OSCL-LXR linux-6.0.1/​drivers/​md/​dm-crypt.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /*
  * Copyright (C) 2003 Jana Saout <jana@saout.de>
  * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
  * Copyright (C) 2006-2020 Red Hat, Inc. All rights reserved.
  * Copyright (C) 2013-2020 Milan Broz <gmazyland@gmail.com>
  *
  * This file is released under the GPL.
  */
 
 #include <linux/completion.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/key.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
 #include <linux/blk-integrity.h>
 #include <linux/mempool.h>
 #include <linux/slab.h>
 #include <linux/crypto.h>
 #include <linux/workqueue.h>
 #include <linux/kthread.h>
 #include <linux/backing-dev.h>
 #include <linux/atomic.h>
 #include <linux/scatterlist.h>
 #include <linux/rbtree.h>
 #include <linux/ctype.h>
 #include <asm/page.h>
 #include <asm/unaligned.h>
 #include <crypto/hash.h>
 #include <crypto/md5.h>
 #include <crypto/algapi.h>
 #include <crypto/skcipher.h>
 #include <crypto/aead.h>
 #include <crypto/authenc.h>
 #include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */
 #include <linux/key-type.h>
 #include <keys/user-type.h>
 #include <keys/encrypted-type.h>
 #include <keys/trusted-type.h>
 
 #include <linux/device-mapper.h>
 
 #include "dm-audit.h"
 
 #define DM_MSG_PREFIX "crypt"
 
 /*
  * context holding the current state of a multi-part conversion
  */
 struct convert_context {
     struct completion restart;
     struct bio *bio_in;
     struct bio *bio_out;
     struct bvec_iter iter_in;
     struct bvec_iter iter_out;
     u64 cc_sector;
     atomic_t cc_pending;
     union {
         struct skcipher_request *req;
         struct aead_request *req_aead;
     } r;
 
 };
 
 /*
  * per bio private data
  */
 struct dm_crypt_io {
     struct crypt_config *cc;
     struct bio *base_bio;
     u8 *integrity_metadata;
     bool integrity_metadata_from_pool;
     struct work_struct work;
     struct tasklet_struct tasklet;
 
     struct convert_context ctx;
 
     atomic_t io_pending;
     blk_status_t error;
     sector_t sector;
 
     struct rb_node rb_node;
 } CRYPTO_MINALIGN_ATTR;
 
 struct dm_crypt_request {
     struct convert_context *ctx;
     struct scatterlist sg_in[4];
     struct scatterlist sg_out[4];
     u64 iv_sector;
 };
 
 struct crypt_config;
 
 struct crypt_iv_operations {
     int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
            const char *opts);
     void (*dtr)(struct crypt_config *cc);
     int (*init)(struct crypt_config *cc);
     int (*wipe)(struct crypt_config *cc);
     int (*generator)(struct crypt_config *cc, u8 *iv,
              struct dm_crypt_request *dmreq);
     int (*post)(struct crypt_config *cc, u8 *iv,
             struct dm_crypt_request *dmreq);
 };
 
 struct iv_benbi_private {
     int shift;
 };
 
 #define LMK_SEED_SIZE 64 /* hash + 0 */
 struct iv_lmk_private {
     struct crypto_shash *hash_tfm;
     u8 *seed;
 };
 
 #define TCW_WHITENING_SIZE 16
 struct iv_tcw_private {
     struct crypto_shash *crc32_tfm;
     u8 *iv_seed;
     u8 *whitening;
 };
 
 #define ELEPHANT_MAX_KEY_SIZE 32
 struct iv_elephant_private {
     struct crypto_skcipher *tfm;
 };
 
 /*
  * Crypt: maps a linear range of a block device
  * and encrypts / decrypts at the same time.
  */
 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
          DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD,
          DM_CRYPT_NO_READ_WORKQUEUE, DM_CRYPT_NO_WRITE_WORKQUEUE,
          DM_CRYPT_WRITE_INLINE };
 
 enum cipher_flags {
     CRYPT_MODE_INTEGRITY_AEAD,  /* Use authenticated mode for cipher */
     CRYPT_IV_LARGE_SECTORS,     /* Calculate IV from sector_size, not 512B sectors */
     CRYPT_ENCRYPT_PREPROCESS,   /* Must preprocess data for encryption (elephant) */
 };
 
 /*
  * The fields in here must be read only after initialization.
  */
 struct crypt_config {
     struct dm_dev *dev;
     sector_t start;
 
     struct percpu_counter n_allocated_pages;
 
     struct workqueue_struct *io_queue;
     struct workqueue_struct *crypt_queue;
 
     spinlock_t write_thread_lock;
     struct task_struct *write_thread;
     struct rb_root write_tree;
 
     char *cipher_string;
     char *cipher_auth;
     char *key_string;
 
     const struct crypt_iv_operations *iv_gen_ops;
     union {
         struct iv_benbi_private benbi;
         struct iv_lmk_private lmk;
         struct iv_tcw_private tcw;
         struct iv_elephant_private elephant;
     } iv_gen_private;
     u64 iv_offset;
     unsigned int iv_size;
     unsigned short int sector_size;
     unsigned char sector_shift;
 
     union {
         struct crypto_skcipher **tfms;
         struct crypto_aead **tfms_aead;
     } cipher_tfm;
     unsigned tfms_count;
     unsigned long cipher_flags;
 
     /*
      * Layout of each crypto request:
      *
      *   struct skcipher_request
      *      context
      *      padding
      *   struct dm_crypt_request
      *      padding
      *   IV
      *
      * The padding is added so that dm_crypt_request and the IV are
      * correctly aligned.
      */
     unsigned int dmreq_start;
 
     unsigned int per_bio_data_size;
 
     unsigned long flags;
     unsigned int key_size;
     unsigned int key_parts;      /* independent parts in key buffer */
     unsigned int key_extra_size; /* additional keys length */
     unsigned int key_mac_size;   /* MAC key size for authenc(...) */
 
     unsigned int integrity_tag_size;
     unsigned int integrity_iv_size;
     unsigned int on_disk_tag_size;
 
     /*
      * pool for per bio private data, crypto requests,
      * encryption requeusts/buffer pages and integrity tags
      */
     unsigned tag_pool_max_sectors;
     mempool_t tag_pool;
     mempool_t req_pool;
     mempool_t page_pool;
 
     struct bio_set bs;
     struct mutex bio_alloc_lock;
 
     u8 *authenc_key; /* space for keys in authenc() format (if used) */
     u8 key[];
 };
 
 #define MIN_IOS     64
 #define MAX_TAG_SIZE    480
 #define POOL_ENTRY_SIZE 512
 
 static DEFINE_SPINLOCK(dm_crypt_clients_lock);
 static unsigned dm_crypt_clients_n = 0;
 static volatile unsigned long dm_crypt_pages_per_client;
 #define DM_CRYPT_MEMORY_PERCENT         2
 #define DM_CRYPT_MIN_PAGES_PER_CLIENT       (BIO_MAX_VECS * 16)
 
 static void crypt_endio(struct bio *clone);
 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
                          struct scatterlist *sg);
 
 static bool crypt_integrity_aead(struct crypt_config *cc);
 
 /*
  * Use this to access cipher attributes that are independent of the key.
  */
 static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
 {
     return cc->cipher_tfm.tfms[0];
 }
 
 static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
 {
     return cc->cipher_tfm.tfms_aead[0];
 }
 
 /*
  * Different IV generation algorithms:
  *
  * plain: the initial vector is the 32-bit little-endian version of the sector
  *        number, padded with zeros if necessary.
  *
  * plain64: the initial vector is the 64-bit little-endian version of the sector
  *        number, padded with zeros if necessary.
  *
  * plain64be: the initial vector is the 64-bit big-endian version of the sector
  *        number, padded with zeros if necessary.
  *
  * essiv: "encrypted sector|salt initial vector", the sector number is
  *        encrypted with the bulk cipher using a salt as key. The salt
  *        should be derived from the bulk cipher's key via hashing.
  *
  * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
  *        (needed for LRW-32-AES and possible other narrow block modes)
  *
  * null: the initial vector is always zero.  Provides compatibility with
  *       obsolete loop_fish2 devices.  Do not use for new devices.
  *
  * lmk:  Compatible implementation of the block chaining mode used
  *       by the Loop-AES block device encryption system
  *       designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
  *       It operates on full 512 byte sectors and uses CBC
  *       with an IV derived from the sector number, the data and
  *       optionally extra IV seed.
  *       This means that after decryption the first block
  *       of sector must be tweaked according to decrypted data.
  *       Loop-AES can use three encryption schemes:
  *         version 1: is plain aes-cbc mode
  *         version 2: uses 64 multikey scheme with lmk IV generator
  *         version 3: the same as version 2 with additional IV seed
  *                   (it uses 65 keys, last key is used as IV seed)
  *
  * tcw:  Compatible implementation of the block chaining mode used
  *       by the TrueCrypt device encryption system (prior to version 4.1).
  *       For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
  *       It operates on full 512 byte sectors and uses CBC
  *       with an IV derived from initial key and the sector number.
  *       In addition, whitening value is applied on every sector, whitening
  *       is calculated from initial key, sector number and mixed using CRC32.
  *       Note that this encryption scheme is vulnerable to watermarking attacks
  *       and should be used for old compatible containers access only.
  *
  * eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode)
  *        The IV is encrypted little-endian byte-offset (with the same key
  *        and cipher as the volume).
  *
  * elephant: The extended version of eboiv with additional Elephant diffuser
  *           used with Bitlocker CBC mode.
  *           This mode was used in older Windows systems
  *           https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf
  */
 
 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
                   struct dm_crypt_request *dmreq)
 {
     memset(iv, 0, cc->iv_size);
     *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
 
     return 0;
 }
 
 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
                 struct dm_crypt_request *dmreq)
 {
     memset(iv, 0, cc->iv_size);
     *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
 
     return 0;
 }
 
 static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv,
                   struct dm_crypt_request *dmreq)
 {
     memset(iv, 0, cc->iv_size);
     /* iv_size is at least of size u64; usually it is 16 bytes */
     *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector);
 
     return 0;
 }
 
 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
                   struct dm_crypt_request *dmreq)
 {
     /*
      * ESSIV encryption of the IV is now handled by the crypto API,
      * so just pass the plain sector number here.
      */
     memset(iv, 0, cc->iv_size);
     *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
 
     return 0;
 }
 
 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
                   const char *opts)
 {
     unsigned bs;
     int log;
 
     if (crypt_integrity_aead(cc))
         bs = crypto_aead_blocksize(any_tfm_aead(cc));
     else
         bs = crypto_skcipher_blocksize(any_tfm(cc));
     log = ilog2(bs);
 
     /* we need to calculate how far we must shift the sector count
      * to get the cipher block count, we use this shift in _gen */
 
     if (1 << log != bs) {
         ti->error = "cypher blocksize is not a power of 2";
         return -EINVAL;
     }
 
     if (log > 9) {
         ti->error = "cypher blocksize is > 512";
         return -EINVAL;
     }
 
     cc->iv_gen_private.benbi.shift = 9 - log;
 
     return 0;
 }
 
 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
 {
 }
 
 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
                   struct dm_crypt_request *dmreq)
 {
     __be64 val;
 
     memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
 
     val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
     put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
 
     return 0;
 }
 
 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
                  struct dm_crypt_request *dmreq)
 {
     memset(iv, 0, cc->iv_size);
 
     return 0;
 }
 
 static void crypt_iv_lmk_dtr(struct crypt_config *cc)
 {
     struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 
     if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
         crypto_free_shash(lmk->hash_tfm);
     lmk->hash_tfm = NULL;
 
     kfree_sensitive(lmk->seed);
     lmk->seed = NULL;
 }
 
 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
                 const char *opts)
 {
     struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 
     if (cc->sector_size != (1 << SECTOR_SHIFT)) {
         ti->error = "Unsupported sector size for LMK";
         return -EINVAL;
     }
 
     lmk->hash_tfm = crypto_alloc_shash("md5", 0,
                        CRYPTO_ALG_ALLOCATES_MEMORY);
     if (IS_ERR(lmk->hash_tfm)) {
         ti->error = "Error initializing LMK hash";
         return PTR_ERR(lmk->hash_tfm);
     }
 
     /* No seed in LMK version 2 */
     if (cc->key_parts == cc->tfms_count) {
         lmk->seed = NULL;
         return 0;
     }
 
     lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
     if (!lmk->seed) {
         crypt_iv_lmk_dtr(cc);
         ti->error = "Error kmallocing seed storage in LMK";
         return -ENOMEM;
     }
 
     return 0;
 }
 
 static int crypt_iv_lmk_init(struct crypt_config *cc)
 {
     struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
     int subkey_size = cc->key_size / cc->key_parts;
 
