FileJournal: queue_pos \in [get_top(), header.max_size)

If queue_pos == header.max_size when we create the entry
header magic, the entry will be rejected at get_top() on
replay.

Fixes: #4436
Backport: bobtail
Signed-off-by: Samuel Just <sam.just@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
(cherry picked from commit de8edb732e3a5ce4471670e43cfe6357ae6a2758)

diff --git a/src/os/FileJournal.cc b/src/os/FileJournal.cc
index 0056f1f23b447326f46be836eb83931b5cc119dc..218347efa4962abc637cb79d04c8791282c83556 100644 (file)
--- a/src/os/FileJournal.cc
+++ b/src/os/FileJournal.cc
@@ -914,7 +914,7 @@ int FileJournal::prepare_single_write(bufferlist& bl, off64_t& queue_pos, uint64
   writing_seq = seq;
 
   queue_pos += size;
-  if (queue_pos > header.max_size)
+  if (queue_pos >= header.max_size)
     queue_pos = queue_pos + get_top() - header.max_size;
 
   return 0;