bug#60474: 30.0.50; `write-region-inhibit-fsync' and copy-on-write file systems

[Eli Zaretskii]

> From: Ihor Radchenko <yantar92@posteo.net>
> Cc: Eli Zaretskii <eliz@gnu.org>, 60474@debbugs.gnu.org,
>  orgmode@tec.tecosaur.net
> Date: Mon, 02 Jan 2023 05:54:11 +0000
> 
> Paul Eggert <eggert@cs.ucla.edu> writes:
> 
> > On 2023-01-01 12:07, Eli Zaretskii wrote:
> >
> >> Paul, any comments?
> >
> > Sure, Emacs should do the reverse of what it's doing now. That is, Emacs 
> > should use fsync only in special situations, instead of avoiding it only 
> > in special situations. In the old days it may have made sense to use 
> > fsync, but nowadays most platforms don't need fsync for the sorts of 
> > things people use interactive Emacs.
> 
> What about Emacs DOS port and the likes? May be there some gotchas about
> specific file systems in non-standard OS?

Those systems have much more conservative filesystems, so they rarely
need fsync in the "usual" cases.

> Also, what would be the special situations you are talking about?

Right, that's my question as well.  I presume when writing some
precious data, or maybe some transaction-like I/O.