From 1645baf65d14b50813dc8846cf66ecd5b62d4f50 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Piotr=20Da=C5=82ek?= <piotr.dalek@corp.ovh.com>
Date: Tue, 18 Apr 2017 16:12:04 +0200
Subject: [PATCH] ReplicatedPG: use new fiemap interface
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

Reduce memory allocator load during sparse reads and recovery by not
encoding sparse file extents from map into bufferlist, then back again
into map.

Signed-off-by: Piotr Dałek <piotr.dalek@corp.ovh.com>
---
 src/osd/PrimaryLogPG.cc      |  7 ++-----
 src/osd/ReplicatedBackend.cc | 18 +++++++-----------
 2 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/src/osd/PrimaryLogPG.cc b/src/osd/PrimaryLogPG.cc
index 71846caabf8..f5e164d770b 100644
--- a/src/osd/PrimaryLogPG.cc
+++ b/src/osd/PrimaryLogPG.cc
@@ -4429,18 +4429,15 @@ int PrimaryLogPG::do_osd_ops(OpContext *ctx, vector<OSDOp>& ops)
 	}
       } else {
 	// read into a buffer
-	bufferlist bl;
+        map<uint64_t, uint64_t> m;
         uint32_t total_read = 0;
 	int r = osd->store->fiemap(ch, ghobject_t(soid, ghobject_t::NO_GEN,
 						  info.pgid.shard),
-				   op.extent.offset, op.extent.length, bl);
+				   op.extent.offset, op.extent.length, m);
 	if (r < 0)  {
 	  result = r;
           break;
 	}
-        map<uint64_t, uint64_t> m;
-        bufferlist::iterator iter = bl.begin();
-        ::decode(m, iter);
         map<uint64_t, uint64_t>::iterator miter;
         bufferlist data_bl;
 	uint64_t last = op.extent.offset;
diff --git a/src/osd/ReplicatedBackend.cc b/src/osd/ReplicatedBackend.cc
index 1364cc62770..2b6ca917a47 100644
--- a/src/osd/ReplicatedBackend.cc
+++ b/src/osd/ReplicatedBackend.cc
@@ -1981,21 +1981,17 @@ int ReplicatedBackend::build_push_op(const ObjectRecoveryInfo &recovery_info,
   if (available > 0) {
     if (!recovery_info.copy_subset.empty()) {
       interval_set<uint64_t> copy_subset = recovery_info.copy_subset;
-      bufferlist bl;
+      map<uint64_t, uint64_t> m;
       int r = store->fiemap(ch, ghobject_t(recovery_info.soid), 0,
-                            copy_subset.range_end(), bl);
+                            copy_subset.range_end(), m);
       if (r >= 0)  {
-        interval_set<uint64_t> fiemap_included;
-        map<uint64_t, uint64_t> m;
-        bufferlist::iterator iter = bl.begin();
-        ::decode(m, iter);
-        map<uint64_t, uint64_t>::iterator miter;
-        for (miter = m.begin(); miter != m.end(); ++miter) {
-          fiemap_included.insert(miter->first, miter->second);
-        }
-
+        interval_set<uint64_t> fiemap_included(m);
         copy_subset.intersection_of(fiemap_included);
+      } else {
+        // intersection of copy_subset and empty interval_set would be empty anyway
+        copy_subset.clear();
       }
+
       out_op->data_included.span_of(copy_subset, progress.data_recovered_to,
                                     available);
       if (out_op->data_included.empty()) // zero filled section, skip to end!
-- 
2.39.5