Hi Chandan,
On Mon, Nov 19, 2018 at 10:53:20AM +0530, Chandan Rajendra wrote:
> In order to have a common code base for fscrypt "post read" processing
> for all filesystems which support encryption, this commit removes
> filesystem specific build config option (e.g. CONFIG_EXT4_FS_ENCRYPTION)
> and replaces it with a build option (i.e. CONFIG_FS_ENCRYPTION) whose
> value affects all the filesystems making use of fscrypt.
>
> Signed-off-by: Chandan Rajendra <chandan@xxxxxxxxxxxxxxxxxx>
Can you grep for EXT4_ENCRYPTION? There are still some references left, one in
Documentation/filesystems/fscrypt.rst and some in defconfig files.
Also in include/linux/fs.h, there are tests of
#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
which after this change should be
#ifdef CONFIG_FS_ENCRYPTION
like is done elsewhere.
Thanks,
- Eric
> ---
> fs/crypto/Kconfig | 2 +-
> fs/ext4/Kconfig | 15 --
> fs/ext4/dir.c | 2 -
> fs/ext4/ext4.h | 7 +-
> fs/ext4/inode.c | 8 +-
> fs/ext4/ioctl.c | 4 +-
> fs/ext4/namei.c | 10 +-
> fs/ext4/page-io.c | 6 +-
> fs/ext4/readpage.c | 2 +-
> fs/ext4/super.c | 6 +-
> fs/ext4/sysfs.c | 4 +-
> fs/f2fs/Kconfig | 11 -
> fs/f2fs/f2fs.h | 7 +-
> fs/f2fs/super.c | 8 +-
> fs/f2fs/sysfs.c | 4 +-
> include/linux/fscrypt.h | 416 +++++++++++++++++++++++++++++++-
> include/linux/fscrypt_notsupp.h | 231 ------------------
> include/linux/fscrypt_supp.h | 204 ----------------
> 18 files changed, 441 insertions(+), 506 deletions(-)
> delete mode 100644 include/linux/fscrypt_notsupp.h
> delete mode 100644 include/linux/fscrypt_supp.h
>
> diff --git a/fs/crypto/Kconfig b/fs/crypto/Kconfig
> index 02b7d91c9231..6e9ae566a8fc 100644
> --- a/fs/crypto/Kconfig
> +++ b/fs/crypto/Kconfig
> @@ -1,5 +1,5 @@
> config FS_ENCRYPTION
> - tristate "FS Encryption (Per-file encryption)"
> + bool "FS Encryption (Per-file encryption)"
> select CRYPTO
> select CRYPTO_AES
> select CRYPTO_CBC
> diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig
> index 5a76125ac0f8..e1002bbf35bf 100644
> --- a/fs/ext4/Kconfig
> +++ b/fs/ext4/Kconfig
> @@ -96,21 +96,6 @@ config EXT4_FS_SECURITY
> If you are not using a security module that requires using
> extended attributes for file security labels, say N.
>
> -config EXT4_ENCRYPTION
> - bool "Ext4 Encryption"
> - depends on EXT4_FS
> - select FS_ENCRYPTION
> - help
> - Enable encryption of ext4 files and directories. This
> - feature is similar to ecryptfs, but it is more memory
> - efficient since it avoids caching the encrypted and
> - decrypted pages in the page cache.
> -
> -config EXT4_FS_ENCRYPTION
> - bool
> - default y
> - depends on EXT4_ENCRYPTION
> -
> config EXT4_FS_VERITY
> bool "Ext4 Verity"
> depends on EXT4_FS
> diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
> index fb7a64ea5679..0ccd51f72048 100644
> --- a/fs/ext4/dir.c
> +++ b/fs/ext4/dir.c
> @@ -283,9 +283,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
> done:
> err = 0;
> errout:
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> fscrypt_fname_free_buffer(&fstr);
> -#endif
> brelse(bh);
> return err;
> }
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 2ae6ab88f218..db21df885186 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -40,7 +40,6 @@
> #include <linux/compat.h>
> #endif
>
> -#define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_EXT4_FS_ENCRYPTION)
> #include <linux/fscrypt.h>
>
> #define __FS_HAS_VERITY IS_ENABLED(CONFIG_EXT4_FS_VERITY)
> @@ -1341,7 +1340,7 @@ struct ext4_super_block {
> #define EXT4_MF_FS_ABORTED 0x0002 /* Fatal error detected */
> #define EXT4_MF_TEST_DUMMY_ENCRYPTION 0x0004
>
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> #define DUMMY_ENCRYPTION_ENABLED(sbi) (unlikely((sbi)->s_mount_flags & \
> EXT4_MF_TEST_DUMMY_ENCRYPTION))
> #else
> @@ -2069,7 +2068,7 @@ struct ext4_filename {
> const struct qstr *usr_fname;
> struct fscrypt_str disk_name;
> struct dx_hash_info hinfo;
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> struct fscrypt_str crypto_buf;
> #endif
> };
> @@ -2306,7 +2305,7 @@ static inline bool ext4_verity_inode(struct inode *inode)
> #endif
> }
>
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> static inline int ext4_fname_setup_filename(struct inode *dir,
> const struct qstr *iname,
> int lookup, struct ext4_filename *fname)
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 725777772f32..ae6794649817 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -1150,7 +1150,7 @@ int do_journal_get_write_access(handle_t *handle,
> return ret;
> }
>
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
> get_block_t *get_block)
> {
> @@ -1303,7 +1303,7 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping,
> /* In case writeback began while the page was unlocked */
> wait_for_stable_page(page);
>
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> if (ext4_should_dioread_nolock(inode))
> ret = ext4_block_write_begin(page, pos, len,
> ext4_get_block_unwritten);
> @@ -3104,7 +3104,7 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
> /* In case writeback began while the page was unlocked */
> wait_for_stable_page(page);
>
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> ret = ext4_block_write_begin(page, pos, len,
> ext4_da_get_block_prep);
> #else
> @@ -3879,7 +3879,7 @@ static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
> loff_t offset = iocb->ki_pos;
> ssize_t ret;
>
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
> return 0;
> #endif
> diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
> index 9bb6cc1ae8ce..892fb1925836 100644
> --- a/fs/ext4/ioctl.c
> +++ b/fs/ext4/ioctl.c
> @@ -210,7 +210,7 @@ static long swap_inode_boot_loader(struct super_block *sb,
> return err;
> }
>
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> static int uuid_is_zero(__u8 u[16])
> {
> int i;
> @@ -978,7 +978,7 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> return fscrypt_ioctl_set_policy(filp, (const void __user *)arg);
>
> case EXT4_IOC_GET_ENCRYPTION_PWSALT: {
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> int err, err2;
> struct ext4_sb_info *sbi = EXT4_SB(sb);
> handle_t *handle;
> diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
> index 0de60207a963..1e1a3c8c3a8b 100644
> --- a/fs/ext4/namei.c
> +++ b/fs/ext4/namei.c
> @@ -611,7 +611,7 @@ static struct stats dx_show_leaf(struct inode *dir,
> {
> if (show_names)
> {
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> int len;
> char *name;
> struct fscrypt_str fname_crypto_str =
> @@ -983,7 +983,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
> top = (struct ext4_dir_entry_2 *) ((char *) de +
> dir->i_sb->s_blocksize -
> EXT4_DIR_REC_LEN(0));
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> /* Check if the directory is encrypted */
> if (IS_ENCRYPTED(dir)) {
> err = fscrypt_get_encryption_info(dir);
> @@ -1046,7 +1046,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
> }
> errout:
> brelse(bh);
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> fscrypt_fname_free_buffer(&fname_crypto_str);
> #endif
> return count;
> @@ -1266,7 +1266,7 @@ static inline bool ext4_match(const struct ext4_filename *fname,
>
> f.usr_fname = fname->usr_fname;
> f.disk_name = fname->disk_name;
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> f.crypto_buf = fname->crypto_buf;
> #endif
> return fscrypt_match_name(&f, de->name, de->name_len);
> @@ -1497,7 +1497,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
> ext4_lblk_t block;
> int retval;
>
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> *res_dir = NULL;
> #endif
> frame = dx_probe(fname, dir, NULL, frames);
> diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
> index 008c20b58f98..7d5f12be07ab 100644
> --- a/fs/ext4/page-io.c
> +++ b/fs/ext4/page-io.c
> @@ -66,7 +66,7 @@ static void ext4_finish_bio(struct bio *bio)
>
> bio_for_each_segment_all(bvec, bio, i) {
> struct page *page = bvec->bv_page;
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> struct page *data_page = NULL;
> #endif
> struct buffer_head *bh, *head;
> @@ -78,7 +78,7 @@ static void ext4_finish_bio(struct bio *bio)
> if (!page)
> continue;
>
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> if (!page->mapping) {
> /* The bounce data pages are unmapped. */
> data_page = page;
> @@ -111,7 +111,7 @@ static void ext4_finish_bio(struct bio *bio)
> bit_spin_unlock(BH_Uptodate_Lock, &head->b_state);
> local_irq_restore(flags);
> if (!under_io) {
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> if (data_page)
> fscrypt_restore_control_page(data_page);
> #endif
> diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
> index 45e707fb9749..7252f0a60cdb 100644
> --- a/fs/ext4/readpage.c
> +++ b/fs/ext4/readpage.c
> @@ -54,7 +54,7 @@ static mempool_t *bio_post_read_ctx_pool;
>
> static inline bool ext4_bio_encrypted(struct bio *bio)
> {
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> return unlikely(bio->bi_private != NULL);
> #else
> return false;
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index fb4e060f28ec..16fb483a6f4a 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -1210,7 +1210,7 @@ static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
> return try_to_free_buffers(page);
> }
>
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
> {
> return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
> @@ -1986,7 +1986,7 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
> *journal_ioprio =
> IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
> } else if (token == Opt_test_dummy_encryption) {
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
> ext4_msg(sb, KERN_WARNING,
> "Test dummy encryption mode enabled");
> @@ -4231,7 +4231,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> sb->s_op = &ext4_sops;
> sb->s_export_op = &ext4_export_ops;
> sb->s_xattr = ext4_xattr_handlers;
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> sb->s_cop = &ext4_cryptops;
> #endif
> #ifdef CONFIG_EXT4_FS_VERITY
> diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
> index 8e86087c2f03..8bc915452a38 100644
> --- a/fs/ext4/sysfs.c
> +++ b/fs/ext4/sysfs.c
> @@ -224,7 +224,7 @@ static struct attribute *ext4_attrs[] = {
> EXT4_ATTR_FEATURE(lazy_itable_init);
> EXT4_ATTR_FEATURE(batched_discard);
> EXT4_ATTR_FEATURE(meta_bg_resize);
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> EXT4_ATTR_FEATURE(encryption);
> #endif
> #ifdef CONFIG_EXT4_FS_VERITY
> @@ -236,7 +236,7 @@ static struct attribute *ext4_feat_attrs[] = {
> ATTR_LIST(lazy_itable_init),
> ATTR_LIST(batched_discard),
> ATTR_LIST(meta_bg_resize),
> -#ifdef CONFIG_EXT4_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> ATTR_LIST(encryption),
> #endif
> #ifdef CONFIG_EXT4_FS_VERITY
> diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig
> index c8396c7220f2..ce60e480fec1 100644
> --- a/fs/f2fs/Kconfig
> +++ b/fs/f2fs/Kconfig
> @@ -70,17 +70,6 @@ config F2FS_CHECK_FS
>
> If you want to improve the performance, say N.