     /* LMK seed is on the position of LMK_KEYS + 1 key */
     if (lmk->seed)
         memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
                crypto_shash_digestsize(lmk->hash_tfm));
 
     return 0;
 }
 
 static int crypt_iv_lmk_wipe(struct crypt_config *cc)
 {
     struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 
     if (lmk->seed)
         memset(lmk->seed, 0, LMK_SEED_SIZE);
 
     return 0;
 }
 
 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
                 struct dm_crypt_request *dmreq,
                 u8 *data)
 {
     struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
     SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
     struct md5_state md5state;
     __le32 buf[4];
     int i, r;
 
     desc->tfm = lmk->hash_tfm;
 
     r = crypto_shash_init(desc);
     if (r)
         return r;
 
     if (lmk->seed) {
         r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
         if (r)
             return r;
     }
 
     /* Sector is always 512B, block size 16, add data of blocks 1-31 */
     r = crypto_shash_update(desc, data + 16, 16 * 31);
     if (r)
         return r;
 
     /* Sector is cropped to 56 bits here */
     buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
     buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
     buf[2] = cpu_to_le32(4024);
     buf[3] = 0;
     r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
     if (r)
         return r;
 
     /* No MD5 padding here */
     r = crypto_shash_export(desc, &md5state);
     if (r)
         return r;
 
     for (i = 0; i < MD5_HASH_WORDS; i++)
         __cpu_to_le32s(&md5state.hash[i]);
     memcpy(iv, &md5state.hash, cc->iv_size);
 
     return 0;
 }
 
 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
                 struct dm_crypt_request *dmreq)
 {
     struct scatterlist *sg;
     u8 *src;
     int r = 0;
 
     if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
         sg = crypt_get_sg_data(cc, dmreq->sg_in);
         src = kmap_atomic(sg_page(sg));
         r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
         kunmap_atomic(src);
     } else
         memset(iv, 0, cc->iv_size);
 
     return r;
 }
 
 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
                  struct dm_crypt_request *dmreq)
 {
     struct scatterlist *sg;
     u8 *dst;
     int r;
 
     if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
         return 0;
 
     sg = crypt_get_sg_data(cc, dmreq->sg_out);
     dst = kmap_atomic(sg_page(sg));
     r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
 
     /* Tweak the first block of plaintext sector */
     if (!r)
         crypto_xor(dst + sg->offset, iv, cc->iv_size);
 
     kunmap_atomic(dst);
     return r;
 }
 
 static void crypt_iv_tcw_dtr(struct crypt_config *cc)
 {
     struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 
     kfree_sensitive(tcw->iv_seed);
     tcw->iv_seed = NULL;
     kfree_sensitive(tcw->whitening);
     tcw->whitening = NULL;
 
     if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
         crypto_free_shash(tcw->crc32_tfm);
     tcw->crc32_tfm = NULL;
 }
 
 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
                 const char *opts)
 {
     struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 
     if (cc->sector_size != (1 << SECTOR_SHIFT)) {
         ti->error = "Unsupported sector size for TCW";
         return -EINVAL;
     }
 
     if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
         ti->error = "Wrong key size for TCW";
         return -EINVAL;
     }
 
     tcw->crc32_tfm = crypto_alloc_shash("crc32", 0,
                         CRYPTO_ALG_ALLOCATES_MEMORY);
     if (IS_ERR(tcw->crc32_tfm)) {
         ti->error = "Error initializing CRC32 in TCW";
         return PTR_ERR(tcw->crc32_tfm);
     }
 
     tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
     tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
     if (!tcw->iv_seed || !tcw->whitening) {
         crypt_iv_tcw_dtr(cc);
         ti->error = "Error allocating seed storage in TCW";
         return -ENOMEM;
     }
 
     return 0;
 }
 
 static int crypt_iv_tcw_init(struct crypt_config *cc)
 {
     struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
     int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
 
     memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
     memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
            TCW_WHITENING_SIZE);
 
     return 0;
 }
 
 static int crypt_iv_tcw_wipe(struct crypt_config *cc)
 {
     struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 
     memset(tcw->iv_seed, 0, cc->iv_size);
     memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
 
     return 0;
 }
 
 static int crypt_iv_tcw_whitening(struct crypt_config *cc,
                   struct dm_crypt_request *dmreq,
                   u8 *data)
 {
     struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
     __le64 sector = cpu_to_le64(dmreq->iv_sector);
     u8 buf[TCW_WHITENING_SIZE];
     SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
     int i, r;
 
     /* xor whitening with sector number */
     crypto_xor_cpy(buf, tcw->whitening, (u8 *)&sector, 8);
     crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)&sector, 8);
 
     /* calculate crc32 for every 32bit part and xor it */
     desc->tfm = tcw->crc32_tfm;
     for (i = 0; i < 4; i++) {
         r = crypto_shash_init(desc);
         if (r)
             goto out;
         r = crypto_shash_update(desc, &buf[i * 4], 4);
         if (r)
             goto out;
         r = crypto_shash_final(desc, &buf[i * 4]);
         if (r)
             goto out;
     }
     crypto_xor(&buf[0], &buf[12], 4);
     crypto_xor(&buf[4], &buf[8], 4);
 
     /* apply whitening (8 bytes) to whole sector */
     for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
         crypto_xor(data + i * 8, buf, 8);
 out:
     memzero_explicit(buf, sizeof(buf));
     return r;
 }
 
 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
                 struct dm_crypt_request *dmreq)
 {
     struct scatterlist *sg;
     struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
     __le64 sector = cpu_to_le64(dmreq->iv_sector);
     u8 *src;
     int r = 0;
 
     /* Remove whitening from ciphertext */
     if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
         sg = crypt_get_sg_data(cc, dmreq->sg_in);
         src = kmap_atomic(sg_page(sg));
         r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
         kunmap_atomic(src);
     }
 
     /* Calculate IV */
     crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)&sector, 8);
     if (cc->iv_size > 8)
         crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)&sector,
                    cc->iv_size - 8);
 
     return r;
 }
 
 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
                  struct dm_crypt_request *dmreq)
 {
     struct scatterlist *sg;
     u8 *dst;
     int r;
 
     if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
         return 0;
 
     /* Apply whitening on ciphertext */
     sg = crypt_get_sg_data(cc, dmreq->sg_out);
     dst = kmap_atomic(sg_page(sg));
     r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
     kunmap_atomic(dst);
 
     return r;
 }
 
 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
                 struct dm_crypt_request *dmreq)
 {
     /* Used only for writes, there must be an additional space to store IV */
     get_random_bytes(iv, cc->iv_size);
     return 0;
 }
 
 static int crypt_iv_eboiv_ctr(struct crypt_config *cc, struct dm_target *ti,
                 const char *opts)
 {
     if (crypt_integrity_aead(cc)) {
         ti->error = "AEAD transforms not supported for EBOIV";
         return -EINVAL;
     }
 
     if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) {
         ti->error = "Block size of EBOIV cipher does "
                 "not match IV size of block cipher";
         return -EINVAL;
     }
 
     return 0;
 }
 
 static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv,
                 struct dm_crypt_request *dmreq)
 {
     u8 buf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(__le64));
     struct skcipher_request *req;
     struct scatterlist src, dst;
     DECLARE_CRYPTO_WAIT(wait);
     int err;
 
     req = skcipher_request_alloc(any_tfm(cc), GFP_NOIO);
     if (!req)
         return -ENOMEM;
 
     memset(buf, 0, cc->iv_size);
     *(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
 
     sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size);
     sg_init_one(&dst, iv, cc->iv_size);
     skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf);
     skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
     err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
     skcipher_request_free(req);
 
     return err;
 }
 
 static void crypt_iv_elephant_dtr(struct crypt_config *cc)
 {
     struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
 
     crypto_free_skcipher(elephant->tfm);
     elephant->tfm = NULL;
 }
 
 static int crypt_iv_elephant_ctr(struct crypt_config *cc, struct dm_target *ti,
                 const char *opts)
 {
     struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
     int r;
 
     elephant->tfm = crypto_alloc_skcipher("ecb(aes)", 0,
                           CRYPTO_ALG_ALLOCATES_MEMORY);
     if (IS_ERR(elephant->tfm)) {
         r = PTR_ERR(elephant->tfm);
         elephant->tfm = NULL;
         return r;
     }
 
     r = crypt_iv_eboiv_ctr(cc, ti, NULL);
     if (r)
         crypt_iv_elephant_dtr(cc);
     return r;
 }
 
 static void diffuser_disk_to_cpu(u32 *d, size_t n)
 {
 #ifndef __LITTLE_ENDIAN
     int i;
 
     for (i = 0; i < n; i++)
         d[i] = le32_to_cpu((__le32)d[i]);
 #endif
 }
 
 static void diffuser_cpu_to_disk(__le32 *d, size_t n)
 {
 #ifndef __LITTLE_ENDIAN
     int i;
 
     for (i = 0; i < n; i++)
         d[i] = cpu_to_le32((u32)d[i]);
 #endif
 }
 
 static void diffuser_a_decrypt(u32 *d, size_t n)
 {
     int i, i1, i2, i3;
 
     for (i = 0; i < 5; i++) {
         i1 = 0;
         i2 = n - 2;
         i3 = n - 5;
 
         while (i1 < (n - 1)) {
             d[i1] += d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
             i1++; i2++; i3++;
 
             if (i3 >= n)
                 i3 -= n;
 
             d[i1] += d[i2] ^ d[i3];
             i1++; i2++; i3++;
 
             if (i2 >= n)
                 i2 -= n;
 
             d[i1] += d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
             i1++; i2++; i3++;
 
             d[i1] += d[i2] ^ d[i3];
             i1++; i2++; i3++;
         }
     }
 }
 
 static void diffuser_a_encrypt(u32 *d, size_t n)
 {
     int i, i1, i2, i3;
 
     for (i = 0; i < 5; i++) {
         i1 = n - 1;
         i2 = n - 2 - 1;
         i3 = n - 5 - 1;
 
         while (i1 > 0) {
             d[i1] -= d[i2] ^ d[i3];
             i1--; i2--; i3--;
 
             d[i1] -= d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
             i1--; i2--; i3--;
 
             if (i2 < 0)
                 i2 += n;
 
             d[i1] -= d[i2] ^ d[i3];
             i1--; i2--; i3--;
 
             if (i3 < 0)
                 i3 += n;
 
             d[i1] -= d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
             i1--; i2--; i3--;
         }
     }
 }
 
 static void diffuser_b_decrypt(u32 *d, size_t n)
 {
     int i, i1, i2, i3;
 
     for (i = 0; i < 3; i++) {
         i1 = 0;
         i2 = 2;
         i3 = 5;
 
         while (i1 < (n - 1)) {
             d[i1] += d[i2] ^ d[i3];
             i1++; i2++; i3++;
 
             d[i1] += d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
             i1++; i2++; i3++;
 
             if (i2 >= n)
                 i2 -= n;
 
             d[i1] += d[i2] ^ d[i3];
             i1++; i2++; i3++;
 
             if (i3 >= n)
                 i3 -= n;
 
             d[i1] += d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
             i1++; i2++; i3++;
         }
     }
 }
 
 static void diffuser_b_encrypt(u32 *d, size_t n)
 {
     int i, i1, i2, i3;
 
     for (i = 0; i < 3; i++) {
         i1 = n - 1;
         i2 = 2 - 1;
         i3 = 5 - 1;
 
         while (i1 > 0) {
             d[i1] -= d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
             i1--; i2--; i3--;
 
             if (i3 < 0)
                 i3 += n;
 
             d[i1] -= d[i2] ^ d[i3];
             i1--; i2--; i3--;
 
             if (i2 < 0)
                 i2 += n;
 
             d[i1] -= d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
             i1--; i2--; i3--;
 
             d[i1] -= d[i2] ^ d[i3];
             i1--; i2--; i3--;
         }
     }
 }
 
 static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *dmreq)
 {
     struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
     u8 *es, *ks, *data, *data2, *data_offset;
     struct skcipher_request *req;
     struct scatterlist *sg, *sg2, src, dst;
     DECLARE_CRYPTO_WAIT(wait);
     int i, r;
 
     req = skcipher_request_alloc(elephant->tfm, GFP_NOIO);
     es = kzalloc(16, GFP_NOIO); /* Key for AES */
     ks = kzalloc(32, GFP_NOIO); /* Elephant sector key */
 
     if (!req || !es || !ks) {
         r = -ENOMEM;
         goto out;
     }
 
     *(__le64 *)es = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
 
     /* E(Ks, e(s)) */
     sg_init_one(&src, es, 16);
     sg_init_one(&dst, ks, 16);
     skcipher_request_set_crypt(req, &src, &dst, 16, NULL);
     skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
     r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
     if (r)
         goto out;
 
