[linux-block.git] / io_uring / cancel.c

// 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,
		  unsigned issue_flags)
{
	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, issue_flags);
	if (ret != -ENOENT)
		return ret;

	spin_lock(&ctx->completion_lock);
	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, issue_flags);
		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;
}

void init_hash_table(struct io_hash_table *table, unsigned size)
{
	unsigned int i;

	for (i = 0; i < size; i++) {
		spin_lock_init(&table->hbs[i].lock);
		INIT_HLIST_HEAD(&table->hbs[i].list);
	}
}
Commit	Line	Data
7aaff708 JA	1	// SPDX-License-Identifier: GPL-2.0
	2	#include <linux/kernel.h>
	3	#include <linux/errno.h>
	4	#include <linux/fs.h>
	5	#include <linux/file.h>
	6	#include <linux/mm.h>
	7	#include <linux/slab.h>
	8	#include <linux/namei.h>
	9	#include <linux/io_uring.h>
	10
	11	#include <uapi/linux/io_uring.h>
	12
	13	#include "io_uring_types.h"
	14	#include "io_uring.h"
	15	#include "tctx.h"
	16	#include "poll.h"
	17	#include "timeout.h"
	18	#include "cancel.h"
	19
	20	struct io_cancel {
	21	struct file *file;
	22	u64 addr;
	23	u32 flags;
	24	s32 fd;
	25	};
	26
	27	#define CANCEL_FLAGS (IORING_ASYNC_CANCEL_ALL \| IORING_ASYNC_CANCEL_FD \| \
	28	IORING_ASYNC_CANCEL_ANY)
	29
	30	static bool io_cancel_cb(struct io_wq_work work, void data)
	31	{
	32	struct io_kiocb *req = container_of(work, struct io_kiocb, work);
	33	struct io_cancel_data *cd = data;
	34
	35	if (req->ctx != cd->ctx)
	36	return false;
	37	if (cd->flags & IORING_ASYNC_CANCEL_ANY) {
	38	;
	39	} else if (cd->flags & IORING_ASYNC_CANCEL_FD) {
	40	if (req->file != cd->file)
	41	return false;
	42	} else {
	43	if (req->cqe.user_data != cd->data)
	44	return false;
	45	}
	46	if (cd->flags & (IORING_ASYNC_CANCEL_ALL\|IORING_ASYNC_CANCEL_ANY)) {
	47	if (cd->seq == req->work.cancel_seq)
	48	return false;
	49	req->work.cancel_seq = cd->seq;
	50	}
	51	return true;
	52	}
	53
	54	static int io_async_cancel_one(struct io_uring_task *tctx,
	55	struct io_cancel_data *cd)
	56	{
	57	enum io_wq_cancel cancel_ret;
	58	int ret = 0;
	59	bool all;
	60
	61	if (!tctx \|\| !tctx->io_wq)
	62	return -ENOENT;
	63
	64	all = cd->flags & (IORING_ASYNC_CANCEL_ALL\|IORING_ASYNC_CANCEL_ANY);
65	cancel_ret = io_wq_cancel_cb(tctx->io_wq, io_cancel_cb, cd, all);
66	switch (cancel_ret) {
67	case IO_WQ_CANCEL_OK:
68	ret = 0;
69	break;
70	case IO_WQ_CANCEL_RUNNING:
71	ret = -EALREADY;
72	break;
73	case IO_WQ_CANCEL_NOTFOUND:
74	ret = -ENOENT;
75	break;
76	}
77
78	return ret;
79	}
80
5d7943d9 PB	81	int io_try_cancel(struct io_kiocb req, struct io_cancel_data cd,
5d7943d9 PB	82	unsigned issue_flags)
7aaff708 JA	83	{
	84	struct io_ring_ctx *ctx = req->ctx;
	85	int ret;
	86
	87	WARN_ON_ONCE(!io_wq_current_is_worker() && req->task != current);
	88
	89	ret = io_async_cancel_one(req->task->io_uring, cd);
	90	/*
	91	* Fall-through even for -EALREADY, as we may have poll armed
	92	* that need unarming.
	93	*/
	94	if (!ret)
	95	return 0;
	96
