc61af2c0490213b9d125482cbd1 ]
> 
> We defer file assignment to ensure that fixed files work with links
> between a direct accept/open and the links that follow it. But this has
> the side effect that normal file assignment is then not complete by the
> time that request submission has been done.
> 
> For deferred execution, if the file is a regular file, assign it when
> we do the async prep anyway.

This one should only go into 5.17-stable, not anything earlier.

-- 
Jens Axboe