kernel/linux.git/include/uapi/linux/io_uring.h, branch linux-5.11.y

io_uring: add timeout update

2020-12-09T19:04:01+00:00

Support timeout updates through IORING_OP_TIMEOUT_REMOVE with passed in IORING_TIMEOUT_UPDATE. Updates doesn't support offset timeout mode. Oirignal timeout.off will be ignored as well. Signed-off-by: Pavel Begunkov [axboe: remove now unused 'ret' variable] Signed-off-by: Jens Axboe

io_uring: add timeout support for io_uring_enter()

2020-12-09T19:03:59+00:00

Now users who want to get woken when waiting for events should submit a timeout command first. It is not safe for applications that split SQ and CQ handling between two threads, such as mysql. Users should synchronize the two threads explicitly to protect SQ and that will impact the performance. This patch adds support for timeout to existing io_uring_enter(). To avoid overloading arguments, it introduces a new parameter structure which contains sigmask and timeout. I have tested the workloads with one thread submiting nop requests while the other reaping the cqe with timeout. It shows 1.8~2x faster when the iodepth is 16. Signed-off-by: Jiufei Xue Signed-off-by: Hao Xu [axboe: various cleanups/fixes, and name change to SIG_IS_DATA] Signed-off-by: Jens Axboe

io_uring: add support for IORING_OP_UNLINKAT

2020-12-09T19:03:59+00:00

IORING_OP_UNLINKAT behaves like unlinkat(2) and takes the same flags and arguments. Signed-off-by: Jens Axboe

io_uring: add support for IORING_OP_RENAMEAT

2020-12-09T19:03:59+00:00

IORING_OP_RENAMEAT behaves like renameat2(), and takes the same flags etc. Signed-off-by: Jens Axboe

io_uring: allow non-fixed files with SQPOLL

2020-12-09T19:03:54+00:00

The restriction of needing fixed files for SQPOLL is problematic, and prevents/inhibits several valid uses cases. With the referenced files_struct that we have now, it's trivially supportable. Treat ->files like we do the mm for the SQPOLL thread - grab a reference to it (and assign it), and drop it when we're done. This feature is exposed as IORING_FEAT_SQPOLL_NONFIXED. Signed-off-by: Jens Axboe

io_uring: add support for shutdown(2)

2020-11-23T16:15:15+00:00

This adds support for the shutdown(2) system call, which is useful for dealing with sockets. shutdown(2) may block, so we have to punt it to async context. Suggested-by: Norman Maurer Signed-off-by: Jens Axboe

io_uring: provide IORING_ENTER_SQ_WAIT for SQPOLL SQ ring waits

2020-10-01T02:32:33+00:00

When using SQPOLL, applications can run into the issue of running out of SQ ring entries because the thread hasn't consumed them yet. The only option for dealing with that is checking later, or busy checking for the condition. Provide IORING_ENTER_SQ_WAIT if applications want to wait on this condition. Signed-off-by: Jens Axboe

io_uring: allow disabling rings during the creation

2020-10-01T02:32:33+00:00

This patch adds a new IORING_SETUP_R_DISABLED flag to start the rings disabled, allowing the user to register restrictions, buffers, files, before to start processing SQEs. When IORING_SETUP_R_DISABLED is set, SQE are not processed and SQPOLL kthread is not started. The restrictions registration are allowed only when the rings are disable to prevent concurrency issue while processing SQEs. The rings can be enabled using IORING_REGISTER_ENABLE_RINGS opcode with io_uring_register(2). Suggested-by: Jens Axboe Signed-off-by: Stefano Garzarella Reviewed-by: Kees Cook Signed-off-by: Jens Axboe

io_uring: add IOURING_REGISTER_RESTRICTIONS opcode

2020-10-01T02:32:33+00:00

The new io_uring_register(2) IOURING_REGISTER_RESTRICTIONS opcode permanently installs a feature allowlist on an io_ring_ctx. The io_ring_ctx can then be passed to untrusted code with the knowledge that only operations present in the allowlist can be executed. The allowlist approach ensures that new features added to io_uring do not accidentally become available when an existing application is launched on a newer kernel version. Currently is it possible to restrict sqe opcodes, sqe flags, and register opcodes. IOURING_REGISTER_RESTRICTIONS can only be made once. Afterwards it is not possible to change restrictions anymore. This prevents untrusted code from removing restrictions. Suggested-by: Stefan Hajnoczi Signed-off-by: Stefano Garzarella Reviewed-by: Kees Cook Signed-off-by: Jens Axboe

io_uring: use an enumeration for io_uring_register(2) opcodes

2020-10-01T02:32:33+00:00

The enumeration allows us to keep track of the last io_uring_register(2) opcode available. Behaviour and opcodes names don't change. Signed-off-by: Stefano Garzarella Reviewed-by: Kees Cook Signed-off-by: Jens Axboe