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| author | Jaegeuk Kim <jaegeuk@kernel.org> | 2016-05-05 05:05:01 (GMT) |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2016-05-07 17:32:33 (GMT) |
| commit | b5a7aef1ef436ec005fef0efe31a676ec5f4ab31 (patch) | |
| tree | c3eb022f963b70eadb066e8c87b7041236955289 /fs/f2fs/f2fs.h | |
| parent | 09210c973af30320edc03a6325422cdd0f03b580 (diff) | |
| download | linux-b5a7aef1ef436ec005fef0efe31a676ec5f4ab31.tar.xz | |
fscrypto/f2fs: allow fs-specific key prefix for fs encryption
This patch allows fscrypto to handle a second key prefix given by filesystem.
The main reason is to provide backward compatibility, since previously f2fs
used "f2fs:" as a crypto prefix instead of "fscrypt:".
Later, ext4 should also provide key_prefix() to give "ext4:".
One concern decribed by Ted would be kinda double check overhead of prefixes.
In x86, for example, validate_user_key consumes 8 ms after boot-up, which turns
out derive_key_aes() consumed most of the time to load specific crypto module.
After such the cold miss, it shows almost zero latencies, which treats as a
negligible overhead.
Note that request_key() detects wrong prefix in prior to derive_key_aes() even.
Cc: Ted Tso <tytso@mit.edu>
Cc: stable@vger.kernel.org # v4.6
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/f2fs.h')
| -rw-r--r-- | fs/f2fs/f2fs.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index ccf8bf4..dbd277e 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -711,6 +711,10 @@ enum { MAX_TIME, }; +#ifdef CONFIG_F2FS_FS_ENCRYPTION +#define F2FS_KEY_DESC_PREFIX "f2fs:" +#define F2FS_KEY_DESC_PREFIX_SIZE 5 +#endif struct f2fs_sb_info { struct super_block *sb; /* pointer to VFS super block */ struct proc_dir_entry *s_proc; /* proc entry */ @@ -718,6 +722,10 @@ struct f2fs_sb_info { int valid_super_block; /* valid super block no */ int s_flag; /* flags for sbi */ +#ifdef CONFIG_F2FS_FS_ENCRYPTION + u8 key_prefix[F2FS_KEY_DESC_PREFIX_SIZE]; + u8 key_prefix_size; +#endif /* for node-related operations */ struct f2fs_nm_info *nm_info; /* node manager */ struct inode *node_inode; /* cache node blocks */ |