Commit 0c98a443 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring/mock: support for async read/write 



Let the user to specify a delay to read/write request. io_uring will
start a timer, return -EIOCBQUEUED and complete the request
asynchronously after the delay pass.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/38f9d2e143fda8522c90a724b74630e68f9bbd16.1750599274.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 2f71d238

include/uapi/linux/io_uring/mock_file.h

+3 −1
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ enum { 
	IORING_MOCK_FEAT_CMD_COPY,

	IORING_MOCK_FEAT_RW_ZERO,

	IORING_MOCK_FEAT_RW_NOWAIT,

	IORING_MOCK_FEAT_RW_ASYNC,



	IORING_MOCK_FEAT_END,

};
@@ -24,7 +25,8 @@ struct io_uring_mock_create { 
	__u32		out_fd;

	__u32		flags;

	__u64		file_size;

	__u64		__resv[14];

	__u64		rw_delay_ns;

	__u64		__resv[13];

};



enum {

io_uring/mock_file.c

+55 −4
Original line number Diff line number Diff line
@@ -4,13 +4,22 @@ 
#include <linux/miscdevice.h>

#include <linux/module.h>

#include <linux/anon_inodes.h>

#include <linux/ktime.h>

#include <linux/hrtimer.h>



#include <linux/io_uring/cmd.h>

#include <linux/io_uring_types.h>

#include <uapi/linux/io_uring/mock_file.h>



struct io_mock_iocb {

	struct kiocb		*iocb;

	struct hrtimer		timer;

	int			res;

};



struct io_mock_file {

	size_t			size;

	u64			rw_delay_ns;

};



#define IO_VALID_COPY_CMD_FLAGS		IORING_MOCK_COPY_FROM
@@ -86,14 +95,48 @@ static int io_mock_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) 
	return -ENOTSUPP;

}



static enum hrtimer_restart io_mock_rw_timer_expired(struct hrtimer *timer)

{

	struct io_mock_iocb *mio = container_of(timer, struct io_mock_iocb, timer);

	struct kiocb *iocb = mio->iocb;



	WRITE_ONCE(iocb->private, NULL);

	iocb->ki_complete(iocb, mio->res);

	kfree(mio);

	return HRTIMER_NORESTART;

}



static ssize_t io_mock_delay_rw(struct kiocb *iocb, size_t len)

{

	struct io_mock_file *mf = iocb->ki_filp->private_data;

	struct io_mock_iocb *mio;



	mio = kzalloc(sizeof(*mio), GFP_KERNEL);

	if (!mio)

		return -ENOMEM;



	mio->iocb = iocb;

	mio->res = len;

	hrtimer_setup(&mio->timer, io_mock_rw_timer_expired,

		      CLOCK_MONOTONIC, HRTIMER_MODE_REL);

	hrtimer_start(&mio->timer, ns_to_ktime(mf->rw_delay_ns),

		      HRTIMER_MODE_REL);

	return -EIOCBQUEUED;

}



static ssize_t io_mock_read_iter(struct kiocb *iocb, struct iov_iter *to)

{

	struct io_mock_file *mf = iocb->ki_filp->private_data;

	size_t len = iov_iter_count(to);

	size_t nr_zeroed;



	if (iocb->ki_pos + len > mf->size)

		return -EINVAL;

	return iov_iter_zero(len, to);

	nr_zeroed = iov_iter_zero(len, to);

	if (!mf->rw_delay_ns || nr_zeroed != len)

		return nr_zeroed;



	return io_mock_delay_rw(iocb, len);

}



static ssize_t io_mock_write_iter(struct kiocb *iocb, struct iov_iter *from)
@@ -103,10 +146,14 @@ static ssize_t io_mock_write_iter(struct kiocb *iocb, struct iov_iter *from) 


	if (iocb->ki_pos + len > mf->size)

		return -EINVAL;

	if (!mf->rw_delay_ns) {

		iov_iter_advance(from, len);

		return len;

	}



	return io_mock_delay_rw(iocb, len);

}



static loff_t io_mock_llseek(struct file *file, loff_t offset, int whence)

{

	struct io_mock_file *mf = file->private_data;
@@ -165,6 +212,9 @@ static int io_create_mock_file(struct io_uring_cmd *cmd, unsigned int issue_flag 
		return -EINVAL;

	if (mc.file_size > SZ_1G)

		return -EINVAL;

	if (mc.rw_delay_ns > NSEC_PER_SEC)

		return -EINVAL;



	mf = kzalloc(sizeof(*mf), GFP_KERNEL_ACCOUNT);

	if (!mf)

		return -ENOMEM;
@@ -174,6 +224,7 @@ static int io_create_mock_file(struct io_uring_cmd *cmd, unsigned int issue_flag 
		goto fail;



	mf->size = mc.file_size;

	mf->rw_delay_ns = mc.rw_delay_ns;

	file = anon_inode_create_getfile("[io_uring_mock]", &io_mock_fops,

					 mf, O_RDWR | O_CLOEXEC, NULL);

	if (IS_ERR(file)) {