1 files changed, 507 insertions, 190 deletions

diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 556f4adf5dc5..4f5f8a651213 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -18,9 +18,22 @@
 #include <linux/slab.h>
 #include <uapi/linux/fscrypt.h>
 
-#define FS_CRYPTO_BLOCK_SIZE		16
+/*
+ * The lengths of all file contents blocks must be divisible by this value.
+ * This is needed to ensure that all contents encryption modes will work, as
+ * some of the supported modes don't support arbitrarily byte-aligned messages.
+ *
+ * Since the needed alignment is 16 bytes, most filesystems will meet this
+ * requirement naturally, as typical block sizes are powers of 2.  However, if a
+ * filesystem can generate arbitrarily byte-aligned block lengths (e.g., via
+ * compression), then it will need to pad to this alignment before encryption.
+ */
+#define FSCRYPT_CONTENTS_ALIGNMENT 16
 
+union fscrypt_policy;
 struct fscrypt_info;
+struct fs_parameter;
+struct seq_file;
 
 struct fscrypt_str {
 	unsigned char *name;
@@ -33,7 +46,7 @@ struct fscrypt_name {
 	u32 hash;
 	u32 minor_hash;
 	struct fscrypt_str crypto_buf;
-	bool is_ciphertext_name;
+	bool is_nokey_name;
 };
 
 #define FSTR_INIT(n, l)		{ .name = n, .len = l }
@@ -45,36 +58,141 @@ struct fscrypt_name {
 #define FSCRYPT_SET_CONTEXT_MAX_SIZE	40
 
 #ifdef CONFIG_FS_ENCRYPTION
+
 /*
- * fscrypt superblock flags
+ * If set, the fscrypt bounce page pool won't be allocated (unless another
+ * filesystem needs it).  Set this if the filesystem always uses its own bounce
+ * pages for writes and therefore won't need the fscrypt bounce page pool.
  */
 #define FS_CFLG_OWN_PAGES (1U << 1)
 
-/*
- * crypto operations for filesystems
- */
+/* Crypto operations for filesystems */
 struct fscrypt_operations {
+
+	/* Set of optional flags; see above for allowed flags */
 	unsigned int flags;
+
+	/*
+	 * If set, this is a filesystem-specific key description prefix that
+	 * will be accepted for "logon" keys for v1 fscrypt policies, in
+	 * addition to the generic prefix "fscrypt:".  This functionality is
+	 * deprecated, so new filesystems shouldn't set this field.
+	 */
 	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;
+
+	/*
+	 * Get the fscrypt context of the given inode.
+	 *
+	 * @inode: the inode whose context to get
+	 * @ctx: the buffer into which to get the context
+	 * @len: length of the @ctx buffer in bytes
+	 *
+	 * Return: On success, returns the length of the context in bytes; this
+	 *	   may be less than @len.  On failure, returns -ENODATA if the
+	 *	   inode doesn't have a context, -ERANGE if the context is
+	 *	   longer than @len, or another -errno code.
+	 */
+	int (*get_context)(struct inode *inode, void *ctx, size_t len);
+
+	/*
+	 * Set an fscrypt context on the given inode.
+	 *
+	 * @inode: the inode whose context to set.  The inode won't already have
+	 *	   an fscrypt context.
+	 * @ctx: the context to set
+	 * @len: length of @ctx in bytes (at most FSCRYPT_SET_CONTEXT_MAX_SIZE)
+	 * @fs_data: If called from fscrypt_set_context(), this will be the
+	 *	     value the filesystem passed to fscrypt_set_context().
+	 *	     Otherwise (i.e. when called from
+	 *	     FS_IOC_SET_ENCRYPTION_POLICY) this will be NULL.
+	 *
+	 * i_rwsem will be held for write.
+	 *
+	 * Return: 0 on success, -errno on failure.
+	 */
+	int (*set_context)(struct inode *inode, const void *ctx, size_t len,
+			   void *fs_data);
+
+	/*
+	 * Get the dummy fscrypt policy in use on the filesystem (if any).
+	 *
+	 * Filesystems only need to implement this function if they support the
+	 * test_dummy_encryption mount option.
+	 *
+	 * Return: A pointer to the dummy fscrypt policy, if the filesystem is
+	 *	   mounted with test_dummy_encryption; otherwise NULL.
+	 */
+	const union fscrypt_policy *(*get_dummy_policy)(struct super_block *sb);
+
+	/*
+	 * Check whether a directory is empty.  i_rwsem will be held for write.
+	 */
+	bool (*empty_dir)(struct inode *inode);
+
+	/*
+	 * Check whether the filesystem's inode numbers and UUID are stable,
+	 * meaning that they will never be changed even by offline operations
+	 * such as filesystem shrinking and therefore can be used in the
+	 * encryption without the possibility of files becoming unreadable.
+	 *
+	 * Filesystems only need to implement this function if they want to
+	 * support the FSCRYPT_POLICY_FLAG_IV_INO_LBLK_{32,64} flags.  These
+	 * flags are designed to work around the limitations of UFS and eMMC
+	 * inline crypto hardware, and they shouldn't be used in scenarios where
+	 * such hardware isn't being used.
+	 *
+	 * Leaving this NULL is equivalent to always returning false.
+	 */
 	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
+	 * only has a single such block device, or an ERR_PTR() on error.
+	 *
+	 * On successful non-NULL return, *num_devs is set to the number of
+	 * devices in the returned array.  The caller must free the returned
+	 * array using kfree().
+	 *
+	 * If the filesystem can use multiple block devices (other than block
+	 * devices that aren't used for encrypted file contents, such as
+	 * external journal devices), and wants to support inline encryption,
+	 * then it must implement this function.  Otherwise it's not needed.
+	 */
+	struct block_device **(*get_devices)(struct super_block *sb,
+					     unsigned int *num_devs);
 };
 
