[RFC 1/4] fscrypt: introduce USE_FS_ENCRYPTION

[Niels de Vos <ndevos@redhat.com>]

The new USE_FS_ENCRYPTION define is added so that filesystems can
opt-out of supporting fscrypt, while other filesystems have fscrypt
enabled.

Signed-off-by: Niels de Vos <ndevos@redhat.com>
---
 fs/crypto/fscrypt_private.h | 2 ++
 fs/ext4/ext4.h              | 4 ++++
 fs/f2fs/f2fs.h              | 4 ++++
 fs/ubifs/ubifs.h            | 3 +++
 include/linux/fscrypt.h     | 6 +++---
 5 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index d5f68a0c5d15..f8dc3aab80b3 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -11,6 +11,8 @@
 #ifndef _FSCRYPT_PRIVATE_H
 #define _FSCRYPT_PRIVATE_H
 
+#define USE_FS_ENCRYPTION
+
 #include <linux/fscrypt.h>
 #include <linux/siphash.h>
 #include <crypto/hash.h>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 8d5453852f98..23c2ceaa074d 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -41,7 +41,11 @@
 #include <linux/compat.h>
 #endif
 
+#ifdef CONFIG_FS_ENCRYPTION
+#define USE_FS_ENCRYPTION
+#endif
 #include <linux/fscrypt.h>
+
 #include <linux/fsverity.h>
 
 #include <linux/compiler.h>
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e6355a5683b7..194844029633 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -26,7 +26,11 @@
 #include <linux/part_stat.h>
 #include <crypto/hash.h>
 
+#ifdef CONFIG_FS_ENCRYPTION
+#define USE_FS_ENCRYPTION
+#endif
 #include <linux/fscrypt.h>
+
 #include <linux/fsverity.h>
 
 struct pagevec;
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 478bbbb5382f..3ef0e9ef5015 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -33,6 +33,9 @@
 #include <crypto/hash.h>
 #include <crypto/algapi.h>
 
+#ifdef CONFIG_FS_ENCRYPTION
+#define USE_FS_ENCRYPTION
+#endif
 #include <linux/fscrypt.h>
 
 #include "ubifs-media.h"
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 4f5f8a651213..403a686619f8 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -57,7 +57,7 @@ struct fscrypt_name {
 /* Maximum value for the third parameter of fscrypt_operations.set_context(). */
 #define FSCRYPT_SET_CONTEXT_MAX_SIZE	40
 
-#ifdef CONFIG_FS_ENCRYPTION
+#if defined(CONFIG_FS_ENCRYPTION) && defined(USE_FS_ENCRYPTION)
 
 /*
  * If set, the fscrypt bounce page pool won't be allocated (unless another
@@ -379,7 +379,7 @@ static inline void fscrypt_set_ops(struct super_block *sb,
 {
 	sb->s_cop = s_cop;
 }
-#else  /* !CONFIG_FS_ENCRYPTION */
+#else  /* !CONFIG_FS_ENCRYPTION || !USE_FS_ENCRYPTION */
 
 static inline struct fscrypt_info *fscrypt_get_info(const struct inode *inode)
 {
@@ -743,7 +743,7 @@ static inline void fscrypt_set_ops(struct super_block *sb,
 {
 }
 
-#endif	/* !CONFIG_FS_ENCRYPTION */
+#endif	/* !CONFIG_FS_ENCRYPTION || !USE_FS_ENCRYPTION */
 
 /* inline_crypt.c */
 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
-- 
2.37.3