From: Yan, Zheng <zheng.z.yan@intel.com>
Date: Tue, 2 Oct 2012 08:55:52 +0000 (+0800)
Subject: mds: Avoid creating unnecessary snaprealm
X-Git-Tag: v0.54~124^2~2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=e8df6a74cae66accb6682129c9c5ad33797f458c;p=ceph.git

mds: Avoid creating unnecessary snaprealm

When moving directory between snaprealms, we can avoid creating snaprealm
if the directory doesn't has its own snaprealm and directory was created
after both realms' newest snapshot.

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

diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index e16800ecebc6..b706b5abf81b 100644
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -4577,7 +4577,8 @@ void Server::_unlink_local(MDRequest *mdr, CDentry *dn, CDentry *straydn)
     mdcache->predirty_journal_parents(mdr, &le->metablob, in, straydn->get_dir(), PREDIRTY_PRIMARY|PREDIRTY_DIR, 1);
 
     // project snaprealm, too
-    in->project_past_snaprealm_parent(straydn->get_dir()->inode->find_snaprealm());
+    if (in->snaprealm || follows + 1 > dn->first)
+      in->project_past_snaprealm_parent(straydn->get_dir()->inode->find_snaprealm());
 
     le->metablob.add_primary_dentry(straydn, true, in);
   } else {
@@ -5247,11 +5248,16 @@ void Server::handle_client_rename(MDRequest *mdr)
   }
 
   // moving between snaprealms?
-  if (srcdnl->is_primary() && !srci->snaprealm &&
-      srci->find_snaprealm() != destdn->get_dir()->inode->find_snaprealm()) {
-    dout(10) << " renaming between snaprealms, creating snaprealm for " << *srci << dendl;
-    mds->mdcache->snaprealm_create(mdr, srci);
-    return;
+  if (srcdnl->is_primary() && srci->is_multiversion() && !srci->snaprealm) {
+    SnapRealm *srcrealm = srci->find_snaprealm();
+    SnapRealm *destrealm = destdn->get_dir()->inode->find_snaprealm();
+    if (srcrealm != destrealm &&
+	(srcrealm->get_newest_seq() + 1 > srcdn->first ||
+	 destrealm->get_newest_seq() + 1 > srcdn->first)) {
+      dout(10) << " renaming between snaprealms, creating snaprealm for " << *srci << dendl;
+      mds->mdcache->snaprealm_create(mdr, srci);
+      return;
+    }
   }
 
   assert(g_conf->mds_kill_rename_at != 1);
@@ -5650,6 +5656,7 @@ void Server::_rename_prepare(MDRequest *mdr,
   if (destdn->is_auth())
     mdcache->predirty_journal_parents(mdr, metablob, srci, destdn->get_dir(), flags, 1);
 
+  SnapRealm *src_realm = srci->find_snaprealm();
   SnapRealm *dest_realm = destdn->get_dir()->inode->find_snaprealm();
   snapid_t next_dest_snap = dest_realm->get_newest_seq() + 1;
 
@@ -5659,7 +5666,8 @@ void Server::_rename_prepare(MDRequest *mdr,
     if (destdnl->is_primary()) {
       if (destdn->is_auth()) {
 	// project snaprealm, too
-	oldin->project_past_snaprealm_parent(straydn->get_dir()->inode->find_snaprealm());
+	if (oldin->snaprealm || src_realm->get_newest_seq() + 1 > srcdn->first)
+	  oldin->project_past_snaprealm_parent(straydn->get_dir()->inode->find_snaprealm());
 	straydn->first = MAX(oldin->first, next_dest_snap);
 	metablob->add_primary_dentry(straydn, true, oldin);
       }
@@ -5703,7 +5711,8 @@ void Server::_rename_prepare(MDRequest *mdr,
     }
   } else if (srcdnl->is_primary()) {
     // project snap parent update?
-    if (destdn->is_auth() && srci->snaprealm)
+    if (destdn->is_auth() &&
+        (srci->snaprealm || src_realm->get_newest_seq() + 1 > srcdn->first))
       srci->project_past_snaprealm_parent(dest_realm);
     
     if (destdn->is_auth() && !destdnl->is_null())