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| author | Michael Halcrow <mhalcrow@google.com> | 2015-04-12 00:43:56 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2015-04-12 00:43:56 -0400 |
| commit | b30ab0e03407d2aa2d9316cba199c757e4bfc8ad (patch) | |
| tree | 900754eb3fe069f90bb5ea2c1df1ed88cf701eb5 /fs/ext4/super.c | |
| parent | 9bd8212f981ea6375911fe055382ad7529be5b28 (diff) | |
| download | lwn-b30ab0e03407d2aa2d9316cba199c757e4bfc8ad.tar.gz lwn-b30ab0e03407d2aa2d9316cba199c757e4bfc8ad.zip | |
ext4 crypto: add ext4 encryption facilities
On encrypt, we will re-assign the buffer_heads to point to a bounce
page rather than the control_page (which is the original page to write
that contains the plaintext). The block I/O occurs against the bounce
page. On write completion, we re-assign the buffer_heads to the
original plaintext page.
On decrypt, we will attach a read completion callback to the bio
struct. This read completion will decrypt the read contents in-place
prior to setting the page up-to-date.
The current encryption mode, AES-256-XTS, lacks cryptographic
integrity. AES-256-GCM is in-plan, but we will need to devise a
mechanism for handling the integrity data.
Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Ildar Muslukhov <ildarm@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/super.c')
| -rw-r--r-- | fs/ext4/super.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index e47a552fea05..1008ca258de4 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -876,6 +876,9 @@ static struct inode *ext4_alloc_inode(struct super_block *sb) atomic_set(&ei->i_ioend_count, 0); atomic_set(&ei->i_unwritten, 0); INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work); +#ifdef CONFIG_EXT4_FS_ENCRYPTION + ei->i_encryption_key.mode = EXT4_ENCRYPTION_MODE_INVALID; +#endif return &ei->vfs_inode; } @@ -3431,6 +3434,11 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) if (sb->s_bdev->bd_part) sbi->s_sectors_written_start = part_stat_read(sb->s_bdev->bd_part, sectors[1]); +#ifdef CONFIG_EXT4_FS_ENCRYPTION + /* Modes of operations for file and directory encryption. */ + sbi->s_file_encryption_mode = EXT4_ENCRYPTION_MODE_AES_256_XTS; + sbi->s_dir_encryption_mode = EXT4_ENCRYPTION_MODE_INVALID; +#endif /* Cleanup superblock name */ for (cp = sb->s_id; (cp = strchr(cp, '/'));) |