RE: [PATCH] eventfs: Have inodes have unique inode numbers

David Laight
2024-01-27T15:27:13Z

From: Linus Torvalds
> Sent: 26 January 2024 21:36
>
> On Fri, 26 Jan 2024 at 13:26, Steven Rostedt <rostedt@goodmis.org> wrote:
> >
> > I'd be happy to change that patch to what I originally did before deciding
> > to copy get_next_ino():
> >
> > unsigned int tracefs_get_next_ino(int files)
> > {
> > static atomic_t next_inode;
> > unsigned int res;
> >
> > do {
> > res = atomic_add_return(files + 1, &next_inode);
> >
> > /* Check for overflow */
> > } while (unlikely(res < files + 1));
> >
> > return res - files;
>
> Still entirely pointless.
>
> If you have more than 4 billion inodes, something is really really wrong.
>
> So why is it ten lines instead of one?

Doesn't Linux support 64bit inode numbers?
They solve the wrap problem...

I also don't know what filesystems like NTFS use - they don't have
the concept of inode.

IIRC NFS used to use the inode number for its 'file handle'.
Rather a pain when trying to write code to export a layered FS
(especially if a layer might be an NFS mount!).

David

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