[PATCH 06/10] fs crypto: add Makefile and Kconfig

[Jaegeuk Kim]

This patch adds a facility to enable per-file encryption.

Arnd fixes a missing CONFIG_BLOCK check in the original patch.
"The newly added generic crypto abstraction for file systems operates
on 'struct bio' objects, which do not exist when CONFIG_BLOCK is
disabled:

fs/crypto/crypto.c: In function 'fscrypt_zeroout_range':
fs/crypto/crypto.c:308:9: error: implicit declaration of function 'bio_alloc' [-Werror=implicit-function-declaration]

This adds a Kconfig dependency that prevents FS_ENCRYPTION from being
enabled without BLOCK."

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
 fs/Kconfig         |  2 ++
 fs/Makefile        |  1 +
 fs/crypto/Kconfig  | 18 ++++++++++++++++++
 fs/crypto/Makefile |  3 +++
 4 files changed, 24 insertions(+)
 create mode 100644 fs/crypto/Kconfig
 create mode 100644 fs/crypto/Makefile

diff --git a/fs/Kconfig b/fs/Kconfig
index 9adee0d..9d75767 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -84,6 +84,8 @@ config MANDATORY_FILE_LOCKING
 
 	  To the best of my knowledge this is dead code that no one cares about.
 
+source "fs/crypto/Kconfig"
+
 source "fs/notify/Kconfig"
 
 source "fs/quota/Kconfig"
diff --git a/fs/Makefile b/fs/Makefile
index 79f5225..252c968 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_EVENTFD)		+= eventfd.o
 obj-$(CONFIG_USERFAULTFD)	+= userfaultfd.o
 obj-$(CONFIG_AIO)               += aio.o
 obj-$(CONFIG_FS_DAX)		+= dax.o
+obj-$(CONFIG_FS_ENCRYPTION)	+= crypto/
 obj-$(CONFIG_FILE_LOCKING)      += locks.o
 obj-$(CONFIG_COMPAT)		+= compat.o compat_ioctl.o
 obj-$(CONFIG_BINFMT_AOUT)	+= binfmt_aout.o
diff --git a/fs/crypto/Kconfig b/fs/crypto/Kconfig
new file mode 100644
index 0000000..92348fa
--- /dev/null
+++ b/fs/crypto/Kconfig
@@ -0,0 +1,18 @@
+config FS_ENCRYPTION
+	tristate "FS Encryption (Per-file encryption)"
+	depends on BLOCK
+	select CRYPTO
+	select CRYPTO_AES
+	select CRYPTO_CBC
+	select CRYPTO_ECB
+	select CRYPTO_XTS
+	select CRYPTO_CTS
+	select CRYPTO_CTR
+	select CRYPTO_SHA256
+	select KEYS
+	select ENCRYPTED_KEYS
+	help
+	  Enable encryption of files and directories.  This
+	  feature is similar to ecryptfs, but it is more memory
+	  efficient since it avoids caching the encrypted and
+	  decrypted pages in the page cache.
diff --git a/fs/crypto/Makefile b/fs/crypto/Makefile
new file mode 100644
index 0000000..f17684c
--- /dev/null
+++ b/fs/crypto/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_FS_ENCRYPTION)	+= fscrypto.o
+
+fscrypto-y := crypto.o fname.o policy.o keyinfo.o
-- 
2.6.3