     /* E(Ks, e'(s)) */
     es[15] = 0x80;
     sg_init_one(&dst, &ks[16], 16);
     r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
     if (r)
         goto out;
 
     sg = crypt_get_sg_data(cc, dmreq->sg_out);
     data = kmap_atomic(sg_page(sg));
     data_offset = data + sg->offset;
 
     /* Cannot modify original bio, copy to sg_out and apply Elephant to it */
     if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
         sg2 = crypt_get_sg_data(cc, dmreq->sg_in);
         data2 = kmap_atomic(sg_page(sg2));
         memcpy(data_offset, data2 + sg2->offset, cc->sector_size);
         kunmap_atomic(data2);
     }
 
     if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
         diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32));
         diffuser_b_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
         diffuser_a_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
         diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32));
     }
 
     for (i = 0; i < (cc->sector_size / 32); i++)
         crypto_xor(data_offset + i * 32, ks, 32);
 
     if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
         diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32));
         diffuser_a_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
         diffuser_b_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
         diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32));
     }
 
     kunmap_atomic(data);
 out:
     kfree_sensitive(ks);
     kfree_sensitive(es);
     skcipher_request_free(req);
     return r;
 }
 
 static int crypt_iv_elephant_gen(struct crypt_config *cc, u8 *iv,
                 struct dm_crypt_request *dmreq)
 {
     int r;
 
     if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
         r = crypt_iv_elephant(cc, dmreq);
         if (r)
             return r;
     }
 
     return crypt_iv_eboiv_gen(cc, iv, dmreq);
 }
 
 static int crypt_iv_elephant_post(struct crypt_config *cc, u8 *iv,
                   struct dm_crypt_request *dmreq)
 {
     if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
         return crypt_iv_elephant(cc, dmreq);
 
     return 0;
 }
 
 static int crypt_iv_elephant_init(struct crypt_config *cc)
 {
     struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
     int key_offset = cc->key_size - cc->key_extra_size;
 
     return crypto_skcipher_setkey(elephant->tfm, &cc->key[key_offset], cc->key_extra_size);
 }
 
 static int crypt_iv_elephant_wipe(struct crypt_config *cc)
 {
     struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
     u8 key[ELEPHANT_MAX_KEY_SIZE];
 
     memset(key, 0, cc->key_extra_size);
     return crypto_skcipher_setkey(elephant->tfm, key, cc->key_extra_size);
 }
 
 static const struct crypt_iv_operations crypt_iv_plain_ops = {
     .generator = crypt_iv_plain_gen
 };
 
 static const struct crypt_iv_operations crypt_iv_plain64_ops = {
     .generator = crypt_iv_plain64_gen
 };
 
 static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
     .generator = crypt_iv_plain64be_gen
 };
 
 static const struct crypt_iv_operations crypt_iv_essiv_ops = {
     .generator = crypt_iv_essiv_gen
 };
 
 static const struct crypt_iv_operations crypt_iv_benbi_ops = {
     .ctr       = crypt_iv_benbi_ctr,
     .dtr       = crypt_iv_benbi_dtr,
     .generator = crypt_iv_benbi_gen
 };
 
 static const struct crypt_iv_operations crypt_iv_null_ops = {
     .generator = crypt_iv_null_gen
 };
 
 static const struct crypt_iv_operations crypt_iv_lmk_ops = {
     .ctr       = crypt_iv_lmk_ctr,
     .dtr       = crypt_iv_lmk_dtr,
     .init      = crypt_iv_lmk_init,
     .wipe      = crypt_iv_lmk_wipe,
     .generator = crypt_iv_lmk_gen,
     .post      = crypt_iv_lmk_post
 };
 
 static const struct crypt_iv_operations crypt_iv_tcw_ops = {
     .ctr       = crypt_iv_tcw_ctr,
     .dtr       = crypt_iv_tcw_dtr,
     .init      = crypt_iv_tcw_init,
     .wipe      = crypt_iv_tcw_wipe,
     .generator = crypt_iv_tcw_gen,
     .post      = crypt_iv_tcw_post
 };
 
 static const struct crypt_iv_operations crypt_iv_random_ops = {
     .generator = crypt_iv_random_gen
 };
 
 static const struct crypt_iv_operations crypt_iv_eboiv_ops = {
     .ctr       = crypt_iv_eboiv_ctr,
     .generator = crypt_iv_eboiv_gen
 };
 
 static const struct crypt_iv_operations crypt_iv_elephant_ops = {
     .ctr       = crypt_iv_elephant_ctr,
     .dtr       = crypt_iv_elephant_dtr,
     .init      = crypt_iv_elephant_init,
     .wipe      = crypt_iv_elephant_wipe,
     .generator = crypt_iv_elephant_gen,
     .post      = crypt_iv_elephant_post
 };
 
 /*
  * Integrity extensions
  */
 static bool crypt_integrity_aead(struct crypt_config *cc)
 {
     return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
 }
 
 static bool crypt_integrity_hmac(struct crypt_config *cc)
 {
     return crypt_integrity_aead(cc) && cc->key_mac_size;
 }
 
 /* Get sg containing data */
 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
                          struct scatterlist *sg)
 {
     if (unlikely(crypt_integrity_aead(cc)))
         return &sg[2];
 
     return sg;
 }
 
 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
 {
     struct bio_integrity_payload *bip;
     unsigned int tag_len;
     int ret;
 
     if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
         return 0;
 
     bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
     if (IS_ERR(bip))
         return PTR_ERR(bip);
 
     tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift);
 
     bip->bip_iter.bi_size = tag_len;
     bip->bip_iter.bi_sector = io->cc->start + io->sector;
 
     ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
                      tag_len, offset_in_page(io->integrity_metadata));
     if (unlikely(ret != tag_len))
         return -ENOMEM;
 
     return 0;
 }
 
 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
 {
 #ifdef CONFIG_BLK_DEV_INTEGRITY
     struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
     struct mapped_device *md = dm_table_get_md(ti->table);
 
     /* From now we require underlying device with our integrity profile */
     if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
         ti->error = "Integrity profile not supported.";
         return -EINVAL;
     }
 
     if (bi->tag_size != cc->on_disk_tag_size ||
         bi->tuple_size != cc->on_disk_tag_size) {
         ti->error = "Integrity profile tag size mismatch.";
         return -EINVAL;
     }
     if (1 << bi->interval_exp != cc->sector_size) {
         ti->error = "Integrity profile sector size mismatch.";
         return -EINVAL;
     }
 
     if (crypt_integrity_aead(cc)) {
         cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
         DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md),
                cc->integrity_tag_size, cc->integrity_iv_size);
 
         if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
             ti->error = "Integrity AEAD auth tag size is not supported.";
             return -EINVAL;
         }
     } else if (cc->integrity_iv_size)
         DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md),
                cc->integrity_iv_size);
 
     if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
         ti->error = "Not enough space for integrity tag in the profile.";
         return -EINVAL;
     }
 
     return 0;
 #else
     ti->error = "Integrity profile not supported.";
     return -EINVAL;
 #endif
 }
 
 static void crypt_convert_init(struct crypt_config *cc,
                    struct convert_context *ctx,
                    struct bio *bio_out, struct bio *bio_in,
                    sector_t sector)
 {
     ctx->bio_in = bio_in;
     ctx->bio_out = bio_out;
     if (bio_in)
         ctx->iter_in = bio_in->bi_iter;
     if (bio_out)
         ctx->iter_out = bio_out->bi_iter;
     ctx->cc_sector = sector + cc->iv_offset;
     init_completion(&ctx->restart);
 }
 
 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
                          void *req)
 {
     return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
 }
 
 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
 {
     return (void *)((char *)dmreq - cc->dmreq_start);
 }
 
 static u8 *iv_of_dmreq(struct crypt_config *cc,
                struct dm_crypt_request *dmreq)
 {
     if (crypt_integrity_aead(cc))
         return (u8 *)ALIGN((unsigned long)(dmreq + 1),
             crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
     else
         return (u8 *)ALIGN((unsigned long)(dmreq + 1),
             crypto_skcipher_alignmask(any_tfm(cc)) + 1);
 }
 
 static u8 *org_iv_of_dmreq(struct crypt_config *cc,
                struct dm_crypt_request *dmreq)
 {
     return iv_of_dmreq(cc, dmreq) + cc->iv_size;
 }
 
 static __le64 *org_sector_of_dmreq(struct crypt_config *cc,
                struct dm_crypt_request *dmreq)
 {
     u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
     return (__le64 *) ptr;
 }
 
 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
                struct dm_crypt_request *dmreq)
 {
     u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
           cc->iv_size + sizeof(uint64_t);
     return (unsigned int*)ptr;
 }
 
 static void *tag_from_dmreq(struct crypt_config *cc,
                 struct dm_crypt_request *dmreq)
 {
     struct convert_context *ctx = dmreq->ctx;
     struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
 
     return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
         cc->on_disk_tag_size];
 }
 
 static void *iv_tag_from_dmreq(struct crypt_config *cc,
                    struct dm_crypt_request *dmreq)
 {
     return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
 }
 
 static int crypt_convert_block_aead(struct crypt_config *cc,
                      struct convert_context *ctx,
                      struct aead_request *req,
                      unsigned int tag_offset)
 {
     struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
     struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
     struct dm_crypt_request *dmreq;
     u8 *iv, *org_iv, *tag_iv, *tag;
     __le64 *sector;
     int r = 0;
 
     BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
 
     /* Reject unexpected unaligned bio. */
     if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
         return -EIO;
 
     dmreq = dmreq_of_req(cc, req);
     dmreq->iv_sector = ctx->cc_sector;
     if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
         dmreq->iv_sector >>= cc->sector_shift;
     dmreq->ctx = ctx;
 
     *org_tag_of_dmreq(cc, dmreq) = tag_offset;
 
     sector = org_sector_of_dmreq(cc, dmreq);
     *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
 
     iv = iv_of_dmreq(cc, dmreq);
     org_iv = org_iv_of_dmreq(cc, dmreq);
     tag = tag_from_dmreq(cc, dmreq);
     tag_iv = iv_tag_from_dmreq(cc, dmreq);
 
     /* AEAD request:
      *  |----- AAD -------|------ DATA -------|-- AUTH TAG --|
      *  | (authenticated) | (auth+encryption) |              |
      *  | sector_LE |  IV |  sector in/out    |  tag in/out  |
      */
     sg_init_table(dmreq->sg_in, 4);
     sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
     sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
     sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
     sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
 
     sg_init_table(dmreq->sg_out, 4);
     sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
     sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
     sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
     sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
 
     if (cc->iv_gen_ops) {
         /* For READs use IV stored in integrity metadata */
         if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
             memcpy(org_iv, tag_iv, cc->iv_size);
         } else {
             r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
             if (r < 0)
                 return r;
             /* Store generated IV in integrity metadata */
             if (cc->integrity_iv_size)
                 memcpy(tag_iv, org_iv, cc->iv_size);
         }
         /* Working copy of IV, to be modified in crypto API */
         memcpy(iv, org_iv, cc->iv_size);
     }
 
     aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
     if (bio_data_dir(ctx->bio_in) == WRITE) {
         aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
                        cc->sector_size, iv);
         r = crypto_aead_encrypt(req);
         if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
             memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
                    cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
     } else {
         aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
                        cc->sector_size + cc->integrity_tag_size, iv);
         r = crypto_aead_decrypt(req);
     }
 
     if (r == -EBADMSG) {
         sector_t s = le64_to_cpu(*sector);
 
         DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu",
                 ctx->bio_in->bi_bdev, s);
         dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
                  ctx->bio_in, s, 0);
     }
 
     if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
         r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
 
     bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
     bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
 
     return r;
 }
 
 static int crypt_convert_block_skcipher(struct crypt_config *cc,
                     struct convert_context *ctx,
                     struct skcipher_request *req,
                     unsigned int tag_offset)
 {
     struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
     struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
     struct scatterlist *sg_in, *sg_out;
     struct dm_crypt_request *dmreq;
     u8 *iv, *org_iv, *tag_iv;
     __le64 *sector;
     int r = 0;
 
     /* Reject unexpected unaligned bio. */
     if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
         return -EIO;
 
     dmreq = dmreq_of_req(cc, req);
     dmreq->iv_sector = ctx->cc_sector;
     if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
         dmreq->iv_sector >>= cc->sector_shift;
     dmreq->ctx = ctx;
 
