Re: [PATCH v2 4/4] doc: document new CephFS mount device syntax

[Jeff Layton <jlayton@redhat.com>]

On Mon, 2021-07-05 at 10:09 +0530, Venky Shankar wrote:
> On Fri, Jul 2, 2021 at 11:38 PM Patrick Donnelly <pdonnell@redhat.com> wrote:
> > 
> > On Thu, Jul 1, 2021 at 11:48 PM Venky Shankar <vshankar@redhat.com> wrote:
> > > 
> > > Signed-off-by: Venky Shankar <vshankar@redhat.com>
> > > ---
> > >  Documentation/filesystems/ceph.rst | 25 ++++++++++++++++++++++---
> > >  1 file changed, 22 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/Documentation/filesystems/ceph.rst b/Documentation/filesystems/ceph.rst
> > > index 7d2ef4e27273..830ea8969d9d 100644
> > > --- a/Documentation/filesystems/ceph.rst
> > > +++ b/Documentation/filesystems/ceph.rst
> > > @@ -82,7 +82,7 @@ Mount Syntax
> > > 
> > >  The basic mount syntax is::
> > > 
> > > - # mount -t ceph monip[:port][,monip2[:port]...]:/[subdir] mnt
> > > + # mount -t ceph user@fsid.fs_name=/[subdir] mnt -o mon_addr=monip1[:port][/monip2[:port]]
> > 
> > Somewhat unrelated question to this patchset: can you specify the mons
> > in the ceph.conf format? i.e. with v2/v1 syntax?
> 
> The problem with that is the delimiter used is comma (",") which
> restricts passing it through the mount option.
> > 

Yeah. I don't see an alternative here. You'd have to escape the comma
somehow. You'd also have to build an in-kernel parser for that format.

Doing this would be a project in and of itself, and it doesn't seem
valuable. mount.ceph is mostly what's going to populate this anyway and
for that we don't really care.

> > >  You only need to specify a single monitor, as the client will get the
> > >  full list when it connects.  (However, if the monitor you specify
> > > @@ -90,16 +90,35 @@ happens to be down, the mount won't succeed.)  The port can be left
> > >  off if the monitor is using the default.  So if the monitor is at
> > >  1.2.3.4::
> > > 
> > > - # mount -t ceph 1.2.3.4:/ /mnt/ceph
> > > + # mount -t ceph cephuser@07fe3187-00d9-42a3-814b-72a4d5e7d5be.cephfs=/ /mnt/ceph -o mon_addr=1.2.3.4
> > > 
> > >  is sufficient.  If /sbin/mount.ceph is installed, a hostname can be
> > > -used instead of an IP address.
> > > +used instead of an IP address and the cluster FSID can be left out
> > > +(as the mount helper will fill it in by reading the ceph configuration
> > > +file)::
> > > 
> > > +  # mount -t ceph cephuser@cephfs=/ /mnt/ceph -o mon_addr=mon-addr
> > > 
> > > +Multiple monitor addresses can be passed by separating each address with a slash (`/`)::
> > > +
> > > +  # mount -t ceph cephuser@cephfs=/ /mnt/ceph -o mon_addr=192.168.1.100/192.168.1.101
> > > +
> > > +When using the mount helper, monitor address can be read from ceph
> > > +configuration file if available. Note that, the cluster FSID (passed as part
> > > +of the device string) is validated by checking it with the FSID reported by
> > > +the monitor.
> > > 
> > >  Mount Options
> > >  =============
> > > 
> > > +  mon_addr=ip_address[:port][/ip_address[:port]]
> > > +       Monitor address to the cluster. This is used to bootstrap the
> > > +        connection to the cluster. Once connection is established, the
> > > +        monitor addresses in the monitor map are followed.
> > > +
> > > +  fsid=cluster-id
> > > +       FSID of the cluster
> > 
> > Let's note it's the output of `ceph fsid`.
> > 
> > >    ip=A.B.C.D[:N]
> > >         Specify the IP and/or port the client should bind to locally.
> > >         There is normally not much reason to do this.  If the IP is not
> > > --
> > > 2.27.0
> > > 
> > 
> > 
> > --
> > Patrick Donnelly, Ph.D.
> > He / Him / His
> > Principal Software Engineer
> > Red Hat Sunnyvale, CA
> > GPG: 19F28A586F808C2402351B93C3301A3E258DD79D
> > 
> 
> 

-- 
Jeff Layton <jlayton@redhat.com>