-static inline bool fscrypt_has_encryption_key(const struct inode *inode)
+static inline struct fscrypt_info *fscrypt_get_info(const struct inode *inode)
 {
-	/* pairs with cmpxchg_release() in fscrypt_get_encryption_info() */
-	return READ_ONCE(inode->i_crypt_info) != NULL;
+	/*
+	 * Pairs with the cmpxchg_release() in fscrypt_setup_encryption_info().
+	 * I.e., another task may publish ->i_crypt_info concurrently, executing
+	 * a RELEASE barrier.  We need to use smp_load_acquire() here to safely
+	 * ACQUIRE the memory the other task published.
+	 */
+	return smp_load_acquire(&inode->i_crypt_info);
 }
 
 /**
  * fscrypt_needs_contents_encryption() - check whether an inode needs
  *					 contents encryption
+ * @inode: the inode to check
  *
  * Return: %true iff the inode is an encrypted regular file and the kernel was
  * built with fscrypt support.
@@ -87,41 +205,63 @@ static inline bool fscrypt_needs_contents_encryption(const struct inode *inode)
 	return IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode);
 }
 
-static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
+/*
+ * When d_splice_alias() moves a directory's no-key alias to its plaintext alias
+ * as a result of the encryption key being added, DCACHE_NOKEY_NAME must be
+ * cleared.  Note that we don't have to support arbitrary moves of this flag
+ * because fscrypt doesn't allow no-key names to be the source or target of a
+ * rename().
+ */
+static inline void fscrypt_handle_d_move(struct dentry *dentry)
 {
-	return inode->i_sb->s_cop->dummy_context &&
-		inode->i_sb->s_cop->dummy_context(inode);
+	dentry->d_flags &= ~DCACHE_NOKEY_NAME;
 }
 
-/*
- * When d_splice_alias() moves a directory's encrypted alias to its decrypted
- * alias as a result of the encryption key being added, DCACHE_ENCRYPTED_NAME
- * must be cleared.  Note that we don't have to support arbitrary moves of this
- * flag because fscrypt doesn't allow encrypted aliases to be the source or
- * target of a rename().
+/**
+ * fscrypt_is_nokey_name() - test whether a dentry is a no-key name
+ * @dentry: the dentry to check
+ *
+ * This returns true if the dentry is a no-key dentry.  A no-key dentry is a
+ * dentry that was created in an encrypted directory that hasn't had its
+ * encryption key added yet.  Such dentries may be either positive or negative.
+ *
+ * When a filesystem is asked to create a new filename in an encrypted directory
+ * and the new filename's dentry is a no-key dentry, it must fail the operation
+ * with ENOKEY.  This includes ->create(), ->mkdir(), ->mknod(), ->symlink(),
+ * ->rename(), and ->link().  (However, ->rename() and ->link() are already
+ * handled by fscrypt_prepare_rename() and fscrypt_prepare_link().)
+ *
+ * This is necessary because creating a filename requires the directory's
+ * encryption key, but just checking for the key on the directory inode during
+ * the final filesystem operation doesn't guarantee that the key was available
+ * during the preceding dentry lookup.  And the key must have already been
+ * available during the dentry lookup in order for it to have been checked
+ * whether the filename already exists in the directory and for the new file's
+ * dentry not to be invalidated due to it incorrectly having the no-key flag.
+ *
+ * Return: %true if the dentry is a no-key name
  */
-static inline void fscrypt_handle_d_move(struct dentry *dentry)
+static inline bool fscrypt_is_nokey_name(const struct dentry *dentry)
 {
-	dentry->d_flags &= ~DCACHE_ENCRYPTED_NAME;
+	return dentry->d_flags & DCACHE_NOKEY_NAME;
 }
 