>
> -config F2FS_FS_ENCRYPTION
> - bool "F2FS Encryption"
> - depends on F2FS_FS
> - depends on F2FS_FS_XATTR
> - select FS_ENCRYPTION
> - help
> - Enable encryption of f2fs files and directories. This
> - feature is similar to ecryptfs, but it is more memory
> - efficient since it avoids caching the encrypted and
> - decrypted pages in the page cache.
> -
> config F2FS_FS_VERITY
> bool "F2FS Verity"
> depends on F2FS_FS
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index dadb5f468f20..ea8a5ffc4f1f 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -24,7 +24,6 @@
> #include <linux/quotaops.h>
> #include <crypto/hash.h>
>
> -#define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_F2FS_FS_ENCRYPTION)
> #include <linux/fscrypt.h>
>
> #define __FS_HAS_VERITY IS_ENABLED(CONFIG_F2FS_FS_VERITY)
> @@ -1145,7 +1144,7 @@ enum fsync_mode {
> FSYNC_MODE_NOBARRIER, /* fsync behaves nobarrier based on posix */
> };
>
> -#ifdef CONFIG_F2FS_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> #define DUMMY_ENCRYPTION_ENABLED(sbi) \
> (unlikely(F2FS_OPTION(sbi).test_dummy_encryption))
> #else
> @@ -3448,7 +3447,7 @@ static inline bool f2fs_encrypted_file(struct inode *inode)
>
> static inline void f2fs_set_encrypted_inode(struct inode *inode)
> {
> -#ifdef CONFIG_F2FS_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> file_set_encrypt(inode);
> f2fs_set_inode_flags(inode);
> #endif
> @@ -3533,7 +3532,7 @@ static inline void set_opt_mode(struct f2fs_sb_info *sbi, unsigned int mt)
>
> static inline bool f2fs_may_encrypt(struct inode *inode)
> {
> -#ifdef CONFIG_F2FS_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> umode_t mode = inode->i_mode;
>
> return (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode));
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index adf38c1b6414..4287cf348d3c 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -757,7 +757,7 @@ static int parse_options(struct super_block *sb, char *options)
> kfree(name);
> break;
> case Opt_test_dummy_encryption:
> -#ifdef CONFIG_F2FS_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> if (!f2fs_sb_has_encrypt(sb)) {
> f2fs_msg(sb, KERN_ERR, "Encrypt feature is off");
> return -EINVAL;
> @@ -1387,7 +1387,7 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> seq_printf(seq, ",whint_mode=%s", "user-based");
> else if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_FS)
> seq_printf(seq, ",whint_mode=%s", "fs-based");
> -#ifdef CONFIG_F2FS_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> if (F2FS_OPTION(sbi).test_dummy_encryption)
> seq_puts(seq, ",test_dummy_encryption");
> #endif
> @@ -2154,7 +2154,7 @@ static const struct super_operations f2fs_sops = {
> .remount_fs = f2fs_remount,
> };
>
> -#ifdef CONFIG_F2FS_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> static int f2fs_get_context(struct inode *inode, void *ctx, size_t len)
> {
> return f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
> @@ -3143,7 +3143,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> #endif
>
> sb->s_op = &f2fs_sops;
> -#ifdef CONFIG_F2FS_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> sb->s_cop = &f2fs_cryptops;
> #endif
> #ifdef CONFIG_F2FS_FS_VERITY
> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> index 5599c9ac4426..737677655bc0 100644
> --- a/fs/f2fs/sysfs.c
> +++ b/fs/f2fs/sysfs.c
> @@ -430,7 +430,7 @@ F2FS_GENERAL_RO_ATTR(lifetime_write_kbytes);
> F2FS_GENERAL_RO_ATTR(features);
> F2FS_GENERAL_RO_ATTR(current_reserved_blocks);
>
> -#ifdef CONFIG_F2FS_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> F2FS_FEATURE_RO_ATTR(encryption, FEAT_CRYPTO);
> #endif
> #ifdef CONFIG_BLK_DEV_ZONED
> @@ -493,7 +493,7 @@ static struct attribute *f2fs_attrs[] = {
> };
>
> static struct attribute *f2fs_feat_attrs[] = {
> -#ifdef CONFIG_F2FS_FS_ENCRYPTION
> +#ifdef CONFIG_FS_ENCRYPTION
> ATTR_LIST(encryption),
> #endif
> #ifdef CONFIG_BLK_DEV_ZONED
> diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
> index 952ab97af325..6ba193c23f37 100644
> --- a/include/linux/fscrypt.h
> +++ b/include/linux/fscrypt.h
> @@ -2,9 +2,8 @@
> /*
> * fscrypt.h: declarations for per-file encryption
> *
> - * Filesystems that implement per-file encryption include this header
> - * file with the __FS_HAS_ENCRYPTION set according to whether that filesystem
> - * is being built with encryption support or not.
> + * Filesystems that implement per-file encryption must include this header
> + * file.
> *
> * Copyright (C) 2015, Google, Inc.
