1 /* SPDX-License-Identifier: GPL-2.0 */
3 * fscrypt.h: declarations for per-file encryption
5 * Filesystems that implement per-file encryption must include this header
8 * Copyright (C) 2015, Google, Inc.
10 * Written by Michael Halcrow, 2015.
11 * Modified by Jaegeuk Kim, 2015.
13 #ifndef _LINUX_FSCRYPT_H
14 #define _LINUX_FSCRYPT_H
18 #include <linux/slab.h>
19 #include <uapi/linux/fscrypt.h>
21 #define FS_CRYPTO_BLOCK_SIZE 16
33 const struct qstr *usr_fname;
34 struct fscrypt_str disk_name;
37 struct fscrypt_str crypto_buf;
41 #define FSTR_INIT(n, l) { .name = n, .len = l }
42 #define FSTR_TO_QSTR(f) QSTR_INIT((f)->name, (f)->len)
43 #define fname_name(p) ((p)->disk_name.name)
44 #define fname_len(p) ((p)->disk_name.len)
46 /* Maximum value for the third parameter of fscrypt_operations.set_context(). */
47 #define FSCRYPT_SET_CONTEXT_MAX_SIZE 40
49 #ifdef CONFIG_FS_ENCRYPTION
51 * fscrypt superblock flags
53 #define FS_CFLG_OWN_PAGES (1U << 1)
56 * crypto operations for filesystems
58 struct fscrypt_operations {
60 const char *key_prefix;
61 int (*get_context)(struct inode *inode, void *ctx, size_t len);
62 int (*set_context)(struct inode *inode, const void *ctx, size_t len,
64 const union fscrypt_policy *(*get_dummy_policy)(struct super_block *sb);
65 bool (*empty_dir)(struct inode *inode);
66 unsigned int max_namelen;
67 bool (*has_stable_inodes)(struct super_block *sb);
68 void (*get_ino_and_lblk_bits)(struct super_block *sb,
69 int *ino_bits_ret, int *lblk_bits_ret);
70 int (*get_num_devices)(struct super_block *sb);
71 void (*get_devices)(struct super_block *sb,
72 struct request_queue **devs);
75 static inline struct fscrypt_info *fscrypt_get_info(const struct inode *inode)
78 * Pairs with the cmpxchg_release() in fscrypt_setup_encryption_info().
79 * I.e., another task may publish ->i_crypt_info concurrently, executing
80 * a RELEASE barrier. We need to use smp_load_acquire() here to safely
81 * ACQUIRE the memory the other task published.
83 return smp_load_acquire(&inode->i_crypt_info);
87 * fscrypt_needs_contents_encryption() - check whether an inode needs
89 * @inode: the inode to check
91 * Return: %true iff the inode is an encrypted regular file and the kernel was
92 * built with fscrypt support.
94 * If you need to know whether the encrypt bit is set even when the kernel was
95 * built without fscrypt support, you must use IS_ENCRYPTED() directly instead.
97 static inline bool fscrypt_needs_contents_encryption(const struct inode *inode)
99 return IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode);
103 * When d_splice_alias() moves a directory's no-key alias to its plaintext alias
104 * as a result of the encryption key being added, DCACHE_NOKEY_NAME must be
105 * cleared. Note that we don't have to support arbitrary moves of this flag
106 * because fscrypt doesn't allow no-key names to be the source or target of a
109 static inline void fscrypt_handle_d_move(struct dentry *dentry)
111 dentry->d_flags &= ~DCACHE_NOKEY_NAME;
115 * fscrypt_is_nokey_name() - test whether a dentry is a no-key name
116 * @dentry: the dentry to check
118 * This returns true if the dentry is a no-key dentry. A no-key dentry is a
119 * dentry that was created in an encrypted directory that hasn't had its
120 * encryption key added yet. Such dentries may be either positive or negative.
122 * When a filesystem is asked to create a new filename in an encrypted directory
123 * and the new filename's dentry is a no-key dentry, it must fail the operation
124 * with ENOKEY. This includes ->create(), ->mkdir(), ->mknod(), ->symlink(),
125 * ->rename(), and ->link(). (However, ->rename() and ->link() are already
126 * handled by fscrypt_prepare_rename() and fscrypt_prepare_link().)
