Merge tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt

Pull fs-verity support from Eric Biggers:
 "fs-verity is a filesystem feature that provides Merkle tree based
  hashing (similar to dm-verity) for individual readonly files, mainly
  for the purpose of efficient authenticity verification.

  This pull request includes:

   (a) The fs/verity/ support layer and documentation.

   (b) fs-verity support for ext4 and f2fs.

  Compared to the original fs-verity patchset from last year, the UAPI
  to enable fs-verity on a file has been greatly simplified. Lots of
  other things were cleaned up too.

  fs-verity is planned to be used by two different projects on Android;
  most of the userspace code is in place already. Another userspace tool
  ("fsverity-utils"), and xfstests, are also available. e2fsprogs and
  f2fs-tools already have fs-verity support. Other people have shown
  interest in using fs-verity too.

  I've tested this on ext4 and f2fs with xfstests, both the existing
  tests and the new fs-verity tests. This has also been in linux-next
  since July 30 with no reported issues except a couple minor ones I
  found myself and folded in fixes for.

  Ted and I will be co-maintaining fs-verity"

* tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
  f2fs: add fs-verity support
  ext4: update on-disk format documentation for fs-verity
  ext4: add fs-verity read support
  ext4: add basic fs-verity support
  fs-verity: support builtin file signatures
  fs-verity: add SHA-512 support
  fs-verity: implement FS_IOC_MEASURE_VERITY ioctl
  fs-verity: implement FS_IOC_ENABLE_VERITY ioctl
  fs-verity: add data verification hooks for ->readpages()
  fs-verity: add the hook for file ->setattr()
  fs-verity: add the hook for file ->open()
  fs-verity: add inode and superblock fields
  fs-verity: add Kconfig and the helper functions for hashing
  fs: uapi: define verity bit for FS_IOC_GETFLAGS
  fs-verity: add UAPI header
  fs-verity: add MAINTAINERS file entry
  fs-verity: add a documentation file

2 files changed, 41 insertions, 0 deletions

diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index 41bd84d25a98..aad225b05be7 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -258,6 +258,7 @@ struct fsxattr {
 #define FS_TOPDIR_FL			0x00020000 /* Top of directory hierarchies*/
 #define FS_HUGE_FILE_FL			0x00040000 /* Reserved for ext4 */
 #define FS_EXTENT_FL			0x00080000 /* Extents */
+#define FS_VERITY_FL			0x00100000 /* Verity protected inode */
 #define FS_EA_INODE_FL			0x00200000 /* Inode used for large EA */
 #define FS_EOFBLOCKS_FL			0x00400000 /* Reserved for ext4 */
 #define FS_NOCOW_FL			0x00800000 /* Do not cow file */
diff --git a/include/uapi/linux/fsverity.h b/include/uapi/linux/fsverity.h
new file mode 100644
index 000000000000..da0daf6c193b
--- /dev/null
+++ b/include/uapi/linux/fsverity.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * fs-verity user API
+ *
+ * These ioctls can be used on filesystems that support fs-verity.  See the
+ * "User API" section of Documentation/filesystems/fsverity.rst.
+ *
+ * Copyright 2019 Google LLC
+ */
+#ifndef _UAPI_LINUX_FSVERITY_H
+#define _UAPI_LINUX_FSVERITY_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+#define FS_VERITY_HASH_ALG_SHA256	1
+#define FS_VERITY_HASH_ALG_SHA512	2
+
+struct fsverity_enable_arg {
+	__u32 version;
+	__u32 hash_algorithm;
+	__u32 block_size;
+	__u32 salt_size;
+	__u64 salt_ptr;
+	__u32 sig_size;
+	__u32 __reserved1;
+	__u64 sig_ptr;
+	__u64 __reserved2[11];
+};
+
+struct fsverity_digest {
+	__u16 digest_algorithm;
+	__u16 digest_size; /* input/output */
+	__u8 digest[];
+};
+
+#define FS_IOC_ENABLE_VERITY	_IOW('f', 133, struct fsverity_enable_arg)
+#define FS_IOC_MEASURE_VERITY	_IOWR('f', 134, struct fsverity_digest)
+
+#endif /* _UAPI_LINUX_FSVERITY_H */