> *
> @@ -15,6 +14,8 @@
> #define _LINUX_FSCRYPT_H
>
> #include <linux/fs.h>
> +#include <linux/mm.h>
> +#include <linux/slab.h>
>
> #define FS_CRYPTO_BLOCK_SIZE 16
>
> @@ -42,11 +43,410 @@ struct fscrypt_name {
> /* Maximum value for the third parameter of fscrypt_operations.set_context(). */
> #define FSCRYPT_SET_CONTEXT_MAX_SIZE 28
>
> -#if __FS_HAS_ENCRYPTION
> -#include <linux/fscrypt_supp.h>
> -#else
> -#include <linux/fscrypt_notsupp.h>
> -#endif
> +#ifdef CONFIG_FS_ENCRYPTION
> +/*
> + * fscrypt superblock flags
> + */
> +#define FS_CFLG_OWN_PAGES (1U << 1)
> +
> +/*
> + * crypto operations for filesystems
> + */
> +struct fscrypt_operations {
> + unsigned int flags;
> + const char *key_prefix;
> + int (*get_context)(struct inode *, void *, size_t);
> + int (*set_context)(struct inode *, const void *, size_t, void *);
> + bool (*dummy_context)(struct inode *);
> + bool (*empty_dir)(struct inode *);
> + unsigned int max_namelen;
> +};
> +
> +struct fscrypt_ctx {
> + union {
> + struct {
> + struct page *bounce_page; /* Ciphertext page */
> + struct page *control_page; /* Original page */
> + } w;
> + struct {
> + struct bio *bio;
> + struct work_struct work;
> + } r;
> + struct list_head free_list; /* Free list */
> + };
> + u8 flags; /* Flags */
> +};
> +
> +static inline bool fscrypt_has_encryption_key(const struct inode *inode)
> +{
> + return (inode->i_crypt_info != NULL);
> +}
> +
> +static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
> +{
> + return inode->i_sb->s_cop->dummy_context &&
> + inode->i_sb->s_cop->dummy_context(inode);
> +}
> +
> +/* crypto.c */
> +extern void fscrypt_enqueue_decrypt_work(struct work_struct *);
> +extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t);
> +extern void fscrypt_release_ctx(struct fscrypt_ctx *);
> +extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *,
> + unsigned int, unsigned int,
> + u64, gfp_t);
> +extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int,
> + unsigned int, u64);
> +
> +static inline struct page *fscrypt_control_page(struct page *page)
> +{
> + return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
> +}
> +
> +extern void fscrypt_restore_control_page(struct page *);
> +
> +/* policy.c */
> +extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
> +extern int fscrypt_ioctl_get_policy(struct file *, void __user *);
> +extern int fscrypt_has_permitted_context(struct inode *, struct inode *);
> +extern int fscrypt_inherit_context(struct inode *, struct inode *,
> + void *, bool);
> +/* keyinfo.c */
> +extern int fscrypt_get_encryption_info(struct inode *);
> +extern void fscrypt_put_encryption_info(struct inode *);
> +
> +/* fname.c */
> +extern int fscrypt_setup_filename(struct inode *, const struct qstr *,
> + int lookup, struct fscrypt_name *);
> +
> +static inline void fscrypt_free_filename(struct fscrypt_name *fname)
> +{
> + kfree(fname->crypto_buf.name);
> +}
> +
> +extern int fscrypt_fname_alloc_buffer(const struct inode *, u32,
> + struct fscrypt_str *);
> +extern void fscrypt_fname_free_buffer(struct fscrypt_str *);
> +extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32,
> + const struct fscrypt_str *, struct fscrypt_str *);
> +
> +#define FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE 32
> +
> +/* Extracts the second-to-last ciphertext block; see explanation below */
> +#define FSCRYPT_FNAME_DIGEST(name, len) \
> + ((name) + round_down((len) - FS_CRYPTO_BLOCK_SIZE - 1, \
> + FS_CRYPTO_BLOCK_SIZE))
> +
> +#define FSCRYPT_FNAME_DIGEST_SIZE FS_CRYPTO_BLOCK_SIZE
> +
> +/**
> + * fscrypt_digested_name - alternate identifier for an on-disk filename
> + *
> + * When userspace lists an encrypted directory without access to the key,
> + * filenames whose ciphertext is longer than FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE
> + * bytes are shown in this abbreviated form (base64-encoded) rather than as the
> + * full ciphertext (base64-encoded). This is necessary to allow supporting
> + * filenames up to NAME_MAX bytes, since base64 encoding expands the length.
> + *
> + * To make it possible for filesystems to still find the correct directory entry
> + * despite not knowing the full on-disk name, we encode any filesystem-specific
> + * 'hash' and/or 'minor_hash' which the filesystem may need for its lookups,
> + * followed by the second-to-last ciphertext block of the filename. Due to the
> + * use of the CBC-CTS encryption mode, the second-to-last ciphertext block
> + * depends on the full plaintext. (Note that ciphertext stealing causes the
> + * last two blocks to appear "flipped".) This makes accidental collisions very
> + * unlikely: just a 1 in 2^128 chance for two filenames to collide even if they
> + * share the same filesystem-specific hashes.
> + *
> + * However, this scheme isn't immune to intentional collisions, which can be
> + * created by anyone able to create arbitrary plaintext filenames and view them
> + * without the key. Making the "digest" be a real cryptographic hash like
> + * SHA-256 over the full ciphertext would prevent this, although it would be
> + * less efficient and harder to implement, especially since the filesystem would
> + * need to calculate it for each directory entry examined during a search.
