On Fri, Oct 12, 2018 at 10:08:57PM -0600, Andreas Dilger wrote:
> It's not that I'm _so_ worried about the values changing, just
> that I was following the ACL code paths around, and the caller
> is passing in MAY_* flags on the one side, but then comparing
> them to values set from S_I*OTH flags on disk and it made me
> wonder if something was broken, or if it might break in the future.
>
> I would definitely agree that S_I* flags are set in stone, but
> I've never really thought of MAY_* flags as being directly tied
> to on-disk values because there are so many more than just
> MAY_{READ,WRITE,EXECUTE} - MAY_APPEND, MAY_OPEN, etc. I'd always
> thought of them like the EXT4_IMMUTABLE_FL on-disk flags vs.
> the S_IMMUTABLE inode flags in memory.
In theory - yes, in practice... imm/append-only are nowhere near
as common and didn't have universal values on-disk (ext* ones are
different from ufs ones, for example).
It might be worth a comment (near the definition of MAY_...,
probably mentioning that MAY_READ/MAY_WRITE/MAY_EXEC are
also equal to R_OK/W_OK/X_OK), but that's about it.