128 * This is necessary because creating a filename requires the directory's
129 * encryption key, but just checking for the key on the directory inode during
130 * the final filesystem operation doesn't guarantee that the key was available
131 * during the preceding dentry lookup. And the key must have already been
132 * available during the dentry lookup in order for it to have been checked
133 * whether the filename already exists in the directory and for the new file's
134 * dentry not to be invalidated due to it incorrectly having the no-key flag.
136 * Return: %true if the dentry is a no-key name
138 static inline bool fscrypt_is_nokey_name(const struct dentry *dentry)
140 return dentry->d_flags & DCACHE_NOKEY_NAME;
144 void fscrypt_enqueue_decrypt_work(struct work_struct *);
146 struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
150 int fscrypt_encrypt_block_inplace(const struct inode *inode, struct page *page,
151 unsigned int len, unsigned int offs,
152 u64 lblk_num, gfp_t gfp_flags);
154 int fscrypt_decrypt_pagecache_blocks(struct page *page, unsigned int len,
156 int fscrypt_decrypt_block_inplace(const struct inode *inode, struct page *page,
157 unsigned int len, unsigned int offs,
160 static inline bool fscrypt_is_bounce_page(struct page *page)
162 return page->mapping == NULL;
165 static inline struct page *fscrypt_pagecache_page(struct page *bounce_page)
167 return (struct page *)page_private(bounce_page);
170 void fscrypt_free_bounce_page(struct page *bounce_page);
173 int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg);
174 int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg);
175 int fscrypt_ioctl_get_policy_ex(struct file *filp, void __user *arg);
176 int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg);
177 int fscrypt_has_permitted_context(struct inode *parent, struct inode *child);
178 int fscrypt_set_context(struct inode *inode, void *fs_data);
180 struct fscrypt_dummy_policy {
181 const union fscrypt_policy *policy;
184 int fscrypt_set_test_dummy_encryption(struct super_block *sb, const char *arg,
185 struct fscrypt_dummy_policy *dummy_policy);
186 void fscrypt_show_test_dummy_encryption(struct seq_file *seq, char sep,
187 struct super_block *sb);
189 fscrypt_free_dummy_policy(struct fscrypt_dummy_policy *dummy_policy)
191 kfree(dummy_policy->policy);
192 dummy_policy->policy = NULL;
196 void fscrypt_sb_free(struct super_block *sb);
197 int fscrypt_ioctl_add_key(struct file *filp, void __user *arg);
198 int fscrypt_ioctl_remove_key(struct file *filp, void __user *arg);
199 int fscrypt_ioctl_remove_key_all_users(struct file *filp, void __user *arg);
200 int fscrypt_ioctl_get_key_status(struct file *filp, void __user *arg);
203 int fscrypt_prepare_new_inode(struct inode *dir, struct inode *inode,
205 void fscrypt_put_encryption_info(struct inode *inode);
206 void fscrypt_free_inode(struct inode *inode);
207 int fscrypt_drop_inode(struct inode *inode);
210 int fscrypt_setup_filename(struct inode *inode, const struct qstr *iname,
211 int lookup, struct fscrypt_name *fname);
213 static inline void fscrypt_free_filename(struct fscrypt_name *fname)
215 kfree(fname->crypto_buf.name);
218 int fscrypt_fname_alloc_buffer(u32 max_encrypted_len,
219 struct fscrypt_str *crypto_str);
220 void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str);
221 int fscrypt_fname_disk_to_usr(const struct inode *inode,
222 u32 hash, u32 minor_hash,
223 const struct fscrypt_str *iname,
224 struct fscrypt_str *oname);
225 bool fscrypt_match_name(const struct fscrypt_name *fname,
226 const u8 *de_name, u32 de_name_len);
227 u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name);
228 int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags);
231 void fscrypt_decrypt_bio(struct bio *bio);
232 int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
233 sector_t pblk, unsigned int len);
