fscrypt: clean up include file mess

Filesystems have to include different header files based on whether they
are compiled with encryption support or not. That's nasty and messy.

Instead, rationalise the headers so we have a single include fscrypt.h
and let it decide what internal implementation to include based on the
__FS_HAS_ENCRYPTION define.  Filesystems set __FS_HAS_ENCRYPTION to 1
before including linux/fscrypt.h if they are built with encryption
support.  Otherwise, they must set __FS_HAS_ENCRYPTION to 0.

Add guards to prevent fscrypt_supp.h and fscrypt_notsupp.h from being
directly included by filesystems.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
[EB: use 1 and 0 rather than defined/undefined]
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index a1d5021c31ef8f494b5ae96cd4e2129976e43ef3..a180981ee6d70ac02f745a185c29187257c7d772 100644 (file)
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -11,7 +11,8 @@
 #ifndef _FSCRYPT_PRIVATE_H
 #define _FSCRYPT_PRIVATE_H
 
-#include <linux/fscrypt_supp.h>
+#define __FS_HAS_ENCRYPTION 1
+#include <linux/fscrypt.h>
 #include <crypto/hash.h>
 
 /* Encryption parameters */

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index e2abe01c8c6bac60e04ef26fd4559c854fbef280..ca6d6166b85c5d04cf9269e8d7c4f30482dd6318 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -33,17 +33,15 @@
 #include <linux/percpu_counter.h>
 #include <linux/ratelimit.h>
 #include <crypto/hash.h>
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
-#include <linux/fscrypt_supp.h>
-#else
-#include <linux/fscrypt_notsupp.h>
-#endif
 #include <linux/falloc.h>
 #include <linux/percpu-rwsem.h>
 #ifdef __KERNEL__
 #include <linux/compat.h>
 #endif
 
+#define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_EXT4_FS_ENCRYPTION)
+#include <linux/fscrypt.h>
+
 /*
  * The fourth extended filesystem constants/structures
  */

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 9a7c903869477835afe192e15b064c6832297520..fc53aebaf3ae868234209d8959a3f36c8925d8bd 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -23,13 +23,11 @@
 #include <linux/bio.h>
 #include <linux/blkdev.h>
 #include <linux/quotaops.h>
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
-#include <linux/fscrypt_supp.h>
-#else
-#include <linux/fscrypt_notsupp.h>
-#endif
 #include <crypto/hash.h>
 
+#define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_F2FS_FS_ENCRYPTION)
+#include <linux/fscrypt.h>
+
 #ifdef CONFIG_F2FS_CHECK_FS
 #define f2fs_bug_on(sbi, condition)    BUG_ON(condition)
 #else

diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index cd43651f173141dd854d07ffc140a953cab92f10..6a346d4af98fa32c96621ca4e859d1de81aa6915 100644 (file)
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -38,12 +38,11 @@
 #include <linux/backing-dev.h>
 #include <linux/security.h>
 #include <linux/xattr.h>
-#ifdef CONFIG_UBIFS_FS_ENCRYPTION
-#include <linux/fscrypt_supp.h>
-#else
-#include <linux/fscrypt_notsupp.h>
-#endif
 #include <linux/random.h>
+
+#define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_UBIFS_FS_ENCRYPTION)
+#include <linux/fscrypt.h>
+
 #include "ubifs-media.h"
 
