drivers/md/dm-vdo/indexer/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
  17 struct buffered_reader;
  18 struct buffered_writer;
  19
  20 struct io_factory;
  21
  22 enum {
  23         UDS_BLOCK_SIZE = 4096,
  24         SECTORS_PER_BLOCK = UDS_BLOCK_SIZE >> SECTOR_SHIFT,
  25 };
  26
  27 int __must_check uds_make_io_factory(struct block_device *bdev,
  28                                      struct io_factory **factory_ptr);
  29
  30 int __must_check uds_replace_storage(struct io_factory *factory,
  31                                      struct block_device *bdev);
  32
  33 void uds_put_io_factory(struct io_factory *factory);
  34
  35 size_t __must_check uds_get_writable_size(struct io_factory *factory);
  36
  37 int __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
  41 int __must_check uds_make_buffered_reader(struct io_factory *factory, off_t offset,
  42                                           u64 block_count,
  43                                           struct buffered_reader **reader_ptr);
  44
  45 void uds_free_buffered_reader(struct buffered_reader *reader);
  46
  47 int __must_check uds_read_from_buffered_reader(struct buffered_reader *reader, u8 *data,
  48                                                size_t length);
  49
  50 int __must_check uds_verify_buffered_data(struct buffered_reader *reader, const u8 *value,
  51                                           size_t length);
  52
  53 int __must_check uds_make_buffered_writer(struct io_factory *factory, off_t offset,
  54                                           u64 block_count,
  55                                           struct buffered_writer **writer_ptr);
  56
  57 void uds_free_buffered_writer(struct buffered_writer *buffer);
  58
  59 int __must_check uds_write_to_buffered_writer(struct buffered_writer *writer,
  60                                               const u8 *data, size_t length);
  61
  62 int __must_check uds_flush_buffered_writer(struct buffered_writer *writer);
  63
  64 #endif /* UDS_IO_FACTORY_H */