> + */
> +struct fscrypt_digested_name {
> + u32 hash;
> + u32 minor_hash;
> + u8 digest[FSCRYPT_FNAME_DIGEST_SIZE];
> +};
> +
> +/**
> + * fscrypt_match_name() - test whether the given name matches a directory entry
> + * @fname: the name being searched for
> + * @de_name: the name from the directory entry
> + * @de_name_len: the length of @de_name in bytes
> + *
> + * Normally @fname->disk_name will be set, and in that case we simply compare
> + * that to the name stored in the directory entry. The only exception is that
> + * if we don't have the key for an encrypted directory and a filename in it is
> + * very long, then we won't have the full disk_name and we'll instead need to
> + * match against the fscrypt_digested_name.
> + *
> + * Return: %true if the name matches, otherwise %false.
> + */
> +static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
> + const u8 *de_name, u32 de_name_len)
> +{
> + if (unlikely(!fname->disk_name.name)) {
> + const struct fscrypt_digested_name *n =
> + (const void *)fname->crypto_buf.name;
> + if (WARN_ON_ONCE(fname->usr_fname->name[0] != '_'))
> + return false;
> + if (de_name_len <= FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE)
> + return false;
> + return !memcmp(FSCRYPT_FNAME_DIGEST(de_name, de_name_len),
> + n->digest, FSCRYPT_FNAME_DIGEST_SIZE);
> + }
> +
> + if (de_name_len != fname->disk_name.len)
> + return false;
> + return !memcmp(de_name, fname->disk_name.name, fname->disk_name.len);
> +}
> +
> +/* bio.c */
> +extern void fscrypt_decrypt_bio(struct bio *);
> +extern void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,
> + struct bio *bio);
> +extern void fscrypt_pullback_bio_page(struct page **, bool);
> +extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
> + unsigned int);
> +
> +/* hooks.c */
> +extern int fscrypt_file_open(struct inode *inode, struct file *filp);
> +extern int __fscrypt_prepare_link(struct inode *inode, struct inode *dir);
> +extern int __fscrypt_prepare_rename(struct inode *old_dir,
> + struct dentry *old_dentry,
> + struct inode *new_dir,
> + struct dentry *new_dentry,
> + unsigned int flags);
> +extern int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry);
> +extern int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len,
> + unsigned int max_len,
> + struct fscrypt_str *disk_link);
> +extern int __fscrypt_encrypt_symlink(struct inode *inode, const char *target,
> + unsigned int len,
> + struct fscrypt_str *disk_link);
> +extern const char *fscrypt_get_symlink(struct inode *inode, const void *caddr,
> + unsigned int max_size,
> + struct delayed_call *done);
> +#else /* ! CONFIG_FS_ENCRYPTION */
> +
> +static inline bool fscrypt_has_encryption_key(const struct inode *inode)
> +{
> + return false;
> +}
> +
> +static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
> +{
> + return false;
> +}
> +
> +/* crypto.c */
> +static inline void fscrypt_enqueue_decrypt_work(struct work_struct *work)
> +{
> +}
> +
> +static inline struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode,
> + gfp_t gfp_flags)
> +{
> + return ERR_PTR(-EOPNOTSUPP);
> +}
> +
> +static inline void fscrypt_release_ctx(struct fscrypt_ctx *ctx)
> +{
> + return;
> +}
> +
> +static inline struct page *fscrypt_encrypt_page(const struct inode *inode,
> + struct page *page,
> + unsigned int len,
> + unsigned int offs,
> + u64 lblk_num, gfp_t gfp_flags)
> +{
> + return ERR_PTR(-EOPNOTSUPP);
> +}
> +
> +static inline int fscrypt_decrypt_page(const struct inode *inode,
> + struct page *page,
> + unsigned int len, unsigned int offs,
> + u64 lblk_num)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline struct page *fscrypt_control_page(struct page *page)
> +{
> + WARN_ON_ONCE(1);
> + return ERR_PTR(-EINVAL);
> +}
> +
> +static inline void fscrypt_restore_control_page(struct page *page)
> +{
> + return;
> +}
> +
> +/* policy.c */
> +static inline int fscrypt_ioctl_set_policy(struct file *filp,
> + const void __user *arg)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int fscrypt_has_permitted_context(struct inode *parent,
> + struct inode *child)
> +{
> + return 0;
> +}
> +
> +static inline int fscrypt_inherit_context(struct inode *parent,
> + struct inode *child,
> + void *fs_data, bool preload)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +/* keyinfo.c */
> +static inline int fscrypt_get_encryption_info(struct inode *inode)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline void fscrypt_put_encryption_info(struct inode *inode)
> +{
> + return;
> +}
> +
> + /* fname.c */
> +static inline int fscrypt_setup_filename(struct inode *dir,
> + const struct qstr *iname,
> + int lookup, struct fscrypt_name *fname)
> +{
> + if (IS_ENCRYPTED(dir))
> + return -EOPNOTSUPP;
> +
> + memset(fname, 0, sizeof(struct fscrypt_name));
> + fname->usr_fname = iname;
> + fname->disk_name.name = (unsigned char *)iname->name;
> + fname->disk_name.len = iname->len;
> + return 0;
> +}
> +
> +static inline void fscrypt_free_filename(struct fscrypt_name *fname)
> +{
> + return;
> +}
> +
> +static inline int fscrypt_fname_alloc_buffer(const struct inode *inode,
> + u32 max_encrypted_len,
> + struct fscrypt_str *crypto_str)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str)
> +{
> + return;
> +}
> +
> +static inline int fscrypt_fname_disk_to_usr(struct inode *inode,
> + u32 hash, u32 minor_hash,
> + const struct fscrypt_str *iname,
> + struct fscrypt_str *oname)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
> + const u8 *de_name, u32 de_name_len)
> +{
> + /* Encryption support disabled; use standard comparison */
> + if (de_name_len != fname->disk_name.len)
> + return false;
> + return !memcmp(de_name, fname->disk_name.name, fname->disk_name.len);
> +}
> +
> +/* bio.c */
> +static inline void fscrypt_decrypt_bio(struct bio *bio)
