mds: auth pin stray dir when purging stray inode

After stray inode gets added to purge queue, mds deletes stray dentry.
MDS needs to make sure stray dir is not being fragmented.

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>

diff --git a/src/mds/StrayManager.cc b/src/mds/StrayManager.cc
index a093dd73fb004fe338a976a5ee16ce3eba9b1d7e..aab044ca68b7115829be7a32b113f2d5c3741959 100644 (file)
--- a/src/mds/StrayManager.cc
+++ b/src/mds/StrayManager.cc
@@ -198,7 +198,10 @@ void StrayManager::_purge_stray_purged(
           this, dn, mds->mdlog->get_current_segment()));
   } else {
     if (in->get_num_ref() != (int)in->is_dirty() ||
-        dn->get_num_ref() != (int)dn->is_dirty() + !!in->get_num_ref() + 1/*PIN_PURGING*/) {
+        dn->get_num_ref() !=
+         (int)dn->is_dirty() +
+         !!dn->state_test(CDentry::STATE_FRAGMENTING) +
+         !!in->get_num_ref() + 1 /* PIN_PURGING */) {
       // Nobody should be taking new references to an inode when it
       // is being purged (aside from it were 
 
@@ -236,29 +239,32 @@ void StrayManager::_purge_stray_purged(
 void StrayManager::_purge_stray_logged(CDentry *dn, version_t pdv, LogSegment *ls)
 {
   CInode *in = dn->get_linkage()->get_inode();
+  CDir *dir = dn->get_dir();
   dout(10) << "_purge_stray_logged " << *dn << " " << *in << dendl;
 
   ceph_assert(!in->state_test(CInode::STATE_RECOVERING));
+  ceph_assert(!dir->is_frozen_dir());
 
   bool new_dn = dn->is_new();
 
   // unlink
   ceph_assert(dn->get_projected_linkage()->is_null());
-  dn->dir->unlink_inode(dn, !new_dn);
+  dir->unlink_inode(dn, !new_dn);
   dn->pop_projected_linkage();
   dn->mark_dirty(pdv, ls);
 
-  dn->dir->pop_and_dirty_projected_fnode(ls);
+  dir->pop_and_dirty_projected_fnode(ls);
 
   in->state_clear(CInode::STATE_ORPHAN);
   dn->state_clear(CDentry::STATE_PURGING | CDentry::STATE_PURGINGPINNED);
   dn->put(CDentry::PIN_PURGING);
 
+
   // drop dentry?
   if (new_dn) {
     dout(20) << " dn is new, removing" << dendl;
     dn->mark_clean();
-    dn->dir->remove_dentry(dn);
+    dir->remove_dentry(dn);
   }
 
   // drop inode
@@ -267,6 +273,8 @@ void StrayManager::_purge_stray_logged(CDentry *dn, version_t pdv, LogSegment *l
     in->mark_clean();
   mds->mdcache->remove_inode(in);
 
+  dir->auth_unpin(this);
+
   if (mds->is_stopping())
     mds->mdcache->shutdown_export_stray_finish(ino);
 }
@@ -308,11 +316,11 @@ void StrayManager::enqueue(CDentry *dn, bool trunc)
     << *dn << dendl;
 }
 
-class C_OpenSnapParents : public StrayManagerContext {
+class C_RetryEnqueue : public StrayManagerContext {
   CDentry *dn;
   bool trunc;
   public:
-    C_OpenSnapParents(StrayManager *sm_, CDentry *dn_, bool t) :
+    C_RetryEnqueue(StrayManager *sm_, CDentry *dn_, bool t) :
       StrayManagerContext(sm_), dn(dn_), trunc(t) { }
     void finish(int r) override {
       sm->_enqueue(dn, trunc);
@@ -323,14 +331,23 @@ void StrayManager::_enqueue(CDentry *dn, bool trunc)
 {
   ceph_assert(started);
 
+  CDir *dir = dn->get_dir();
+  if (!dir->can_auth_pin()) {
+    dout(10) << " can't auth_pin (freezing?) " << *dir << ", waiting" << dendl;
+    dir->add_waiter(CDir::WAIT_UNFREEZE, new C_RetryEnqueue(this, dn, trunc));
+    return;
+  }
+
   CInode *in = dn->get_linkage()->get_inode();
   if (in->snaprealm &&
       !in->snaprealm->have_past_parents_open() &&
-      !in->snaprealm->open_parents(new C_OpenSnapParents(this, dn, trunc))) {
+      !in->snaprealm->open_parents(new C_RetryEnqueue(this, dn, trunc))) {
     // this can happen if the dentry had been trimmed from cache.
     return;
   }
 
+  dn->get_dir()->auth_pin(this);
+
   if (trunc) {
     truncate(dn);
   } else {
@@ -739,6 +756,8 @@ void StrayManager::_truncate_stray_logged(CDentry *dn, LogSegment *ls)
   dn->state_clear(CDentry::STATE_PURGING | CDentry::STATE_PURGINGPINNED);
   dn->put(CDentry::PIN_PURGING);
 
+  dn->get_dir()->auth_unpin(this);
+
   eval_stray(dn);
 
   if (!dn->state_test(CDentry::STATE_PURGING) &&  mds->is_stopping())

diff --git a/src/mds/StrayManager.h b/src/mds/StrayManager.h
index 46335e1d472019c256d15f71a584beeff5b3b49d..0ad8a53f0cad6d01526cccdbd7e31d43bc204c55 100644 (file)
--- a/src/mds/StrayManager.h
+++ b/src/mds/StrayManager.h
@@ -103,7 +103,7 @@ protected:
   friend class StrayManagerContext;
 
   friend class C_StraysFetched;
-  friend class C_OpenSnapParents;
+  friend class C_RetryEnqueue;
   friend class C_PurgeStrayLogged;
   friend class C_TruncateStrayLogged;
   friend class C_IO_PurgeStrayPurged;