kernel/linux.git/include/uapi/linux/io_uring.h, branch v6.6.132

io_uring: don't use int for ABI

2025-08-28T14:28:09+00:00

commit cf73d9970ea4f8cace5d8f02d2565a2723003112 upstream. __kernel_rwf_t is defined as int, the actual size of which is implementation defined. It won't go well if some compiler / archs ever defines it as i64, so replace it with __u32, hoping that there is no one using i16 for it. Cc: stable@vger.kernel.org Fixes: 2b188cc1bb857 ("Add io_uring IO interface") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/47c666c4ee1df2018863af3a2028af18feef11ed.1751412511.git.asml.silence@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

io_uring: add option to remove SQ indirection

2023-08-24T23:16:19+00:00

Not many aware, but io_uring submission queue has two levels. The first level usually appears as sq_array and stores indexes into the actual SQ. To my knowledge, no one has ever seriously used it, nor liburing exposes it to users. Add IORING_SETUP_NO_SQARRAY, when set we don't bother creating and using the sq_array and SQ heads/tails will be pointing directly into the SQ. Improves memory footprint, in term of both allocations as well as cache usage, and also should make io_get_sqe() less branchy in the end. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/0ffa3268a5ef61d326201ff43a233315c96312e0.1692916914.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: Add io_uring command support for sockets

2023-08-09T16:46:15+00:00

Enable io_uring commands on network sockets. Create two new SOCKET_URING_OP commands that will operate on sockets. In order to call ioctl on sockets, use the file_operations->io_uring_cmd callbacks, and map it to a uring socket function, which handles the SOCKET_URING_OP accordingly, and calls socket ioctls. This patches was tested by creating a new test case in liburing. Link: https://github.com/leitao/liburing/tree/io_uring_cmd Signed-off-by: Breno Leitao Acked-by: Jakub Kicinski Link: https://lore.kernel.org/r/20230627134424.2784797-1-leitao@debian.org Signed-off-by: Jens Axboe

io_uring/cancel: wire up IORING_ASYNC_CANCEL_OP for sync cancel

2023-07-17T16:05:48+00:00

Allow usage of IORING_ASYNC_CANCEL_OP through the sync cancelation API as well. Signed-off-by: Jens Axboe

io_uring/cancel: support opcode based lookup and cancelation

2023-07-17T16:05:48+00:00

Add IORING_ASYNC_CANCEL_OP flag for cancelation, which allows the application to target cancelation based on the opcode of the original request. Signed-off-by: Jens Axboe

io_uring/cancel: add IORING_ASYNC_CANCEL_USERDATA

2023-07-17T16:05:48+00:00

Add a flag to explicitly match on user_data in the request for cancelation purposes. This is the default behavior if none of the other match flags are set, but if we ALSO want to match on user_data, then this flag can be set. Signed-off-by: Jens Axboe

nvme: improved uring polling

2023-06-28T22:09:41+00:00

Drivers can poll requests directly, so use that. We just need to ensure the driver's request was allocated from a polled hctx, so a special driver flag is added to struct io_uring_cmd. The allows unshared and multipath namespaces to use the same polling callback, and multipath is guaranteed to get the same queue as the command was submitted on. Previously multipath polling might check a different path and poll the wrong info. The other bonus is we don't need a bio payload in order to poll, allowing commands like 'flush' and 'write zeroes' to be submitted on the same high priority queue as read and write commands. Finally, using the request based polling skips the unnecessary bio overhead. Signed-off-by: Keith Busch Reviewed-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20230612190343.2087040-3-kbusch@meta.com Signed-off-by: Jens Axboe

io_uring: Add io_uring_setup flag to pre-register ring fd and never install it

2023-05-16T14:06:00+00:00

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 Link: https://lore.kernel.org/r/bc8f431bada371c183b95a83399628b605e978a3.1682699803.git.josh@joshtriplett.org Signed-off-by: Jens Axboe

io_uring: support for user allocated memory for rings/sqes

2023-05-16T14:04:55+00:00

Currently io_uring applications must call mmap(2) twice to map the rings themselves, and the sqes array. This works fine, but it does not support using huge pages to back the rings/sqes. Provide a way for the application to pass in pre-allocated memory for the rings/sqes, which can then suitably be allocated from shmfs or via mmap to get huge page support. Particularly for larger rings, this reduces the TLBs needed. If an application wishes to take advantage of that, it must pre-allocate the memory needed for the sq/cq ring, and the sqes. The former must be passed in via the io_uring_params->cq_off.user_data field, while the latter is passed in via the io_uring_params->sq_off.user_data field. Then it must set IORING_SETUP_NO_MMAP in the io_uring_params->flags field, and io_uring will then map the existing memory into the kernel for shared use. The application must not call mmap(2) to map rings as it otherwise would have, that will now fail with -EINVAL if this setup flag was used. The pages used for the rings and sqes must be contigious. The intent here is clearly that huge pages should be used, otherwise the normal setup procedure works fine as-is. The application may use one huge page for both the rings and sqes. Outside of those initialization changes, everything works like it did before. Signed-off-by: Jens Axboe

io_uring: add support for multishot timeouts

2023-04-19T01:38:36+00:00

A multishot timeout submission will repeatedly generate completions with the IORING_CQE_F_MORE cflag set. Depending on the value of the `off' field in the submission, these timeouts can either repeat indefinitely until cancelled (`off' = 0) or for a fixed number of times (`off' > 0). Only noseq timeouts (i.e. not dependent on the number of I/O completions) are supported. An indefinite timer will be cancelled if the CQ ever overflows. Signed-off-by: David Wei Link: https://lore.kernel.org/r/20230418225817.1905027-1-davidhwei@meta.com Signed-off-by: Jens Axboe