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

Pull fsverity updates from Eric Biggers:
 "Expose the fs-verity bit through statx()"

* tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
  docs: fs-verity: mention statx() support
  f2fs: support STATX_ATTR_VERITY
  ext4: support STATX_ATTR_VERITY
  statx: define STATX_ATTR_VERITY
  docs: fs-verity: document first supported kernel version

Documentation/filesystems/fsverity.rst

@@ -226,6 +226,14 @@ To do so, check for FS_VERITY_FL (0x00100000) in the returned flags.
 The verity flag is not settable via FS_IOC_SETFLAGS.  You must use
 FS_IOC_ENABLE_VERITY instead, since parameters must be provided.
 
+statx
+-----
+
+Since Linux v5.5, the statx() system call sets STATX_ATTR_VERITY if
+the file has fs-verity enabled.  This can perform better than
+FS_IOC_GETFLAGS and FS_IOC_MEASURE_VERITY because it doesn't require
+opening the file, and opening verity files can be expensive.
+
 Accessing verity files
 ======================
 
@@ -398,7 +406,7 @@ pages have been read into the pagecache.  (See `Verifying data`_.)
 ext4
 ----
 
-ext4 supports fs-verity since Linux TODO and e2fsprogs v1.45.2.
+ext4 supports fs-verity since Linux v5.4 and e2fsprogs v1.45.2.
 
 To create verity files on an ext4 filesystem, the filesystem must have
 been formatted with ``-O verity`` or had ``tune2fs -O verity`` run on
@@ -434,7 +442,7 @@ also only supports extent-based files.
 f2fs
 ----
 
-f2fs supports fs-verity since Linux TODO and f2fs-tools v1.11.0.
+f2fs supports fs-verity since Linux v5.4 and f2fs-tools v1.11.0.
 
 To create verity files on an f2fs filesystem, the filesystem must have
 been formatted with ``-O verity``.

fs/ext4/inode.c

@@ -5717,12 +5717,15 @@ int ext4_getattr(const struct path *path, struct kstat *stat,
 		stat->attributes |= STATX_ATTR_IMMUTABLE;
 	if (flags & EXT4_NODUMP_FL)
 		stat->attributes |= STATX_ATTR_NODUMP;
+	if (flags & EXT4_VERITY_FL)
+		stat->attributes |= STATX_ATTR_VERITY;
 
 	stat->attributes_mask |= (STATX_ATTR_APPEND |
 				  STATX_ATTR_COMPRESSED |
 				  STATX_ATTR_ENCRYPTED |
 				  STATX_ATTR_IMMUTABLE |
-				  STATX_ATTR_NODUMP);
+				  STATX_ATTR_NODUMP |
+				  STATX_ATTR_VERITY);
 
 	generic_fillattr(inode, stat);
 	return 0;

fs/f2fs/file.c

@@ -726,11 +726,14 @@ int f2fs_getattr(const struct path *path, struct kstat *stat,
 		stat->attributes |= STATX_ATTR_IMMUTABLE;
 	if (flags & F2FS_NODUMP_FL)
 		stat->attributes |= STATX_ATTR_NODUMP;
+	if (IS_VERITY(inode))
+		stat->attributes |= STATX_ATTR_VERITY;
 
 	stat->attributes_mask |= (STATX_ATTR_APPEND |
 				  STATX_ATTR_ENCRYPTED |
 				  STATX_ATTR_IMMUTABLE |
-				  STATX_ATTR_NODUMP);
+				  STATX_ATTR_NODUMP |
+				  STATX_ATTR_VERITY);
 
 	generic_fillattr(inode, stat);
 

include/linux/stat.h

@@ -33,7 +33,8 @@ struct kstat {
 	 STATX_ATTR_IMMUTABLE |				\
 	 STATX_ATTR_APPEND |				\
 	 STATX_ATTR_NODUMP |				\
-	 STATX_ATTR_ENCRYPTED				\
+	 STATX_ATTR_ENCRYPTED |				\
+	 STATX_ATTR_VERITY				\
 	 )/* Attrs corresponding to FS_*_FL flags */
 	u64		ino;
 	dev_t		dev;

include/uapi/linux/stat.h

@@ -167,8 +167,8 @@ struct statx {
 #define STATX_ATTR_APPEND		0x00000020 /* [I] File is append-only */
 #define STATX_ATTR_NODUMP		0x00000040 /* [I] File is not to be dumped */
 #define STATX_ATTR_ENCRYPTED		0x00000800 /* [I] File requires key to decrypt in fs */
-
 #define STATX_ATTR_AUTOMOUNT		0x00001000 /* Dir: Automount trigger */
+#define STATX_ATTR_VERITY		0x00100000 /* [I] Verity protected file */
 
 
 #endif /* _UAPI_LINUX_STAT_H */