> +{
> +}
> +
> +static inline void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,
> + struct bio *bio)
> +{
> +}
> +
> +static inline void fscrypt_pullback_bio_page(struct page **page, bool restore)
> +{
> + return;
> +}
> +
> +static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
> + sector_t pblk, unsigned int len)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +/* hooks.c */
> +
> +static inline int fscrypt_file_open(struct inode *inode, struct file *filp)
> +{
> + if (IS_ENCRYPTED(inode))
> + return -EOPNOTSUPP;
> + return 0;
> +}
> +
> +static inline int __fscrypt_prepare_link(struct inode *inode,
> + struct inode *dir)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int __fscrypt_prepare_rename(struct inode *old_dir,
> + struct dentry *old_dentry,
> + struct inode *new_dir,
> + struct dentry *new_dentry,
> + unsigned int flags)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int __fscrypt_prepare_lookup(struct inode *dir,
> + struct dentry *dentry)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline int __fscrypt_prepare_symlink(struct inode *dir,
> + unsigned int len,
> + unsigned int max_len,
> + struct fscrypt_str *disk_link)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +
> +static inline int __fscrypt_encrypt_symlink(struct inode *inode,
> + const char *target,
> + unsigned int len,
> + struct fscrypt_str *disk_link)
> +{
> + return -EOPNOTSUPP;
> +}
> +
> +static inline const char *fscrypt_get_symlink(struct inode *inode,
> + const void *caddr,
> + unsigned int max_size,
> + struct delayed_call *done)
> +{
> + return ERR_PTR(-EOPNOTSUPP);
> +}
> +#endif /* ! CONFIG_FS_ENCRYPTION */
>
> /**
> * fscrypt_require_key - require an inode's encryption key
> diff --git a/include/linux/fscrypt_notsupp.h b/include/linux/fscrypt_notsupp.h
> deleted file mode 100644
> index ee8b43e4c15a..000000000000
> --- a/include/linux/fscrypt_notsupp.h
> +++ /dev/null
> @@ -1,231 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -/*
> - * fscrypt_notsupp.h
> - *
> - * This stubs out the fscrypt functions for filesystems configured without
> - * encryption support.
> - *
> - * Do not include this file directly. Use fscrypt.h instead!
> - */
> -#ifndef _LINUX_FSCRYPT_H
> -#error "Incorrect include of linux/fscrypt_notsupp.h!"
> -#endif
> -
> -#ifndef _LINUX_FSCRYPT_NOTSUPP_H
> -#define _LINUX_FSCRYPT_NOTSUPP_H
> -
> -static inline bool fscrypt_has_encryption_key(const struct inode *inode)
> -{
> - return false;
> -}
> -
> -static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
> -{
> - return false;
> -}
> -
> -/* crypto.c */
> -static inline void fscrypt_enqueue_decrypt_work(struct work_struct *work)
> -{
> -}
> -
> -static inline struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode,
> - gfp_t gfp_flags)
> -{
> - return ERR_PTR(-EOPNOTSUPP);
> -}
> -
> -static inline void fscrypt_release_ctx(struct fscrypt_ctx *ctx)
> -{
> - return;
> -}
> -
> -static inline struct page *fscrypt_encrypt_page(const struct inode *inode,
> - struct page *page,
> - unsigned int len,
> - unsigned int offs,
> - u64 lblk_num, gfp_t gfp_flags)
> -{
> - return ERR_PTR(-EOPNOTSUPP);
> -}
> -
> -static inline int fscrypt_decrypt_page(const struct inode *inode,
> - struct page *page,
> - unsigned int len, unsigned int offs,
> - u64 lblk_num)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -static inline struct page *fscrypt_control_page(struct page *page)
> -{
> - WARN_ON_ONCE(1);
> - return ERR_PTR(-EINVAL);
> -}
> -
> -static inline void fscrypt_restore_control_page(struct page *page)
> -{
> - return;
> -}
> -
> -/* policy.c */
> -static inline int fscrypt_ioctl_set_policy(struct file *filp,
> - const void __user *arg)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -static inline int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -static inline int fscrypt_has_permitted_context(struct inode *parent,
> - struct inode *child)
> -{
> - return 0;
> -}
> -
> -static inline int fscrypt_inherit_context(struct inode *parent,
> - struct inode *child,
> - void *fs_data, bool preload)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -/* keyinfo.c */
> -static inline int fscrypt_get_encryption_info(struct inode *inode)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -static inline void fscrypt_put_encryption_info(struct inode *inode)
> -{
> - return;
> -}
> -
> - /* fname.c */
> -static inline int fscrypt_setup_filename(struct inode *dir,
> - const struct qstr *iname,
> - int lookup, struct fscrypt_name *fname)
> -{
> - if (IS_ENCRYPTED(dir))
> - return -EOPNOTSUPP;
> -
> - memset(fname, 0, sizeof(struct fscrypt_name));
> - fname->usr_fname = iname;
> - fname->disk_name.name = (unsigned char *)iname->name;
> - fname->disk_name.len = iname->len;
> - return 0;
> -}
> -
> -static inline void fscrypt_free_filename(struct fscrypt_name *fname)
> -{
> - return;
> -}
> -
> -static inline int fscrypt_fname_alloc_buffer(const struct inode *inode,
> - u32 max_encrypted_len,
> - struct fscrypt_str *crypto_str)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -static inline void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str)
> -{
> - return;
> -}
> -
> -static inline int fscrypt_fname_disk_to_usr(struct inode *inode,
> - u32 hash, u32 minor_hash,
> - const struct fscrypt_str *iname,
> - struct fscrypt_str *oname)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
> - const u8 *de_name, u32 de_name_len)
> -{
> - /* Encryption support disabled; use standard comparison */
> - if (de_name_len != fname->disk_name.len)
> - return false;
> - return !memcmp(de_name, fname->disk_name.name, fname->disk_name.len);
> -}
> -
> -/* bio.c */
> -static inline void fscrypt_decrypt_bio(struct bio *bio)
> -{
> -}
> -
> -static inline void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,
