mds: update backtrace when old format inode is touchedwip-backtrace

We updated inode format version to 7 when introducing inode backtrace.
If we found a inode's format version < 7 when fetching the inode, set
the inode's backtrace_version to 0, to indicate the inode's backtrace
is out of data. When touching a inode with backtrace_version == 0, we
also update its backtrace.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/mds/Locker.cc b/src/mds/Locker.cc
index 7f852519714..e11bbd8fe9a 100644
--- a/src/mds/Locker.cc
+++ b/src/mds/Locker.cc
@@ -2900,6 +2900,10 @@ bool Locker::_do_cap_update(CInode *in, Capability *cap,
 
     wrlock_force(&in->xattrlock, mut);
   }
+
+  // update backtrace for old format inode. (see inode_t::decode)
+  if (pi->backtrace_version == 0)
+    pi->update_backtrace();
   
   mut->auth_pin(in);
   mdcache->predirty_journal_parents(mut, &le->metablob, in, 0, PREDIRTY_PRIMARY, 0, follows);