On Tue, 2021-07-27 at 15:46 +0100, Luis Henriques wrote: > On Tue, Jul 27, 2021 at 07:35:09AM -0400, Jeff Layton wrote: > > Add a new vxattr that shows what MDS is authoritative for an inode (if > > we happen to have auth caps). If we don't have an auth cap for the inode > > then just return -1. > > > > URL: https://tracker.ceph.com/issues/1276 > > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx> > > --- > > fs/ceph/xattr.c | 16 ++++++++++++++++ > > 1 file changed, 16 insertions(+) > > > > diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c > > index 1242db8d3444..70664a19b8dc 100644 > > --- a/fs/ceph/xattr.c > > +++ b/fs/ceph/xattr.c > > @@ -340,6 +340,15 @@ static ssize_t ceph_vxattrcb_caps(struct ceph_inode_info *ci, char *val, > > ceph_cap_string(issued), issued); > > } > > > > +static ssize_t ceph_vxattrcb_auth_mds(struct ceph_inode_info *ci, > > + char *val, size_t size) > > +{ > > + /* return -1 if we don't have auth caps (and thus can't tell) */ > > + if (!ci->i_auth_cap) > > + return ceph_fmt_xattr(val, size, "-1"); > > I don't really have an opinion on this as I don't have a usecase for this > xattr (other than debug, of course). But I just checked a similar function > ceph_vxattrcb_layout_pool_namespace() and, if there's no value for ns for an > inode, it just returns 0. > > Anyway, just my 5c, as I'm OK with returning a '-1' string too. > TBH, I don't have much of a use-case for this either, but it was requested by Sage long ago. That said, I figure it might be useful in some cases, particularly when troubleshooting pinning issues. Pool numbering is a bit different, as I think pool 0 is not valid, whereas we index mds's starting with 0. I'm fine with a different convention here, but I considered it as a safe way to say "I don't know" in this situation. > > + return ceph_fmt_xattr(val, size, "%d", ci->i_auth_cap->session->s_mds); > > +} > > + > > #define CEPH_XATTR_NAME(_type, _name) XATTR_CEPH_PREFIX #_type "." #_name > > #define CEPH_XATTR_NAME2(_type, _name, _name2) \ > > XATTR_CEPH_PREFIX #_type "." #_name "." #_name2 > > @@ -473,6 +482,13 @@ static struct ceph_vxattr ceph_common_vxattrs[] = { > > .exists_cb = NULL, > > .flags = VXATTR_FLAG_READONLY, > > }, > > + { > > + .name = "ceph.auth_mds", > > + .name_size = sizeof("ceph.auth_mds"), > > + .getxattr_cb = ceph_vxattrcb_auth_mds, > > + .exists_cb = NULL, > > + .flags = VXATTR_FLAG_READONLY, > > + }, > > { .name = NULL, 0 } /* Required table terminator */ > > }; > > > > -- > > 2.31.1 > > -- Jeff Layton <jlayton@xxxxxxxxxx>