 /* crypto.c */
-extern void fscrypt_enqueue_decrypt_work(struct work_struct *);
-
-extern struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
-						     unsigned int len,
-						     unsigned int offs,
-						     gfp_t gfp_flags);
-extern int fscrypt_encrypt_block_inplace(const struct inode *inode,
-					 struct page *page, unsigned int len,
-					 unsigned int offs, u64 lblk_num,
-					 gfp_t gfp_flags);
-
-extern int fscrypt_decrypt_pagecache_blocks(struct page *page, unsigned int len,
-					    unsigned int offs);
-extern int fscrypt_decrypt_block_inplace(const struct inode *inode,
-					 struct page *page, unsigned int len,
-					 unsigned int offs, u64 lblk_num);
+void fscrypt_enqueue_decrypt_work(struct work_struct *);
+
+struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
+					      unsigned int len,
+					      unsigned int offs,
+					      gfp_t gfp_flags);
+int fscrypt_encrypt_block_inplace(const struct inode *inode, struct page *page,
+				  unsigned int len, unsigned int offs,
+				  u64 lblk_num, gfp_t gfp_flags);
+
+int fscrypt_decrypt_pagecache_blocks(struct page *page, unsigned int len,
+				     unsigned int offs);
+int fscrypt_decrypt_block_inplace(const struct inode *inode, struct page *page,
+				  unsigned int len, unsigned int offs,
+				  u64 lblk_num);
 
 static inline bool fscrypt_is_bounce_page(struct page *page)
 {
@@ -133,77 +273,107 @@ static inline struct page *fscrypt_pagecache_page(struct page *bounce_page)
 	return (struct page *)page_private(bounce_page);
 }
 
-extern void fscrypt_free_bounce_page(struct page *bounce_page);
+void fscrypt_free_bounce_page(struct page *bounce_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_ioctl_get_policy_ex(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);
+int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg);
+int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg);
+int fscrypt_ioctl_get_policy_ex(struct file *filp, void __user *arg);
+int fscrypt_ioctl_get_nonce(struct file *filp, void __user *arg);
+int fscrypt_has_permitted_context(struct inode *parent, struct inode *child);
+int fscrypt_context_for_new_inode(void *ctx, struct inode *inode);
+int fscrypt_set_context(struct inode *inode, void *fs_data);
+
+struct fscrypt_dummy_policy {
+	const union fscrypt_policy *policy;
+};
+
+int fscrypt_parse_test_dummy_encryption(const struct fs_parameter *param,
+				    struct fscrypt_dummy_policy *dummy_policy);
+bool fscrypt_dummy_policies_equal(const struct fscrypt_dummy_policy *p1,
+				  const struct fscrypt_dummy_policy *p2);
+void fscrypt_show_test_dummy_encryption(struct seq_file *seq, char sep,
+					struct super_block *sb);
+static inline bool
+fscrypt_is_dummy_policy_set(const struct fscrypt_dummy_policy *dummy_policy)
+{
+	return dummy_policy->policy != NULL;
+}
+static inline void
+fscrypt_free_dummy_policy(struct fscrypt_dummy_policy *dummy_policy)
+{
+	kfree(dummy_policy->policy);
+	dummy_policy->policy = NULL;
+}
+
 /* keyring.c */
-extern void fscrypt_sb_free(struct super_block *sb);
-extern int fscrypt_ioctl_add_key(struct file *filp, void __user *arg);
-extern int fscrypt_ioctl_remove_key(struct file *filp, void __user *arg);
-extern int fscrypt_ioctl_remove_key_all_users(struct file *filp,
-					      void __user *arg);
-extern int fscrypt_ioctl_get_key_status(struct file *filp, void __user *arg);
+void fscrypt_destroy_keyring(struct super_block *sb);
+int fscrypt_ioctl_add_key(struct file *filp, void __user *arg);
+int fscrypt_add_test_dummy_key(struct super_block *sb,
+			       const struct fscrypt_dummy_policy *dummy_policy);
+int fscrypt_ioctl_remove_key(struct file *filp, void __user *arg);
+int fscrypt_ioctl_remove_key_all_users(struct file *filp, void __user *arg);
+int fscrypt_ioctl_get_key_status(struct file *filp, void __user *arg);
 
