James Bottomley [off-list ref] wrote:

It sort of petered out into a long winding thread about why not use
sysfs instead, which really doesn't look like a good idea to me.

It seemed to turn into a set of procfs symlinks that pointed at a bunch of
sysfs stuff - or possibly some special filesystem.

Could I make a suggestion about how this should be done in a way that
doesn't actually require the fsinfo syscall at all: it could just be
done with fsconfig.

I'd prefer to keep it separate.  The interface for fsconfig() is intended to
move stuff into the kernel, not out of it.  Better to add a parallel syscall
to go the other way (kind of like we have setxattr/getxattr, sendmsg/recvmsg).

Further, fsinfo() can refer directly to a file/fd/mount/whatever, but
fsconfig() doesn't do that.  You have to use fspick() to get a context before
you can use fsconfig().  Now, that's fine if you want to gather several pieces
of information from a particular object, but it's not so good if you want to
get one piece of information from each of several objects.

... make it table configured...

I did, kind of (though I didn't call it that).  Al rewrote the code to get rid
of it.

David