     *org_tag_of_dmreq(cc, dmreq) = tag_offset;
 
     iv = iv_of_dmreq(cc, dmreq);
     org_iv = org_iv_of_dmreq(cc, dmreq);
     tag_iv = iv_tag_from_dmreq(cc, dmreq);
 
     sector = org_sector_of_dmreq(cc, dmreq);
     *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
 
     /* For skcipher we use only the first sg item */
     sg_in  = &dmreq->sg_in[0];
     sg_out = &dmreq->sg_out[0];
 
     sg_init_table(sg_in, 1);
     sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
 
     sg_init_table(sg_out, 1);
     sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
 
     if (cc->iv_gen_ops) {
         /* For READs use IV stored in integrity metadata */
         if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
             memcpy(org_iv, tag_iv, cc->integrity_iv_size);
         } else {
             r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
             if (r < 0)
                 return r;
             /* Data can be already preprocessed in generator */
             if (test_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags))
                 sg_in = sg_out;
             /* Store generated IV in integrity metadata */
             if (cc->integrity_iv_size)
                 memcpy(tag_iv, org_iv, cc->integrity_iv_size);
         }
         /* Working copy of IV, to be modified in crypto API */
         memcpy(iv, org_iv, cc->iv_size);
     }
 
     skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
 
     if (bio_data_dir(ctx->bio_in) == WRITE)
         r = crypto_skcipher_encrypt(req);
     else
         r = crypto_skcipher_decrypt(req);
 
     if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
         r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
 
     bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
     bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
 
     return r;
 }
 
 static void kcryptd_async_done(struct crypto_async_request *async_req,
                    int error);
 
 static int crypt_alloc_req_skcipher(struct crypt_config *cc,
                      struct convert_context *ctx)
 {
     unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
 
     if (!ctx->r.req) {
         ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
         if (!ctx->r.req)
             return -ENOMEM;
     }
 
     skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
 
     /*
      * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
      * requests if driver request queue is full.
      */
     skcipher_request_set_callback(ctx->r.req,
         CRYPTO_TFM_REQ_MAY_BACKLOG,
         kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
 
     return 0;
 }
 
 static int crypt_alloc_req_aead(struct crypt_config *cc,
                  struct convert_context *ctx)
 {
     if (!ctx->r.req_aead) {
         ctx->r.req_aead = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
         if (!ctx->r.req_aead)
             return -ENOMEM;
     }
 
     aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
 
     /*
      * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
      * requests if driver request queue is full.
      */
     aead_request_set_callback(ctx->r.req_aead,
         CRYPTO_TFM_REQ_MAY_BACKLOG,
         kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
 
     return 0;
 }
 
 static int crypt_alloc_req(struct crypt_config *cc,
                 struct convert_context *ctx)
 {
     if (crypt_integrity_aead(cc))
         return crypt_alloc_req_aead(cc, ctx);
     else
         return crypt_alloc_req_skcipher(cc, ctx);
 }
 
 static void crypt_free_req_skcipher(struct crypt_config *cc,
                     struct skcipher_request *req, struct bio *base_bio)
 {
     struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
 
     if ((struct skcipher_request *)(io + 1) != req)
         mempool_free(req, &cc->req_pool);
 }
 
 static void crypt_free_req_aead(struct crypt_config *cc,
                 struct aead_request *req, struct bio *base_bio)
 {
     struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
 
     if ((struct aead_request *)(io + 1) != req)
         mempool_free(req, &cc->req_pool);
 }
 
 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
 {
     if (crypt_integrity_aead(cc))
         crypt_free_req_aead(cc, req, base_bio);
     else
         crypt_free_req_skcipher(cc, req, base_bio);
 }
 
 /*
  * Encrypt / decrypt data from one bio to another one (can be the same one)
  */
 static blk_status_t crypt_convert(struct crypt_config *cc,
              struct convert_context *ctx, bool atomic, bool reset_pending)
 {
     unsigned int tag_offset = 0;
     unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
     int r;
 
     /*
      * if reset_pending is set we are dealing with the bio for the first time,
      * else we're continuing to work on the previous bio, so don't mess with
      * the cc_pending counter
      */
     if (reset_pending)
         atomic_set(&ctx->cc_pending, 1);
 
     while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
 
         r = crypt_alloc_req(cc, ctx);
         if (r) {
             complete(&ctx->restart);
             return BLK_STS_DEV_RESOURCE;
         }
 
         atomic_inc(&ctx->cc_pending);
 
         if (crypt_integrity_aead(cc))
             r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);
         else
             r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset);
 
         switch (r) {
         /*
          * The request was queued by a crypto driver
          * but the driver request queue is full, let's wait.
          */
         case -EBUSY:
             if (in_interrupt()) {
                 if (try_wait_for_completion(&ctx->restart)) {
                     /*
                      * we don't have to block to wait for completion,
                      * so proceed
                      */
                 } else {
                     /*
                      * we can't wait for completion without blocking
                      * exit and continue processing in a workqueue
                      */
                     ctx->r.req = NULL;
                     ctx->cc_sector += sector_step;
                     tag_offset++;
                     return BLK_STS_DEV_RESOURCE;
                 }
             } else {
                 wait_for_completion(&ctx->restart);
             }
             reinit_completion(&ctx->restart);
             fallthrough;
         /*
          * The request is queued and processed asynchronously,
          * completion function kcryptd_async_done() will be called.
          */
         case -EINPROGRESS:
             ctx->r.req = NULL;
             ctx->cc_sector += sector_step;
             tag_offset++;
             continue;
         /*
          * The request was already processed (synchronously).
          */
         case 0:
             atomic_dec(&ctx->cc_pending);
             ctx->cc_sector += sector_step;
             tag_offset++;
             if (!atomic)
                 cond_resched();
             continue;
         /*
          * There was a data integrity error.
          */
         case -EBADMSG:
             atomic_dec(&ctx->cc_pending);
             return BLK_STS_PROTECTION;
         /*
          * There was an error while processing the request.
          */
         default:
             atomic_dec(&ctx->cc_pending);
             return BLK_STS_IOERR;
         }
     }
 
     return 0;
 }
 
 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
 
 /*
  * Generate a new unfragmented bio with the given size
  * This should never violate the device limitations (but only because
  * max_segment_size is being constrained to PAGE_SIZE).
  *
  * This function may be called concurrently. If we allocate from the mempool
  * concurrently, there is a possibility of deadlock. For example, if we have
  * mempool of 256 pages, two processes, each wanting 256, pages allocate from
  * the mempool concurrently, it may deadlock in a situation where both processes
  * have allocated 128 pages and the mempool is exhausted.
  *
  * In order to avoid this scenario we allocate the pages under a mutex.
  *
  * In order to not degrade performance with excessive locking, we try
  * non-blocking allocations without a mutex first but on failure we fallback
  * to blocking allocations with a mutex.
  */
 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
 {
     struct crypt_config *cc = io->cc;
     struct bio *clone;
     unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
     gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
     unsigned i, len, remaining_size;
     struct page *page;
 
 retry:
     if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
         mutex_lock(&cc->bio_alloc_lock);
 
     clone = bio_alloc_bioset(cc->dev->bdev, nr_iovecs, io->base_bio->bi_opf,
                  GFP_NOIO, &cc->bs);
     clone->bi_private = io;
     clone->bi_end_io = crypt_endio;
 
     remaining_size = size;
 
     for (i = 0; i < nr_iovecs; i++) {
         page = mempool_alloc(&cc->page_pool, gfp_mask);
         if (!page) {
             crypt_free_buffer_pages(cc, clone);
             bio_put(clone);
             gfp_mask |= __GFP_DIRECT_RECLAIM;
             goto retry;
         }
 
         len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
 
         bio_add_page(clone, page, len, 0);
 
         remaining_size -= len;
     }
 
     /* Allocate space for integrity tags */
     if (dm_crypt_integrity_io_alloc(io, clone)) {
         crypt_free_buffer_pages(cc, clone);
         bio_put(clone);
         clone = NULL;
     }
 
     if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
         mutex_unlock(&cc->bio_alloc_lock);
 
     return clone;
 }
 
 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
 {
     struct bio_vec *bv;
     struct bvec_iter_all iter_all;
 
     bio_for_each_segment_all(bv, clone, iter_all) {
         BUG_ON(!bv->bv_page);
         mempool_free(bv->bv_page, &cc->page_pool);
     }
 }
 
 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
               struct bio *bio, sector_t sector)
 {
     io->cc = cc;
     io->base_bio = bio;
     io->sector = sector;
     io->error = 0;
     io->ctx.r.req = NULL;
     io->integrity_metadata = NULL;
     io->integrity_metadata_from_pool = false;
     atomic_set(&io->io_pending, 0);
 }
 
 static void crypt_inc_pending(struct dm_crypt_io *io)
 {
     atomic_inc(&io->io_pending);
 }
 
 static void kcryptd_io_bio_endio(struct work_struct *work)
 {
     struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
     bio_endio(io->base_bio);
 }
 
 /*
  * One of the bios was finished. Check for completion of
  * the whole request and correctly clean up the buffer.
  */
 static void crypt_dec_pending(struct dm_crypt_io *io)
 {
     struct crypt_config *cc = io->cc;
     struct bio *base_bio = io->base_bio;
     blk_status_t error = io->error;
 
     if (!atomic_dec_and_test(&io->io_pending))
         return;
 
     if (io->ctx.r.req)
         crypt_free_req(cc, io->ctx.r.req, base_bio);
 
     if (unlikely(io->integrity_metadata_from_pool))
         mempool_free(io->integrity_metadata, &io->cc->tag_pool);
     else
         kfree(io->integrity_metadata);
 
     base_bio->bi_status = error;
 
     /*
      * If we are running this function from our tasklet,
      * we can't call bio_endio() here, because it will call
      * clone_endio() from dm.c, which in turn will
      * free the current struct dm_crypt_io structure with
      * our tasklet. In this case we need to delay bio_endio()
      * execution to after the tasklet is done and dequeued.
      */
     if (tasklet_trylock(&io->tasklet)) {
         tasklet_unlock(&io->tasklet);
         bio_endio(base_bio);
         return;
     }
 
     INIT_WORK(&io->work, kcryptd_io_bio_endio);
     queue_work(cc->io_queue, &io->work);
 }
 
 /*
  * kcryptd/kcryptd_io:
  *
  * Needed because it would be very unwise to do decryption in an
  * interrupt context.
  *
  * kcryptd performs the actual encryption or decryption.
  *
  * kcryptd_io performs the IO submission.
  *
  * They must be separated as otherwise the final stages could be
  * starved by new requests which can block in the first stages due
  * to memory allocation.
  *
  * The work is done per CPU global for all dm-crypt instances.
  * They should not depend on each other and do not block.
  */
 static void crypt_endio(struct bio *clone)
 {
     struct dm_crypt_io *io = clone->bi_private;
     struct crypt_config *cc = io->cc;
     unsigned rw = bio_data_dir(clone);
     blk_status_t error;
 
     /*
      * free the processed pages
      */
     if (rw == WRITE)
         crypt_free_buffer_pages(cc, clone);
 
     error = clone->bi_status;
     bio_put(clone);
 
     if (rw == READ && !error) {
         kcryptd_queue_crypt(io);
         return;
     }
 
     if (unlikely(error))
         io->error = error;
 
     crypt_dec_pending(io);
 }
 
 #define CRYPT_MAP_READ_GFP GFP_NOWAIT
 
 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
 {
     struct crypt_config *cc = io->cc;
     struct bio *clone;
 
     /*
      * We need the original biovec array in order to decrypt the whole bio
      * data *afterwards* -- thanks to immutable biovecs we don't need to
      * worry about the block layer modifying the biovec array; so leverage
      * bio_alloc_clone().
      */
     clone = bio_alloc_clone(cc->dev->bdev, io->base_bio, gfp, &cc->bs);
     if (!clone)
         return 1;
     clone->bi_private = io;
     clone->bi_end_io = crypt_endio;
 
     crypt_inc_pending(io);
 
     clone->bi_iter.bi_sector = cc->start + io->sector;
 
     if (dm_crypt_integrity_io_alloc(io, clone)) {
         crypt_dec_pending(io);
         bio_put(clone);
         return 1;
     }
 
     dm_submit_bio_remap(io->base_bio, clone);
     return 0;
 }
 
 static void kcryptd_io_read_work(struct work_struct *work)
 {
     struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
 
     crypt_inc_pending(io);
     if (kcryptd_io_read(io, GFP_NOIO))
         io->error = BLK_STS_RESOURCE;
     crypt_dec_pending(io);
 }
 
 static void kcryptd_queue_read(struct dm_crypt_io *io)
 {
     struct crypt_config *cc = io->cc;
 
