From: xie xingguo <xie.xingguo@zte.com.cn>
Date: Wed, 6 Jul 2016 07:13:38 +0000 (+0800)
Subject: os/bluestore: add support for allocating 0-sized extent
X-Git-Tag: ses5-milestone5~437^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F10040%2Fhead;p=ceph.git

os/bluestore: add support for allocating 0-sized extent

For testing, we may choose randomized length of extent to allocate,
which means we could trim down the length to 0.

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

diff --git a/src/os/bluestore/BitMapAllocator.cc b/src/os/bluestore/BitMapAllocator.cc
index d42093e79b1f..ac3037e20143 100644
--- a/src/os/bluestore/BitMapAllocator.cc
+++ b/src/os/bluestore/BitMapAllocator.cc
@@ -105,6 +105,8 @@ int BitMapAllocator::allocate(
   uint64_t want_size, uint64_t alloc_unit, int64_t hint,
   uint64_t *offset, uint32_t *length)
 {
+  if (want_size == 0)
+    return 0;
 
   assert(!(alloc_unit % m_block_size));
   int64_t nblks = (want_size + m_block_size - 1) / m_block_size;