kernel/io_uring/nop.c, branch 0x221E-v0.0.1-v6.19

io_uring/nop: add support for IORING_SETUP_CQE_MIXED

2025-08-27T17:24:15Z

This adds support for setting IORING_NOP_CQE32 as a flag for a NOP command, in which case a 32b CQE will be posted rather than a regular one. This is the default if the ring has been setup with IORING_SETUP_CQE32. If the ring has been setup with IORING_SETUP_CQE_MIXED, then 16b CQEs will be posted without this flag set, and 32b CQEs if this flag is set. For the latter case, sqe->off is what will be posted as cqe->big_cqe[0] and sqe->addr is what will be posted as cqe->big_cqe[1]. Signed-off-by: Jens Axboe

io_uring/nop: add IORING_NOP_TW completion flag

2025-06-23T14:59:13Z

To test and profile the overhead of io_uring task_work and the various types of it, add IORING_NOP_TW which tells nop to signal completions through task_work rather than complete them inline. Signed-off-by: Jens Axboe

io_uring: finish IOU_OK -> IOU_COMPLETE transition

2025-05-21T14:41:16Z

IOU_COMPLETE is more descriptive, in that it explicitly says that the return value means "please post a completion for this request". This patch completes the transition from IOU_OK to IOU_COMPLETE, replacing existing IOU_OK users. This is a purely mechanical change. Signed-off-by: Jens Axboe

io_uring/nop: use io_find_buf_node()

2025-03-01T02:35:37Z

Call io_find_buf_node() to avoid duplicating it in io_nop(). Signed-off-by: Caleb Sander Mateos Link: https://lore.kernel.org/r/20250301001610.678223-2-csander@purestorage.com Signed-off-by: Jens Axboe

io_uring/nop: reuse req->buf_index

2025-02-27T14:17:39Z

There is already a field in io_kiocb that can store a registered buffer index, use that instead of stashing the value into struct io_nop. Signed-off-by: Keith Busch Reviewed-by: Pavel Begunkov Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20250224213116.3509093-3-kbusch@meta.com Signed-off-by: Jens Axboe

io_uring/nop: ensure nop->fd is always initialized

2024-11-21T14:15:30Z

A previous commit added file support for nop, but it only initializes nop->fd if IORING_NOP_FIXED_FILE is set. That check should be IORING_NOP_FILE. Fix up the condition in nop preparation, and initialize it to a sane value even if we're not going to be directly using it. While in there, do the same thing for the nop->buffer field. Reported-by: syzbot+9a8500a45c2cabdf9577@syzkaller.appspotmail.com Fixes: a85f31052bce ("io_uring/nop: add support for testing registered files and buffers") Signed-off-by: Jens Axboe

io_uring/rsrc: add & apply io_req_assign_buf_node()

2024-11-07T22:24:33Z

The following pattern becomes more and more: + io_req_assign_rsrc_node(&req->buf_node, node); + req->flags |= REQ_F_BUF_NODE; so make it a helper, which is less fragile to use than above code, for example, the BUF_NODE flag is even missed in current io_uring_cmd_prep(). Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20241107110149.890530-4-ming.lei@redhat.com Signed-off-by: Jens Axboe

io_uring/rsrc: split io_kiocb node type assignments

2024-11-06T20:55:36Z

Currently the io_rsrc_node assignment in io_kiocb is an array of two pointers, as two nodes may be assigned to a request - one file node, and one buffer node. However, the buffer node can co-exist with the provided buffers, as currently it's not supported to use both provided and registered buffers at the same time. This crucially brings struct io_kiocb down to 4 cache lines again, as before it spilled into the 5th cacheline. Signed-off-by: Jens Axboe

io_uring/rsrc: add io_rsrc_node_lookup() helper

2024-11-02T21:45:30Z

There are lots of spots open-coding this functionality, add a generic helper that does the node lookup in a speculation safe way. Signed-off-by: Jens Axboe

io_uring/rsrc: unify file and buffer resource tables

2024-11-02T21:45:23Z

For files, there's nr_user_files/file_table/file_data, and buffers have nr_user_bufs/user_bufs/buf_data. There's no reason why file_table and file_data can't be the same thing, and ditto for the buffer side. That gets rid of more io_ring_ctx state that's in two spots rather than just being in one spot, as it should be. Put all the registered file data in one locations, and ditto on the buffer front. This also avoids having both io_rsrc_data->nodes being an allocated array, and ->user_bufs[] or ->file_table.nodes. There's no reason to have this information duplicated. Keep it in one spot, io_rsrc_data, along with how many resources are available. Signed-off-by: Jens Axboe