From: Pavel Begunkov asml.silence@gmail.com
commit 5da28edd7bd5518f97175ecea77615bb729a7a28 upstream.
msg_ring requests transferring files support auto index selection via IORING_FILE_INDEX_ALLOC, however they don't return the selected index to the target ring and there is no other good way for the userspace to know where is the receieved file.
Return the index for allocated slots and 0 otherwise, which is consistent with other fixed file installing requests.
Cc: stable@vger.kernel.org # v6.0+ Fixes: e6130eba8a848 ("io_uring: add support for passing fixed file descriptors") Signed-off-by: Pavel Begunkov asml.silence@gmail.com Link: https://github.com/axboe/liburing/issues/809 Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- io_uring/msg_ring.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/io_uring/msg_ring.c +++ b/io_uring/msg_ring.c @@ -84,6 +84,8 @@ static int io_msg_send_fd(struct io_kioc struct file *src_file; int ret;
+ if (msg->len) + return -EINVAL; if (target_ctx == ctx) return -EINVAL; if (target_ctx->flags & IORING_SETUP_R_DISABLED) @@ -120,7 +122,7 @@ static int io_msg_send_fd(struct io_kioc * completes with -EOVERFLOW, then the sender must ensure that a * later IORING_OP_MSG_RING delivers the message. */ - if (!io_post_aux_cqe(target_ctx, msg->user_data, msg->len, 0, true)) + if (!io_post_aux_cqe(target_ctx, msg->user_data, ret, 0, true)) ret = -EOVERFLOW; out_unlock: io_double_unlock_ctx(ctx, target_ctx, issue_flags);