236 int fscrypt_file_open(struct inode *inode, struct file *filp);
237 int __fscrypt_prepare_link(struct inode *inode, struct inode *dir,
238 struct dentry *dentry);
239 int __fscrypt_prepare_rename(struct inode *old_dir, struct dentry *old_dentry,
240 struct inode *new_dir, struct dentry *new_dentry,
242 int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry,
243 struct fscrypt_name *fname);
244 int __fscrypt_prepare_readdir(struct inode *dir);
245 int __fscrypt_prepare_setattr(struct dentry *dentry, struct iattr *attr);
246 int fscrypt_prepare_setflags(struct inode *inode,
247 unsigned int oldflags, unsigned int flags);
248 int fscrypt_prepare_symlink(struct inode *dir, const char *target,
249 unsigned int len, unsigned int max_len,
250 struct fscrypt_str *disk_link);
251 int __fscrypt_encrypt_symlink(struct inode *inode, const char *target,
252 unsigned int len, struct fscrypt_str *disk_link);
253 const char *fscrypt_get_symlink(struct inode *inode, const void *caddr,
254 unsigned int max_size,
255 struct delayed_call *done);
256 int fscrypt_symlink_getattr(const struct path *path, struct kstat *stat);
257 static inline void fscrypt_set_ops(struct super_block *sb,
258 const struct fscrypt_operations *s_cop)
262 #else /* !CONFIG_FS_ENCRYPTION */
264 static inline struct fscrypt_info *fscrypt_get_info(const struct inode *inode)
269 static inline bool fscrypt_needs_contents_encryption(const struct inode *inode)
274 static inline void fscrypt_handle_d_move(struct dentry *dentry)
278 static inline bool fscrypt_is_nokey_name(const struct dentry *dentry)
284 static inline void fscrypt_enqueue_decrypt_work(struct work_struct *work)
288 static inline struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
293 return ERR_PTR(-EOPNOTSUPP);
296 static inline int fscrypt_encrypt_block_inplace(const struct inode *inode,
299 unsigned int offs, u64 lblk_num,
305 static inline int fscrypt_decrypt_pagecache_blocks(struct page *page,
312 static inline int fscrypt_decrypt_block_inplace(const struct inode *inode,
315 unsigned int offs, u64 lblk_num)
320 static inline bool fscrypt_is_bounce_page(struct page *page)
325 static inline struct page *fscrypt_pagecache_page(struct page *bounce_page)
328 return ERR_PTR(-EINVAL);
331 static inline void fscrypt_free_bounce_page(struct page *bounce_page)
336 static inline int fscrypt_ioctl_set_policy(struct file *filp,
337 const void __user *arg)
342 static inline int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg)
347 static inline int fscrypt_ioctl_get_policy_ex(struct file *filp,
353 static inline int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg)
358 static inline int fscrypt_has_permitted_context(struct inode *parent,
364 static inline int fscrypt_set_context(struct inode *inode, void *fs_data)
369 struct fscrypt_dummy_policy {
372 static inline void fscrypt_show_test_dummy_encryption(struct seq_file *seq,
374 struct super_block *sb)
379 fscrypt_free_dummy_policy(struct fscrypt_dummy_policy *dummy_policy)
384 static inline void fscrypt_sb_free(struct super_block *sb)
388 static inline int fscrypt_ioctl_add_key(struct file *filp, void __user *arg)
393 static inline int fscrypt_ioctl_remove_key(struct file *filp, void __user *arg)
398 static inline int fscrypt_ioctl_remove_key_all_users(struct file *filp,
404 static inline int fscrypt_ioctl_get_key_status(struct file *filp,
412 static inline int fscrypt_prepare_new_inode(struct inode *dir,
416 if (IS_ENCRYPTED(dir))
421 static inline void fscrypt_put_encryption_info(struct inode *inode)
426 static inline void fscrypt_free_inode(struct inode *inode)
430 static inline int fscrypt_drop_inode(struct inode *inode)
436 static inline int fscrypt_setup_filename(struct inode *dir,
437 const struct qstr *iname,
438 int lookup, struct fscrypt_name *fname)
440 if (IS_ENCRYPTED(dir))
443 memset(fname, 0, sizeof(*fname));
444 fname->usr_fname = iname;
