drivers/md/dm-verity.h

Source file repositories/reference/linux-study-clean/drivers/md/dm-verity.h

File Facts

System
Linux kernel
Corpus path
drivers/md/dm-verity.h
Extension
.h
Size
4562 bytes
Lines
149
Domain
Driver Families
Bucket
drivers/md
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

struct dm_verity {
	struct dm_dev *data_dev;
	struct dm_dev *hash_dev;
	struct dm_target *ti;
	struct dm_bufio_client *bufio;
	char *alg_name;
	struct crypto_shash *shash_tfm;
	u8 *root_digest;	/* digest of the root block */
	u8 *salt;		/* salt: its size is salt_size */
	union {
		struct sha256_ctx *sha256;	/* for use_sha256_lib=1 */
		u8 *shash;			/* for use_sha256_lib=0 */
	} initial_hashstate; /* salted initial state, if version >= 1 */
	u8 *zero_digest;	/* digest for a zero block */
#ifdef CONFIG_SECURITY
	u8 *root_digest_sig;	/* signature of the root digest */
	unsigned int sig_size;	/* root digest signature size */
#endif /* CONFIG_SECURITY */
	unsigned int salt_size;
	sector_t hash_start;	/* index of first hash block on hash_dev */
	sector_t hash_end;	/* 1 + index of last hash block on hash dev */
	sector_t data_blocks;	/* the number of data blocks */
	unsigned char data_dev_block_bits;	/* log2(data blocksize) */
	unsigned char hash_dev_block_bits;	/* log2(hash blocksize) */
	unsigned char hash_per_block_bits;	/* log2(hashes in hash block) */
	unsigned char levels;	/* the number of tree levels */
	unsigned char version;
	bool hash_failed:1;	/* set if hash of any block failed */
	bool use_bh_wq:1;	/* try to verify in BH wq before normal work-queue */
	bool use_sha256_lib:1;	/* use SHA-256 library instead of generic crypto API */
	bool use_sha256_finup_2x:1; /* use interleaved hashing optimization */
	unsigned int digest_size;	/* digest size for the current hash algorithm */
	enum verity_mode mode;	/* mode for handling verification errors */
	enum verity_mode error_mode;/* mode for handling I/O errors */
	unsigned int corrupted_errs;/* Number of errors for corrupted blocks */

	struct workqueue_struct *verify_wq;

	/* starting blocks for each tree level. 0 is the lowest level. */
	sector_t hash_level_block[DM_VERITY_MAX_LEVELS];

	struct dm_verity_fec *fec;	/* forward error correction */
	unsigned long *validated_blocks; /* bitset blocks validated */

	char *signature_key_desc; /* signature keyring reference */

	struct dm_io_client *io;
	mempool_t recheck_pool;
};

struct pending_block {
	void *data;
	sector_t blkno;
	u8 want_digest[HASH_MAX_DIGESTSIZE];
	u8 real_digest[HASH_MAX_DIGESTSIZE];
};

struct dm_verity_io {
	struct dm_verity *v;

	/* original value of bio->bi_end_io */
	bio_end_io_t *orig_bi_end_io;

	struct bvec_iter iter;

	sector_t block;
	unsigned int n_blocks;
	bool in_bh;
	bool had_mismatch;

#ifdef CONFIG_DM_VERITY_FEC
	struct dm_verity_fec_io *fec_io;
#endif

	struct work_struct work;

	u8 tmp_digest[HASH_MAX_DIGESTSIZE];

	/*
	 * This is the queue of data blocks that are pending verification.  When
	 * the crypto layer supports interleaved hashing, we allow multiple
	 * blocks to be queued up in order to utilize it.  This can improve
	 * performance significantly vs. sequential hashing of each block.
	 */
	int num_pending;
	struct pending_block pending_blocks[2];

	/*
	 * Temporary space for hashing.  Either sha256 or shash is used,
	 * depending on the value of use_sha256_lib.  If shash is used,

Annotation

Implementation Notes