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From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Fri, 26 Jan 2024 15:17:14 -0800
Message-ID: <CAHk-=whqu_21AnXM9_ohxONvmotGqE=98YS2pLZq+qcY8z85SQ@mail.gmail.com>
Subject: Re: [PATCH] eventfs: Have inodes have unique inode numbers
To: Matthew Wilcox <willy@infradead.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>, Steven Rostedt <rostedt@goodmis.org>, 
	LKML <linux-kernel@vger.kernel.org>, 
	Linux Trace Devel <linux-trace-devel@vger.kernel.org>, Masami Hiramatsu <mhiramat@kernel.org>, 
	Christian Brauner <brauner@kernel.org>, Ajay Kaher <ajay.kaher@broadcom.com>, 
	Geert Uytterhoeven <geert@linux-m68k.org>, linux-fsdevel <linux-fsdevel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"

On Fri, 26 Jan 2024 at 15:11, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> On Fri, 26 Jan 2024 at 15:04, Matthew Wilcox <willy@infradead.org> wrote:
> >
> > Maybe we should take advantage of that historical oddity.  All files
> > in eventfs have inode number 0, problem solved.
>
> That might not be a horrible idea.

Note the "might". I don't know why glibc would have special-cased
st_ino of 0, but I suspect it's some internal oddity in the readdir()
implementation.

So considering that we do have that commit 2adc376c5519, I suspect it
would just be more pain than its worth to try to teach user space
about the whole "no inode number" thing.

It might be safer to pick something like -1 instead.

               Linus