^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Inline encryption support for fscrypt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright 2019 Google LLC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * With "inline encryption", the block layer handles the decryption/encryption
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * as part of the bio, instead of the filesystem doing the crypto itself via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * crypto API. See Documentation/block/inline-encryption.rst. fscrypt still
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * provides the key and IV to use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/blk-crypto.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/blkdev.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/buffer_head.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/keyslot-manager.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/sched/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/uio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include "fscrypt_private.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) struct fscrypt_blk_crypto_key {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) struct blk_crypto_key base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) int num_devs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) struct request_queue *devs[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) static int fscrypt_get_num_devices(struct super_block *sb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) if (sb->s_cop->get_num_devices)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) return sb->s_cop->get_num_devices(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) static void fscrypt_get_devices(struct super_block *sb, int num_devs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) struct request_queue **devs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) if (num_devs == 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) devs[0] = bdev_get_queue(sb->s_bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) sb->s_cop->get_devices(sb, devs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) static unsigned int fscrypt_get_dun_bytes(const struct fscrypt_info *ci)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) struct super_block *sb = ci->ci_inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) unsigned int flags = fscrypt_policy_flags(&ci->ci_policy);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) int ino_bits = 64, lblk_bits = 64;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) if (flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) return offsetofend(union fscrypt_iv, nonce);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) if (flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) return sizeof(__le64);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) if (flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) return sizeof(__le32);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) /* Default case: IVs are just the file logical block number */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) if (sb->s_cop->get_ino_and_lblk_bits)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) sb->s_cop->get_ino_and_lblk_bits(sb, &ino_bits, &lblk_bits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) return DIV_ROUND_UP(lblk_bits, 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) /* Enable inline encryption for this file if supported. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) int fscrypt_select_encryption_impl(struct fscrypt_info *ci,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) bool is_hw_wrapped_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) const struct inode *inode = ci->ci_inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) struct super_block *sb = inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) struct blk_crypto_config crypto_cfg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) int num_devs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) struct request_queue **devs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) /* The file must need contents encryption, not filenames encryption */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (!S_ISREG(inode->i_mode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) /* The crypto mode must have a blk-crypto counterpart */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) if (ci->ci_mode->blk_crypto_mode == BLK_ENCRYPTION_MODE_INVALID)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) /* The filesystem must be mounted with -o inlinecrypt */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) if (!(sb->s_flags & SB_INLINECRYPT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) * When a page contains multiple logically contiguous filesystem blocks,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) * some filesystem code only calls fscrypt_mergeable_bio() for the first
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) * block in the page. This is fine for most of fscrypt's IV generation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) * strategies, where contiguous blocks imply contiguous IVs. But it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) * doesn't work with IV_INO_LBLK_32. For now, simply exclude
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * IV_INO_LBLK_32 with blocksize != PAGE_SIZE from inline encryption.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) if ((fscrypt_policy_flags(&ci->ci_policy) &
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) sb->s_blocksize != PAGE_SIZE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) * On all the filesystem's devices, blk-crypto must support the crypto
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) * configuration that the file would use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) crypto_cfg.crypto_mode = ci->ci_mode->blk_crypto_mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) crypto_cfg.data_unit_size = sb->s_blocksize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) crypto_cfg.dun_bytes = fscrypt_get_dun_bytes(ci);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) crypto_cfg.is_hw_wrapped = is_hw_wrapped_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) num_devs = fscrypt_get_num_devices(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) devs = kmalloc_array(num_devs, sizeof(*devs), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) if (!devs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) fscrypt_get_devices(sb, num_devs, devs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) for (i = 0; i < num_devs; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) if (!blk_crypto_config_supported(devs[i], &crypto_cfg))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) goto out_free_devs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) ci->ci_inlinecrypt = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) out_free_devs:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) kfree(devs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) const u8 *raw_key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) unsigned int raw_key_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) bool is_hw_wrapped,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) const struct fscrypt_info *ci)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) const struct inode *inode = ci->ci_inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) struct super_block *sb = inode->i_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) enum blk_crypto_mode_num crypto_mode = ci->ci_mode->blk_crypto_mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) int num_devs = fscrypt_get_num_devices(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) int queue_refs = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) struct fscrypt_blk_crypto_key *blk_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) blk_key = kzalloc(struct_size(blk_key, devs, num_devs), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) if (!blk_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) blk_key->num_devs = num_devs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) fscrypt_get_devices(sb, num_devs, blk_key->devs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) BUILD_BUG_ON(FSCRYPT_MAX_HW_WRAPPED_KEY_SIZE >
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) BLK_CRYPTO_MAX_WRAPPED_KEY_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) err = blk_crypto_init_key(&blk_key->base, raw_key, raw_key_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) is_hw_wrapped, crypto_mode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) fscrypt_get_dun_bytes(ci), sb->s_blocksize);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) fscrypt_err(inode, "error %d initializing blk-crypto key", err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) * We have to start using blk-crypto on all the filesystem's devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) * We also have to save all the request_queue's for later so that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) * key can be evicted from them. This is needed because some keys
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) * aren't destroyed until after the filesystem was already unmounted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * (namely, the per-mode keys in struct fscrypt_master_key).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) for (i = 0; i < num_devs; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) if (!blk_get_queue(blk_key->devs[i])) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) fscrypt_err(inode, "couldn't get request_queue");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) err = -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) queue_refs++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) err = blk_crypto_start_using_key(&blk_key->base,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) blk_key->devs[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) fscrypt_err(inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) "error %d starting to use blk-crypto", err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) * Pairs with the smp_load_acquire() in fscrypt_is_key_prepared().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) * I.e., here we publish ->blk_key with a RELEASE barrier so that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) * concurrent tasks can ACQUIRE it. Note that this concurrency is only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) * possible for per-mode keys, not for per-file keys.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) smp_store_release(&prep_key->blk_key, blk_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) for (i = 0; i < queue_refs; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) blk_put_queue(blk_key->devs[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) kfree_sensitive(blk_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) void fscrypt_destroy_inline_crypt_key(struct fscrypt_prepared_key *prep_key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) struct fscrypt_blk_crypto_key *blk_key = prep_key->blk_key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) if (blk_key) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) for (i = 0; i < blk_key->num_devs; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) blk_crypto_evict_key(blk_key->devs[i], &blk_key->base);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) blk_put_queue(blk_key->devs[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) kfree_sensitive(blk_key);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) int fscrypt_derive_raw_secret(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) const u8 *wrapped_key,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) unsigned int wrapped_key_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) u8 *raw_secret, unsigned int raw_secret_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) struct request_queue *q;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) q = bdev_get_queue(sb->s_bdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) if (!q->ksm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) return -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) return blk_ksm_derive_raw_secret(q->ksm, wrapped_key, wrapped_key_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) raw_secret, raw_secret_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) bool __fscrypt_inode_uses_inline_crypto(const struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) return inode->i_crypt_info->ci_inlinecrypt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) EXPORT_SYMBOL_GPL(__fscrypt_inode_uses_inline_crypto);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) static void fscrypt_generate_dun(const struct fscrypt_info *ci, u64 lblk_num,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) union fscrypt_iv iv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) fscrypt_generate_iv(&iv, lblk_num, ci);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) BUILD_BUG_ON(FSCRYPT_MAX_IV_SIZE > BLK_CRYPTO_MAX_IV_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) memset(dun, 0, BLK_CRYPTO_MAX_IV_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) for (i = 0; i < ci->ci_mode->ivsize/sizeof(dun[0]); i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) dun[i] = le64_to_cpu(iv.dun[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) * fscrypt_set_bio_crypt_ctx() - prepare a file contents bio for inline crypto
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) * @bio: a bio which will eventually be submitted to the file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) * @inode: the file's inode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) * @first_lblk: the first file logical block number in the I/O
