diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index 7b34949e49de..32709dad9762 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -118,11 +118,11 @@ static bool supported_direct_key_modes(const struct inode *inode, } static bool supported_iv_ino_lblk_policy(const struct fscrypt_policy_v2 *policy, - const struct inode *inode, - const char *type, int max_ino_bits) + const struct inode *inode) { + const char *type = (policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) + ? "IV_INO_LBLK_64" : "IV_INO_LBLK_32"; struct super_block *sb = inode->i_sb; - int ino_bits = 64, lblk_bits = 64; /* * IV_INO_LBLK_* exist only because of hardware limitations, and @@ -149,9 +149,15 @@ static bool supported_iv_ino_lblk_policy(const struct fscrypt_policy_v2 *policy, type, sb->s_id); return false; } - if (sb->s_cop->get_ino_and_lblk_bits) - sb->s_cop->get_ino_and_lblk_bits(sb, &ino_bits, &lblk_bits); - if (ino_bits > max_ino_bits) { + + /* + * IV_INO_LBLK_64 and IV_INO_LBLK_32 both require that inode numbers fit + * in 32 bits. In principle, IV_INO_LBLK_32 could support longer inode + * numbers because it hashes the inode number; however, currently the + * inode number is gotten from inode::i_ino which is 'unsigned long'. + * So for now the implementation limit is 32 bits. + */ + if (!sb->s_cop->has_32bit_inodes) { fscrypt_warn(inode, "Can't use %s policy on filesystem '%s' because its inode numbers are too long", type, sb->s_id); @@ -242,18 +248,9 @@ static bool fscrypt_supported_v2_policy(const struct fscrypt_policy_v2 *policy, policy->filenames_encryption_mode)) return false; - if ((policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) && - !supported_iv_ino_lblk_policy(policy, inode, "IV_INO_LBLK_64", 32)) - return false; - - /* - * IV_INO_LBLK_32 hashes the inode number, so in principle it can - * support any ino_bits. However, currently the inode number is gotten - * from inode::i_ino which is 'unsigned long'. So for now the - * implementation limit is 32 bits. - */ - if ((policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32) && - !supported_iv_ino_lblk_policy(policy, inode, "IV_INO_LBLK_32", 32)) + if ((policy->flags & (FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 | + FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) && + !supported_iv_ino_lblk_policy(policy, inode)) return false; if (memchr_inv(policy->__reserved, 0, sizeof(policy->__reserved))) { diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 5cd7bcfae46b..9e36731701ba 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -232,20 +232,13 @@ static bool ext4_has_stable_inodes(struct super_block *sb) return ext4_has_feature_stable_inodes(sb); } -static void ext4_get_ino_and_lblk_bits(struct super_block *sb, - int *ino_bits_ret, int *lblk_bits_ret) -{ - *ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count); - *lblk_bits_ret = 8 * sizeof(ext4_lblk_t); -} - const struct fscrypt_operations ext4_cryptops = { .needs_bounce_pages = 1, + .has_32bit_inodes = 1, .legacy_key_prefix = "ext4:", .get_context = ext4_get_context, .set_context = ext4_set_context, .get_dummy_policy = ext4_get_dummy_policy, .empty_dir = ext4_empty_dir, .has_stable_inodes = ext4_has_stable_inodes, - .get_ino_and_lblk_bits = ext4_get_ino_and_lblk_bits, }; diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 55aa0ed531f2..c44915713264 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -3203,13 +3203,6 @@ static bool f2fs_has_stable_inodes(struct super_block *sb) return true; } -static void f2fs_get_ino_and_lblk_bits(struct super_block *sb, - int *ino_bits_ret, int *lblk_bits_ret) -{ - *ino_bits_ret = 8 * sizeof(nid_t); - *lblk_bits_ret = 8 * sizeof(block_t); -} - static struct block_device **f2fs_get_devices(struct super_block *sb, unsigned int *num_devs) { @@ -3232,13 +3225,13 @@ static struct block_device **f2fs_get_devices(struct super_block *sb, static const struct fscrypt_operations f2fs_cryptops = { .needs_bounce_pages = 1, + .has_32bit_inodes = 1, .legacy_key_prefix = "f2fs:", .get_context = f2fs_get_context, .set_context = f2fs_set_context, .get_dummy_policy = f2fs_get_dummy_policy, .empty_dir = f2fs_empty_dir, .has_stable_inodes = f2fs_has_stable_inodes, - .get_ino_and_lblk_bits = f2fs_get_ino_and_lblk_bits, .get_devices = f2fs_get_devices, }; #endif diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index 4505078e89b7..09a3cacbf62a 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -74,6 +74,17 @@ struct fscrypt_operations { */ unsigned int needs_bounce_pages : 1; + /* + * If set, then fs/crypto/ will allow the use of encryption settings + * that assume inode numbers fit in 32 bits (i.e. + * FSCRYPT_POLICY_FLAG_IV_INO_LBLK_{32,64}), provided that the other + * prerequisites for these settings are also met. This is only useful + * if the filesystem wants to support inline encryption hardware that is + * limited to 32-bit or 64-bit data unit numbers and where programming + * keyslots is very slow. + */ + unsigned int has_32bit_inodes : 1; + /* * This field exists only for backwards compatibility reasons and should * only be set by the filesystems that are setting it already. It @@ -151,21 +162,6 @@ struct fscrypt_operations { */ bool (*has_stable_inodes)(struct super_block *sb); - /* - * Get the number of bits that the filesystem uses to represent inode - * numbers and file logical block numbers. - * - * By default, both of these are assumed to be 64-bit. This function - * can be implemented to declare that either or both of these numbers is - * shorter, which may allow the use of the - * FSCRYPT_POLICY_FLAG_IV_INO_LBLK_{32,64} flags and/or the use of - * inline crypto hardware whose maximum DUN length is less than 64 bits - * (e.g., eMMC v5.2 spec compliant hardware). This function only needs - * to be implemented if support for one of these features is needed. - */ - void (*get_ino_and_lblk_bits)(struct super_block *sb, - int *ino_bits_ret, int *lblk_bits_ret); - /* * Return an array of pointers to the block devices to which the * filesystem may write encrypted file contents, NULL if the filesystem