[PATCH 5.7 100/120] io_uring: always allow drain/link/hardlink/async sqe flags

[Greg Kroah-Hartman]

From: Daniele Albano <d.albano@xxxxxxxxx>

[ Upstream commit 61710e437f2807e26a3402543bdbb7217a9c8620 ]

We currently filter these for timeout_remove/async_cancel/files_update,
but we only should be filtering for fixed file and buffer select. This
also causes a second read of sqe->flags, which isn't needed.

Just check req->flags for the relevant bits. This then allows these
commands to be used in links, for example, like everything else.

Signed-off-by: Daniele Albano <d.albano@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/io_uring.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index d0d3efaaa4d4f..4e09af1d5d223 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4808,7 +4808,9 @@ static int io_timeout_remove_prep(struct io_kiocb *req,
 {
 	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
 		return -EINVAL;
-	if (sqe->flags || sqe->ioprio || sqe->buf_index || sqe->len)
+	if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+		return -EINVAL;
+	if (sqe->ioprio || sqe->buf_index || sqe->len)
 		return -EINVAL;
 
 	req->timeout.addr = READ_ONCE(sqe->addr);
@@ -5014,8 +5016,9 @@ static int io_async_cancel_prep(struct io_kiocb *req,
 {
 	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
 		return -EINVAL;
-	if (sqe->flags || sqe->ioprio || sqe->off || sqe->len ||
-	    sqe->cancel_flags)
+	if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+		return -EINVAL;
+	if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags)
 		return -EINVAL;
 
 	req->cancel.addr = READ_ONCE(sqe->addr);
@@ -5033,7 +5036,9 @@ static int io_async_cancel(struct io_kiocb *req)
 static int io_files_update_prep(struct io_kiocb *req,
 				const struct io_uring_sqe *sqe)
 {
-	if (sqe->flags || sqe->ioprio || sqe->rw_flags)
+	if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
+		return -EINVAL;
+	if (sqe->ioprio || sqe->rw_flags)
 		return -EINVAL;
 
 	req->files_update.offset = READ_ONCE(sqe->off);
-- 
2.25.1