     INIT_WORK(&io->work, kcryptd_io_read_work);
     queue_work(cc->io_queue, &io->work);
 }
 
 static void kcryptd_io_write(struct dm_crypt_io *io)
 {
     struct bio *clone = io->ctx.bio_out;
 
     dm_submit_bio_remap(io->base_bio, clone);
 }
 
 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
 
 static int dmcrypt_write(void *data)
 {
     struct crypt_config *cc = data;
     struct dm_crypt_io *io;
 
     while (1) {
         struct rb_root write_tree;
         struct blk_plug plug;
 
         spin_lock_irq(&cc->write_thread_lock);
 continue_locked:
 
         if (!RB_EMPTY_ROOT(&cc->write_tree))
             goto pop_from_list;
 
         set_current_state(TASK_INTERRUPTIBLE);
 
         spin_unlock_irq(&cc->write_thread_lock);
 
         if (unlikely(kthread_should_stop())) {
             set_current_state(TASK_RUNNING);
             break;
         }
 
         schedule();
 
         set_current_state(TASK_RUNNING);
         spin_lock_irq(&cc->write_thread_lock);
         goto continue_locked;
 
 pop_from_list:
         write_tree = cc->write_tree;
         cc->write_tree = RB_ROOT;
         spin_unlock_irq(&cc->write_thread_lock);
 
         BUG_ON(rb_parent(write_tree.rb_node));
 
         /*
          * Note: we cannot walk the tree here with rb_next because
          * the structures may be freed when kcryptd_io_write is called.
          */
         blk_start_plug(&plug);
         do {
             io = crypt_io_from_node(rb_first(&write_tree));
             rb_erase(&io->rb_node, &write_tree);
             kcryptd_io_write(io);
         } while (!RB_EMPTY_ROOT(&write_tree));
         blk_finish_plug(&plug);
     }
     return 0;
 }
 
 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
 {
     struct bio *clone = io->ctx.bio_out;
     struct crypt_config *cc = io->cc;
     unsigned long flags;
     sector_t sector;
     struct rb_node **rbp, *parent;
 
     if (unlikely(io->error)) {
         crypt_free_buffer_pages(cc, clone);
         bio_put(clone);
         crypt_dec_pending(io);
         return;
     }
 
     /* crypt_convert should have filled the clone bio */
     BUG_ON(io->ctx.iter_out.bi_size);
 
     clone->bi_iter.bi_sector = cc->start + io->sector;
 
     if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) ||
         test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) {
         dm_submit_bio_remap(io->base_bio, clone);
         return;
     }
 
     spin_lock_irqsave(&cc->write_thread_lock, flags);
     if (RB_EMPTY_ROOT(&cc->write_tree))
         wake_up_process(cc->write_thread);
     rbp = &cc->write_tree.rb_node;
     parent = NULL;
     sector = io->sector;
     while (*rbp) {
         parent = *rbp;
         if (sector < crypt_io_from_node(parent)->sector)
             rbp = &(*rbp)->rb_left;
         else
             rbp = &(*rbp)->rb_right;
     }
     rb_link_node(&io->rb_node, parent, rbp);
     rb_insert_color(&io->rb_node, &cc->write_tree);
     spin_unlock_irqrestore(&cc->write_thread_lock, flags);
 }
 
 static bool kcryptd_crypt_write_inline(struct crypt_config *cc,
                        struct convert_context *ctx)
 
 {
     if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags))
         return false;
 
     /*
      * Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering
      * constraints so they do not need to be issued inline by
      * kcryptd_crypt_write_convert().
      */
     switch (bio_op(ctx->bio_in)) {
     case REQ_OP_WRITE:
     case REQ_OP_WRITE_ZEROES:
         return true;
     default:
         return false;
     }
 }
 
 static void kcryptd_crypt_write_continue(struct work_struct *work)
 {
     struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
     struct crypt_config *cc = io->cc;
     struct convert_context *ctx = &io->ctx;
     int crypt_finished;
     sector_t sector = io->sector;
     blk_status_t r;
 
     wait_for_completion(&ctx->restart);
     reinit_completion(&ctx->restart);
 
     r = crypt_convert(cc, &io->ctx, true, false);
     if (r)
         io->error = r;
     crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
     if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
         /* Wait for completion signaled by kcryptd_async_done() */
         wait_for_completion(&ctx->restart);
         crypt_finished = 1;
     }
 
     /* Encryption was already finished, submit io now */
     if (crypt_finished) {
         kcryptd_crypt_write_io_submit(io, 0);
         io->sector = sector;
     }
 
     crypt_dec_pending(io);
 }
 
 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 {
     struct crypt_config *cc = io->cc;
     struct convert_context *ctx = &io->ctx;
     struct bio *clone;
     int crypt_finished;
     sector_t sector = io->sector;
     blk_status_t r;
 
     /*
      * Prevent io from disappearing until this function completes.
      */
     crypt_inc_pending(io);
     crypt_convert_init(cc, ctx, NULL, io->base_bio, sector);
 
     clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
     if (unlikely(!clone)) {
         io->error = BLK_STS_IOERR;
         goto dec;
     }
 
     io->ctx.bio_out = clone;
     io->ctx.iter_out = clone->bi_iter;
 
     sector += bio_sectors(clone);
 
     crypt_inc_pending(io);
     r = crypt_convert(cc, ctx,
               test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags), true);
     /*
      * Crypto API backlogged the request, because its queue was full
      * and we're in softirq context, so continue from a workqueue
      * (TODO: is it actually possible to be in softirq in the write path?)
      */
     if (r == BLK_STS_DEV_RESOURCE) {
         INIT_WORK(&io->work, kcryptd_crypt_write_continue);
         queue_work(cc->crypt_queue, &io->work);
         return;
     }
     if (r)
         io->error = r;
     crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
     if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
         /* Wait for completion signaled by kcryptd_async_done() */
         wait_for_completion(&ctx->restart);
         crypt_finished = 1;
     }
 
     /* Encryption was already finished, submit io now */
     if (crypt_finished) {
         kcryptd_crypt_write_io_submit(io, 0);
         io->sector = sector;
     }
 
 dec:
     crypt_dec_pending(io);
 }
 
 static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
 {
     crypt_dec_pending(io);
 }
 
 static void kcryptd_crypt_read_continue(struct work_struct *work)
 {
     struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
     struct crypt_config *cc = io->cc;
     blk_status_t r;
 
     wait_for_completion(&io->ctx.restart);
     reinit_completion(&io->ctx.restart);
 
     r = crypt_convert(cc, &io->ctx, true, false);
     if (r)
         io->error = r;
 
     if (atomic_dec_and_test(&io->ctx.cc_pending))
         kcryptd_crypt_read_done(io);
 
     crypt_dec_pending(io);
 }
 
 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
 {
     struct crypt_config *cc = io->cc;
     blk_status_t r;
 
     crypt_inc_pending(io);
 
     crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
                io->sector);
 
     r = crypt_convert(cc, &io->ctx,
               test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true);
     /*
      * Crypto API backlogged the request, because its queue was full
      * and we're in softirq context, so continue from a workqueue
      */
     if (r == BLK_STS_DEV_RESOURCE) {
         INIT_WORK(&io->work, kcryptd_crypt_read_continue);
         queue_work(cc->crypt_queue, &io->work);
         return;
     }
     if (r)
         io->error = r;
 
     if (atomic_dec_and_test(&io->ctx.cc_pending))
         kcryptd_crypt_read_done(io);
 
     crypt_dec_pending(io);
 }
 
 static void kcryptd_async_done(struct crypto_async_request *async_req,
                    int error)
 {
     struct dm_crypt_request *dmreq = async_req->data;
     struct convert_context *ctx = dmreq->ctx;
     struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
     struct crypt_config *cc = io->cc;
 
     /*
      * A request from crypto driver backlog is going to be processed now,
      * finish the completion and continue in crypt_convert().
      * (Callback will be called for the second time for this request.)
      */
     if (error == -EINPROGRESS) {
         complete(&ctx->restart);
         return;
     }
 
     if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
         error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq);
 
     if (error == -EBADMSG) {
         sector_t s = le64_to_cpu(*org_sector_of_dmreq(cc, dmreq));
 
         DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu",
                 ctx->bio_in->bi_bdev, s);
         dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
                  ctx->bio_in, s, 0);
         io->error = BLK_STS_PROTECTION;
     } else if (error < 0)
         io->error = BLK_STS_IOERR;
 
     crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
 
     if (!atomic_dec_and_test(&ctx->cc_pending))
         return;
 
     /*
      * The request is fully completed: for inline writes, let
      * kcryptd_crypt_write_convert() do the IO submission.
      */
     if (bio_data_dir(io->base_bio) == READ) {
         kcryptd_crypt_read_done(io);
         return;
     }
 
     if (kcryptd_crypt_write_inline(cc, ctx)) {
         complete(&ctx->restart);
         return;
     }
 
     kcryptd_crypt_write_io_submit(io, 1);
 }
 
 static void kcryptd_crypt(struct work_struct *work)
 {
     struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
 
     if (bio_data_dir(io->base_bio) == READ)
         kcryptd_crypt_read_convert(io);
     else
         kcryptd_crypt_write_convert(io);
 }
 
 static void kcryptd_crypt_tasklet(unsigned long work)
 {
     kcryptd_crypt((struct work_struct *)work);
 }
 
 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
 {
     struct crypt_config *cc = io->cc;
 
     if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) ||
         (bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) {
         /*
          * in_hardirq(): Crypto API's skcipher_walk_first() refuses to work in hard IRQ context.
          * irqs_disabled(): the kernel may run some IO completion from the idle thread, but
          * it is being executed with irqs disabled.
          */
         if (in_hardirq() || irqs_disabled()) {
             tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work);
             tasklet_schedule(&io->tasklet);
             return;
         }
 
         kcryptd_crypt(&io->work);
         return;
     }
 
     INIT_WORK(&io->work, kcryptd_crypt);
     queue_work(cc->crypt_queue, &io->work);
 }
 
 static void crypt_free_tfms_aead(struct crypt_config *cc)
 {
     if (!cc->cipher_tfm.tfms_aead)
         return;
 
     if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
         crypto_free_aead(cc->cipher_tfm.tfms_aead[0]);
         cc->cipher_tfm.tfms_aead[0] = NULL;
     }
 
     kfree(cc->cipher_tfm.tfms_aead);
     cc->cipher_tfm.tfms_aead = NULL;
 }
 
 static void crypt_free_tfms_skcipher(struct crypt_config *cc)
 {
     unsigned i;
 
     if (!cc->cipher_tfm.tfms)
         return;
 
     for (i = 0; i < cc->tfms_count; i++)
         if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) {
             crypto_free_skcipher(cc->cipher_tfm.tfms[i]);
             cc->cipher_tfm.tfms[i] = NULL;
         }
 
     kfree(cc->cipher_tfm.tfms);
     cc->cipher_tfm.tfms = NULL;
 }
 
 static void crypt_free_tfms(struct crypt_config *cc)
 {
     if (crypt_integrity_aead(cc))
         crypt_free_tfms_aead(cc);
     else
         crypt_free_tfms_skcipher(cc);
 }
 
 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
 {
     unsigned i;
     int err;
 
     cc->cipher_tfm.tfms = kcalloc(cc->tfms_count,
                       sizeof(struct crypto_skcipher *),
                       GFP_KERNEL);
     if (!cc->cipher_tfm.tfms)
         return -ENOMEM;
 
     for (i = 0; i < cc->tfms_count; i++) {
         cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0,
                         CRYPTO_ALG_ALLOCATES_MEMORY);
         if (IS_ERR(cc->cipher_tfm.tfms[i])) {
             err = PTR_ERR(cc->cipher_tfm.tfms[i]);
             crypt_free_tfms(cc);
             return err;
         }
     }
 
     /*
      * dm-crypt performance can vary greatly depending on which crypto
      * algorithm implementation is used.  Help people debug performance
      * problems by logging the ->cra_driver_name.
      */
     DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
            crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name);
     return 0;
 }
 
 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
 {
     int err;
 
     cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
     if (!cc->cipher_tfm.tfms)
         return -ENOMEM;
 
     cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0,
                         CRYPTO_ALG_ALLOCATES_MEMORY);
     if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
         err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
         crypt_free_tfms(cc);
         return err;
     }
 
     DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
            crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name);
     return 0;
 }
 
