From da12abbd0f07fe05dbdf4c0971a5a1fffbd03b4b Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zyan@redhat.com>
Date: Mon, 7 Aug 2017 15:23:18 +0800
Subject: [PATCH] mds: fix CInode::find_snaprealm()

If inode has no parent dentry (newly created), CInode::find_snaprealm()
should try the oldest projected parent.

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
---
 src/mds/CInode.cc    | 32 ++++++++++++++++++++++++--------
 src/mds/CInode.h     | 10 ++++++++--
 src/mds/SnapRealm.cc | 25 ++++---------------------
 3 files changed, 36 insertions(+), 31 deletions(-)

diff --git a/src/mds/CInode.cc b/src/mds/CInode.cc
index 581ae2d0d91..4ba7a6f12f8 100644
--- a/src/mds/CInode.cc
+++ b/src/mds/CInode.cc
@@ -809,14 +809,32 @@ CInode *CInode::get_parent_inode()
   return NULL;
 }
 
-bool CInode::is_projected_ancestor_of(CInode *other)
+bool CInode::is_ancestor_of(const CInode *other) const
 {
   while (other) {
     if (other == this)
       return true;
-    if (!other->get_projected_parent_dn())
+    const CDentry *pdn = other->get_oldest_parent_dn();
+    if (!pdn) {
+      assert(other->is_base());
       break;
-    other = other->get_projected_parent_dn()->get_dir()->get_inode();
+    }
+    other = pdn->get_dir()->get_inode();
+  }
+  return false;
+}
+
+bool CInode::is_projected_ancestor_of(const CInode *other) const
+{
+  while (other) {
+    if (other == this)
+      return true;
+    const CDentry *pdn = other->get_projected_parent_dn();
+    if (!pdn) {
+      assert(other->is_base());
+      break;
+    }
+    other = pdn->get_dir()->get_inode();
   }
   return false;
 }
@@ -2661,12 +2679,10 @@ SnapRealm *CInode::find_snaprealm() const
 {
   const CInode *cur = this;
   while (!cur->snaprealm) {
-    if (cur->get_parent_dn())
-      cur = cur->get_parent_dn()->get_dir()->get_inode();
-    else if (get_projected_parent_dn())
-      cur = cur->get_projected_parent_dn()->get_dir()->get_inode();
-    else
+    const CDentry *pdn = cur->get_oldest_parent_dn();
+    if (!pdn)
       break;
+    cur = pdn->get_dir()->get_inode();
   }
   return cur->snaprealm;
 }
diff --git a/src/mds/CInode.h b/src/mds/CInode.h
index 01c942c9cf5..be6ecd7c1f5 100644
--- a/src/mds/CInode.h
+++ b/src/mds/CInode.h
@@ -727,8 +727,13 @@ public:
   inode_t& get_inode() { return inode; }
   CDentry* get_parent_dn() { return parent; }
   const CDentry* get_parent_dn() const { return parent; }
-  const CDentry* get_projected_parent_dn() const { return !projected_parent.empty() ? projected_parent.back() : parent; }
   CDentry* get_projected_parent_dn() { return !projected_parent.empty() ? projected_parent.back() : parent; }
+  const CDentry* get_projected_parent_dn() const { return !projected_parent.empty() ? projected_parent.back() : parent; }
+  const CDentry* get_oldest_parent_dn() const {
+    if (parent)
+      return parent;
+    return !projected_parent.empty() ? projected_parent.front(): NULL;
+  }
   CDir *get_parent_dir();
   const CDir *get_projected_parent_dir() const;
   CDir *get_projected_parent_dir();
@@ -741,7 +746,8 @@ public:
   }
 
   // -- misc -- 
-  bool is_projected_ancestor_of(CInode *other);
+  bool is_ancestor_of(const CInode *other) const;
+  bool is_projected_ancestor_of(const CInode *other) const;
 
   void make_path_string(std::string& s, bool projected=false, const CDentry *use_parent=NULL) const;
   void make_path(filepath& s, bool projected=false) const;
diff --git a/src/mds/SnapRealm.cc b/src/mds/SnapRealm.cc
index df5cb12df7f..55bc49cb731 100644
--- a/src/mds/SnapRealm.cc
+++ b/src/mds/SnapRealm.cc
@@ -455,7 +455,7 @@ void SnapRealm::split_at(SnapRealm *child)
        p != open_children.end(); ) {
     SnapRealm *realm = *p;
     if (realm != child &&
-	child->inode->is_projected_ancestor_of(realm->inode)) {
+	child->inode->is_ancestor_of(realm->inode)) {
       dout(20) << " child gets child realm " << *realm << " on " << *realm->inode << dendl;
       realm->parent = child;
       child->open_children.insert(realm);
@@ -467,29 +467,12 @@ void SnapRealm::split_at(SnapRealm *child)
   }
 
   // split inodes_with_caps
-  elist<CInode*>::iterator p = inodes_with_caps.begin(member_offset(CInode, item_caps));
-  while (!p.end()) {
+  for (elist<CInode*>::iterator p = inodes_with_caps.begin(member_offset(CInode, item_caps));
+       !p.end(); ) {
     CInode *in = *p;
     ++p;
-
     // does inode fall within the child realm?
-    bool under_child = false;
-
-    if (in == child->inode) {
-      under_child = true;
-    } else {
-      CInode *t = in;
-      while (t->get_parent_dn()) {
-	t = t->get_parent_dn()->get_dir()->get_inode();
-	if (t == child->inode) {
-	  under_child = true;
-	  break;
-	}
-	if (t == in)
-	  break;
-      }
-    }
-    if (under_child) {
+    if (child->inode->is_ancestor_of(in)) {
       dout(20) << " child gets " << *in << dendl;
       in->move_to_realm(child);
     } else {
-- 
2.39.5