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) * @gfp_mask: memory allocation flags - these must be a waiting mask so that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) * bio_crypt_set_ctx can't fail.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) * If the contents of the file should be encrypted (or decrypted) with inline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) * encryption, then assign the appropriate encryption context to the bio.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) * Normally the bio should be newly allocated (i.e. no pages added yet), as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) * otherwise fscrypt_mergeable_bio() won't work as intended.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) * The encryption context will be freed automatically when the bio is freed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) * This function also handles setting bi_skip_dm_default_key when needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) void fscrypt_set_bio_crypt_ctx(struct bio *bio, const struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) u64 first_lblk, gfp_t gfp_mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) const struct fscrypt_info *ci;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) if (fscrypt_inode_should_skip_dm_default_key(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) bio_set_skip_dm_default_key(bio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) if (!fscrypt_inode_uses_inline_crypto(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) ci = inode->i_crypt_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) fscrypt_generate_dun(ci, first_lblk, dun);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) bio_crypt_set_ctx(bio, &ci->ci_enc_key.blk_key->base, dun, gfp_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) /* Extract the inode and logical block number from a buffer_head. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) static bool bh_get_inode_and_lblk_num(const struct buffer_head *bh,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) const struct inode **inode_ret,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) u64 *lblk_num_ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) struct page *page = bh->b_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) const struct address_space *mapping;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) const struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) * The ext4 journal (jbd2) can submit a buffer_head it directly created
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) * for a non-pagecache page. fscrypt doesn't care about these.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) mapping = page_mapping(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) if (!mapping)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) inode = mapping->host;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) *inode_ret = inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) *lblk_num_ret = ((u64)page->index << (PAGE_SHIFT - inode->i_blkbits)) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) (bh_offset(bh) >> inode->i_blkbits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) * fscrypt_set_bio_crypt_ctx_bh() - prepare a file contents bio for inline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) * crypto
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) * @bio: a bio which will eventually be submitted to the file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) * @first_bh: the first buffer_head for which I/O will be submitted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) * @gfp_mask: memory allocation flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) * Same as fscrypt_set_bio_crypt_ctx(), except this takes a buffer_head instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) * of an inode and block number directly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) void fscrypt_set_bio_crypt_ctx_bh(struct bio *bio,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) const struct buffer_head *first_bh,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) gfp_t gfp_mask)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) const struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) u64 first_lblk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) if (bh_get_inode_and_lblk_num(first_bh, &inode, &first_lblk))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) fscrypt_set_bio_crypt_ctx(bio, inode, first_lblk, gfp_mask);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx_bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) * fscrypt_mergeable_bio() - test whether data can be added to a bio
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) * @bio: the bio being built up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) * @inode: the inode for the next part of the I/O
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) * @next_lblk: the next file logical block number in the I/O
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) * When building a bio which may contain data which should undergo inline
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) * encryption (or decryption) via fscrypt, filesystems should call this function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) * to ensure that the resulting bio contains only contiguous data unit numbers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) * This will return false if the next part of the I/O cannot be merged with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) * bio because either the encryption key would be different or the encryption
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) * data unit numbers would be discontiguous.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) * fscrypt_set_bio_crypt_ctx() must have already been called on the bio.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) * This function also returns false if the next part of the I/O would need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) * have a different value for the bi_skip_dm_default_key flag.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) * Return: true iff the I/O is mergeable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) u64 next_lblk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) const struct bio_crypt_ctx *bc = bio->bi_crypt_context;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) if (!!bc != fscrypt_inode_uses_inline_crypto(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) if (bio_should_skip_dm_default_key(bio) !=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) fscrypt_inode_should_skip_dm_default_key(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) if (!bc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) * Comparing the key pointers is good enough, as all I/O for each key
