I agree this needs some more explanation in the source code, the idea is that once we have modified all file systems to correctly set the actual limits, we can then detect any newly added file system that forgets to set them, so we don't get accidental incorrect limits.
But if a superblock supports full 64 bit time resolution (i.e. MIN_VFS_TIME to MAX_VFS_TIME) then you can't tell the difference and will warn inappropriately.
No, this will not happen. The max and min values are reversed for invalid values and the condition as mentioned in the commit text for catching invalid ranges in the vfs layer is max_time < min_time.
I will add a comment in the code to clarify.
Quoting from the patch:
+#define MAX_INVALID_VFS_TIME S64_MIN +#define MIN_INVALID_VFS_TIME S64_MAX
I will post a v2 which removes these macros and makes use of MAX/MIN_VFS_TIME macros instead.
-Deepa