[PATCH v3 05/28] fs: add FS_XFLAG_VERITY for fs-verity sealed inodes

[Andrey Albershteyn <aalbersh@redhat.com>]

Add extended file attribute FS_XFLAG_VERITY for inodes sealed with
fs-verity.

Signed-off-by: Andrey Albershteyn <aalbersh@redhat.com>
---
 Documentation/filesystems/fsverity.rst | 9 +++++++++
 include/uapi/linux/fs.h                | 1 +
 2 files changed, 10 insertions(+)

diff --git a/Documentation/filesystems/fsverity.rst b/Documentation/filesystems/fsverity.rst
index 13e4b18e5dbb..af889512c6ac 100644
--- a/Documentation/filesystems/fsverity.rst
+++ b/Documentation/filesystems/fsverity.rst
@@ -326,6 +326,15 @@ 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.
 
+Extended file attributes
+------------------------
+
+For fs-verity sealed files the FS_XFLAG_VERITY extended file
+attribute is set. The attribute can be observed via lsattr.
+
+    [root@vm:~]# lsattr /mnt/test/foo
+    --------------------V- /mnt/test/foo
+
 .. _accessing_verity_files:
 
 Accessing verity files
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index b7b56871029c..5172a2eb902c 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -140,6 +140,7 @@ struct fsxattr {
 #define FS_XFLAG_FILESTREAM	0x00004000	/* use filestream allocator */
 #define FS_XFLAG_DAX		0x00008000	/* use DAX for IO */
 #define FS_XFLAG_COWEXTSIZE	0x00010000	/* CoW extent size allocator hint */
+#define FS_XFLAG_VERITY		0x00020000	/* fs-verity sealed inode */
 #define FS_XFLAG_HASATTR	0x80000000	/* no DIFLAG for this	*/
 
 /* the read-only stuff doesn't really belong here, but any other place is
-- 
2.40.1