 /* Version of this UBIFS implementation */

diff --git a/include/linux/fscrypt_common.h b/include/linux/fscrypt.h
similarity index 80%
rename from include/linux/fscrypt_common.h
rename to include/linux/fscrypt.h
index 97f738628b36e2684622a67e01d37f2e0c77e6be..bfc962e62078c1d3ab700af8e5ee44b6d62309f5 100644 (file)
--- a/include/linux/fscrypt_common.h
+++ b/include/linux/fscrypt.h
@@ -1,14 +1,17 @@
 /*
- * fscrypt_common.h: common declarations for per-file encryption
+ * fscrypt.h: declarations for per-file encryption
+ *
+ * Filesystems that implement per-file encryption include this header
+ * file with the __FS_HAS_ENCRYPTION set according to whether that filesystem
+ * is being built with encryption support or not.
  *
  * Copyright (C) 2015, Google, Inc.
  *
  * Written by Michael Halcrow, 2015.
  * Modified by Jaegeuk Kim, 2015.
  */
-
-#ifndef _LINUX_FSCRYPT_COMMON_H
-#define _LINUX_FSCRYPT_COMMON_H
+#ifndef _LINUX_FSCRYPT_H
+#define _LINUX_FSCRYPT_H
 
 #include <linux/key.h>
 #include <linux/fs.h>
@@ -119,23 +122,35 @@ static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
        return false;
 }
 
+#if __FS_HAS_ENCRYPTION
+
 static inline struct page *fscrypt_control_page(struct page *page)
 {
-#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
        return ((struct fscrypt_ctx *)page_private(page))->w.control_page;
-#else
+}
+
+static inline bool fscrypt_has_encryption_key(const struct inode *inode)
+{
+       return (inode->i_crypt_info != NULL);
+}
+
+#include <linux/fscrypt_supp.h>
+
+#else /* !__FS_HAS_ENCRYPTION */
+
+static inline struct page *fscrypt_control_page(struct page *page)
+{
        WARN_ON_ONCE(1);
        return ERR_PTR(-EINVAL);
-#endif
 }
 
-static inline int fscrypt_has_encryption_key(const struct inode *inode)
+static inline bool fscrypt_has_encryption_key(const struct inode *inode)
 {
-#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
-       return (inode->i_crypt_info != NULL);
-#else
        return 0;
-#endif
 }
 
-#endif /* _LINUX_FSCRYPT_COMMON_H */
+#include <linux/fscrypt_notsupp.h>
+#endif /* __FS_HAS_ENCRYPTION */
+
+
+#endif /* _LINUX_FSCRYPT_H */

diff --git a/include/linux/fscrypt_notsupp.h b/include/linux/fscrypt_notsupp.h
index ec406aed2f2f8c3331d0002fba8a83036e75c08b..2d0b6960831e44e764570cb86c3c9176afb30f56 100644 (file)
--- a/include/linux/fscrypt_notsupp.h
+++ b/include/linux/fscrypt_notsupp.h
@@ -3,13 +3,16 @@
  *
  * This stubs out the fscrypt functions for filesystems configured without
  * encryption support.
+ *
+ * Do not include this file directly. Use fscrypt.h instead!
  */
+#ifndef _LINUX_FSCRYPT_H
+#error "Incorrect include of linux/fscrypt_notsupp.h!"
+#endif
 
 #ifndef _LINUX_FSCRYPT_NOTSUPP_H
 #define _LINUX_FSCRYPT_NOTSUPP_H
 
-#include <linux/fscrypt_common.h>
-
 /* crypto.c */
 static inline struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *inode,
                                                  gfp_t gfp_flags)

diff --git a/include/linux/fscrypt_supp.h b/include/linux/fscrypt_supp.h
index 32e2fcf13b015ed198381c06c750b84ada99cafd..5a90e5ef4687f2d4923134dd0e75be670cbacc92 100644 (file)
--- a/include/linux/fscrypt_supp.h
+++ b/include/linux/fscrypt_supp.h
@@ -1,14 +1,15 @@
 /*
  * fscrypt_supp.h
  *
- * This is included by filesystems configured with encryption support.
+ * Do not include this file directly. Use fscrypt.h instead!
  */
+#ifndef _LINUX_FSCRYPT_H
+#error "Incorrect include of linux/fscrypt_supp.h!"
+#endif
 
 #ifndef _LINUX_FSCRYPT_SUPP_H
 #define _LINUX_FSCRYPT_SUPP_H
 
-#include <linux/fscrypt_common.h>
-
 /* crypto.c */
 extern struct kmem_cache *fscrypt_info_cachep;
 extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t);