 /* keysetup.c */
-extern int fscrypt_get_encryption_info(struct inode *);
-extern void fscrypt_put_encryption_info(struct inode *);
-extern void fscrypt_free_inode(struct inode *);
-extern int fscrypt_drop_inode(struct inode *inode);
+int fscrypt_prepare_new_inode(struct inode *dir, struct inode *inode,
+			      bool *encrypt_ret);
+void fscrypt_put_encryption_info(struct inode *inode);
+void fscrypt_free_inode(struct inode *inode);
+int fscrypt_drop_inode(struct inode *inode);
 
 /* fname.c */
-extern int fscrypt_setup_filename(struct inode *, const struct qstr *,
-				int lookup, struct fscrypt_name *);
+int fscrypt_fname_encrypt(const struct inode *inode, const struct qstr *iname,
+			  u8 *out, unsigned int olen);
+bool fscrypt_fname_encrypted_size(const struct inode *inode, u32 orig_len,
+				  u32 max_len, u32 *encrypted_len_ret);
+int fscrypt_setup_filename(struct inode *inode, const struct qstr *iname,
+			   int lookup, struct fscrypt_name *fname);
 
 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(const struct inode *inode,
-				     u32 hash, u32 minor_hash,
-				     const struct fscrypt_str *iname,
-				     struct fscrypt_str *oname);
-extern bool fscrypt_match_name(const struct fscrypt_name *fname,
-			       const u8 *de_name, u32 de_name_len);
-extern u64 fscrypt_fname_siphash(const struct inode *dir,
-				 const struct qstr *name);
+int fscrypt_fname_alloc_buffer(u32 max_encrypted_len,
+			       struct fscrypt_str *crypto_str);
+void fscrypt_fname_free_buffer(struct fscrypt_str *crypto_str);
+int fscrypt_fname_disk_to_usr(const struct inode *inode,
+			      u32 hash, u32 minor_hash,
+			      const struct fscrypt_str *iname,
+			      struct fscrypt_str *oname);
+bool fscrypt_match_name(const struct fscrypt_name *fname,
+			const u8 *de_name, u32 de_name_len);
+u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name);
+int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags);
 
 /* bio.c */
-extern void fscrypt_decrypt_bio(struct bio *);
-extern int fscrypt_zeroout_range(const struct inode *, pgoff_t, sector_t,
-				 unsigned int);
+bool fscrypt_decrypt_bio(struct bio *bio);
+int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
+			  sector_t pblk, unsigned int len);
 
 /* hooks.c */
-extern int fscrypt_file_open(struct inode *inode, struct file *filp);
-extern int __fscrypt_prepare_link(struct inode *inode, struct inode *dir,
-				  struct dentry *dentry);
-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,
-				    struct fscrypt_name *fname);
-extern int fscrypt_prepare_setflags(struct inode *inode,
-				    unsigned int oldflags, unsigned int flags);
-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);
+int fscrypt_file_open(struct inode *inode, struct file *filp);
+int __fscrypt_prepare_link(struct inode *inode, struct inode *dir,
+			   struct dentry *dentry);
+int __fscrypt_prepare_rename(struct inode *old_dir, struct dentry *old_dentry,
+			     struct inode *new_dir, struct dentry *new_dentry,
+			     unsigned int flags);
+int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry,
+			     struct fscrypt_name *fname);
+int __fscrypt_prepare_readdir(struct inode *dir);
+int __fscrypt_prepare_setattr(struct dentry *dentry, struct iattr *attr);
+int fscrypt_prepare_setflags(struct inode *inode,
+			     unsigned int oldflags, unsigned int flags);
+int fscrypt_prepare_symlink(struct inode *dir, const char *target,
+			    unsigned int len, unsigned int max_len,
+			    struct fscrypt_str *disk_link);
+int __fscrypt_encrypt_symlink(struct inode *inode, const char *target,
+			      unsigned int len, struct fscrypt_str *disk_link);
+const char *fscrypt_get_symlink(struct inode *inode, const void *caddr,
+				unsigned int max_size,
+				struct delayed_call *done);
+int fscrypt_symlink_getattr(const struct path *path, struct kstat *stat);
 static inline void fscrypt_set_ops(struct super_block *sb,
 				   const struct fscrypt_operations *s_cop)
 {
@@ -211,9 +381,9 @@ static inline void fscrypt_set_ops(struct super_block *sb,
 }
 #else  /* !CONFIG_FS_ENCRYPTION */
 
