Re: [PATCH] fs/nfsd: Fix creation time serialization order

[Tavian Barnes]

On Fri, Jun 23, 2023 at 5:48 PM Chuck Lever <cel@xxxxxxxxxx> wrote:
> On Fri, Jun 23, 2023 at 05:09:06PM -0400, tavianator@xxxxxxxxxxxxxx wrote:
> > From: Tavian Barnes <tavianator@xxxxxxxxxxxxxx>
> >
> > In nfsd4_encode_fattr(), TIME_CREATE was being written out after all
> > other times.  However, they should be written out in an order that
> > matches the bit flags in bmval1, which in this case are
> >
> >     #define FATTR4_WORD1_TIME_ACCESS        (1UL << 15)
> >     #define FATTR4_WORD1_TIME_CREATE        (1UL << 18)
> >     #define FATTR4_WORD1_TIME_DELTA         (1UL << 19)
> >     #define FATTR4_WORD1_TIME_METADATA      (1UL << 20)
> >     #define FATTR4_WORD1_TIME_MODIFY        (1UL << 21)
> >
> > so TIME_CREATE should come second.
> >
> > I noticed this on a FreeBSD NFSv4.2 client, which supports creation
> > times.  On this client, file times were weirdly permuted.  With this
> > patch applied on the server, times looked normal on the client.
> >
> > Fixes: e377a3e698fb ("nfsd: Add support for the birth time attribute")
> > Link: https://unix.stackexchange.com/q/749605/56202
> > Signed-off-by: Tavian Barnes <tavianator@xxxxxxxxxxxxxx>
>
> I'm not especially familiar with this area of the protocol, but this
> looks correct at first glance. I've applied this to nfsd-fixes for
> v6.5.

Great, thanks!

> Out of interest, what type of filesystem does your server export?

It's a btrfs filesystem.

-- 
Tavian Barnes