 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
 {
     if (crypt_integrity_aead(cc))
         return crypt_alloc_tfms_aead(cc, ciphermode);
     else
         return crypt_alloc_tfms_skcipher(cc, ciphermode);
 }
 
 static unsigned crypt_subkey_size(struct crypt_config *cc)
 {
     return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
 }
 
 static unsigned crypt_authenckey_size(struct crypt_config *cc)
 {
     return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
 }
 
 /*
  * If AEAD is composed like authenc(hmac(sha256),xts(aes)),
  * the key must be for some reason in special format.
  * This funcion converts cc->key to this special format.
  */
 static void crypt_copy_authenckey(char *p, const void *key,
                   unsigned enckeylen, unsigned authkeylen)
 {
     struct crypto_authenc_key_param *param;
     struct rtattr *rta;
 
     rta = (struct rtattr *)p;
     param = RTA_DATA(rta);
     param->enckeylen = cpu_to_be32(enckeylen);
     rta->rta_len = RTA_LENGTH(sizeof(*param));
     rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
     p += RTA_SPACE(sizeof(*param));
     memcpy(p, key + enckeylen, authkeylen);
     p += authkeylen;
     memcpy(p, key, enckeylen);
 }
 
 static int crypt_setkey(struct crypt_config *cc)
 {
     unsigned subkey_size;
     int err = 0, i, r;
 
     /* Ignore extra keys (which are used for IV etc) */
     subkey_size = crypt_subkey_size(cc);
 
     if (crypt_integrity_hmac(cc)) {
         if (subkey_size < cc->key_mac_size)
             return -EINVAL;
 
         crypt_copy_authenckey(cc->authenc_key, cc->key,
                       subkey_size - cc->key_mac_size,
                       cc->key_mac_size);
     }
 
     for (i = 0; i < cc->tfms_count; i++) {
         if (crypt_integrity_hmac(cc))
             r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
                 cc->authenc_key, crypt_authenckey_size(cc));
         else if (crypt_integrity_aead(cc))
             r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
                            cc->key + (i * subkey_size),
                            subkey_size);
         else
             r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
                            cc->key + (i * subkey_size),
                            subkey_size);
         if (r)
             err = r;
     }
 
     if (crypt_integrity_hmac(cc))
         memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
 
     return err;
 }
 
 #ifdef CONFIG_KEYS
 
 static bool contains_whitespace(const char *str)
 {
     while (*str)
         if (isspace(*str++))
             return true;
     return false;
 }
 
 static int set_key_user(struct crypt_config *cc, struct key *key)
 {
     const struct user_key_payload *ukp;
 
     ukp = user_key_payload_locked(key);
     if (!ukp)
         return -EKEYREVOKED;
 
     if (cc->key_size != ukp->datalen)
         return -EINVAL;
 
     memcpy(cc->key, ukp->data, cc->key_size);
 
     return 0;
 }
 
 static int set_key_encrypted(struct crypt_config *cc, struct key *key)
 {
     const struct encrypted_key_payload *ekp;
 
     ekp = key->payload.data[0];
     if (!ekp)
         return -EKEYREVOKED;
 
     if (cc->key_size != ekp->decrypted_datalen)
         return -EINVAL;
 
     memcpy(cc->key, ekp->decrypted_data, cc->key_size);
 
     return 0;
 }
 
 static int set_key_trusted(struct crypt_config *cc, struct key *key)
 {
     const struct trusted_key_payload *tkp;
 
     tkp = key->payload.data[0];
     if (!tkp)
         return -EKEYREVOKED;
 
     if (cc->key_size != tkp->key_len)
         return -EINVAL;
 
     memcpy(cc->key, tkp->key, cc->key_size);
 
     return 0;
 }
 
 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
 {
     char *new_key_string, *key_desc;
     int ret;
     struct key_type *type;
     struct key *key;
     int (*set_key)(struct crypt_config *cc, struct key *key);
 
     /*
      * Reject key_string with whitespace. dm core currently lacks code for
      * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
      */
     if (contains_whitespace(key_string)) {
         DMERR("whitespace chars not allowed in key string");
         return -EINVAL;
     }
 
     /* look for next ':' separating key_type from key_description */
     key_desc = strpbrk(key_string, ":");
     if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
         return -EINVAL;
 
     if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) {
         type = &key_type_logon;
         set_key = set_key_user;
     } else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) {
         type = &key_type_user;
         set_key = set_key_user;
     } else if (IS_ENABLED(CONFIG_ENCRYPTED_KEYS) &&
            !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) {
         type = &key_type_encrypted;
         set_key = set_key_encrypted;
     } else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) &&
                !strncmp(key_string, "trusted:", key_desc - key_string + 1)) {
         type = &key_type_trusted;
         set_key = set_key_trusted;
     } else {
         return -EINVAL;
     }
 
     new_key_string = kstrdup(key_string, GFP_KERNEL);
     if (!new_key_string)
         return -ENOMEM;
 
     key = request_key(type, key_desc + 1, NULL);
     if (IS_ERR(key)) {
         kfree_sensitive(new_key_string);
         return PTR_ERR(key);
     }
 
     down_read(&key->sem);
 
     ret = set_key(cc, key);
     if (ret < 0) {
         up_read(&key->sem);
         key_put(key);
         kfree_sensitive(new_key_string);
         return ret;
     }
 
     up_read(&key->sem);
     key_put(key);
 
     /* clear the flag since following operations may invalidate previously valid key */
     clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
 
     ret = crypt_setkey(cc);
 
     if (!ret) {
         set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
         kfree_sensitive(cc->key_string);
         cc->key_string = new_key_string;
     } else
         kfree_sensitive(new_key_string);
 
     return ret;
 }
 
 static int get_key_size(char **key_string)
 {
     char *colon, dummy;
     int ret;
 
     if (*key_string[0] != ':')
         return strlen(*key_string) >> 1;
 
     /* look for next ':' in key string */
     colon = strpbrk(*key_string + 1, ":");
     if (!colon)
         return -EINVAL;
 
     if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
         return -EINVAL;
 
     *key_string = colon;
 
     /* remaining key string should be :<logon|user>:<key_desc> */
 
     return ret;
 }
 
 #else
 
 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
 {
     return -EINVAL;
 }
 
 static int get_key_size(char **key_string)
 {
     return (*key_string[0] == ':') ? -EINVAL : (int)(strlen(*key_string) >> 1);
 }
 
 #endif /* CONFIG_KEYS */
 
 static int crypt_set_key(struct crypt_config *cc, char *key)
 {
     int r = -EINVAL;
     int key_string_len = strlen(key);
 
     /* Hyphen (which gives a key_size of zero) means there is no key. */
     if (!cc->key_size && strcmp(key, "-"))
         goto out;
 
     /* ':' means the key is in kernel keyring, short-circuit normal key processing */
     if (key[0] == ':') {
         r = crypt_set_keyring_key(cc, key + 1);
         goto out;
     }
 
     /* clear the flag since following operations may invalidate previously valid key */
     clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
 
     /* wipe references to any kernel keyring key */
     kfree_sensitive(cc->key_string);
     cc->key_string = NULL;
 
     /* Decode key from its hex representation. */
     if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
         goto out;
 
     r = crypt_setkey(cc);
     if (!r)
         set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
 
 out:
     /* Hex key string not needed after here, so wipe it. */
     memset(key, '0', key_string_len);
 
     return r;
 }
 
 static int crypt_wipe_key(struct crypt_config *cc)
 {
     int r;
 
     clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
     get_random_bytes(&cc->key, cc->key_size);
 
     /* Wipe IV private keys */
     if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
         r = cc->iv_gen_ops->wipe(cc);
         if (r)
             return r;
     }
 
     kfree_sensitive(cc->key_string);
     cc->key_string = NULL;
     r = crypt_setkey(cc);
     memset(&cc->key, 0, cc->key_size * sizeof(u8));
 
     return r;
 }
 
 static void crypt_calculate_pages_per_client(void)
 {
     unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100;
 
     if (!dm_crypt_clients_n)
         return;
 
     pages /= dm_crypt_clients_n;
     if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT)
         pages = DM_CRYPT_MIN_PAGES_PER_CLIENT;
     dm_crypt_pages_per_client = pages;
 }
 
 static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data)
 {
     struct crypt_config *cc = pool_data;
     struct page *page;
 
     /*
      * Note, percpu_counter_read_positive() may over (and under) estimate
      * the current usage by at most (batch - 1) * num_online_cpus() pages,
      * but avoids potential spinlock contention of an exact result.
      */
     if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) >= dm_crypt_pages_per_client) &&
         likely(gfp_mask & __GFP_NORETRY))
         return NULL;
 
     page = alloc_page(gfp_mask);
     if (likely(page != NULL))
         percpu_counter_add(&cc->n_allocated_pages, 1);
 
     return page;
 }
 
 static void crypt_page_free(void *page, void *pool_data)
 {
     struct crypt_config *cc = pool_data;
 
     __free_page(page);
     percpu_counter_sub(&cc->n_allocated_pages, 1);
 }
 
 static void crypt_dtr(struct dm_target *ti)
 {
     struct crypt_config *cc = ti->private;
 
     ti->private = NULL;
 
     if (!cc)
         return;
 
     if (cc->write_thread)
         kthread_stop(cc->write_thread);
 
     if (cc->io_queue)
         destroy_workqueue(cc->io_queue);
     if (cc->crypt_queue)
         destroy_workqueue(cc->crypt_queue);
 
     crypt_free_tfms(cc);
 
     bioset_exit(&cc->bs);
 
     mempool_exit(&cc->page_pool);
     mempool_exit(&cc->req_pool);
     mempool_exit(&cc->tag_pool);
 
     WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
     percpu_counter_destroy(&cc->n_allocated_pages);
 
     if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
         cc->iv_gen_ops->dtr(cc);
 
     if (cc->dev)
         dm_put_device(ti, cc->dev);
 
     kfree_sensitive(cc->cipher_string);
     kfree_sensitive(cc->key_string);
     kfree_sensitive(cc->cipher_auth);
     kfree_sensitive(cc->authenc_key);
 
     mutex_destroy(&cc->bio_alloc_lock);
 
     /* Must zero key material before freeing */
     kfree_sensitive(cc);
 
     spin_lock(&dm_crypt_clients_lock);
     WARN_ON(!dm_crypt_clients_n);
     dm_crypt_clients_n--;
     crypt_calculate_pages_per_client();
     spin_unlock(&dm_crypt_clients_lock);
 
     dm_audit_log_dtr(DM_MSG_PREFIX, ti, 1);
 }
 
 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
 {
     struct crypt_config *cc = ti->private;
 
     if (crypt_integrity_aead(cc))
         cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
     else
         cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
 
     if (cc->iv_size)
         /* at least a 64 bit sector number should fit in our buffer */
         cc->iv_size = max(cc->iv_size,
                   (unsigned int)(sizeof(u64) / sizeof(u8)));
     else if (ivmode) {
         DMWARN("Selected cipher does not support IVs");
         ivmode = NULL;
     }
 
