From: xie xingguo <xie.xingguo@zte.com.cn>
Date: Mon, 12 Jun 2017 12:48:25 +0000 (+0800)
Subject: os/bluestore: narrow shard combination condition
X-Git-Tag: v12.1.0~135^2~1
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=1593c8715835869f1696e04d996eed5c4f7e3b8e;p=ceph.git

os/bluestore: narrow shard combination condition

We have confirmed that we are not the last shard!

Signed-off-by: xie xingguo <xie.xingguo@zte.com.cn>
---

diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index 479857664a5..da82a3ba6d4 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -1976,20 +1976,13 @@ void BlueStore::ExtentMap::update(KeyValueDB::Transaction t,
 	  // avoid resharding the trailing shard, even if it is small
 	  else if (n != shards.end() &&
 		   len < g_conf->bluestore_extent_map_shard_min_size) {
-	    // we are small; combine with a neighbor
-	    if (p == shards.begin() && endoff == OBJECT_MAX_SIZE) {
-	      // we are an only shard
-	      request_reshard(0, OBJECT_MAX_SIZE);
-	      return;
-	    } else if (p == shards.begin()) {
-	      // combine with next shard
+            assert(endoff != OBJECT_MAX_SIZE);
+	    if (p == shards.begin()) {
+	      // we are the first shard, combine with next shard
 	      request_reshard(p->shard_info->offset, endoff + 1);
-	    } else if (endoff == OBJECT_MAX_SIZE) {
-	      // combine with previous shard
-	      request_reshard(prev_p->shard_info->offset, endoff);
-	      return;
 	    } else {
-	      // combine with the smaller of the two
+	      // combine either with the previous shard or the next,
+	      // whichever is smaller
 	      if (prev_p->shard_info->bytes > n->shard_info->bytes) {
 		request_reshard(p->shard_info->offset, endoff + 1);
 	      } else {