From 2f9ea76fba50722eecf578eb3520304d281759e5 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Wed, 30 Jun 2010 08:34:26 -0700
Subject: [PATCH] filejournal: fix buffer realignment condition; useful debug
 output on error

We don't care about contiguous, only about page alignment.
---
 src/os/FileJournal.cc | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/os/FileJournal.cc b/src/os/FileJournal.cc
index 4f5cbcc93c4..00df2092834 100644
--- a/src/os/FileJournal.cc
+++ b/src/os/FileJournal.cc
@@ -498,9 +498,13 @@ int FileJournal::prepare_single_write(bufferlist& bl, off64_t& queue_pos, uint64
 
 void FileJournal::write_bl(off64_t& pos, bufferlist& bl)
 {
-  // make sure this is a single, contiguous buffer
-  if (directio && !bl.is_contiguous()) {
+  // make sure list segments are page aligned
+  if (directio && (!bl.is_page_aligned() ||
+		   !bl.is_n_page_sized())) {
     bl.rebuild_page_aligned();
+    if ((bl.length() & ~PAGE_MASK) != 0 ||
+	(pos & ~PAGE_MASK) != 0)
+      dout(0) << "rebuild_page_aligned failed, " << bl << dendl;
     assert((bl.length() & ~PAGE_MASK) == 0);
     assert((pos & ~PAGE_MASK) == 0);
   }