Re: [PATCH v4 2/2] interpret-trailers: add option for in-place editing

> Eric Sunshine <sunshine@sunshineco.com> writes:
>> My understanding is that SANITY is an expectation that directory
>> permissions work in an expected POSIXy way: that is, a file can't be
>> deleted when its containing directory lacks 'write', and a file can't
>> be read/accessed when the directory has neither 'read' nor 'execute'.
>> This doesn't say anything about root not being allowed to read a file
>> when the file itself lacks 'read'.
>
> In short, SANITY is "does looking at permission bits sufficient to
> anticipate what the filesystem would do?" while POSIXPERM is "can
> chmod be used to tweak permission bits of the filesystem" (a
> filesystem that lacks permission bits support would qualify as
> !POSIXPERM, as there is nothing to tweak in the first place).
>
> I suspect the comment added by f400e51c and its patch description
> stressed too much about permission of a directory affecting what we
> can do to files inside the directory, and failed to describe another
> criteria for a sane environment: "files whose permission bits say
> you shouldn't be able to read or write cannot be read or written".