io-factory.h

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * Copyright 2023 Red Hat
 4 */
 5
 6#ifndef UDS_IO_FACTORY_H
 7#define UDS_IO_FACTORY_H
 8
 9#include <linux/dm-bufio.h>
10
11/*
12 * The I/O factory manages all low-level I/O operations to the underlying storage device. Its main
13 * clients are the index layout and the volume. The buffered reader and buffered writer interfaces
14 * are helpers for accessing data in a contiguous range of storage blocks.
15 */
16
17struct buffered_reader;
18struct buffered_writer;
19
20struct io_factory;
21
22enum {
23	UDS_BLOCK_SIZE = 4096,
24	SECTORS_PER_BLOCK = UDS_BLOCK_SIZE >> SECTOR_SHIFT,
25};
26
27int __must_check uds_make_io_factory(struct block_device *bdev,
28				     struct io_factory **factory_ptr);
29
30int __must_check uds_replace_storage(struct io_factory *factory,
31				     struct block_device *bdev);
32
33void uds_put_io_factory(struct io_factory *factory);
34
35size_t __must_check uds_get_writable_size(struct io_factory *factory);
36
37int __must_check uds_make_bufio(struct io_factory *factory, off_t block_offset,
38				size_t block_size, unsigned int reserved_buffers,
39				struct dm_bufio_client **client_ptr);
40
41int __must_check uds_make_buffered_reader(struct io_factory *factory, off_t offset,
42					  u64 block_count,
43					  struct buffered_reader **reader_ptr);
44
45void uds_free_buffered_reader(struct buffered_reader *reader);
46
47int __must_check uds_read_from_buffered_reader(struct buffered_reader *reader, u8 *data,
48					       size_t length);
49
50int __must_check uds_verify_buffered_data(struct buffered_reader *reader, const u8 *value,
51					  size_t length);
52
53int __must_check uds_make_buffered_writer(struct io_factory *factory, off_t offset,
54					  u64 block_count,
55					  struct buffered_writer **writer_ptr);
56
57void uds_free_buffered_writer(struct buffered_writer *buffer);
58
59int __must_check uds_write_to_buffered_writer(struct buffered_writer *writer,
60					      const u8 *data, size_t length);
61
62int __must_check uds_flush_buffered_writer(struct buffered_writer *writer);
63
64#endif /* UDS_IO_FACTORY_H */