Re: [ceph-users] cephfs snap mkdir strange timestamp

[Jeff Layton <jlayton@kernel.org>]

On Tue, 2020-03-10 at 13:46 +0000, Luis Henriques wrote:
> [ CC'ing Jeff and ceph-devel@ ]
> 
> On Tue, Mar 10, 2020 at 11:41:19AM +0100, Marc Roos wrote:
> >  
> > 
> > If I make a directory in linux the directory has the date of now, why is 
> > this not with creating a snap dir? Is this not a bug? One expects this 
> > to be the same as in linux not????
> 
> I've noticed that long time ago, but I never checked the fuse client
> behaviour, which turns out to be different.  The fuse client seems to set
> ctime and atime to the same value as the parent directory (see
> Client::open_snapdir()).
> 
> The patch below mimics that behaviour, by simply copying those timestamps
> from the parent inode.
> 
> Cheers,
> --
> Luis
> 
> From 2c8e06e66e5453ddf8b634cf1689a812dc05a0c6 Mon Sep 17 00:00:00 2001
> From: Luis Henriques <lhenriques@suse.com>
> Date: Tue, 10 Mar 2020 13:35:11 +0000
> Subject: [PATCH] ceph: fix snapshot dir ctime and mtime
> 
> The .snap directory timestamps are kept at 0 (1970-01-01 00:00), which
> isn't consistent with what the fuse client does.  This patch makes the
> behaviour consistent, by setting these timestamps to those of the parent
> directory.
> 
> Signed-off-by: Luis Henriques <lhenriques@suse.com>
> ---
>  fs/ceph/inode.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
> index d01710a16a4a..f4e78ade0871 100644
> --- a/fs/ceph/inode.c
> +++ b/fs/ceph/inode.c
> @@ -82,6 +82,8 @@ struct inode *ceph_get_snapdir(struct inode *parent)
>  	inode->i_mode = parent->i_mode;
>  	inode->i_uid = parent->i_uid;
>  	inode->i_gid = parent->i_gid;
> +	inode->i_mtime = parent->i_mtime;
> +	inode->i_ctime = parent->i_ctime;
>  	inode->i_op = &ceph_snapdir_iops;
>  	inode->i_fop = &ceph_snapdir_fops;
>  	ci->i_snap_caps = CEPH_CAP_PIN; /* so we can open */

What about the atime, and the ci->i_btime ?
-- 
Jeff Layton <jlayton@kernel.org>