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) * uses the same pointer. I.e., there's currently no need to support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) * merging requests where the keys are the same but the pointers differ.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) if (bc->bc_key != &inode->i_crypt_info->ci_enc_key.blk_key->base)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) fscrypt_generate_dun(inode->i_crypt_info, next_lblk, next_dun);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) return bio_crypt_dun_is_contiguous(bc, bio->bi_iter.bi_size, next_dun);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) EXPORT_SYMBOL_GPL(fscrypt_mergeable_bio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) * fscrypt_mergeable_bio_bh() - test whether data can be added to a bio
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) * @bio: the bio being built up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) * @next_bh: the next buffer_head for which I/O will be submitted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) * Same as fscrypt_mergeable_bio(), except this takes a buffer_head instead of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) * an inode and block number directly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) * Return: true iff the I/O is mergeable
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) bool fscrypt_mergeable_bio_bh(struct bio *bio,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) const struct buffer_head *next_bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) const struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) u64 next_lblk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) if (!bh_get_inode_and_lblk_num(next_bh, &inode, &next_lblk))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) return !bio->bi_crypt_context &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) !bio_should_skip_dm_default_key(bio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) return fscrypt_mergeable_bio(bio, inode, next_lblk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) EXPORT_SYMBOL_GPL(fscrypt_mergeable_bio_bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) * fscrypt_dio_supported() - check whether a direct I/O request is unsupported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) * due to encryption constraints
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) * @iocb: the file and position the I/O is targeting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) * @iter: the I/O data segment(s)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) * Return: true if direct I/O is supported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) bool fscrypt_dio_supported(struct kiocb *iocb, struct iov_iter *iter)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) const struct inode *inode = file_inode(iocb->ki_filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) const unsigned int blocksize = i_blocksize(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) /* If the file is unencrypted, no veto from us. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) if (!fscrypt_needs_contents_encryption(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) /* We only support direct I/O with inline crypto, not fs-layer crypto */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) if (!fscrypt_inode_uses_inline_crypto(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) * Since the granularity of encryption is filesystem blocks, the I/O
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) * must be block aligned -- not just disk sector aligned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) if (!IS_ALIGNED(iocb->ki_pos | iov_iter_alignment(iter), blocksize))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) return false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) EXPORT_SYMBOL_GPL(fscrypt_dio_supported);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) * fscrypt_limit_io_blocks() - limit I/O blocks to avoid discontiguous DUNs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) * @inode: the file on which I/O is being done
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) * @lblk: the block at which the I/O is being started from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) * @nr_blocks: the number of blocks we want to submit starting at @pos
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) * Determine the limit to the number of blocks that can be submitted in the bio
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) * targeting @pos without causing a data unit number (DUN) discontinuity.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) * This is normally just @nr_blocks, as normally the DUNs just increment along
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) * with the logical blocks. (Or the file is not encrypted.)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) * In rare cases, fscrypt can be using an IV generation method that allows the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) * DUN to wrap around within logically continuous blocks, and that wraparound
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) * will occur. If this happens, a value less than @nr_blocks will be returned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) * so that the wraparound doesn't occur in the middle of the bio.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) * Return: the actual number of blocks that can be submitted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) u64 fscrypt_limit_io_blocks(const struct inode *inode, u64 lblk, u64 nr_blocks)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) const struct fscrypt_info *ci = inode->i_crypt_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) u32 dun;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) if (!fscrypt_inode_uses_inline_crypto(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) return nr_blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) if (nr_blocks <= 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) return nr_blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) if (!(fscrypt_policy_flags(&ci->ci_policy) &
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) return nr_blocks;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) /* With IV_INO_LBLK_32, the DUN can wrap around from U32_MAX to 0. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) dun = ci->ci_hashed_ino + lblk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) return min_t(u64, nr_blocks, (u64)U32_MAX + 1 - dun);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) EXPORT_SYMBOL_GPL(fscrypt_limit_io_blocks);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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