ext4 crypto: migrate into vfs's crypto engine

This patch removes the most parts of internal crypto codes.
And then, it modifies and adds some ext4-specific crypt codes to use the generic
facility.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 74 insertions, 134 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 96c73e6..ea31931 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -32,6 +32,7 @@
 #include <linux/percpu_counter.h>
 #include <linux/ratelimit.h>
 #include <crypto/hash.h>
+#include <linux/fscrypto.h>
 #include <linux/falloc.h>
 #include <linux/percpu-rwsem.h>
 #ifdef __KERNEL__
@@ -608,15 +609,6 @@ enum {
 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER	0x0010
 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER	0x0020
 
-/* Encryption algorithms */
-#define EXT4_ENCRYPTION_MODE_INVALID		0
-#define EXT4_ENCRYPTION_MODE_AES_256_XTS	1
-#define EXT4_ENCRYPTION_MODE_AES_256_GCM	2
-#define EXT4_ENCRYPTION_MODE_AES_256_CBC	3
-#define EXT4_ENCRYPTION_MODE_AES_256_CTS	4
-
-#include "ext4_crypto.h"
-
 /*
  * ioctl commands
  */
@@ -638,9 +630,9 @@ enum {
 #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
 #define EXT4_IOC_SWAP_BOOT		_IO('f', 17)
 #define EXT4_IOC_PRECACHE_EXTENTS	_IO('f', 18)
-#define EXT4_IOC_SET_ENCRYPTION_POLICY	_IOR('f', 19, struct ext4_encryption_policy)
-#define EXT4_IOC_GET_ENCRYPTION_PWSALT	_IOW('f', 20, __u8[16])
-#define EXT4_IOC_GET_ENCRYPTION_POLICY	_IOW('f', 21, struct ext4_encryption_policy)
+#define EXT4_IOC_SET_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
+#define EXT4_IOC_GET_ENCRYPTION_PWSALT	FS_IOC_GET_ENCRYPTION_PWSALT
+#define EXT4_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY
 
 #ifndef FS_IOC_FSGETXATTR
 /* Until the uapi changes get merged for project quota... */
@@ -1082,10 +1074,6 @@ struct ext4_inode_info {
 	/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
 	__u32 i_csum_seed;
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-	/* Encryption params */
-	struct ext4_crypt_info *i_crypt_info;
-#endif
 	kprojid_t i_projid;
 };
 
@@ -1344,6 +1332,11 @@ struct ext4_super_block {
 /* Number of quota types we support */
 #define EXT4_MAXQUOTAS 3
 
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#define EXT4_KEY_DESC_PREFIX "ext4:"
+#define EXT4_KEY_DESC_PREFIX_SIZE 5
+#endif
+
 /*
  * fourth extended-fs super-block data in memory
  */
@@ -1513,6 +1506,12 @@ struct ext4_sb_info {
 
 	/* Barrier between changing inodes' journal flags and writepages ops. */
 	struct percpu_rw_semaphore s_journal_flag_rwsem;
+
+	/* Encryption support */
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+	u8 key_prefix[EXT4_KEY_DESC_PREFIX_SIZE];
+	u8 key_prefix_size;
+#endif
 };
 
 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
@@ -1611,15 +1610,6 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
 /*
  * Returns true if the inode is inode is encrypted
  */
-static inline int ext4_encrypted_inode(struct inode *inode)
-{
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-	return ext4_test_inode_flag(inode, EXT4_INODE_ENCRYPT);
-#else
-	return 0;
-#endif
-}
-
 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
 
 /*
@@ -2083,10 +2073,10 @@ struct dx_hash_info
 
 struct ext4_filename {
 	const struct qstr *usr_fname;
-	struct ext4_str disk_name;
+	struct fscrypt_str disk_name;
 	struct dx_hash_info hinfo;
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-	struct ext4_str crypto_buf;
+	struct fscrypt_str crypto_buf;
 #endif
 };
 
@@ -2297,132 +2287,82 @@ extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
 					      struct ext4_group_desc *gdp);
 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
 