> - struct bio *bio)
> -{
> -}
> -
> -static inline void fscrypt_pullback_bio_page(struct page **page, bool restore)
> -{
> - return;
> -}
> -
> -static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
> - sector_t pblk, unsigned int len)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -/* hooks.c */
> -
> -static inline int fscrypt_file_open(struct inode *inode, struct file *filp)
> -{
> - if (IS_ENCRYPTED(inode))
> - return -EOPNOTSUPP;
> - return 0;
> -}
> -
> -static inline int __fscrypt_prepare_link(struct inode *inode,
> - struct inode *dir)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -static inline int __fscrypt_prepare_rename(struct inode *old_dir,
> - struct dentry *old_dentry,
> - struct inode *new_dir,
> - struct dentry *new_dentry,
> - unsigned int flags)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -static inline int __fscrypt_prepare_lookup(struct inode *dir,
> - struct dentry *dentry)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -static inline int __fscrypt_prepare_symlink(struct inode *dir,
> - unsigned int len,
> - unsigned int max_len,
> - struct fscrypt_str *disk_link)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -static inline int __fscrypt_encrypt_symlink(struct inode *inode,
> - const char *target,
> - unsigned int len,
> - struct fscrypt_str *disk_link)
> -{
> - return -EOPNOTSUPP;
> -}
> -
> -static inline const char *fscrypt_get_symlink(struct inode *inode,
> - const void *caddr,
> - unsigned int max_size,
> - struct delayed_call *done)
> -{
> - return ERR_PTR(-EOPNOTSUPP);
> -}
> -
> -#endif /* _LINUX_FSCRYPT_NOTSUPP_H */
> diff --git a/include/linux/fscrypt_supp.h b/include/linux/fscrypt_supp.h
> deleted file mode 100644
> index 6456c6b2005f..000000000000
> --- a/include/linux/fscrypt_supp.h
> +++ /dev/null
> @@ -1,204 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -/*
> - * fscrypt_supp.h
> - *
> - * Do not include this file directly. Use fscrypt.h instead!
> - */
> -#ifndef _LINUX_FSCRYPT_H
> -#error "Incorrect include of linux/fscrypt_supp.h!"
> -#endif
> -
> -#ifndef _LINUX_FSCRYPT_SUPP_H
> -#define _LINUX_FSCRYPT_SUPP_H
> -
> -#include <linux/mm.h>
> -#include <linux/slab.h>
> -
> -/*
> - * fscrypt superblock flags
> - */
> -#define FS_CFLG_OWN_PAGES (1U << 1)
> -
> -/*
> - * crypto operations for filesystems
> - */
> -struct fscrypt_operations {
> - unsigned int flags;
> - const char *key_prefix;
> - int (*get_context)(struct inode *, void *, size_t);
> - int (*set_context)(struct inode *, const void *, size_t, void *);
> - bool (*dummy_context)(struct inode *);
> - bool (*empty_dir)(struct inode *);
> - unsigned int max_namelen;
> -};
> -
> -struct fscrypt_ctx {
> - union {
> - struct {
> - struct page *bounce_page; /* Ciphertext page */
> - struct page *control_page; /* Original page */
> - } w;
> - struct {
> - struct bio *bio;
> - struct work_struct work;
> - } r;
> - struct list_head free_list; /* Free list */
> - };
> - u8 flags; /* Flags */
> -};
> -
> -static inline bool fscrypt_has_encryption_key(const struct inode *inode)
> -{
> - return (inode->i_crypt_info != NULL);
> -}
> -
> -static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
> -{
> - return inode->i_sb->s_cop->dummy_context &&
> - inode->i_sb->s_cop->dummy_context(inode);
> -}
> -
> -/* crypto.c */
> -extern void fscrypt_enqueue_decrypt_work(struct work_struct *);
> -extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t);
> -extern void fscrypt_release_ctx(struct fscrypt_ctx *);
> -extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *,
> - unsigned int, unsigned int,
> - u64, gfp_t);
> -extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int,
> - unsigned int, u64);
> -
> -static inline struct page *fscrypt_control_page(struct page *page)
> -{
> - return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
> -}
> -
> -extern void fscrypt_restore_control_page(struct page *);
> -
> -/* policy.c */
> -extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
> -extern int fscrypt_ioctl_get_policy(struct file *, void __user *);
> -extern int fscrypt_has_permitted_context(struct inode *, struct inode *);
> -extern int fscrypt_inherit_context(struct inode *, struct inode *,
> - void *, bool);
> -/* keyinfo.c */
> -extern int fscrypt_get_encryption_info(struct inode *);
> -extern void fscrypt_put_encryption_info(struct inode *);
> -
> -/* fname.c */
> -extern int fscrypt_setup_filename(struct inode *, const struct qstr *,
> - int lookup, struct fscrypt_name *);
> -
> -static inline void fscrypt_free_filename(struct fscrypt_name *fname)
> -{
> - kfree(fname->crypto_buf.name);
> -}
> -
> -extern int fscrypt_fname_alloc_buffer(const struct inode *, u32,
> - struct fscrypt_str *);
> -extern void fscrypt_fname_free_buffer(struct fscrypt_str *);
> -extern int fscrypt_fname_disk_to_usr(struct inode *, u32, u32,
> - const struct fscrypt_str *, struct fscrypt_str *);
> -
> -#define FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE 32
> -
> -/* Extracts the second-to-last ciphertext block; see explanation below */
> -#define FSCRYPT_FNAME_DIGEST(name, len) \
> - ((name) + round_down((len) - FS_CRYPTO_BLOCK_SIZE - 1, \
> - FS_CRYPTO_BLOCK_SIZE))
> -
> -#define FSCRYPT_FNAME_DIGEST_SIZE FS_CRYPTO_BLOCK_SIZE
> -
> -/**
> - * fscrypt_digested_name - alternate identifier for an on-disk filename
> - *
> - * When userspace lists an encrypted directory without access to the key,
> - * filenames whose ciphertext is longer than FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE
> - * bytes are shown in this abbreviated form (base64-encoded) rather than as the
> - * full ciphertext (base64-encoded). This is necessary to allow supporting
> - * filenames up to NAME_MAX bytes, since base64 encoding expands the length.
