Fix Allocate test

Summary: For some reason, on a subset of our continuous build machines, preallocation is allocating 8 block more than it should be. Let's relax the test a little bit -- now we require the test to allocate *at least* the number of blocks as we told them to.

Test Plan: no

Reviewers: ljin, haobo, sdong

Reviewed By: ljin

CC: leveldb

Differential Revision: https://reviews.facebook.net/D18141

util/env_test.cc

@@ -302,7 +302,11 @@ TEST(EnvPosixTest, AllocateTest) {
   stat(fname.c_str(), &f_stat);
   ASSERT_EQ((unsigned int)data.size(), f_stat.st_size);
   // verify that blocks are preallocated
-  ASSERT_EQ((unsigned int)(kPreallocateSize / kBlockSize), f_stat.st_blocks);
+  // Note here that we don't check the exact number of blocks preallocated --
+  // we only require that number of allocated blocks is at least what we expect.
+  // It looks like some FS give us more blocks that we asked for. That's fine.
+  // It might be worth investigating further.
+  ASSERT_LE((unsigned int)(kPreallocateSize / kBlockSize), f_stat.st_blocks);
 
   // close the file, should deallocate the blocks
   wfile.reset();