cancel.c 4.5 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include <linux/io_uring.h>

#include <uapi/linux/io_uring.h>

#include "io_uring_types.h"
#include "io_uring.h"
#include "tctx.h"
#include "poll.h"
#include "timeout.h"
#include "cancel.h"

struct io_cancel {
	struct file			*file;
	u64				addr;
	u32				flags;
	s32				fd;
};

#define CANCEL_FLAGS	(IORING_ASYNC_CANCEL_ALL | IORING_ASYNC_CANCEL_FD | \
			 IORING_ASYNC_CANCEL_ANY)

static bool io_cancel_cb(struct io_wq_work *work, void *data)
{
	struct io_kiocb *req = container_of(work, struct io_kiocb, work);
	struct io_cancel_data *cd = data;

	if (req->ctx != cd->ctx)
		return false;
	if (cd->flags & IORING_ASYNC_CANCEL_ANY) {
		;
	} else if (cd->flags & IORING_ASYNC_CANCEL_FD) {
		if (req->file != cd->file)
			return false;
	} else {
		if (req->cqe.user_data != cd->data)
			return false;
	}
	if (cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY)) {
		if (cd->seq == req->work.cancel_seq)
			return false;
		req->work.cancel_seq = cd->seq;
	}
	return true;
}

static int io_async_cancel_one(struct io_uring_task *tctx,
			       struct io_cancel_data *cd)
{
	enum io_wq_cancel cancel_ret;
	int ret = 0;
	bool all;

	if (!tctx || !tctx->io_wq)
		return -ENOENT;

	all = cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY);
	cancel_ret = io_wq_cancel_cb(tctx->io_wq, io_cancel_cb, cd, all);
	switch (cancel_ret) {
	case IO_WQ_CANCEL_OK:
		ret = 0;
		break;
	case IO_WQ_CANCEL_RUNNING:
		ret = -EALREADY;
		break;
	case IO_WQ_CANCEL_NOTFOUND:
		ret = -ENOENT;
		break;
	}

	return ret;
}

int io_try_cancel(struct io_kiocb *req, struct io_cancel_data *cd)
{
	struct io_ring_ctx *ctx = req->ctx;
	int ret;

	WARN_ON_ONCE(!io_wq_current_is_worker() && req->task != current);

	ret = io_async_cancel_one(req->task->io_uring, cd);
	/*
	 * Fall-through even for -EALREADY, as we may have poll armed
	 * that need unarming.
	 */
	if (!ret)
		return 0;

	ret = io_poll_cancel(ctx, cd);
	if (ret != -ENOENT)
98 99
		return ret;

100
	spin_lock(&ctx->completion_lock);
101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194
	if (!(cd->flags & IORING_ASYNC_CANCEL_FD))
		ret = io_timeout_cancel(ctx, cd);
	spin_unlock(&ctx->completion_lock);
	return ret;
}


int io_async_cancel_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
	struct io_cancel *cancel = io_kiocb_to_cmd(req);

	if (unlikely(req->flags & REQ_F_BUFFER_SELECT))
		return -EINVAL;
	if (sqe->off || sqe->len || sqe->splice_fd_in)
		return -EINVAL;

	cancel->addr = READ_ONCE(sqe->addr);
	cancel->flags = READ_ONCE(sqe->cancel_flags);
	if (cancel->flags & ~CANCEL_FLAGS)
		return -EINVAL;
	if (cancel->flags & IORING_ASYNC_CANCEL_FD) {
		if (cancel->flags & IORING_ASYNC_CANCEL_ANY)
			return -EINVAL;
		cancel->fd = READ_ONCE(sqe->fd);
	}

	return 0;
}

static int __io_async_cancel(struct io_cancel_data *cd, struct io_kiocb *req,
			     unsigned int issue_flags)
{
	bool all = cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY);
	struct io_ring_ctx *ctx = cd->ctx;
	struct io_tctx_node *node;
	int ret, nr = 0;

	do {
		ret = io_try_cancel(req, cd);
		if (ret == -ENOENT)
			break;
		if (!all)
			return ret;
		nr++;
	} while (1);

	/* slow path, try all io-wq's */
	io_ring_submit_lock(ctx, issue_flags);
	ret = -ENOENT;
	list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
		struct io_uring_task *tctx = node->task->io_uring;

		ret = io_async_cancel_one(tctx, cd);
		if (ret != -ENOENT) {
			if (!all)
				break;
			nr++;
		}
	}
	io_ring_submit_unlock(ctx, issue_flags);
	return all ? nr : ret;
}

int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_cancel *cancel = io_kiocb_to_cmd(req);
	struct io_cancel_data cd = {
		.ctx	= req->ctx,
		.data	= cancel->addr,
		.flags	= cancel->flags,
		.seq	= atomic_inc_return(&req->ctx->cancel_seq),
	};
	int ret;

	if (cd.flags & IORING_ASYNC_CANCEL_FD) {
		if (req->flags & REQ_F_FIXED_FILE)
			req->file = io_file_get_fixed(req, cancel->fd,
							issue_flags);
		else
			req->file = io_file_get_normal(req, cancel->fd);
		if (!req->file) {
			ret = -EBADF;
			goto done;
		}
		cd.file = req->file;
	}

	ret = __io_async_cancel(&cd, req, issue_flags);
done:
	if (ret < 0)
		req_set_fail(req);
	io_req_set_res(req, ret, 0);
	return IOU_OK;
}
195 196 197 198 199 200 201 202 203 204

void init_hash_table(struct io_hash_bucket *hash_table, unsigned size)
{
	unsigned int i;

	for (i = 0; i < size; i++) {
		spin_lock_init(&hash_table[i].lock);
		INIT_HLIST_HEAD(&hash_table[i].list);
	}
}
新手
引导
客服 返回
顶部