5d7943d9	97	ret = io_poll_cancel(ctx, cd, issue_flags);
7aaff708	98	if (ret != -ENOENT)
4dfab8ab PB	99	return ret;
4dfab8ab PB	100
38513c46	101	spin_lock(&ctx->completion_lock);
7aaff708 JA	102	if (!(cd->flags & IORING_ASYNC_CANCEL_FD))
7aaff708 JA	103	ret = io_timeout_cancel(ctx, cd);
7aaff708 JA	104	spin_unlock(&ctx->completion_lock);
	105	return ret;
	106	}
	107
	108
	109	int io_async_cancel_prep(struct io_kiocb req, const struct io_uring_sqe sqe)
	110	{
	111	struct io_cancel *cancel = io_kiocb_to_cmd(req);
	112
	113	if (unlikely(req->flags & REQ_F_BUFFER_SELECT))
	114	return -EINVAL;
	115	if (sqe->off \|\| sqe->len \|\| sqe->splice_fd_in)
	116	return -EINVAL;
	117
	118	cancel->addr = READ_ONCE(sqe->addr);
	119	cancel->flags = READ_ONCE(sqe->cancel_flags);
	120	if (cancel->flags & ~CANCEL_FLAGS)
	121	return -EINVAL;
	122	if (cancel->flags & IORING_ASYNC_CANCEL_FD) {
	123	if (cancel->flags & IORING_ASYNC_CANCEL_ANY)
	124	return -EINVAL;
	125	cancel->fd = READ_ONCE(sqe->fd);
	126	}
	127
	128	return 0;
	129	}
	130
	131	static int __io_async_cancel(struct io_cancel_data cd, struct io_kiocb req,
	132	unsigned int issue_flags)
	133	{
	134	bool all = cd->flags & (IORING_ASYNC_CANCEL_ALL\|IORING_ASYNC_CANCEL_ANY);
	135	struct io_ring_ctx *ctx = cd->ctx;
	136	struct io_tctx_node *node;
	137	int ret, nr = 0;
	138
	139	do {
5d7943d9	140	ret = io_try_cancel(req, cd, issue_flags);
7aaff708 JA	141	if (ret == -ENOENT)
	142	break;
	143	if (!all)
	144	return ret;
	145	nr++;
	146	} while (1);
	147
	148	/* slow path, try all io-wq's */
	149	io_ring_submit_lock(ctx, issue_flags);
	150	ret = -ENOENT;
	151	list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
	152	struct io_uring_task *tctx = node->task->io_uring;
	153
	154	ret = io_async_cancel_one(tctx, cd);
	155	if (ret != -ENOENT) {
	156	if (!all)
	157	break;
	158	nr++;
	159	}
	160	}
	161	io_ring_submit_unlock(ctx, issue_flags);
	162	return all ? nr : ret;
	163	}
	164
	165	int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags)
	166	{
	167	struct io_cancel *cancel = io_kiocb_to_cmd(req);
	168	struct io_cancel_data cd = {
	169	.ctx = req->ctx,
	170	.data = cancel->addr,
	171	.flags = cancel->flags,
	172	.seq = atomic_inc_return(&req->ctx->cancel_seq),
	173	};
	174	int ret;
	175
	176	if (cd.flags & IORING_ASYNC_CANCEL_FD) {
	177	if (req->flags & REQ_F_FIXED_FILE)
	178	req->file = io_file_get_fixed(req, cancel->fd,
	179	issue_flags);
	180	else
	181	req->file = io_file_get_normal(req, cancel->fd);
	182	if (!req->file) {
	183	ret = -EBADF;
	184	goto done;
	185	}
	186	cd.file = req->file;
	187	}
	188
	189	ret = __io_async_cancel(&cd, req, issue_flags);
	190	done:
	191	if (ret < 0)
	192	req_set_fail(req);
	193	io_req_set_res(req, ret, 0);
	194	return IOU_OK;
	195	}
38513c46	196
e6f89be6	197	void init_hash_table(struct io_hash_table *table, unsigned size)
38513c46 HX	198	{
	199	unsigned int i;
	200
	201	for (i = 0; i < size; i++) {
e6f89be6 PB	202	spin_lock_init(&table->hbs[i].lock);
e6f89be6 PB	203	INIT_HLIST_HEAD(&table->hbs[i].list);
38513c46 HX	204	}
38513c46 HX	205	}