f2fs crypto: add encryption policy and password salt support

This patch adds encryption policy and password salt support through ioctl
implementation.

It adds three ioctls:
 F2FS_IOC_SET_ENCRYPTION_POLICY,
 F2FS_IOC_GET_ENCRYPTION_POLICY,
 F2FS_IOC_GET_ENCRYPTION_PWSALT, which use xattr operations.

Note that, these definition and codes are taken from ext4 crypto support.
For f2fs, xattr operations and on-disk flags for superblock and inode were
changed.

Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Ildar Muslukhov <muslukhovi@gmail.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 2c2948fbc35f..709660bd926a 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -229,6 +229,13 @@ static inline bool __has_cursum_space(struct f2fs_summary_block *sum, int size,
 #define F2FS_IOC_RELEASE_VOLATILE_WRITE _IO(F2FS_IOCTL_MAGIC, 4)
 #define F2FS_IOC_ABORT_VOLATILE_WRITE   _IO(F2FS_IOCTL_MAGIC, 5)
 
+#define F2FS_IOC_SET_ENCRYPTION_POLICY                                  \
+                _IOR('f', 19, struct f2fs_encryption_policy)
+#define F2FS_IOC_GET_ENCRYPTION_PWSALT                                  \
+                _IOW('f', 20, __u8[16])
+#define F2FS_IOC_GET_ENCRYPTION_POLICY                                  \
+                _IOW('f', 21, struct f2fs_encryption_policy)
+
 /*
  * should be same as XFS_IOC_GOINGDOWN.
  * Flags for going down operation used by FS_IOC_GOINGDOWN
@@ -367,6 +374,8 @@ struct f2fs_map_blocks {
 #define F2FS_ENCRYPTION_MODE_AES_256_CBC        3
 #define F2FS_ENCRYPTION_MODE_AES_256_CTS        4
 
+#include "f2fs_crypto.h"
+
 #define DEF_DIR_LEVEL           0
 
 struct f2fs_inode_info {
@@ -1946,4 +1955,11 @@ static inline int f2fs_sb_has_crypto(struct super_block *sb)
         return 0;
 #endif
 }
+
+/* crypto_policy.c */
+int f2fs_is_child_context_consistent_with_parent(struct inode *,
+                                                        struct inode *);
+int f2fs_inherit_context(struct inode *, struct inode *, struct page *);
+int f2fs_process_policy(const struct f2fs_encryption_policy *, struct inode *);
+int f2fs_get_policy(struct inode *, struct f2fs_encryption_policy *);
 #endif