-static inline bool fscrypt_has_encryption_key(const struct inode *inode)
+static inline struct fscrypt_info *fscrypt_get_info(const struct inode *inode)
 {
-	return false;
+	return NULL;
 }
 
 static inline bool fscrypt_needs_contents_encryption(const struct inode *inode)
@@ -221,13 +391,13 @@ static inline bool fscrypt_needs_contents_encryption(const struct inode *inode)
 	return false;
 }
 
-static inline bool fscrypt_dummy_context_enabled(struct inode *inode)
+static inline void fscrypt_handle_d_move(struct dentry *dentry)
 {
-	return false;
 }
 
-static inline void fscrypt_handle_d_move(struct dentry *dentry)
+static inline bool fscrypt_is_nokey_name(const struct dentry *dentry)
 {
+	return false;
 }
 
 /* crypto.c */
@@ -300,21 +470,58 @@ static inline int fscrypt_ioctl_get_policy_ex(struct file *filp,
 	return -EOPNOTSUPP;
 }
 
+static inline int fscrypt_ioctl_get_nonce(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)
+static inline int fscrypt_set_context(struct inode *inode, void *fs_data)
 {
 	return -EOPNOTSUPP;
 }
 
+struct fscrypt_dummy_policy {
+};
+
+static inline int
+fscrypt_parse_test_dummy_encryption(const struct fs_parameter *param,
+				    struct fscrypt_dummy_policy *dummy_policy)
+{
+	return -EINVAL;
+}
+
+static inline bool
+fscrypt_dummy_policies_equal(const struct fscrypt_dummy_policy *p1,
+			     const struct fscrypt_dummy_policy *p2)
+{
+	return true;
+}
+
+static inline void fscrypt_show_test_dummy_encryption(struct seq_file *seq,
+						      char sep,
+						      struct super_block *sb)
+{
+}
+
+static inline bool
+fscrypt_is_dummy_policy_set(const struct fscrypt_dummy_policy *dummy_policy)
+{
+	return false;
+}
+
+static inline void
+fscrypt_free_dummy_policy(struct fscrypt_dummy_policy *dummy_policy)
+{
+}
+
 /* keyring.c */
-static inline void fscrypt_sb_free(struct super_block *sb)
+static inline void fscrypt_destroy_keyring(struct super_block *sb)
 {
 }
 
@@ -323,6 +530,13 @@ static inline int fscrypt_ioctl_add_key(struct file *filp, void __user *arg)
 	return -EOPNOTSUPP;
 }
 
+static inline int
+fscrypt_add_test_dummy_key(struct super_block *sb,
+			   const struct fscrypt_dummy_policy *dummy_policy)
+{
+	return 0;
+}
+
 static inline int fscrypt_ioctl_remove_key(struct file *filp, void __user *arg)
 {
 	return -EOPNOTSUPP;
@@ -341,9 +555,14 @@ static inline int fscrypt_ioctl_get_key_status(struct file *filp,
 }
 
 /* keysetup.c */
-static inline int fscrypt_get_encryption_info(struct inode *inode)
+
+static inline int fscrypt_prepare_new_inode(struct inode *dir,
+					    struct inode *inode,
+					    bool *encrypt_ret)
 {
-	return -EOPNOTSUPP;
+	if (IS_ENCRYPTED(dir))
+		return -EOPNOTSUPP;
+	return 0;
 }
 
 static inline void fscrypt_put_encryption_info(struct inode *inode)
@@ -380,8 +599,7 @@ 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,
+static inline int fscrypt_fname_alloc_buffer(u32 max_encrypted_len,
 					     struct fscrypt_str *crypto_str)
 {
 	return -EOPNOTSUPP;
@@ -416,9 +634,16 @@ static inline u64 fscrypt_fname_siphash(const struct inode *dir,
 	return 0;
 }
 
+static inline int fscrypt_d_revalidate(struct dentry *dentry,
+				       unsigned int flags)
+{
+	return 1;
+}
+
 /* bio.c */
-static inline void fscrypt_decrypt_bio(struct bio *bio)
+static inline bool fscrypt_decrypt_bio(struct bio *bio)
 {
+	return true;
 }
 
 static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
@@ -458,6 +683,17 @@ static inline int __fscrypt_prepare_lookup(struct inode *dir,
 	return -EOPNOTSUPP;
 }
 
