diff options
| author | Jens Axboe <[email protected]> | 2023-12-07 20:06:02 -0700 |
|---|---|---|
| committer | Jens Axboe <[email protected]> | 2023-12-12 07:42:57 -0700 |
| commit | dc18b89ab113e9c6c7a529316ddf7029fb55132d (patch) | |
| tree | 682c2a5f7e58b4af465e4e59fba5bf417420e2cf /include/uapi/linux | |
| parent | 055c15626a45b1ebc9f2f34981e705e1af171236 (diff) | |
io_uring/openclose: add support for IORING_OP_FIXED_FD_INSTALL
io_uring can currently open/close regular files or fixed/direct
descriptors. Or you can instantiate a fixed descriptor from a regular
one, and then close the regular descriptor. But you currently can't turn
a purely fixed/direct descriptor into a regular file descriptor.
IORING_OP_FIXED_FD_INSTALL adds support for installing a direct
descriptor into the normal file table, just like receiving a file
descriptor or opening a new file would do. This is all nicely abstracted
into receive_fd(), and hence adding support for this is truly trivial.
Since direct descriptors are only usable within io_uring itself, it can
be useful to turn them into real file descriptors if they ever need to
be accessed via normal syscalls. This can either be a transitory thing,
or just a permanent transition for a given direct descriptor.
By default, new fds are installed with O_CLOEXEC set. The application
can disable O_CLOEXEC by setting IORING_FIXED_FD_NO_CLOEXEC in the
sqe->install_fd_flags member.
Suggested-by: Christian Brauner <[email protected]>
Reviewed-by: Christian Brauner <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Diffstat (limited to 'include/uapi/linux')
| -rw-r--r-- | include/uapi/linux/io_uring.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index f1c16f817742..db4b913e6b39 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -71,6 +71,7 @@ struct io_uring_sqe { __u32 uring_cmd_flags; __u32 waitid_flags; __u32 futex_flags; + __u32 install_fd_flags; }; __u64 user_data; /* data to be passed back at completion time */ /* pack this to avoid bogus arm OABI complaints */ @@ -253,6 +254,7 @@ enum io_uring_op { IORING_OP_FUTEX_WAIT, IORING_OP_FUTEX_WAKE, IORING_OP_FUTEX_WAITV, + IORING_OP_FIXED_FD_INSTALL, /* this goes last, obviously */ IORING_OP_LAST, @@ -387,6 +389,13 @@ enum { #define IORING_MSG_RING_FLAGS_PASS (1U << 1) /* + * IORING_OP_FIXED_FD_INSTALL flags (sqe->install_fd_flags) + * + * IORING_FIXED_FD_NO_CLOEXEC Don't mark the fd as O_CLOEXEC + */ +#define IORING_FIXED_FD_NO_CLOEXEC (1U << 0) + +/* * IO completion data structure (Completion Queue Entry) */ struct io_uring_cqe { |