kernel/linux.git/include/uapi/linux/io_uring.h, branch v6.1.168

io_uring/cancel: support opcode based lookup and cancelation

2026-03-04T12:20:02+00:00

[ Upstream commit d7b8b079a8f6bc007d06d9ee468659dae6053e13 ] 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 Stable-dep-of: 22dbb0987bd1 ("io_uring/cancel: de-unionize file and user_data in struct io_cancel_data") Signed-off-by: Sasha Levin

io_uring/cancel: add IORING_ASYNC_CANCEL_USERDATA

2026-03-04T12:20:01+00:00

[ Upstream commit 8165b566049b14152873011ea540eb22eae5111d ] 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 Stable-dep-of: 22dbb0987bd1 ("io_uring/cancel: de-unionize file and user_data in struct io_cancel_data") Signed-off-by: Sasha Levin

io_uring: don't use int for ABI

2025-08-28T14:25:47+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: get rid of remap_pfn_range() for mapping rings/sqes

2025-03-28T20:58:53+00:00

Commit 3ab1db3c6039e02a9deb9d5091d28d559917a645 upstream. Rather than use remap_pfn_range() for this and manually free later, switch to using vm_insert_pages() and have it Just Work. If possible, allocate a single compound page that covers the range that is needed. If that works, then we can just use page_address() on that page. If we fail to get a compound page, allocate single pages and use vmap() to map them into the kernel virtual address space. This just covers the rings/sqes, the other remaining user of the mmap remap_pfn_range() user will be converted separately. Once that is done, we can kill the old alloc/free code. Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

io_uring: Replace 0-length array with flexible array

2023-03-10T08:34:03+00:00

commit 36632d062975a9ff4410c90dd6d37922b68d0920 upstream. Zero-length arrays are deprecated[1]. Replace struct io_uring_buf_ring's "bufs" with a flexible array member. (How is the size of this array verified?) Detected with GCC 13, using -fstrict-flex-arrays=3: In function 'io_ring_buffer_select', inlined from 'io_buffer_select' at io_uring/kbuf.c:183:10: io_uring/kbuf.c:141:23: warning: array subscript 255 is outside the bounds of an interior zero-length array 'struct io_uring_buf[0]' [-Wzero-length-bounds] 141 | buf = &br->bufs[head]; | ^~~~~~~~~~~~~~~ In file included from include/linux/io_uring.h:7, from io_uring/kbuf.c:10: include/uapi/linux/io_uring.h: In function 'io_buffer_select': include/uapi/linux/io_uring.h:628:41: note: while referencing 'bufs' 628 | struct io_uring_buf bufs[0]; | ^~~~ [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays Fixes: c7fb19428d67 ("io_uring: add support for ring mapped supplied buffers") Cc: Jens Axboe Cc: Pavel Begunkov Cc: "Gustavo A. R. Silva" Cc: stable@vger.kernel.org Cc: io-uring@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/20230105190507.gonna.131-kees@kernel.org Signed-off-by: Greg Kroah-Hartman

io_uring/net: introduce IORING_SEND_ZC_REPORT_USAGE flag

2022-12-31T12:33:11+00:00

commit e307e6698165ca6508ed42c69cb1be76c8eb6a3c upstream. It might be useful for applications to detect if a zero copy transfer with SEND[MSG]_ZC was actually possible or not. The application can fallback to plain SEND[MSG] in order to avoid the overhead of two cqes per request. Or it can generate a log message that could indicate to an administrator that no zero copy was possible and could explain degraded performance. Cc: stable@vger.kernel.org # 6.1 Link: https://lore.kernel.org/io-uring/fb6a7599-8a9b-15e5-9b64-6cd9d01c6ff4@gmail.com/T/#m2b0d9df94ce43b0e69e6c089bdff0ce6babbdfaa Signed-off-by: Stefan Metzmacher Reviewed-by: Pavel Begunkov Link: https://lore.kernel.org/r/8945b01756d902f5d5b0667f20b957ad3f742e5e.1666895626.git.metze@samba.org Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

io_uring: fix typo in io_uring.h comment

2022-11-06T20:17:27+00:00

Just a basic s/thig/this swap, fixing up a typo introduced by a commit added in the 6.1 release. Fixes: 9cda70f622cd ("io_uring: introduce fixed buffer support for io_uring_cmd") Signed-off-by: Jens Axboe

io_uring: introduce fixed buffer support for io_uring_cmd

2022-09-30T13:50:59+00:00

Add IORING_URING_CMD_FIXED flag that is to be used for sending io_uring command with previously registered buffers. User-space passes the buffer index in sqe->buf_index, same as done in read/write variants that uses fixed buffers. Signed-off-by: Anuj Gupta Signed-off-by: Kanchan Joshi Link: https://lore.kernel.org/r/20220930062749.152261-3-anuj20.g@samsung.com [axboe: shuffle valid flags check before acting on it] Signed-off-by: Jens Axboe

io_uring/net: zerocopy sendmsg

2022-09-21T19:15:02+00:00

Add a zerocopy version of sendmsg. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/6aabc4bdfc0ec78df6ec9328137e394af9d4e7ef.1663668091.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring: add IORING_SETUP_DEFER_TASKRUN

2022-09-21T16:30:42+00:00

Allow deferring async tasks until the user calls io_uring_enter(2) with the IORING_ENTER_GETEVENTS flag. Enable this mode with a flag at io_uring_setup time. This functionality requires that the later io_uring_enter will be called from the same submission task, and therefore restrict this flag to work only when IORING_SETUP_SINGLE_ISSUER is also set. Being able to hand pick when tasks are run prevents the problem where there is current work to be done, however task work runs anyway. For example, a common workload would obtain a batch of CQEs, and process each one. Interrupting this to additional taskwork would add latency but not gain anything. If instead task work is deferred to just before more CQEs are obtained then no additional latency is added. The way this is implemented is by trying to keep task work local to a io_ring_ctx, rather than to the submission task. This is required, as the application will want to wake up only a single io_ring_ctx at a time to process work, and so the lists of work have to be kept separate. This has some other benefits like not having to check the task continually in handle_tw_list (and potentially unlocking/locking those), and reducing locks in the submit & process completions path. There are networking cases where using this option can reduce request latency by 50%. For example a contrived example using [1] where the client sends 2k data and receives the same data back while doing some system calls (to trigger task work) shows this reduction. The reason ends up being that if sending responses is delayed by processing task work, then the client side sits idle. Whereas reordering the sends first means that the client runs it's workload in parallel with the local task work. [1]: Using https://github.com/DylanZA/netbench/tree/defer_run Client: ./netbench --client_only 1 --control_port 10000 --host --tx "epoll --threads 16 --per_thread 1 --size 2048 --resp 2048 --workload 1000" Server: ./netbench --server_only 1 --control_port 10000 --rx "io_uring --defer_taskrun 0 --workload 100" --rx "io_uring --defer_taskrun 1 --workload 100" Signed-off-by: Dylan Yudaken Link: https://lore.kernel.org/r/20220830125013.570060-5-dylany@fb.com Signed-off-by: Jens Axboe