Merge pull request #12921 from xiaoxichen/wip-18520-jewel

Jewel: speed up readdir by skipping unwanted dn
ceph · Jan 31, 2017 · 916e95d · 916e95d
2 parents 384a425 + 8404426
commit 916e95d
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Showing 2 changed files with 4 additions and 1 deletion.
diff --git a/src/mds/CDir.h b/src/mds/CDir.h
@@ -428,6 +428,7 @@ class CDir : public MDSCacheObject {
 
   map_t::iterator begin() { return items.begin(); }
   map_t::iterator end() { return items.end(); }
+  map_t::iterator lower_bound(dentry_key_t key) { return items.lower_bound(key); }
 
   unsigned get_num_head_items() const { return num_head_items; }
   unsigned get_num_head_null() const { return num_head_null; }

diff --git a/src/mds/Server.cc b/src/mds/Server.cc
@@ -3394,7 +3394,9 @@ void Server::handle_client_readdir(MDRequestRef& mdr)
   bufferlist dnbl;
   __u32 numfiles = 0;
   bool end = (dir->begin() == dir->end());
-  for (CDir::map_t::iterator it = dir->begin();
+  // skip all dns < dentry_key_t(snapid, offset_str, offset_hash)
+  dentry_key_t skip_key(snapid, offset_str.c_str(), offset_hash);
+  for (CDir::map_t::iterator it = offset_str.empty() ? dir->begin() : dir->lower_bound(skip_key);
        !end && numfiles < max;
        end = (it == dir->end())) {
     CDentry *dn = it->second;