Re: [for-linus][PATCH 1/3] eventfs: Have the inodes all for files and directories all be the same

From: Linus Torvalds <torvalds@linux-foundation.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Christian Brauner <brauner@kernel.org>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	 Kees Cook <keescook@chromium.org>,
	linux-kernel@vger.kernel.org,
	 Masami Hiramatsu <mhiramat@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	 Al Viro <viro@zeniv.linux.org.uk>,
	Ajay Kaher <ajay.kaher@broadcom.com>
Subject: Re: [for-linus][PATCH 1/3] eventfs: Have the inodes all for files and directories all be the same
Date: Fri, 26 Jan 2024 11:09:35 -0800	[thread overview]
Message-ID: <CAHk-=whu43G8zdLwTLkshziaA8_N3+jZd9-a8HEjyagPDvZRNQ@mail.gmail.com> (raw)
In-Reply-To: <20240126112551.6b8c0450@gandalf.local.home>

On Fri, 26 Jan 2024 at 08:26, Steven Rostedt <rostedt@goodmis.org> wrote:
>
> On Fri, 26 Jan 2024 11:11:39 +0100
> Christian Brauner <brauner@kernel.org> wrote:
>
> > The size would be one thing. The other is that tar requires unique inode
> > numbers for all files iirc (That's why we have this whole btrfs problem
> > - let's not get into this here -  where inode numbers aren't unique and
> > are duplicated per subvolume.).
>
> Well, I guess that answers Linus's question about wondering if there's any
> user space program that actually cares what the inodes are for files. The
> answer is "yes" and the program is "tar".

Well, the fact that it hits snapshots, shows that the real problem is
just "tar does stupid things that it shouldn't do".

Yes, inode numbers used to be special, and there's history behind it.
But we should basically try very hard to walk away from that broken
history.

An inode number just isn't a unique descriptor any more. We're not
living in the 1970s, and filesystems have changed.

              Linus