I've started implementing support for O_TMPFILE in xfs_io in preparation for proper testcases and found something rather annoying: Given that we implicitly pass O_DIRECTORY as part of the full O_TMPFILE flag an open using O_TMPFILE will simply succeed on a kernel old enough to not have O_TMPFILE support, and give you a file descriptor for the directory passed in. Of course this only works if you open the fd read-only which isn't all that useful for real temporary files, but it would be the natural choice for a feature test. I guess we can't really fix this up any more, but does anyone have a good idea how to document this properly in the man page? -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html