From: xie xingguo <xie.xingguo@zte.com.cn>
Date: Mon, 20 Jun 2016 12:02:41 +0000 (+0800)
Subject: os/bluestore: simplify BufferSpace::read() a little
X-Git-Tag: v11.0.0~97^2~1
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=d2baf233fcfa47d14b3fa4f8315f64159a4d19b8;p=ceph.git

os/bluestore: simplify BufferSpace::read() a little

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 26c208aae857d..e5ed108359322 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -606,14 +606,14 @@ void BlueStore::BufferSpace::_discard(uint64_t offset, uint64_t length)
   uint64_t end = offset + length;
   while (i != buffer_map.end()) {
     Buffer *b = i->second.get();
-    if (b->offset >= offset + length) {
+    if (b->offset >= end) {
       break;
     }
     if (b->offset < offset) {
       uint64_t front = offset - b->offset;
-      if (b->offset + b->length > offset + length) {
+      if (b->end() > end) {
 	// drop middle (split)
-	uint64_t tail = b->offset + b->length - (offset + length);
+	uint64_t tail = b->end() - end;
 	if (b->data.length()) {
 	  bufferlist bl;
 	  bl.substr_of(b->data, b->length - tail, tail);
@@ -621,12 +621,14 @@ void BlueStore::BufferSpace::_discard(uint64_t offset, uint64_t length)
 	} else {
 	  _add_buffer(new Buffer(this, b->state, b->seq, end, tail));
 	}
+        assert(cache->buffer_size >= b->length - front);
 	cache->buffer_size -= b->length - front;
 	b->truncate(front);
 	cache->_audit_lru("discard end 1");
 	return;
       } else {
 	// drop tail
+	assert(cache->buffer_size >= b->length - front);
 	cache->buffer_size -= b->length - front;
 	b->truncate(front);
 	++i;