diff options
author | Josh Triplett <josh@joshtriplett.org> | 2023-04-28 19:40:30 +0300 |
---|---|---|
committer | Jens Axboe <axboe@kernel.dk> | 2023-05-16 17:06:00 +0300 |
commit | 6e76ac595855db27bbdaef337173294a6fd6eb2c (patch) | |
tree | 29175a90e7330051dd3175e1ab659233e54d7c3a /io_uring/io_uring.h | |
parent | 03d89a2de25bbc5c77e61a0cf77663978c4b6ea7 (diff) | |
download | linux-6e76ac595855db27bbdaef337173294a6fd6eb2c.tar.xz |
io_uring: Add io_uring_setup flag to pre-register ring fd and never install it
With IORING_REGISTER_USE_REGISTERED_RING, an application can register
the ring fd and use it via registered index rather than installed fd.
This allows using a registered ring for everything *except* the initial
mmap.
With IORING_SETUP_NO_MMAP, io_uring_setup uses buffers allocated by the
user, rather than requiring a subsequent mmap.
The combination of the two allows a user to operate *entirely* via a
registered ring fd, making it unnecessary to ever install the fd in the
first place. So, add a flag IORING_SETUP_REGISTERED_FD_ONLY to make
io_uring_setup register the fd and return a registered index, without
installing the fd.
This allows an application to avoid touching the fd table at all, and
allows a library to never even momentarily install a file descriptor.
This splits out an io_ring_add_registered_file helper from
io_ring_add_registered_fd, for use by io_uring_setup.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Link: https://lore.kernel.org/r/bc8f431bada371c183b95a83399628b605e978a3.1682699803.git.josh@joshtriplett.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/io_uring.h')
-rw-r--r-- | io_uring/io_uring.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h index 259bf798a390..9b8dfb3bb2b4 100644 --- a/io_uring/io_uring.h +++ b/io_uring/io_uring.h @@ -75,6 +75,9 @@ __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd); int io_uring_alloc_task_context(struct task_struct *task, struct io_ring_ctx *ctx); +int io_ring_add_registered_file(struct io_uring_task *tctx, struct file *file, + int start, int end); + int io_poll_issue(struct io_kiocb *req, struct io_tw_state *ts); int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr); int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin); |