Merge branch 'wip-journaler-4618' into next

Reviewed-by: Sam Lang <sam.lang@inktank.com>

2 files changed, 13 insertions, 9 deletions

diff --git a/src/osdc/Journaler.cc b/src/osdc/Journaler.cc
index 544ac8c49c4..cd9b9edc4c7 100644
--- a/src/osdc/Journaler.cc
+++ b/src/osdc/Journaler.cc
@@ -64,7 +64,6 @@ void Journaler::set_layout(ceph_file_layout *l)
   if (periods < 2)
     periods = 2;  // we need at least 2 periods to make progress.
   fetch_len = layout.fl_stripe_count * layout.fl_object_size * periods;
-  prefetch_from = fetch_len / 2;
 }
 
 
@@ -835,6 +834,7 @@ void Journaler::_issue_read(uint64_t len)
 
 void Journaler::_prefetch()
 {
+  ldout(cct, 10) << "_prefetch" << dendl;
   // prefetch
   uint64_t pf;
   if (temp_fetch_len) {
@@ -847,9 +847,11 @@ void Journaler::_prefetch()
 
   uint64_t raw_target = read_pos + pf;
 
-  // only read full log segments
+  // read full log segments, so increase if necessary
   uint64_t period = get_layout_period();
-  uint64_t target = raw_target - (raw_target % period);
+  uint64_t remainder = raw_target % period;
+  uint64_t adjustment = remainder ? period - remainder : 0;
+  uint64_t target = raw_target + adjustment;
 
   // don't read past the log tail
   if (target > write_pos)
@@ -883,7 +885,9 @@ bool Journaler::_is_readable()
       read_buf.length() >= sizeof(s) + s) 
     return true;  // yep, next entry is ready.
 
-  // darn it!
+  ldout (cct, 10) << "_is_readable read_buf.length() == " << read_buf.length()
+		  << ", but need " << s + sizeof(s)
+		  << " for next entry; fetch_len is " << fetch_len << dendl;
 
   // partial fragment at the end?
   if (received_pos == write_pos) {
@@ -902,12 +906,14 @@ bool Journaler::_is_readable()
     return false;
   }
 
-  uint64_t need = (sizeof(s)+s-read_buf.length());
+  uint64_t need = sizeof(s) + s;
   if (need > fetch_len) {
+    temp_fetch_len = sizeof(s) + s;
     ldout(cct, 10) << "_is_readable noting temp_fetch_len " << temp_fetch_len
 	     << " for len " << s << " entry" << dendl;
-    temp_fetch_len = need;
   }
+
+  ldout(cct, 10) << "_is_readable: not readable, returning false" << dendl;
   return false;
 }
 
diff --git a/src/osdc/Journaler.h b/src/osdc/Journaler.h
index 81a39d21a5b..dfc2115c18b 100644
--- a/src/osdc/Journaler.h
+++ b/src/osdc/Journaler.h
@@ -194,7 +194,6 @@ private:
 
   uint64_t fetch_len;     // how much to read at a time
   uint64_t temp_fetch_len;
-  uint64_t prefetch_from; // how far from end do we read next chunk
 
   // for wait_for_readable()
   Context    *on_readable;
@@ -251,7 +250,7 @@ public:
     prezeroing_pos(0), prezero_pos(0), write_pos(0), flush_pos(0), safe_pos(0),
     waiting_for_zero(false),
     read_pos(0), requested_pos(0), received_pos(0),
-    fetch_len(0), temp_fetch_len(0), prefetch_from(0),
+    fetch_len(0), temp_fetch_len(0),
     on_readable(0), on_write_error(NULL),
     expire_pos(0), trimming_pos(0), trimmed_pos(0) 
   {
@@ -273,7 +272,6 @@ public:
     requested_pos = 0;
     received_pos = 0;
     fetch_len = 0;
-    prefetch_from = 0;
     assert(!on_readable);
     expire_pos = 0;
     trimming_pos = 0;