Commit 492dddb4 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: add zc notification flush requests 



Overlay notification control onto IORING_OP_RSRC_UPDATE (former
IORING_OP_FILES_UPDATE). It allows to flush a range of zc notifications
from slots with indexes [sqe->off, sqe->off+sqe->len). If sqe->arg is
not zero, it also copies sqe->arg as a new tag for all flushed
notifications.

Note, it doesn't flush a notification of a slot if there was no requests
attached to it (since last flush or registration).

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/df13e2363400682a73dd9e71c3b990b8d1ff0333.1657643355.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 4379d5f1

include/uapi/linux/io_uring.h

+1 −0
Original line number Diff line number Diff line
@@ -297,6 +297,7 @@ enum io_uring_op { 
 */

enum {

	IORING_RSRC_UPDATE_FILES,

	IORING_RSRC_UPDATE_NOTIF,

};



/*

io_uring/rsrc.c

+38 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include "io_uring.h"

#include "openclose.h"

#include "rsrc.h"

#include "notif.h"



struct io_rsrc_update {

	struct file			*file;
@@ -744,6 +745,41 @@ static int io_files_update(struct io_kiocb *req, unsigned int issue_flags) 
	return IOU_OK;

}



static int io_notif_update(struct io_kiocb *req, unsigned int issue_flags)

{

	struct io_rsrc_update *up = io_kiocb_to_cmd(req);

	struct io_ring_ctx *ctx = req->ctx;

	unsigned len = up->nr_args;

	unsigned idx_end, idx = up->offset;

	int ret = 0;



	io_ring_submit_lock(ctx, issue_flags);

	if (unlikely(check_add_overflow(idx, len, &idx_end))) {

		ret = -EOVERFLOW;

		goto out;

	}

	if (unlikely(idx_end > ctx->nr_notif_slots)) {

		ret = -EINVAL;

		goto out;

	}



	for (; idx < idx_end; idx++) {

		struct io_notif_slot *slot = &ctx->notif_slots[idx];



		if (!slot->notif)

			continue;

		if (up->arg)

			slot->tag = up->arg;

		io_notif_slot_flush_submit(slot, issue_flags);

	}

out:

	io_ring_submit_unlock(ctx, issue_flags);

	if (ret < 0)

		req_set_fail(req);

	io_req_set_res(req, ret, 0);

	return IOU_OK;

}



int io_rsrc_update(struct io_kiocb *req, unsigned int issue_flags)

{

	struct io_rsrc_update *up = io_kiocb_to_cmd(req);
@@ -751,6 +787,8 @@ int io_rsrc_update(struct io_kiocb *req, unsigned int issue_flags) 
	switch (up->type) {

	case IORING_RSRC_UPDATE_FILES:

		return io_files_update(req, issue_flags);

	case IORING_RSRC_UPDATE_NOTIF:

		return io_notif_update(req, issue_flags);

	}

	return -EINVAL;

}