+static inline int __fscrypt_prepare_readdir(struct inode *dir)
+{
+	return -EOPNOTSUPP;
+}
+
+static inline int __fscrypt_prepare_setattr(struct dentry *dentry,
+					    struct iattr *attr)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline int fscrypt_prepare_setflags(struct inode *inode,
 					   unsigned int oldflags,
 					   unsigned int flags)
@@ -465,15 +701,21 @@ static inline int fscrypt_prepare_setflags(struct inode *inode,
 	return 0;
 }
 
-static inline int __fscrypt_prepare_symlink(struct inode *dir,
-					    unsigned int len,
-					    unsigned int max_len,
-					    struct fscrypt_str *disk_link)
+static inline int fscrypt_prepare_symlink(struct inode *dir,
+					  const char *target,
+					  unsigned int len,
+					  unsigned int max_len,
+					  struct fscrypt_str *disk_link)
 {
-	return -EOPNOTSUPP;
+	if (IS_ENCRYPTED(dir))
+		return -EOPNOTSUPP;
+	disk_link->name = (unsigned char *)target;
+	disk_link->len = len + 1;
+	if (disk_link->len > max_len)
+		return -ENAMETOOLONG;
+	return 0;
 }
 
-
 static inline int __fscrypt_encrypt_symlink(struct inode *inode,
 					    const char *target,
 					    unsigned int len,
@@ -490,6 +732,12 @@ static inline const char *fscrypt_get_symlink(struct inode *inode,
 	return ERR_PTR(-EOPNOTSUPP);
 }
 
+static inline int fscrypt_symlink_getattr(const struct path *path,
+					  struct kstat *stat)
+{
+	return -EOPNOTSUPP;
+}
+
 static inline void fscrypt_set_ops(struct super_block *sb,
 				   const struct fscrypt_operations *s_cop)
 {
@@ -497,42 +745,124 @@ static inline void fscrypt_set_ops(struct super_block *sb,
 
 #endif	/* !CONFIG_FS_ENCRYPTION */
 
+/* inline_crypt.c */
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+
+bool __fscrypt_inode_uses_inline_crypto(const struct inode *inode);
+
+void fscrypt_set_bio_crypt_ctx(struct bio *bio,
+			       const struct inode *inode, u64 first_lblk,
+			       gfp_t gfp_mask);
+
+void fscrypt_set_bio_crypt_ctx_bh(struct bio *bio,
+				  const struct buffer_head *first_bh,
+				  gfp_t gfp_mask);
+
+bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode,
+			   u64 next_lblk);
+
+bool fscrypt_mergeable_bio_bh(struct bio *bio,
+			      const struct buffer_head *next_bh);
+
+bool fscrypt_dio_supported(struct inode *inode);
+
+u64 fscrypt_limit_io_blocks(const struct inode *inode, u64 lblk, u64 nr_blocks);
+
+#else /* CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+
+static inline bool __fscrypt_inode_uses_inline_crypto(const struct inode *inode)
+{
+	return false;
+}
+
+static inline void fscrypt_set_bio_crypt_ctx(struct bio *bio,
+					     const struct inode *inode,
+					     u64 first_lblk, gfp_t gfp_mask) { }
+
+static inline void fscrypt_set_bio_crypt_ctx_bh(
+					 struct bio *bio,
+					 const struct buffer_head *first_bh,
+					 gfp_t gfp_mask) { }
+
+static inline bool fscrypt_mergeable_bio(struct bio *bio,
+					 const struct inode *inode,
+					 u64 next_lblk)
+{
+	return true;
+}
+
+static inline bool fscrypt_mergeable_bio_bh(struct bio *bio,
+					    const struct buffer_head *next_bh)
+{
+	return true;
+}
+
+static inline bool fscrypt_dio_supported(struct inode *inode)
+{
+	return !fscrypt_needs_contents_encryption(inode);
+}
+
+static inline u64 fscrypt_limit_io_blocks(const struct inode *inode, u64 lblk,
+					  u64 nr_blocks)
+{
+	return nr_blocks;
+}
+#endif /* !CONFIG_FS_ENCRYPTION_INLINE_CRYPT */
+
 /**
- * fscrypt_require_key - require an inode's encryption key
- * @inode: the inode we need the key for
+ * fscrypt_inode_uses_inline_crypto() - test whether an inode uses inline
+ *					encryption
+ * @inode: an inode. If encrypted, its key must be set up.
  *
- * If the inode is encrypted, set up its encryption key if not already done.
- * Then require that the key be present and return -ENOKEY otherwise.
- *
- * No locks are needed, and the key will live as long as the struct inode --- so
- * it won't go away from under you.
+ * Return: true if the inode requires file contents encryption and if the
+ *	   encryption should be done in the block layer via blk-crypto rather
+ *	   than in the filesystem layer.
+ */
+static inline bool fscrypt_inode_uses_inline_crypto(const struct inode *inode)
+{
+	return fscrypt_needs_contents_encryption(inode) &&
+	       __fscrypt_inode_uses_inline_crypto(inode);
+}
+
+/**
+ * fscrypt_inode_uses_fs_layer_crypto() - test whether an inode uses fs-layer
+ *					  encryption
+ * @inode: an inode. If encrypted, its key must be set up.
  *
- * Return: 0 on success, -ENOKEY if the key is missing, or another -errno code
- * if a problem occurred while setting up the encryption key.
+ * Return: true if the inode requires file contents encryption and if the
+ *	   encryption should be done in the filesystem layer rather than in the
+ *	   block layer via blk-crypto.
  */
-static inline int fscrypt_require_key(struct inode *inode)
+static inline bool fscrypt_inode_uses_fs_layer_crypto(const struct inode *inode)
 {
-	if (IS_ENCRYPTED(inode)) {
-		int err = fscrypt_get_encryption_info(inode);
+	return fscrypt_needs_contents_encryption(inode) &&
+	       !__fscrypt_inode_uses_inline_crypto(inode);
+}
 
