Re: [PATCH] tracefs/eventfs: Use root and instance inodes as default ownership

Al Viro
2024-01-04T21:28:51Z

On Thu, Jan 04, 2024 at 11:35:37AM -0800, Linus Torvalds wrote:

> > "file description" - is how the file is accessed (position in the file and
> > flags associated to how it was opened)
>
> That's a horrible term that shouldn't be used at all. Apparently some
> people use it for what is our 'struct file *", also known as a "file
> table entry". Avoid it.

Worse, really. As far as I can reconstruct what happened it was something
along the lines of "colloquial expression is 'opened file', but that is
confusing - sounds like a property+noun, so it might be misparsed as
a member of subset of files satisfying the property of 'being opened';
can't have that in a standard, let's come up with something else".
Except that what they did come up with had been much worse, for obvious
linguistic reasons.

The *ONLY* uses for that expression I can think of are
1. When reading POSIX texts, watch out for that one - if you
see them talking about a file descriptor in context where it really
should be about an opened file, check the wording. If it really says
"file descriptOR", it's probably a bug in standard or a codified
bullshit practice. If it says "file descriptION" instead, replace with
"opened file" and move on.
2. An outstanding example of the taste of that bunch.

IO channel would be a saner variant, but it's far too late for that.

The 3-way distinction between descriptor/opened file/file as collection of data
needs to be explained in UNIX 101; it is userland-visible and it has to be
understood. Unfortunately, it's often done in a way that leaves students
seriously confused ;-/