445 fname->disk_name.name = (unsigned char *)iname->name;
446 fname->disk_name.len = iname->len;
450 static inline void fscrypt_free_filename(struct fscrypt_name *fname)
455 static inline int fscrypt_fname_alloc_buffer(u32 max_encrypted_len,
456 struct fscrypt_str *crypto_str)
461 static inline void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str)
466 static inline int fscrypt_fname_disk_to_usr(const struct inode *inode,
467 u32 hash, u32 minor_hash,
468 const struct fscrypt_str *iname,
469 struct fscrypt_str *oname)
474 static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
475 const u8 *de_name, u32 de_name_len)
477 /* Encryption support disabled; use standard comparison */
478 if (de_name_len != fname->disk_name.len)
480 return !memcmp(de_name, fname->disk_name.name, fname->disk_name.len);
483 static inline u64 fscrypt_fname_siphash(const struct inode *dir,
484 const struct qstr *name)
490 static inline int fscrypt_d_revalidate(struct dentry *dentry,
497 static inline void fscrypt_decrypt_bio(struct bio *bio)
501 static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
502 sector_t pblk, unsigned int len)
509 static inline int fscrypt_file_open(struct inode *inode, struct file *filp)
511 if (IS_ENCRYPTED(inode))
516 static inline int __fscrypt_prepare_link(struct inode *inode, struct inode *dir,
517 struct dentry *dentry)
522 static inline int __fscrypt_prepare_rename(struct inode *old_dir,
523 struct dentry *old_dentry,
524 struct inode *new_dir,
525 struct dentry *new_dentry,
531 static inline int __fscrypt_prepare_lookup(struct inode *dir,
532 struct dentry *dentry,
533 struct fscrypt_name *fname)
538 static inline int __fscrypt_prepare_readdir(struct inode *dir)
543 static inline int __fscrypt_prepare_setattr(struct dentry *dentry,
549 static inline int fscrypt_prepare_setflags(struct inode *inode,
550 unsigned int oldflags,
556 static inline int fscrypt_prepare_symlink(struct inode *dir,
559 unsigned int max_len,
560 struct fscrypt_str *disk_link)
562 if (IS_ENCRYPTED(dir))
564 disk_link->name = (unsigned char *)target;
565 disk_link->len = len + 1;
566 if (disk_link->len > max_len)
567 return -ENAMETOOLONG;
571 static inline int __fscrypt_encrypt_symlink(struct inode *inode,
574 struct fscrypt_str *disk_link)
579 static inline const char *fscrypt_get_symlink(struct inode *inode,
581 unsigned int max_size,
582 struct delayed_call *done)
584 return ERR_PTR(-EOPNOTSUPP);
587 static inline int fscrypt_symlink_getattr(const struct path *path,
593 static inline void fscrypt_set_ops(struct super_block *sb,
594 const struct fscrypt_operations *s_cop)
598 #endif /* !CONFIG_FS_ENCRYPTION */
601 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
603 bool __fscrypt_inode_uses_inline_crypto(const struct inode *inode);
605 void fscrypt_set_bio_crypt_ctx(struct bio *bio,
606 const struct inode *inode, u64 first_lblk,
609 void fscrypt_set_bio_crypt_ctx_bh(struct bio *bio,
610 const struct buffer_head *first_bh,
613 bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode,
616 bool fscrypt_mergeable_bio_bh(struct bio *bio,
617 const struct buffer_head *next_bh);
619 #else /* CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
621 static inline bool __fscrypt_inode_uses_inline_crypto(const struct inode *inode)
626 static inline void fscrypt_set_bio_crypt_ctx(struct bio *bio,
627 const struct inode *inode,
628 u64 first_lblk, gfp_t gfp_mask) { }
630 static inline void fscrypt_set_bio_crypt_ctx_bh(
632 const struct buffer_head *first_bh,
635 static inline bool fscrypt_mergeable_bio(struct bio *bio,
636 const struct inode *inode,
642 static inline bool fscrypt_mergeable_bio_bh(struct bio *bio,
643 const struct buffer_head *next_bh)
647 #endif /* !CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
650 * fscrypt_inode_uses_inline_crypto() - test whether an inode uses inline
652 * @inode: an inode. If encrypted, its key must be set up.