-		if (err)
-			return err;
-		if (!fscrypt_has_encryption_key(inode))
-			return -ENOKEY;
-	}
-	return 0;
+/**
+ * fscrypt_has_encryption_key() - check whether an inode has had its key set up
+ * @inode: the inode to check
+ *
+ * Return: %true if the inode has had its encryption key set up, else %false.
+ *
+ * Usually this should be preceded by fscrypt_get_encryption_info() to try to
+ * set up the key first.
+ */
+static inline bool fscrypt_has_encryption_key(const struct inode *inode)
+{
+	return fscrypt_get_info(inode) != NULL;
 }
 
 /**
- * fscrypt_prepare_link - prepare to link an inode into a possibly-encrypted directory
+ * fscrypt_prepare_link() - prepare to link an inode into a possibly-encrypted
+ *			    directory
  * @old_dentry: an existing dentry for the inode being linked
  * @dir: the target directory
  * @dentry: negative dentry for the target filename
  *
  * A new link can only be added to an encrypted directory if the directory's
  * encryption key is available --- since otherwise we'd have no way to encrypt
- * the filename.  Therefore, we first set up the directory's encryption key (if
- * not already done) and return an error if it's unavailable.
+ * the filename.
  *
  * We also verify that the link will not violate the constraint that all files
  * in an encrypted directory tree use the same encryption policy.
@@ -551,7 +881,8 @@ static inline int fscrypt_prepare_link(struct dentry *old_dentry,
 }
 
 /**
- * fscrypt_prepare_rename - prepare for a rename between possibly-encrypted directories
+ * fscrypt_prepare_rename() - prepare for a rename between possibly-encrypted
+ *			      directories
  * @old_dir: source directory
  * @old_dentry: dentry for source file
  * @new_dir: target directory
@@ -584,23 +915,27 @@ static inline int fscrypt_prepare_rename(struct inode *old_dir,
 }
 
 /**
- * fscrypt_prepare_lookup - prepare to lookup a name in a possibly-encrypted directory
+ * fscrypt_prepare_lookup() - prepare to lookup a name in a possibly-encrypted
+ *			      directory
  * @dir: directory being searched
  * @dentry: filename being looked up
  * @fname: (output) the name to use to search the on-disk directory
  *
  * Prepare for ->lookup() in a directory which may be encrypted by determining
- * the name that will actually be used to search the directory on-disk.  Lookups
- * can be done with or without the directory's encryption key; without the key,
- * filenames are presented in encrypted form.  Therefore, we'll try to set up
- * the directory's encryption key, but even without it the lookup can continue.
+ * the name that will actually be used to search the directory on-disk.  If the
+ * directory's encryption policy is supported by this kernel and its encryption
+ * key is available, then the lookup is assumed to be by plaintext name;
+ * otherwise, it is assumed to be by no-key name.
  *
- * This also installs a custom ->d_revalidate() method which will invalidate the
- * dentry if it was created without the key and the key is later added.
+ * This will set DCACHE_NOKEY_NAME on the dentry if the lookup is by no-key
+ * name.  In this case the filesystem must assign the dentry a dentry_operations
+ * which contains fscrypt_d_revalidate (or contains a d_revalidate method that
+ * calls fscrypt_d_revalidate), so that the dentry will be invalidated if the
+ * directory's encryption key is later added.
  *
- * Return: 0 on success; -ENOENT if key is unavailable but the filename isn't a
- * correctly formed encoded ciphertext name, so a negative dentry should be
- * created; or another -errno code.
+ * Return: 0 on success; -ENOENT if the directory's key is unavailable but the
+ * filename isn't a valid no-key name, so a negative dentry should be created;
+ * or another -errno code.
  */
 static inline int fscrypt_prepare_lookup(struct inode *dir,
 					 struct dentry *dentry,
@@ -617,7 +952,28 @@ static inline int fscrypt_prepare_lookup(struct inode *dir,
 }
 
