Commit 4aac001f authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring/mock: add cmd using vectored regbufs 



There is a command api allowing to import vectored registered buffers,
add a new mock command that uses the feature and simply copies the
specified registered buffer into user space or vice versa.

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/229a113fd7de6b27dbef9567f7c0bf4475c9017d.1750599274.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 3a0ae385

include/uapi/linux/io_uring/mock_file.h

+14 −0
Original line number Diff line number Diff line
@@ -3,6 +3,12 @@ 


#include <linux/types.h>



enum {

	IORING_MOCK_FEAT_CMD_COPY,



	IORING_MOCK_FEAT_END,

};



struct io_uring_mock_probe {

	__u64		features;

	__u64		__resv[9];
@@ -19,4 +25,12 @@ enum { 
	IORING_MOCK_MGR_CMD_CREATE,

};



enum {

	IORING_MOCK_CMD_COPY_REGBUF,

};



enum {

	IORING_MOCK_COPY_FROM			= 1,

};



#endif

io_uring/mock_file.c

+69 −1
Original line number Diff line number Diff line
@@ -9,8 +9,76 @@ 
#include <linux/io_uring_types.h>

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



#define IO_VALID_COPY_CMD_FLAGS		IORING_MOCK_COPY_FROM



static int io_copy_regbuf(struct iov_iter *reg_iter, void __user *ubuf)

{

	size_t ret, copied = 0;

	size_t buflen = PAGE_SIZE;

	void *tmp_buf;



	tmp_buf = kzalloc(buflen, GFP_KERNEL);

	if (!tmp_buf)

		return -ENOMEM;



	while (iov_iter_count(reg_iter)) {

		size_t len = min(iov_iter_count(reg_iter), buflen);



		if (iov_iter_rw(reg_iter) == ITER_SOURCE) {

			ret = copy_from_iter(tmp_buf, len, reg_iter);

			if (ret <= 0)

				break;

			if (copy_to_user(ubuf, tmp_buf, ret))

				break;

		} else {

			if (copy_from_user(tmp_buf, ubuf, len))

				break;

			ret = copy_to_iter(tmp_buf, len, reg_iter);

			if (ret <= 0)

				break;

		}

		ubuf += ret;

		copied += ret;

	}



	kfree(tmp_buf);

	return copied;

}



static int io_cmd_copy_regbuf(struct io_uring_cmd *cmd, unsigned int issue_flags)

{

	const struct io_uring_sqe *sqe = cmd->sqe;

	const struct iovec __user *iovec;

	unsigned flags, iovec_len;

	struct iov_iter iter;

	void __user *ubuf;

	int dir, ret;



	ubuf = u64_to_user_ptr(READ_ONCE(sqe->addr3));

	iovec = u64_to_user_ptr(READ_ONCE(sqe->addr));

	iovec_len = READ_ONCE(sqe->len);

	flags = READ_ONCE(sqe->file_index);



	if (unlikely(sqe->ioprio || sqe->__pad1))

		return -EINVAL;

	if (flags & ~IO_VALID_COPY_CMD_FLAGS)

		return -EINVAL;



	dir = (flags & IORING_MOCK_COPY_FROM) ? ITER_SOURCE : ITER_DEST;

	ret = io_uring_cmd_import_fixed_vec(cmd, iovec, iovec_len, dir, &iter,

					    issue_flags);

	if (ret)

		return ret;

	ret = io_copy_regbuf(&iter, ubuf);

	return ret ? ret : -EFAULT;

}



static int io_mock_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)

{

	switch (cmd->cmd_op) {

	case IORING_MOCK_CMD_COPY_REGBUF:

		return io_cmd_copy_regbuf(cmd, issue_flags);

	}

	return -ENOTSUPP;

}
@@ -91,7 +159,7 @@ static int io_probe_mock(struct io_uring_cmd *cmd) 
	if (!mem_is_zero(&mp, sizeof(mp)))

		return -EINVAL;



	mp.features = 0;

	mp.features = IORING_MOCK_FEAT_END;



	if (copy_to_user(uarg, &mp, uarg_size))

		return -EFAULT;