654 * Return: true if the inode requires file contents encryption and if the
655 * encryption should be done in the block layer via blk-crypto rather
656 * than in the filesystem layer.
658 static inline bool fscrypt_inode_uses_inline_crypto(const struct inode *inode)
660 return fscrypt_needs_contents_encryption(inode) &&
661 __fscrypt_inode_uses_inline_crypto(inode);
665 * fscrypt_inode_uses_fs_layer_crypto() - test whether an inode uses fs-layer
667 * @inode: an inode. If encrypted, its key must be set up.
669 * Return: true if the inode requires file contents encryption and if the
670 * encryption should be done in the filesystem layer rather than in the
671 * block layer via blk-crypto.
673 static inline bool fscrypt_inode_uses_fs_layer_crypto(const struct inode *inode)
675 return fscrypt_needs_contents_encryption(inode) &&
676 !__fscrypt_inode_uses_inline_crypto(inode);
680 * fscrypt_has_encryption_key() - check whether an inode has had its key set up
681 * @inode: the inode to check
683 * Return: %true if the inode has had its encryption key set up, else %false.
685 * Usually this should be preceded by fscrypt_get_encryption_info() to try to
686 * set up the key first.
688 static inline bool fscrypt_has_encryption_key(const struct inode *inode)
690 return fscrypt_get_info(inode) != NULL;
694 * fscrypt_prepare_link() - prepare to link an inode into a possibly-encrypted
696 * @old_dentry: an existing dentry for the inode being linked
697 * @dir: the target directory
698 * @dentry: negative dentry for the target filename
700 * A new link can only be added to an encrypted directory if the directory's
701 * encryption key is available --- since otherwise we'd have no way to encrypt
704 * We also verify that the link will not violate the constraint that all files
705 * in an encrypted directory tree use the same encryption policy.
707 * Return: 0 on success, -ENOKEY if the directory's encryption key is missing,
708 * -EXDEV if the link would result in an inconsistent encryption policy, or
709 * another -errno code.
711 static inline int fscrypt_prepare_link(struct dentry *old_dentry,
713 struct dentry *dentry)
715 if (IS_ENCRYPTED(dir))
716 return __fscrypt_prepare_link(d_inode(old_dentry), dir, dentry);
721 * fscrypt_prepare_rename() - prepare for a rename between possibly-encrypted
723 * @old_dir: source directory
724 * @old_dentry: dentry for source file
725 * @new_dir: target directory
726 * @new_dentry: dentry for target location (may be negative unless exchanging)
727 * @flags: rename flags (we care at least about %RENAME_EXCHANGE)
729 * Prepare for ->rename() where the source and/or target directories may be
730 * encrypted. A new link can only be added to an encrypted directory if the
731 * directory's encryption key is available --- since otherwise we'd have no way
732 * to encrypt the filename. A rename to an existing name, on the other hand,
733 * *is* cryptographically possible without the key. However, we take the more
734 * conservative approach and just forbid all no-key renames.
736 * We also verify that the rename will not violate the constraint that all files
737 * in an encrypted directory tree use the same encryption policy.
739 * Return: 0 on success, -ENOKEY if an encryption key is missing, -EXDEV if the
740 * rename would cause inconsistent encryption policies, or another -errno code.
742 static inline int fscrypt_prepare_rename(struct inode *old_dir,
743 struct dentry *old_dentry,
744 struct inode *new_dir,
745 struct dentry *new_dentry,
748 if (IS_ENCRYPTED(old_dir) || IS_ENCRYPTED(new_dir))
749 return __fscrypt_prepare_rename(old_dir, old_dentry,
750 new_dir, new_dentry, flags);
755 * fscrypt_prepare_lookup() - prepare to lookup a name in a possibly-encrypted
757 * @dir: directory being searched
758 * @dentry: filename being looked up
759 * @fname: (output) the name to use to search the on-disk directory
761 * Prepare for ->lookup() in a directory which may be encrypted by determining
762 * the name that will actually be used to search the directory on-disk. If the
763 * directory's encryption policy is supported by this kernel and its encryption
764 * key is available, then the lookup is assumed to be by plaintext name;
765 * otherwise, it is assumed to be by no-key name.