 /**
- * fscrypt_prepare_setattr - prepare to change a possibly-encrypted inode's attributes
+ * fscrypt_prepare_readdir() - prepare to read a possibly-encrypted directory
+ * @dir: the directory inode
+ *
+ * If the directory is encrypted and it doesn't already have its encryption key
+ * set up, try to set it up so that the filenames will be listed in plaintext
+ * form rather than in no-key form.
+ *
+ * Return: 0 on success; -errno on error.  Note that the encryption key being
+ *	   unavailable is not considered an error.  It is also not an error if
+ *	   the encryption policy is unsupported by this kernel; that is treated
+ *	   like the key being unavailable, so that files can still be deleted.
+ */
+static inline int fscrypt_prepare_readdir(struct inode *dir)
+{
+	if (IS_ENCRYPTED(dir))
+		return __fscrypt_prepare_readdir(dir);
+	return 0;
+}
+
+/**
+ * fscrypt_prepare_setattr() - prepare to change a possibly-encrypted inode's
+ *			       attributes
  * @dentry: dentry through which the inode is being changed
  * @attr: attributes to change
  *
@@ -636,52 +992,13 @@ static inline int fscrypt_prepare_lookup(struct inode *dir,
 static inline int fscrypt_prepare_setattr(struct dentry *dentry,
 					  struct iattr *attr)
 {
-	if (attr->ia_valid & ATTR_SIZE)
-		return fscrypt_require_key(d_inode(dentry));
-	return 0;
-}
-
-/**
- * fscrypt_prepare_symlink - prepare to create a possibly-encrypted symlink
- * @dir: directory in which the symlink is being created
- * @target: plaintext symlink target
- * @len: length of @target excluding null terminator
- * @max_len: space the filesystem has available to store the symlink target
- * @disk_link: (out) the on-disk symlink target being prepared
- *
- * This function computes the size the symlink target will require on-disk,
- * stores it in @disk_link->len, and validates it against @max_len.  An
- * encrypted symlink may be longer than the original.
- *
- * Additionally, @disk_link->name is set to @target if the symlink will be
- * unencrypted, but left NULL if the symlink will be encrypted.  For encrypted
- * symlinks, the filesystem must call fscrypt_encrypt_symlink() to create the
- * on-disk target later.  (The reason for the two-step process is that some
- * filesystems need to know the size of the symlink target before creating the
- * inode, e.g. to determine whether it will be a "fast" or "slow" symlink.)
- *
- * Return: 0 on success, -ENAMETOOLONG if the symlink target is too long,
- * -ENOKEY if the encryption key is missing, or another -errno code if a problem
- * occurred while setting up the encryption key.
- */
-static inline int fscrypt_prepare_symlink(struct inode *dir,
-					  const char *target,
-					  unsigned int len,
-					  unsigned int max_len,
-					  struct fscrypt_str *disk_link)
-{
-	if (IS_ENCRYPTED(dir) || fscrypt_dummy_context_enabled(dir))
-		return __fscrypt_prepare_symlink(dir, len, max_len, disk_link);
-
-	disk_link->name = (unsigned char *)target;
-	disk_link->len = len + 1;
-	if (disk_link->len > max_len)
-		return -ENAMETOOLONG;
+	if (IS_ENCRYPTED(d_inode(dentry)))
+		return __fscrypt_prepare_setattr(dentry, attr);
 	return 0;
 }
 
 /**
- * fscrypt_encrypt_symlink - encrypt the symlink target if needed
+ * fscrypt_encrypt_symlink() - encrypt the symlink target if needed
  * @inode: symlink inode
  * @target: plaintext symlink target
  * @len: length of @target excluding null terminator