From 1339f24b336db5ded9811f3fe7b948e0de207785 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sat, 7 May 2022 14:18:44 -0600 Subject: io_uring: allow allocated fixed files for openat/openat2 If the application passes in IORING_FILE_INDEX_ALLOC as the file_slot, then that's a hint to allocate a fixed file descriptor rather than have one be passed in directly. This can be useful for having io_uring manage the direct descriptor space. Normal open direct requests will complete with 0 for success, and < 0 in case of error. If io_uring is asked to allocated the direct descriptor, then the direct descriptor is returned in case of success. Reviewed-by: Hao Xu Signed-off-by: Jens Axboe --- include/uapi/linux/io_uring.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 06621a278cb6..b7f02a55032a 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -63,6 +63,15 @@ struct io_uring_sqe { __u64 __pad2[2]; }; +/* + * If sqe->file_index is set to this for opcodes that instantiate a new + * direct descriptor (like openat/openat2/accept), then io_uring will allocate + * an available direct descriptor instead of having the application pass one + * in. The picked direct descriptor will be returned in cqe->res, or -ENFILE + * if the space is full. + */ +#define IORING_FILE_INDEX_ALLOC (~0U) + enum { IOSQE_FIXED_FILE_BIT, IOSQE_IO_DRAIN_BIT, -- cgit