767 * This will set DCACHE_NOKEY_NAME on the dentry if the lookup is by no-key
768 * name. In this case the filesystem must assign the dentry a dentry_operations
769 * which contains fscrypt_d_revalidate (or contains a d_revalidate method that
770 * calls fscrypt_d_revalidate), so that the dentry will be invalidated if the
771 * directory's encryption key is later added.
773 * Return: 0 on success; -ENOENT if the directory's key is unavailable but the
774 * filename isn't a valid no-key name, so a negative dentry should be created;
775 * or another -errno code.
777 static inline int fscrypt_prepare_lookup(struct inode *dir,
778 struct dentry *dentry,
779 struct fscrypt_name *fname)
781 if (IS_ENCRYPTED(dir))
782 return __fscrypt_prepare_lookup(dir, dentry, fname);
784 memset(fname, 0, sizeof(*fname));
785 fname->usr_fname = &dentry->d_name;
786 fname->disk_name.name = (unsigned char *)dentry->d_name.name;
787 fname->disk_name.len = dentry->d_name.len;
792 * fscrypt_prepare_readdir() - prepare to read a possibly-encrypted directory
793 * @dir: the directory inode
795 * If the directory is encrypted and it doesn't already have its encryption key
796 * set up, try to set it up so that the filenames will be listed in plaintext
797 * form rather than in no-key form.
799 * Return: 0 on success; -errno on error. Note that the encryption key being
800 * unavailable is not considered an error. It is also not an error if
801 * the encryption policy is unsupported by this kernel; that is treated
802 * like the key being unavailable, so that files can still be deleted.
804 static inline int fscrypt_prepare_readdir(struct inode *dir)
806 if (IS_ENCRYPTED(dir))
807 return __fscrypt_prepare_readdir(dir);
812 * fscrypt_prepare_setattr() - prepare to change a possibly-encrypted inode's
814 * @dentry: dentry through which the inode is being changed
815 * @attr: attributes to change
817 * Prepare for ->setattr() on a possibly-encrypted inode. On an encrypted file,
818 * most attribute changes are allowed even without the encryption key. However,
819 * without the encryption key we do have to forbid truncates. This is needed
820 * because the size being truncated to may not be a multiple of the filesystem
821 * block size, and in that case we'd have to decrypt the final block, zero the
822 * portion past i_size, and re-encrypt it. (We *could* allow truncating to a
823 * filesystem block boundary, but it's simpler to just forbid all truncates ---
824 * and we already forbid all other contents modifications without the key.)
826 * Return: 0 on success, -ENOKEY if the key is missing, or another -errno code
827 * if a problem occurred while setting up the encryption key.
829 static inline int fscrypt_prepare_setattr(struct dentry *dentry,
832 if (IS_ENCRYPTED(d_inode(dentry)))
833 return __fscrypt_prepare_setattr(dentry, attr);
838 * fscrypt_encrypt_symlink() - encrypt the symlink target if needed
839 * @inode: symlink inode
840 * @target: plaintext symlink target
841 * @len: length of @target excluding null terminator
842 * @disk_link: (in/out) the on-disk symlink target being prepared
844 * If the symlink target needs to be encrypted, then this function encrypts it
845 * into @disk_link->name. fscrypt_prepare_symlink() must have been called
846 * previously to compute @disk_link->len. If the filesystem did not allocate a
847 * buffer for @disk_link->name after calling fscrypt_prepare_link(), then one
848 * will be kmalloc()'ed and the filesystem will be responsible for freeing it.
850 * Return: 0 on success, -errno on failure
852 static inline int fscrypt_encrypt_symlink(struct inode *inode,
855 struct fscrypt_str *disk_link)
857 if (IS_ENCRYPTED(inode))
858 return __fscrypt_encrypt_symlink(inode, target, len, disk_link);
862 /* If *pagep is a bounce page, free it and set *pagep to the pagecache page */
863 static inline void fscrypt_finalize_bounce_page(struct page **pagep)
865 struct page *page = *pagep;
867 if (fscrypt_is_bounce_page(page)) {
868 *pagep = fscrypt_pagecache_page(page);
869 fscrypt_free_bounce_page(page);
873 #endif /* _LINUX_FSCRYPT_H */