[PATCH] umount: always use umount2 syscall with specified flags

[Jody Bruchon]

On 2015-10-13 08:42, Denys Vlasenko wrote:
 > On Tue, Oct 13, 2015 at 1:00 PM, Jody Bruchon <jody at jodybruchon.com> 
wrote:
 >> I agree. There is no good reason for doing this at all. It looks 
like someone has intentionally obfuscated the code. If it's for throwing 
an error on invalid configurations, other constructs exist that are much 
more clear and are better supported.
 >
 > What construct do you propose?

This makes it sound like the whole OPT_FORCE/OPT_LAZY thing is unnecessary:
// MNT_FORCE and MNT_DETACH (from linux/fs.h) must match
// OPT_FORCE and OPT_LAZY.

If OPT_FORCE and OPT_LAZY must be the same as MNT_FORCE and MNT_DETACH 
respectively, and we're including the system header where those values 
are defined, why not use the header's names directly and thereby 
eliminate the perverted typedef? Does it have to do with elimination of 
options in the build system (i.e. does OPT_* cause items in 
OPTION_STRING to be modified during building?)

Ignoring that observation, I would propose that #ifdef comparison(s) and 
an #error where they mismatch would be much clearer than using a 
conditionally invalid typedef that is not intended to be functional C code.