-/* crypto_policy.c */
-int ext4_is_child_context_consistent_with_parent(struct inode *parent,
-						 struct inode *child);
-int ext4_inherit_context(struct inode *parent, struct inode *child);
-void ext4_to_hex(char *dst, char *src, size_t src_size);
-int ext4_process_policy(const struct ext4_encryption_policy *policy,
-			struct inode *inode);
-int ext4_get_policy(struct inode *inode,
-		    struct ext4_encryption_policy *policy);
-
-/* crypto.c */
-extern struct kmem_cache *ext4_crypt_info_cachep;
-bool ext4_valid_contents_enc_mode(uint32_t mode);
-uint32_t ext4_validate_encryption_key_size(uint32_t mode, uint32_t size);
-extern struct workqueue_struct *ext4_read_workqueue;
-struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode,
-					    gfp_t gfp_flags);
-void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx);
-void ext4_restore_control_page(struct page *data_page);
-struct page *ext4_encrypt(struct inode *inode,
-			  struct page *plaintext_page,
-			  gfp_t gfp_flags);
-int ext4_decrypt(struct page *page);
-int ext4_encrypted_zeroout(struct inode *inode, ext4_lblk_t lblk,
-			   ext4_fsblk_t pblk, ext4_lblk_t len);
-extern const struct dentry_operations ext4_encrypted_d_ops;
-
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-int ext4_init_crypto(void);
-void ext4_exit_crypto(void);
 static inline int ext4_sb_has_crypto(struct super_block *sb)
 {
 	return ext4_has_feature_encrypt(sb);
 }
-#else
-static inline int ext4_init_crypto(void) { return 0; }
-static inline void ext4_exit_crypto(void) { }
-static inline int ext4_sb_has_crypto(struct super_block *sb)
+
+static inline bool ext4_encrypted_inode(struct inode *inode)
 {
-	return 0;
+	return ext4_test_inode_flag(inode, EXT4_INODE_ENCRYPT);
 }
-#endif
 
-/* crypto_fname.c */
-bool ext4_valid_filenames_enc_mode(uint32_t mode);
-u32 ext4_fname_crypto_round_up(u32 size, u32 blksize);
-unsigned ext4_fname_encrypted_size(struct inode *inode, u32 ilen);
-int ext4_fname_crypto_alloc_buffer(struct inode *inode,
-				   u32 ilen, struct ext4_str *crypto_str);
-int _ext4_fname_disk_to_usr(struct inode *inode,
-			    struct dx_hash_info *hinfo,
-			    const struct ext4_str *iname,
-			    struct ext4_str *oname);
-int ext4_fname_disk_to_usr(struct inode *inode,
-			   struct dx_hash_info *hinfo,
-			   const struct ext4_dir_entry_2 *de,
-			   struct ext4_str *oname);
-int ext4_fname_usr_to_disk(struct inode *inode,
-			   const struct qstr *iname,
-			   struct ext4_str *oname);
 #ifdef CONFIG_EXT4_FS_ENCRYPTION
-void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str);
-int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
-			      int lookup, struct ext4_filename *fname);
-void ext4_fname_free_filename(struct ext4_filename *fname);
-#else
-static inline
-int ext4_setup_fname_crypto(struct inode *inode)
-{
-	return 0;
-}
-static inline void ext4_fname_crypto_free_buffer(struct ext4_str *p) { }
 static inline int ext4_fname_setup_filename(struct inode *dir,
-				     const struct qstr *iname,
-				     int lookup, struct ext4_filename *fname)
+			const struct qstr *iname,
+			int lookup, struct ext4_filename *fname)
 {
-	fname->usr_fname = iname;
-	fname->disk_name.name = (unsigned char *) iname->name;
-	fname->disk_name.len = iname->len;
-	return 0;
-}
-static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
-#endif
-
+	struct fscrypt_name name;
+	int err;
 
-/* crypto_key.c */
-void ext4_free_crypt_info(struct ext4_crypt_info *ci);
-void ext4_free_encryption_info(struct inode *inode, struct ext4_crypt_info *ci);
-int _ext4_get_encryption_info(struct inode *inode);
+	memset(fname, 0, sizeof(struct ext4_filename));
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-int ext4_has_encryption_key(struct inode *inode);
+	err = fscrypt_setup_filename(dir, iname, lookup, &name);
 
-static inline int ext4_get_encryption_info(struct inode *inode)
-{
-	struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
-
-	if (!ci ||
-	    (ci->ci_keyring_key &&
-	     (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
-					   (1 << KEY_FLAG_REVOKED) |
-					   (1 << KEY_FLAG_DEAD)))))
-		return _ext4_get_encryption_info(inode);
-	return 0;
+	fname->usr_fname = name.usr_fname;
+	fname->disk_name = name.disk_name;
+	fname->hinfo.hash = name.hash;
+	fname->hinfo.minor_hash = name.minor_hash;
+	fname->crypto_buf = name.crypto_buf;
+	return err;
 }
 
