From mboxrd@z Thu Jan 1 00:00:00 1970 MIME-Version: 1.0 In-Reply-To: References: <385c85ca703ac8d441c4227d1bb24643@u2.inri> <9c545c7fbde6ddecb82def2dc66194ed@lilly.quanstro.net> Date: Mon, 12 Oct 2015 22:25:25 +0200 Message-ID: From: Giacomo Tesio To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net> Content-Type: multipart/alternative; boundary=f46d04428cc02331c10521ee2128 Subject: Re: [9fans] off topic - a good Git reference Topicbox-Message-UUID: 73220984-ead9-11e9-9d60-3106f5b1d025 --f46d04428cc02331c10521ee2128 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 2015-10-12 19:00 GMT+02:00 Charles Forsyth : > > On 12 October 2015 at 17:49, =C3=81lvaro Jurado wr= ote: > >> what ensures sha key is in fs. > > > The reason many of us are a little sceptical about it being fsync as such > preventing the data appearing > is that if the git function that writes the key does a write or pwrite, > the key will be in the file system on Plan 9: there's no need for an fsyn= c > just to get it there. > In fact, in Linux there's no need for an fsync just to get it there: it > only matters in the case of a crash. > > If the file system fails or you reset the machine, the intention of the > fsync will be frustrated, but > it shouldn't affect normal operation where no file server crash occurs. > > As it happens, a wstat that changes nothing can be interpreted by a file > server to have a similar effect as fsync (see stat(5)). > Thus Plan9 HAS fsync! :-o And it also has server-defined semantics! Very impressive! Giacomo --f46d04428cc02331c10521ee2128 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
2015-10-12 19:00 GMT+02:00 Charles Forsyth <charles.forsyth@gmail.com>:

On 12 October 2015 at 17:49, =C3=81lvaro Jurado <elbingmiss@gmail.com= > wrote:
what ensures sha k= ey is in fs.

The reason many of us are a littl= e sceptical about it being fsync as such preventing the data appearing
is that if the git function that writes the key= does a write or pwrite,
the key will be in= the file system on Plan 9: there's no need for an fsync just to get it= there.
In fact, in Linux there's no ne= ed for an fsync just to get it there: it only matters in the case of a cras= h.

If = the file system fails or you reset the machine, the intention of the fsync = will be frustrated, but
it shouldn't af= fect normal operation where no file server crash occurs.

As it happens, a wstat t= hat changes nothing can be interpreted by a file server to have a similar e= ffect as fsync (see stat(5)).

Thus Plan9 HAS fsync! :-o
And it also= has server-defined semantics! Very impressive!


=
Giacomo
<= /div>
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