From: Yan, Zheng <zyan@redhat.com>
Date: Fri, 7 Jul 2017 06:03:15 +0000 (+0800)
Subject: tools/cephfs: handle removed dentries when replaying journal
X-Git-Tag: ses5-milestone9~1^2~22^2~2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=6055e4fb2675016cb0e8890e30aefba444dbcb2a;p=ceph.git

tools/cephfs: handle removed dentries when replaying journal

Fixes: http://tracker.ceph.com/issues/20440
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
---

diff --git a/src/tools/cephfs/JournalTool.cc b/src/tools/cephfs/JournalTool.cc
index 057e79cb86bf..20c83acecf3d 100644
--- a/src/tools/cephfs/JournalTool.cc
+++ b/src/tools/cephfs/JournalTool.cc
@@ -720,6 +720,15 @@ int JournalTool::recover_dentries(
       read_keys.insert(key);
     }
 
+    list<EMetaBlob::nullbit> const &nb_list = lump.get_dnull();
+    for (auto& nb : nb_list) {
+      // Get a key like "foobar_head"
+      std::string key;
+      dentry_key_t dn_key(nb.dnlast, nb.dn.c_str());
+      dn_key.encode(key);
+      read_keys.insert(key);
+    }
+
     // Perform bulk read of existing dentries
     std::map<std::string, bufferlist> read_vals;
     r = input.omap_get_vals_by_keys(frag_oid.name, read_keys, &read_vals);
@@ -866,6 +875,48 @@ int JournalTool::recover_dentries(
       }
     }
 
+    std::set<std::string> null_vals;
+    for (auto& nb : nb_list) {
+      std::string key;
+      dentry_key_t dn_key(nb.dnlast, nb.dn.c_str());
+      dn_key.encode(key);
+
+      dout(4) << "inspecting nullbit " << frag_oid.name << "/" << nb.dn
+	<< dendl;
+
+      auto it = read_vals.find(key);
+      if (it != read_vals.end()) {
+	dout(4) << "dentry exists, will remove" << dendl;
+
+	bufferlist::iterator q = it->second.begin();
+	snapid_t dnfirst;
+	::decode(dnfirst, q);
+	char dentry_type;
+	::decode(dentry_type, q);
+
+	bool remove_dentry = false;
+	if (dentry_type == 'L') {
+	  dout(10) << "Existing hardlink inode in slot to be (maybe) removed "
+	    << "by null journal dn '" << nb.dn.c_str()
+	    << "' with lump fnode version " << lump.fnode.version
+	    << "vs existing fnode version " << old_fnode_version << dendl;
+	  remove_dentry = old_fnode_version < lump.fnode.version;
+	} else if (dentry_type == 'I') {
+	  dout(10) << "Existing full inode in slot to be (maybe) removed "
+	    << "by null journal dn '" << nb.dn.c_str()
+	    << "' with lump fnode version " << lump.fnode.version
+	    << "vs existing fnode version " << old_fnode_version << dendl;
+	  remove_dentry = old_fnode_version < lump.fnode.version;
+	} else {
+	  dout(4) << "corrupt dentry in backing store, will remove" << dendl;
+	  remove_dentry = true;
+	}
+
+	if (remove_dentry)
+	  null_vals.insert(key);
+      }
+    }
+
     // Write back any new/changed dentries
     if (!write_vals.empty()) {
       r = output.omap_set(frag_oid.name, write_vals);
@@ -875,6 +926,16 @@ int JournalTool::recover_dentries(
 	return r;
       }
     }
+
+    // remove any null dentries
+    if (!null_vals.empty()) {
+      r = output.omap_rm_keys(frag_oid.name, null_vals);
+      if (r != 0) {
+	derr << "error removing dentries from " << frag_oid.name
+	  << ": " << cpp_strerror(r) << dendl;
+	return r;
+      }
+    }
   }
 
   /* Now that we've looked at the dirlumps, we finally pay attention to