     /* Choose ivmode, see comments at iv code. */
     if (ivmode == NULL)
         cc->iv_gen_ops = NULL;
     else if (strcmp(ivmode, "plain") == 0)
         cc->iv_gen_ops = &crypt_iv_plain_ops;
     else if (strcmp(ivmode, "plain64") == 0)
         cc->iv_gen_ops = &crypt_iv_plain64_ops;
     else if (strcmp(ivmode, "plain64be") == 0)
         cc->iv_gen_ops = &crypt_iv_plain64be_ops;
     else if (strcmp(ivmode, "essiv") == 0)
         cc->iv_gen_ops = &crypt_iv_essiv_ops;
     else if (strcmp(ivmode, "benbi") == 0)
         cc->iv_gen_ops = &crypt_iv_benbi_ops;
     else if (strcmp(ivmode, "null") == 0)
         cc->iv_gen_ops = &crypt_iv_null_ops;
     else if (strcmp(ivmode, "eboiv") == 0)
         cc->iv_gen_ops = &crypt_iv_eboiv_ops;
     else if (strcmp(ivmode, "elephant") == 0) {
         cc->iv_gen_ops = &crypt_iv_elephant_ops;
         cc->key_parts = 2;
         cc->key_extra_size = cc->key_size / 2;
         if (cc->key_extra_size > ELEPHANT_MAX_KEY_SIZE)
             return -EINVAL;
         set_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags);
     } else if (strcmp(ivmode, "lmk") == 0) {
         cc->iv_gen_ops = &crypt_iv_lmk_ops;
         /*
          * Version 2 and 3 is recognised according
          * to length of provided multi-key string.
          * If present (version 3), last key is used as IV seed.
          * All keys (including IV seed) are always the same size.
          */
         if (cc->key_size % cc->key_parts) {
             cc->key_parts++;
             cc->key_extra_size = cc->key_size / cc->key_parts;
         }
     } else if (strcmp(ivmode, "tcw") == 0) {
         cc->iv_gen_ops = &crypt_iv_tcw_ops;
         cc->key_parts += 2; /* IV + whitening */
         cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
     } else if (strcmp(ivmode, "random") == 0) {
         cc->iv_gen_ops = &crypt_iv_random_ops;
         /* Need storage space in integrity fields. */
         cc->integrity_iv_size = cc->iv_size;
     } else {
         ti->error = "Invalid IV mode";
         return -EINVAL;
     }
 
     return 0;
 }
 
 /*
  * Workaround to parse HMAC algorithm from AEAD crypto API spec.
  * The HMAC is needed to calculate tag size (HMAC digest size).
  * This should be probably done by crypto-api calls (once available...)
  */
 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
 {
     char *start, *end, *mac_alg = NULL;
     struct crypto_ahash *mac;
 
     if (!strstarts(cipher_api, "authenc("))
         return 0;
 
     start = strchr(cipher_api, '(');
     end = strchr(cipher_api, ',');
     if (!start || !end || ++start > end)
         return -EINVAL;
 
     mac_alg = kzalloc(end - start + 1, GFP_KERNEL);
     if (!mac_alg)
         return -ENOMEM;
     strncpy(mac_alg, start, end - start);
 
     mac = crypto_alloc_ahash(mac_alg, 0, CRYPTO_ALG_ALLOCATES_MEMORY);
     kfree(mac_alg);
 
     if (IS_ERR(mac))
         return PTR_ERR(mac);
 
     cc->key_mac_size = crypto_ahash_digestsize(mac);
     crypto_free_ahash(mac);
 
     cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
     if (!cc->authenc_key)
         return -ENOMEM;
 
     return 0;
 }
 
 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
                 char **ivmode, char **ivopts)
 {
     struct crypt_config *cc = ti->private;
     char *tmp, *cipher_api, buf[CRYPTO_MAX_ALG_NAME];
     int ret = -EINVAL;
 
     cc->tfms_count = 1;
 
     /*
      * New format (capi: prefix)
      * capi:cipher_api_spec-iv:ivopts
      */
     tmp = &cipher_in[strlen("capi:")];
 
     /* Separate IV options if present, it can contain another '-' in hash name */
     *ivopts = strrchr(tmp, ':');
     if (*ivopts) {
         **ivopts = '\0';
         (*ivopts)++;
     }
     /* Parse IV mode */
     *ivmode = strrchr(tmp, '-');
     if (*ivmode) {
         **ivmode = '\0';
         (*ivmode)++;
     }
     /* The rest is crypto API spec */
     cipher_api = tmp;
 
     /* Alloc AEAD, can be used only in new format. */
     if (crypt_integrity_aead(cc)) {
         ret = crypt_ctr_auth_cipher(cc, cipher_api);
         if (ret < 0) {
             ti->error = "Invalid AEAD cipher spec";
             return -ENOMEM;
         }
     }
 
     if (*ivmode && !strcmp(*ivmode, "lmk"))
         cc->tfms_count = 64;
 
     if (*ivmode && !strcmp(*ivmode, "essiv")) {
         if (!*ivopts) {
             ti->error = "Digest algorithm missing for ESSIV mode";
             return -EINVAL;
         }
         ret = snprintf(buf, CRYPTO_MAX_ALG_NAME, "essiv(%s,%s)",
                    cipher_api, *ivopts);
         if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
             ti->error = "Cannot allocate cipher string";
             return -ENOMEM;
         }
         cipher_api = buf;
     }
 
     cc->key_parts = cc->tfms_count;
 
     /* Allocate cipher */
     ret = crypt_alloc_tfms(cc, cipher_api);
     if (ret < 0) {
         ti->error = "Error allocating crypto tfm";
         return ret;
     }
 
     if (crypt_integrity_aead(cc))
         cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
     else
         cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
 
     return 0;
 }
 
 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
                 char **ivmode, char **ivopts)
 {
     struct crypt_config *cc = ti->private;
     char *tmp, *cipher, *chainmode, *keycount;
     char *cipher_api = NULL;
     int ret = -EINVAL;
     char dummy;
 
     if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
         ti->error = "Bad cipher specification";
         return -EINVAL;
     }
 
     /*
      * Legacy dm-crypt cipher specification
      * cipher[:keycount]-mode-iv:ivopts
      */
     tmp = cipher_in;
     keycount = strsep(&tmp, "-");
     cipher = strsep(&keycount, ":");
 
     if (!keycount)
         cc->tfms_count = 1;
     else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
          !is_power_of_2(cc->tfms_count)) {
         ti->error = "Bad cipher key count specification";
         return -EINVAL;
     }
     cc->key_parts = cc->tfms_count;
 
     chainmode = strsep(&tmp, "-");
     *ivmode = strsep(&tmp, ":");
     *ivopts = tmp;
 
     /*
      * For compatibility with the original dm-crypt mapping format, if
      * only the cipher name is supplied, use cbc-plain.
      */
     if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
         chainmode = "cbc";
         *ivmode = "plain";
     }
 
     if (strcmp(chainmode, "ecb") && !*ivmode) {
         ti->error = "IV mechanism required";
         return -EINVAL;
     }
 
     cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
     if (!cipher_api)
         goto bad_mem;
 
     if (*ivmode && !strcmp(*ivmode, "essiv")) {
         if (!*ivopts) {
             ti->error = "Digest algorithm missing for ESSIV mode";
             kfree(cipher_api);
             return -EINVAL;
         }
         ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
                    "essiv(%s(%s),%s)", chainmode, cipher, *ivopts);
     } else {
         ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
                    "%s(%s)", chainmode, cipher);
     }
     if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
         kfree(cipher_api);
         goto bad_mem;
     }
 
     /* Allocate cipher */
     ret = crypt_alloc_tfms(cc, cipher_api);
     if (ret < 0) {
         ti->error = "Error allocating crypto tfm";
         kfree(cipher_api);
         return ret;
     }
     kfree(cipher_api);
 
     return 0;
 bad_mem:
     ti->error = "Cannot allocate cipher strings";
     return -ENOMEM;
 }
 
 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
 {
     struct crypt_config *cc = ti->private;
     char *ivmode = NULL, *ivopts = NULL;
     int ret;
 
     cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
     if (!cc->cipher_string) {
         ti->error = "Cannot allocate cipher strings";
         return -ENOMEM;
     }
 
     if (strstarts(cipher_in, "capi:"))
         ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
     else
         ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
     if (ret)
         return ret;
 
     /* Initialize IV */
     ret = crypt_ctr_ivmode(ti, ivmode);
     if (ret < 0)
         return ret;
 
     /* Initialize and set key */
     ret = crypt_set_key(cc, key);
     if (ret < 0) {
         ti->error = "Error decoding and setting key";
         return ret;
     }
 
     /* Allocate IV */
     if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
         ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
         if (ret < 0) {
             ti->error = "Error creating IV";
             return ret;
         }
     }
 
     /* Initialize IV (set keys for ESSIV etc) */
     if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
         ret = cc->iv_gen_ops->init(cc);
         if (ret < 0) {
             ti->error = "Error initialising IV";
             return ret;
         }
     }
 
     /* wipe the kernel key payload copy */
     if (cc->key_string)
         memset(cc->key, 0, cc->key_size * sizeof(u8));
 
     return ret;
 }
 
 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
 {
     struct crypt_config *cc = ti->private;
     struct dm_arg_set as;
     static const struct dm_arg _args[] = {
         {0, 8, "Invalid number of feature args"},
     };
     unsigned int opt_params, val;
     const char *opt_string, *sval;
     char dummy;
     int ret;
 
     /* Optional parameters */
     as.argc = argc;
     as.argv = argv;
 
     ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
     if (ret)
         return ret;
 
     while (opt_params--) {
         opt_string = dm_shift_arg(&as);
         if (!opt_string) {
             ti->error = "Not enough feature arguments";
             return -EINVAL;
         }
 
         if (!strcasecmp(opt_string, "allow_discards"))
             ti->num_discard_bios = 1;
 
         else if (!strcasecmp(opt_string, "same_cpu_crypt"))
             set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
 
         else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
             set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
         else if (!strcasecmp(opt_string, "no_read_workqueue"))
             set_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
         else if (!strcasecmp(opt_string, "no_write_workqueue"))
             set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
         else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
             if (val == 0 || val > MAX_TAG_SIZE) {
                 ti->error = "Invalid integrity arguments";
                 return -EINVAL;
             }
             cc->on_disk_tag_size = val;
             sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
             if (!strcasecmp(sval, "aead")) {
                 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
             } else  if (strcasecmp(sval, "none")) {
                 ti->error = "Unknown integrity profile";
                 return -EINVAL;
             }
 
             cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
             if (!cc->cipher_auth)
                 return -ENOMEM;
         } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
             if (cc->sector_size < (1 << SECTOR_SHIFT) ||
                 cc->sector_size > 4096 ||
                 (cc->sector_size & (cc->sector_size - 1))) {
                 ti->error = "Invalid feature value for sector_size";
                 return -EINVAL;
             }
             if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) {
                 ti->error = "Device size is not multiple of sector_size feature";
                 return -EINVAL;
             }
             cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
         } else if (!strcasecmp(opt_string, "iv_large_sectors"))
             set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
         else {
             ti->error = "Invalid feature arguments";
             return -EINVAL;
         }
     }
 
     return 0;
 }
 
 #ifdef CONFIG_BLK_DEV_ZONED
 static int crypt_report_zones(struct dm_target *ti,
         struct dm_report_zones_args *args, unsigned int nr_zones)
 {
     struct crypt_config *cc = ti->private;
 
     return dm_report_zones(cc->dev->bdev, cc->start,
             cc->start + dm_target_offset(ti, args->next_sector),
             args, nr_zones);
 }
 #else
 #define crypt_report_zones NULL
 #endif
 
 /*
  * Construct an encryption mapping:
  * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
  */
 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 {
     struct crypt_config *cc;
     const char *devname = dm_table_device_name(ti->table);
     int key_size;
     unsigned int align_mask;
     unsigned long long tmpll;
     int ret;
     size_t iv_size_padding, additional_req_size;
     char dummy;
 
     if (argc < 5) {
         ti->error = "Not enough arguments";
         return -EINVAL;
     }
 
     key_size = get_key_size(&argv[1]);
     if (key_size < 0) {
         ti->error = "Cannot parse key size";
         return -EINVAL;
     }
 
     cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL);
     if (!cc) {
         ti->error = "Cannot allocate encryption context";
         return -ENOMEM;
     }
     cc->key_size = key_size;
     cc->sector_size = (1 << SECTOR_SHIFT);
     cc->sector_shift = 0;
 
     ti->private = cc;
 
     spin_lock(&dm_crypt_clients_lock);
     dm_crypt_clients_n++;
     crypt_calculate_pages_per_client();
     spin_unlock(&dm_crypt_clients_lock);
 
     ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL);
     if (ret < 0)
         goto bad;
 
     /* Optional parameters need to be read before cipher constructor */
     if (argc > 5) {
         ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
         if (ret)
             goto bad;
     }
 
     ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
     if (ret < 0)
         goto bad;
 
     if (crypt_integrity_aead(cc)) {
         cc->dmreq_start = sizeof(struct aead_request);
         cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
         align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
     } else {
         cc->dmreq_start = sizeof(struct skcipher_request);
         cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
         align_mask = crypto_skcipher_alignmask(any_tfm(cc));
     }
     cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
 
     if (align_mask < CRYPTO_MINALIGN) {
         /* Allocate the padding exactly */
         iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
                 & align_mask;
     } else {
         /*
          * If the cipher requires greater alignment than kmalloc
          * alignment, we don't know the exact position of the
          * initialization vector. We must assume worst case.
          */
         iv_size_padding = align_mask;
     }
 
     /*  ...| IV + padding | original IV | original sec. number | bio tag offset | */
     additional_req_size = sizeof(struct dm_crypt_request) +
         iv_size_padding + cc->iv_size +
         cc->iv_size +
         sizeof(uint64_t) +
         sizeof(unsigned int);
 
     ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size);
     if (ret) {
         ti->error = "Cannot allocate crypt request mempool";
         goto bad;
     }
 
     cc->per_bio_data_size = ti->per_io_data_size =
         ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
               ARCH_KMALLOC_MINALIGN);
 
     ret = mempool_init(&cc->page_pool, BIO_MAX_VECS, crypt_page_alloc, crypt_page_free, cc);
     if (ret) {
         ti->error = "Cannot allocate page mempool";
         goto bad;
     }
 
     ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS);
     if (ret) {
         ti->error = "Cannot allocate crypt bioset";
         goto bad;
     }
 
     mutex_init(&cc->bio_alloc_lock);
 
     ret = -EINVAL;
     if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
         (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
         ti->error = "Invalid iv_offset sector";
         goto bad;
     }
     cc->iv_offset = tmpll;
 
     ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
     if (ret) {
         ti->error = "Device lookup failed";
         goto bad;
     }
 
     ret = -EINVAL;
     if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
         ti->error = "Invalid device sector";
         goto bad;
     }
     cc->start = tmpll;
 
     if (bdev_is_zoned(cc->dev->bdev)) {
         /*
          * For zoned block devices, we need to preserve the issuer write
          * ordering. To do so, disable write workqueues and force inline
          * encryption completion.
          */
         set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
         set_bit(DM_CRYPT_WRITE_INLINE, &cc->flags);
 
         /*
          * All zone append writes to a zone of a zoned block device will
          * have the same BIO sector, the start of the zone. When the
          * cypher IV mode uses sector values, all data targeting a
          * zone will be encrypted using the first sector numbers of the
          * zone. This will not result in write errors but will
          * cause most reads to fail as reads will use the sector values
          * for the actual data locations, resulting in IV mismatch.
          * To avoid this problem, ask DM core to emulate zone append
          * operations with regular writes.
          */
         DMDEBUG("Zone append operations will be emulated");
         ti->emulate_zone_append = true;
     }
 
     if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
         ret = crypt_integrity_ctr(cc, ti);
         if (ret)
             goto bad;
 
         cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
         if (!cc->tag_pool_max_sectors)
             cc->tag_pool_max_sectors = 1;
 
         ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS,
             cc->tag_pool_max_sectors * cc->on_disk_tag_size);
         if (ret) {
             ti->error = "Cannot allocate integrity tags mempool";
             goto bad;
         }
 
         cc->tag_pool_max_sectors <<= cc->sector_shift;
     }
 
     ret = -ENOMEM;
     cc->io_queue = alloc_workqueue("kcryptd_io/%s", WQ_MEM_RECLAIM, 1, devname);
     if (!cc->io_queue) {
         ti->error = "Couldn't create kcryptd io queue";
         goto bad;
     }
 
     if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
         cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
                           1, devname);
     else
         cc->crypt_queue = alloc_workqueue("kcryptd/%s",
                           WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
                           num_online_cpus(), devname);
     if (!cc->crypt_queue) {
         ti->error = "Couldn't create kcryptd queue";
         goto bad;
     }
 
     spin_lock_init(&cc->write_thread_lock);
     cc->write_tree = RB_ROOT;
 
     cc->write_thread = kthread_run(dmcrypt_write, cc, "dmcrypt_write/%s", devname);
     if (IS_ERR(cc->write_thread)) {
         ret = PTR_ERR(cc->write_thread);
         cc->write_thread = NULL;
         ti->error = "Couldn't spawn write thread";
         goto bad;
     }
 
     ti->num_flush_bios = 1;
     ti->limit_swap_bios = true;
     ti->accounts_remapped_io = true;
 
     dm_audit_log_ctr(DM_MSG_PREFIX, ti, 1);
     return 0;
 
 bad:
     dm_audit_log_ctr(DM_MSG_PREFIX, ti, 0);
     crypt_dtr(ti);
     return ret;
 }
 
 static int crypt_map(struct dm_target *ti, struct bio *bio)
 {
     struct dm_crypt_io *io;
     struct crypt_config *cc = ti->private;
 
     /*
      * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
      * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
      * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
      */
     if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
         bio_op(bio) == REQ_OP_DISCARD)) {
         bio_set_dev(bio, cc->dev->bdev);
         if (bio_sectors(bio))
             bio->bi_iter.bi_sector = cc->start +
                 dm_target_offset(ti, bio->bi_iter.bi_sector);
         return DM_MAPIO_REMAPPED;
     }
 
     /*
      * Check if bio is too large, split as needed.
      */
     if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_VECS << PAGE_SHIFT)) &&
         (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size))
         dm_accept_partial_bio(bio, ((BIO_MAX_VECS << PAGE_SHIFT) >> SECTOR_SHIFT));
 
     /*
      * Ensure that bio is a multiple of internal sector encryption size
      * and is aligned to this size as defined in IO hints.
      */
     if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
         return DM_MAPIO_KILL;
 
     if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
         return DM_MAPIO_KILL;
 
     io = dm_per_bio_data(bio, cc->per_bio_data_size);
     crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
 
     if (cc->on_disk_tag_size) {
         unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
 
         if (unlikely(tag_len > KMALLOC_MAX_SIZE) ||
             unlikely(!(io->integrity_metadata = kmalloc(tag_len,
                 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) {
             if (bio_sectors(bio) > cc->tag_pool_max_sectors)
                 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
             io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO);
             io->integrity_metadata_from_pool = true;
         }
     }
 
     if (crypt_integrity_aead(cc))
         io->ctx.r.req_aead = (struct aead_request *)(io + 1);
     else
         io->ctx.r.req = (struct skcipher_request *)(io + 1);
 
     if (bio_data_dir(io->base_bio) == READ) {
         if (kcryptd_io_read(io, CRYPT_MAP_READ_GFP))
             kcryptd_queue_read(io);
     } else
         kcryptd_queue_crypt(io);
 
     return DM_MAPIO_SUBMITTED;
 }
 
 static char hex2asc(unsigned char c)
 {
     return c + '0' + ((unsigned)(9 - c) >> 4 & 0x27);
 }
 
 static void crypt_status(struct dm_target *ti, status_type_t type,
              unsigned status_flags, char *result, unsigned maxlen)
 {
     struct crypt_config *cc = ti->private;
     unsigned i, sz = 0;
     int num_feature_args = 0;
 
     switch (type) {
     case STATUSTYPE_INFO:
         result[0] = '\0';
         break;
 
     case STATUSTYPE_TABLE:
         DMEMIT("%s ", cc->cipher_string);
 
         if (cc->key_size > 0) {
             if (cc->key_string)
                 DMEMIT(":%u:%s", cc->key_size, cc->key_string);
             else {
                 for (i = 0; i < cc->key_size; i++) {
                     DMEMIT("%c%c", hex2asc(cc->key[i] >> 4),
                            hex2asc(cc->key[i] & 0xf));
                 }
             }
         } else
             DMEMIT("-");
 
         DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
                 cc->dev->name, (unsigned long long)cc->start);
 
         num_feature_args += !!ti->num_discard_bios;
         num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
         num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
         num_feature_args += test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
         num_feature_args += test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
         num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
         num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
         if (cc->on_disk_tag_size)
             num_feature_args++;
         if (num_feature_args) {
             DMEMIT(" %d", num_feature_args);
             if (ti->num_discard_bios)
                 DMEMIT(" allow_discards");
             if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
                 DMEMIT(" same_cpu_crypt");
             if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
                 DMEMIT(" submit_from_crypt_cpus");
             if (test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags))
                 DMEMIT(" no_read_workqueue");
             if (test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))
                 DMEMIT(" no_write_workqueue");
             if (cc->on_disk_tag_size)
                 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
             if (cc->sector_size != (1 << SECTOR_SHIFT))
                 DMEMIT(" sector_size:%d", cc->sector_size);
             if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
                 DMEMIT(" iv_large_sectors");
         }
         break;
 
     case STATUSTYPE_IMA:
         DMEMIT_TARGET_NAME_VERSION(ti->type);
         DMEMIT(",allow_discards=%c", ti->num_discard_bios ? 'y' : 'n');
         DMEMIT(",same_cpu_crypt=%c", test_bit(DM_CRYPT_SAME_CPU, &cc->flags) ? 'y' : 'n');
         DMEMIT(",submit_from_crypt_cpus=%c", test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags) ?
                'y' : 'n');
         DMEMIT(",no_read_workqueue=%c", test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags) ?
                'y' : 'n');
         DMEMIT(",no_write_workqueue=%c", test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags) ?
                'y' : 'n');
         DMEMIT(",iv_large_sectors=%c", test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags) ?
                'y' : 'n');
 
         if (cc->on_disk_tag_size)
             DMEMIT(",integrity_tag_size=%u,cipher_auth=%s",
                    cc->on_disk_tag_size, cc->cipher_auth);
         if (cc->sector_size != (1 << SECTOR_SHIFT))
             DMEMIT(",sector_size=%d", cc->sector_size);
         if (cc->cipher_string)
             DMEMIT(",cipher_string=%s", cc->cipher_string);
 
         DMEMIT(",key_size=%u", cc->key_size);
         DMEMIT(",key_parts=%u", cc->key_parts);
         DMEMIT(",key_extra_size=%u", cc->key_extra_size);
         DMEMIT(",key_mac_size=%u", cc->key_mac_size);
         DMEMIT(";");
         break;
     }
 }
 
 static void crypt_postsuspend(struct dm_target *ti)
 {
     struct crypt_config *cc = ti->private;
 
     set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
 }
 
 static int crypt_preresume(struct dm_target *ti)
 {
     struct crypt_config *cc = ti->private;
 
     if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
         DMERR("aborting resume - crypt key is not set.");
         return -EAGAIN;
     }
 
     return 0;
 }
 
 static void crypt_resume(struct dm_target *ti)
 {
     struct crypt_config *cc = ti->private;
 
     clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
 }
 
 /* Message interface
  *  key set <key>
  *  key wipe
  */
 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv,
              char *result, unsigned maxlen)
 {
     struct crypt_config *cc = ti->private;
     int key_size, ret = -EINVAL;
 
     if (argc < 2)
         goto error;
 
     if (!strcasecmp(argv[0], "key")) {
         if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
             DMWARN("not suspended during key manipulation.");
             return -EINVAL;
         }
         if (argc == 3 && !strcasecmp(argv[1], "set")) {
             /* The key size may not be changed. */
             key_size = get_key_size(&argv[2]);
             if (key_size < 0 || cc->key_size != key_size) {
                 memset(argv[2], '0', strlen(argv[2]));
                 return -EINVAL;
             }
 
             ret = crypt_set_key(cc, argv[2]);
             if (ret)
                 return ret;
             if (cc->iv_gen_ops && cc->iv_gen_ops->init)
                 ret = cc->iv_gen_ops->init(cc);
             /* wipe the kernel key payload copy */
             if (cc->key_string)
                 memset(cc->key, 0, cc->key_size * sizeof(u8));
             return ret;
         }
         if (argc == 2 && !strcasecmp(argv[1], "wipe"))
             return crypt_wipe_key(cc);
     }
 
 error:
     DMWARN("unrecognised message received.");
     return -EINVAL;
 }
 
 static int crypt_iterate_devices(struct dm_target *ti,
                  iterate_devices_callout_fn fn, void *data)
 {
     struct crypt_config *cc = ti->private;
 
     return fn(ti, cc->dev, cc->start, ti->len, data);
 }
 
 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
 {
     struct crypt_config *cc = ti->private;
 
     /*
      * Unfortunate constraint that is required to avoid the potential
      * for exceeding underlying device's max_segments limits -- due to
      * crypt_alloc_buffer() possibly allocating pages for the encryption
      * bio that are not as physically contiguous as the original bio.
      */
     limits->max_segment_size = PAGE_SIZE;
 
     limits->logical_block_size =
         max_t(unsigned, limits->logical_block_size, cc->sector_size);
     limits->physical_block_size =
         max_t(unsigned, limits->physical_block_size, cc->sector_size);
     limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size);
 }
 
 static struct target_type crypt_target = {
     .name   = "crypt",
     .version = {1, 24, 0},
     .module = THIS_MODULE,
     .ctr    = crypt_ctr,
     .dtr    = crypt_dtr,
     .features = DM_TARGET_ZONED_HM,
     .report_zones = crypt_report_zones,
     .map    = crypt_map,
     .status = crypt_status,
     .postsuspend = crypt_postsuspend,
     .preresume = crypt_preresume,
     .resume = crypt_resume,
     .message = crypt_message,
     .iterate_devices = crypt_iterate_devices,
     .io_hints = crypt_io_hints,
 };
 
 static int __init dm_crypt_init(void)
 {
     int r;
 
     r = dm_register_target(&crypt_target);
     if (r < 0)
         DMERR("register failed %d", r);
 
     return r;
 }
 
 static void __exit dm_crypt_exit(void)
 {
     dm_unregister_target(&crypt_target);
 }
 
 module_init(dm_crypt_init);
 module_exit(dm_crypt_exit);
 
 MODULE_AUTHOR("Jana Saout <jana@saout.de>");
 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
 MODULE_LICENSE("GPL");