mds: fix infinite loop of MDCache::populate_mydir().dumpling

make MDCache::populate_mydir() only fetch bare-bone stray dirs.
After all stray dirs are populated, call MDCache::scan_stray_dir(),
it fetches incomplete stray dirs.

Fixes: #4405
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
(cherry picked from commit 007f06ec174d4ee5cfb578c8b3f1c96b2bb0c238)

Conflicts:

	src/mds/MDCache.h

Reviewed-by: Greg Farnum <greg@inktank.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/mds/MDCache.h b/src/mds/MDCache.h
index 36a322c6324..2574e755c9b 100644
--- a/src/mds/MDCache.h
+++ b/src/mds/MDCache.h
@@ -858,7 +858,6 @@ public:
 
   // -- stray --
 public:
-  void scan_stray_dir();
   void eval_stray(CDentry *dn);
   void eval_remote(CDentry *dn);
 
@@ -872,6 +871,7 @@ public:
       eval_stray(dn);
   }
 protected:
+  void scan_stray_dir(dirfrag_t next=dirfrag_t());
   void fetch_backtrace(inodeno_t ino, int64_t pool, bufferlist& bl, Context *fin);
   void remove_backtrace(inodeno_t ino, int64_t pool, Context *fin);
   void _purge_forwarding_pointers(bufferlist& bl, CDentry *dn, int r);
@@ -880,6 +880,7 @@ protected:
   void _purge_stray_purged(CDentry *dn, int r=0);
   void _purge_stray_logged(CDentry *dn, version_t pdv, LogSegment *ls);
   void _purge_stray_logged_truncate(CDentry *dn, LogSegment *ls);
+  friend class C_MDC_RetryScanStray;
   friend class C_MDC_FetchedBacktrace;
   friend class C_MDC_PurgeForwardingPointers;
   friend class C_MDC_PurgeStray;