-static inline struct ext4_crypt_info *ext4_encryption_info(struct inode *inode)
+static inline void ext4_fname_free_filename(struct ext4_filename *fname)
 {
-	return EXT4_I(inode)->i_crypt_info;
-}
+	struct fscrypt_name name;
 
-#else
-static inline int ext4_has_encryption_key(struct inode *inode)
-{
-	return 0;
+	name.crypto_buf = fname->crypto_buf;
+	fscrypt_free_filename(&name);
+
+	fname->crypto_buf.name = NULL;
+	fname->usr_fname = NULL;
+	fname->disk_name.name = NULL;
 }
-static inline int ext4_get_encryption_info(struct inode *inode)
+#else
+static inline int ext4_fname_setup_filename(struct inode *dir,
+		const struct qstr *iname,
+		int lookup, struct ext4_filename *fname)
 {
+	fname->usr_fname = iname;
+	fname->disk_name.name = (unsigned char *) iname->name;
+	fname->disk_name.len = iname->len;
 	return 0;
 }
-static inline struct ext4_crypt_info *ext4_encryption_info(struct inode *inode)
-{
-	return NULL;
-}
-#endif
+static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
 
+#define fscrypt_set_d_op(i)
+#define fscrypt_get_ctx			fscrypt_notsupp_get_ctx
+#define fscrypt_release_ctx		fscrypt_notsupp_release_ctx
+#define fscrypt_encrypt_page		fscrypt_notsupp_encrypt_page
+#define fscrypt_decrypt_page		fscrypt_notsupp_decrypt_page
+#define fscrypt_decrypt_bio_pages	fscrypt_notsupp_decrypt_bio_pages
+#define fscrypt_pullback_bio_page	fscrypt_notsupp_pullback_bio_page
+#define fscrypt_restore_control_page	fscrypt_notsupp_restore_control_page
+#define fscrypt_zeroout_range		fscrypt_notsupp_zeroout_range
+#define fscrypt_process_policy		fscrypt_notsupp_process_policy
+#define fscrypt_get_policy		fscrypt_notsupp_get_policy
+#define fscrypt_has_permitted_context	fscrypt_notsupp_has_permitted_context
+#define fscrypt_inherit_context		fscrypt_notsupp_inherit_context
+#define fscrypt_get_encryption_info	fscrypt_notsupp_get_encryption_info
+#define fscrypt_put_encryption_info	fscrypt_notsupp_put_encryption_info
+#define fscrypt_setup_filename		fscrypt_notsupp_setup_filename
+#define fscrypt_free_filename		fscrypt_notsupp_free_filename
+#define fscrypt_fname_encrypted_size	fscrypt_notsupp_fname_encrypted_size
+#define fscrypt_fname_alloc_buffer	fscrypt_notsupp_fname_alloc_buffer
+#define fscrypt_fname_free_buffer	fscrypt_notsupp_fname_free_buffer
+#define fscrypt_fname_disk_to_usr	fscrypt_notsupp_fname_disk_to_usr
+#define fscrypt_fname_usr_to_disk	fscrypt_notsupp_fname_usr_to_disk
+#endif
 
 /* dir.c */
 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
@@ -2436,7 +2376,7 @@ extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
 				__u32 minor_hash,
 				struct ext4_dir_entry_2 *dirent,
-				struct ext4_str *ent_name);
+				struct fscrypt_str *ent_name);
 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
 			     struct buffer_head *bh,
@@ -2624,7 +2564,7 @@ extern int ext4_generic_delete_entry(handle_t *handle,
 				     void *entry_buf,
 				     int buf_size,
 				     int csum_size);
-extern int ext4_empty_dir(struct inode *inode);
+extern bool ext4_empty_dir(struct inode *inode);
 
 /* resize.c */
 extern int ext4_group_add(struct super_block *sb,
@@ -3106,7 +3046,7 @@ extern int ext4_delete_inline_entry(handle_t *handle,
 				    struct ext4_dir_entry_2 *de_del,
 				    struct buffer_head *bh,
 				    int *has_inline_data);
-extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
+extern bool empty_inline_dir(struct inode *dir, int *has_inline_data);
 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
 					struct ext4_dir_entry_2 **parent_de,
 					int *retval);