> - *
> - * To make it possible for filesystems to still find the correct directory entry
> - * despite not knowing the full on-disk name, we encode any filesystem-specific
> - * 'hash' and/or 'minor_hash' which the filesystem may need for its lookups,
> - * followed by the second-to-last ciphertext block of the filename. Due to the
> - * use of the CBC-CTS encryption mode, the second-to-last ciphertext block
> - * depends on the full plaintext. (Note that ciphertext stealing causes the
> - * last two blocks to appear "flipped".) This makes accidental collisions very
> - * unlikely: just a 1 in 2^128 chance for two filenames to collide even if they
> - * share the same filesystem-specific hashes.
> - *
> - * However, this scheme isn't immune to intentional collisions, which can be
> - * created by anyone able to create arbitrary plaintext filenames and view them
> - * without the key. Making the "digest" be a real cryptographic hash like
> - * SHA-256 over the full ciphertext would prevent this, although it would be
> - * less efficient and harder to implement, especially since the filesystem would
> - * need to calculate it for each directory entry examined during a search.
> - */
> -struct fscrypt_digested_name {
> - u32 hash;
> - u32 minor_hash;
> - u8 digest[FSCRYPT_FNAME_DIGEST_SIZE];
> -};
> -
> -/**
> - * fscrypt_match_name() - test whether the given name matches a directory entry
> - * @fname: the name being searched for
> - * @de_name: the name from the directory entry
> - * @de_name_len: the length of @de_name in bytes
> - *
> - * Normally @fname->disk_name will be set, and in that case we simply compare
> - * that to the name stored in the directory entry. The only exception is that
> - * if we don't have the key for an encrypted directory and a filename in it is
> - * very long, then we won't have the full disk_name and we'll instead need to
> - * match against the fscrypt_digested_name.
> - *
> - * Return: %true if the name matches, otherwise %false.
> - */
> -static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
> - const u8 *de_name, u32 de_name_len)
> -{
> - if (unlikely(!fname->disk_name.name)) {
> - const struct fscrypt_digested_name *n =
> - (const void *)fname->crypto_buf.name;
> - if (WARN_ON_ONCE(fname->usr_fname->name[0] != '_'))
> - return false;
> - if (de_name_len <= FSCRYPT_FNAME_MAX_UNDIGESTED_SIZE)
> - return false;
> - return !memcmp(FSCRYPT_FNAME_DIGEST(de_name, de_name_len),
> - n->digest, FSCRYPT_FNAME_DIGEST_SIZE);
> - }
> -
> - if (de_name_len != fname->disk_name.len)
> - return false;
> - return !memcmp(de_name, fname->disk_name.name, fname->disk_name.len);
> -}
> -
> -/* bio.c */
> -extern void fscrypt_decrypt_bio(struct bio *);
> -extern void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,
> - struct bio *bio);
> -extern void fscrypt_pullback_bio_page(struct page **, bool);
> -extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
> - unsigned int);
> -
> -/* hooks.c */
> -extern int fscrypt_file_open(struct inode *inode, struct file *filp);
> -extern int __fscrypt_prepare_link(struct inode *inode, struct inode *dir);
> -extern int __fscrypt_prepare_rename(struct inode *old_dir,
> - struct dentry *old_dentry,
> - struct inode *new_dir,
> - struct dentry *new_dentry,
> - unsigned int flags);
> -extern int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry);
> -extern int __fscrypt_prepare_symlink(struct inode *dir, unsigned int len,
> - unsigned int max_len,
> - struct fscrypt_str *disk_link);
> -extern int __fscrypt_encrypt_symlink(struct inode *inode, const char *target,
> - unsigned int len,
> - struct fscrypt_str *disk_link);
> -extern const char *fscrypt_get_symlink(struct inode *inode, const void *caddr,
> - unsigned int max_size,
> - struct delayed_call *done);
> -
> -#endif /* _LINUX_FSCRYPT_SUPP_H */
> --
> 2.19.1
>
