On Thu, Mar 14, 2019 at 1:10 PM Patrick Donnelly <pdonnell@xxxxxxxxxx> wrote: > > Hello David, > > On Thu, Mar 14, 2019 at 12:20 PM David Disseldorp <ddiss@xxxxxxx> wrote: > > I'm working on adding Samba integration with CephFS snapshots, so that > > they can be accessed in Explorer via file/folder right-click -> > > restore previous versions. > > How are you actually planning to effect a restore from snapshot? > > > For this we need return a list of "@GMT-%Y.%m.%d-%H.%M.%S" labels back > > to SMB clients in response to snapshot enumeration requests, where each > > label corresponds to a snapshot. > > To avoid the requirement for special @GMT-* snapshot naming in the .snap > > directory, I'd hoped to determine the snapshot creation time from the > > stat.btime field and return a label based on that. However, snapshot btime > > fields appear to directly reference the btime of the snapshot source. > > > > Is there any way to determine the snapshot creation time? If not, would > > anyone object to me adding a new xattr which carries this information, > > e.g. "ceph.snap.btime", assuming the value is stored somewhere on the > > MDS? > > The snapshot creation time appears to be available in the > ceph_mds_snap_realm struct. It would just need wired up somehow. An > xattr sounds appropriate. That's a snapid, not a timestamp (see SnapRealmInfo in src/common/snap_types.h). Happily I do see a SnapInfo::stamp member of long standing that appears to be the create time. -Greg > > -- > Patrick Donnelly
