linux/drivers/md/dm-io-rewind.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2022 Red Hat, Inc.
 */

#include <linux/bio.h>
#include <linux/blk-crypto.h>
#include <linux/blk-integrity.h>

#include "dm-core.h"

static inline bool dm_bvec_iter_rewind(const struct bio_vec *bv,
				       struct bvec_iter *iter,
				       unsigned int bytes)
{ … }

#if defined(CONFIG_BLK_DEV_INTEGRITY)

/**
 * dm_bio_integrity_rewind - Rewind integrity vector
 * @bio:	bio whose integrity vector to update
 * @bytes_done:	number of data bytes to rewind
 *
 * Description: This function calculates how many integrity bytes the
 * number of completed data bytes correspond to and rewind the
 * integrity vector accordingly.
 */
static void dm_bio_integrity_rewind(struct bio *bio, unsigned int bytes_done)
{ … }

#else /* CONFIG_BLK_DEV_INTEGRITY */

static inline void dm_bio_integrity_rewind(struct bio *bio,
					   unsigned int bytes_done)
{
}

#endif

#if defined(CONFIG_BLK_INLINE_ENCRYPTION)

/* Decrements @dun by @dec, treating @dun as a multi-limb integer. */
static void dm_bio_crypt_dun_decrement(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
				       unsigned int dec)
{ … }

static void dm_bio_crypt_rewind(struct bio *bio, unsigned int bytes)
{ … }

#else /* CONFIG_BLK_INLINE_ENCRYPTION */

static inline void dm_bio_crypt_rewind(struct bio *bio, unsigned int bytes)
{
}

#endif

static inline void dm_bio_rewind_iter(const struct bio *bio,
				      struct bvec_iter *iter, unsigned int bytes)
{ … }

/**
 * dm_bio_rewind - update ->bi_iter of @bio by rewinding @bytes.
 * @bio: bio to rewind
 * @bytes: how many bytes to rewind
 *
 * WARNING:
 * Caller must ensure that @bio has a fixed end sector, to allow
 * rewinding from end of bio and restoring its original position.
 * Caller is also responsibile for restoring bio's size.
 */
static void dm_bio_rewind(struct bio *bio, unsigned int bytes)
{ … }

void dm_io_rewind(struct dm_io *io, struct bio_set *bs)
{ … }