From 7a0263dc904f3467f474e4088ae092eda9a5a99b Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sun, 24 Sep 2023 22:54:50 -0700 Subject: fscrypt: replace get_ino_and_lblk_bits with just has_32bit_inodes Now that fs/crypto/ computes the filesystem's lblk_bits from its maximum file size, it is no longer necessary for filesystems to provide lblk_bits via fscrypt_operations::get_ino_and_lblk_bits. It is still necessary for fs/crypto/ to retrieve ino_bits from the filesystem. However, this is used only to decide whether inode numbers fit in 32 bits. Also, ino_bits is static for all relevant filesystems, i.e. it doesn't depend on the filesystem instance. Therefore, in the interest of keeping things as simple as possible, replace 'get_ino_and_lblk_bits' with a flag 'has_32bit_inodes'. This can always be changed back to a function if a filesystem needs it to be dynamic, but for now a static flag is all that's needed. Link: https://lore.kernel.org/r/20230925055451.59499-5-ebiggers@kernel.org Signed-off-by: Eric Biggers --- include/linux/fscrypt.h | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-) (limited to 'include/linux') 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 -- cgit v1.2.3