Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt

Pull fscrypt updates from Eric Biggers:

 - Preparations for supporting encryption on ext4 filesystems where the
   filesystem block size is smaller than PAGE_SIZE.

 - Don't allow setting encryption policies on dead directories.

 - Various cleanups.

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
  fscrypt: document testing with xfstests
  fscrypt: remove selection of CONFIG_CRYPTO_SHA256
  fscrypt: remove unnecessary includes of ratelimit.h
  fscrypt: don't set policy for a dead directory
  ext4: encrypt only up to last block in ext4_bio_write_page()
  ext4: decrypt only the needed block in __ext4_block_zero_page_range()
  ext4: decrypt only the needed blocks in ext4_block_write_begin()
  ext4: clear BH_Uptodate flag on decryption error
  fscrypt: decrypt only the needed blocks in __fscrypt_decrypt_bio()
  fscrypt: support decrypting multiple filesystem blocks per page
  fscrypt: introduce fscrypt_decrypt_block_inplace()
  fscrypt: handle blocksize < PAGE_SIZE in fscrypt_zeroout_range()
  fscrypt: support encrypting multiple filesystem blocks per page
  fscrypt: introduce fscrypt_encrypt_block_inplace()
  fscrypt: clean up some BUG_ON()s in block encryption/decryption
  fscrypt: rename fscrypt_do_page_crypto() to fscrypt_crypt_block()
  fscrypt: remove the "write" part of struct fscrypt_ctx
  fscrypt: simplify bounce page handling

1 files changed, 66 insertions, 30 deletions

diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index f7680ef1abd2..bd8f207a2fb6 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -63,16 +63,13 @@ struct fscrypt_operations {
 	unsigned int max_namelen;
 };
 
+/* Decryption work */
 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 */
@@ -106,18 +103,33 @@ static inline void fscrypt_handle_d_move(struct dentry *dentry)
 extern void fscrypt_enqueue_decrypt_work(struct work_struct *);
 extern struct fscrypt_ctx *fscrypt_get_ctx(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)
+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);
+
+static inline bool fscrypt_is_bounce_page(struct page *page)
+{
+	return page->mapping == NULL;
+}
+
+static inline struct page *fscrypt_pagecache_page(struct page *bounce_page)
 {
-	return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
+	return (struct page *)page_private(bounce_page);
 }
 
-extern void fscrypt_restore_control_page(struct page *);
+extern void fscrypt_free_bounce_page(struct page *bounce_page);
 
 /* policy.c */
 extern int fscrypt_ioctl_set_policy(struct file *, const void __user *);
@@ -223,7 +235,6 @@ static inline bool fscrypt_match_name(const struct fscrypt_name *fname,
 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);
 
@@ -283,32 +294,51 @@ static inline void fscrypt_release_ctx(struct fscrypt_ctx *ctx)
 	return;
 }
 
-static inline struct page *fscrypt_encrypt_page(const struct inode *inode,
+static inline struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
+							    unsigned int len,
+							    unsigned int offs,
+							    gfp_t gfp_flags)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+
+static inline 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)
+						unsigned int offs, u64 lblk_num,
+						gfp_t gfp_flags)
 {
-	return ERR_PTR(-EOPNOTSUPP);
+	return -EOPNOTSUPP;
+}
+
+static inline int fscrypt_decrypt_pagecache_blocks(struct page *page,
+						   unsigned int len,
+						   unsigned int offs)
+{
+	return -EOPNOTSUPP;
 }
 
-static inline int fscrypt_decrypt_page(const struct inode *inode,
-				       struct page *page,
-				       unsigned int len, unsigned int offs,
-				       u64 lblk_num)
+static inline int fscrypt_decrypt_block_inplace(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)
+static inline bool fscrypt_is_bounce_page(struct page *page)
+{
+	return false;
+}
+
+static inline struct page *fscrypt_pagecache_page(struct page *bounce_page)
 {
 	WARN_ON_ONCE(1);
 	return ERR_PTR(-EINVAL);
 }
 
-static inline void fscrypt_restore_control_page(struct page *page)
+static inline void fscrypt_free_bounce_page(struct page *bounce_page)
 {
-	return;
 }
 
 /* policy.c */
@@ -410,11 +440,6 @@ static inline void fscrypt_enqueue_decrypt_bio(struct fscrypt_ctx *ctx,
 {
 }
 
-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)
 {
@@ -692,4 +717,15 @@ static inline int fscrypt_encrypt_symlink(struct inode *inode,
 	return 0;
 }
 
+/* If *pagep is a bounce page, free it and set *pagep to the pagecache page */
+static inline void fscrypt_finalize_bounce_page(struct page **pagep)
+{
+	struct page *page = *pagep;
+
+	if (fscrypt_is_bounce_page(page)) {
+		*pagep = fscrypt_pagecache_page(page);
+		fscrypt_free_bounce_page(page);
+	}
+}
+
 #endif	/* _LINUX_FSCRYPT_H */