Merge bk-internal.mysql.com:/home/bk/mysql-maria

into  janus.mylan:/usr/home/serg/Abk/mysql-maria1

storage/maria/ma_loghandler.c

@@ -104,7 +104,7 @@ struct st_buffer_cursor
   struct st_translog_buffer *buffer;
   /* current page fill */
   uint16 current_page_fill;
-  /* how many times we finish this page to write it */
+  /* how many times we finish this page to write it (for sector protection) */
   uint16 write_counter;
   /* previous write offset */
   uint16 previous_offset;
@@ -6066,10 +6066,10 @@ translog_size_t translog_read_record(LSN lsn,
 
 
 /*
-  Force skipping to the next buffer
+  @brief Force skipping to the next buffer
 
-  SYNOPSIS
-    translog_force_current_buffer_to_finish()
+  @todo Do not copy old page content if all page protections are switched off
+  (because we do not need calculate something or change old parts of the page)
 */
 
 static void translog_force_current_buffer_to_finish()
@@ -6142,6 +6142,7 @@ static void translog_force_current_buffer_to_finish()
   write_counter= log_descriptor.bc.write_counter;
   previous_offset= log_descriptor.bc.previous_offset;
   translog_start_buffer(new_buffer, &log_descriptor.bc, new_buffer_no);
+  /* Fix buffer offset (which was incorrectly set to horizon) */
   log_descriptor.bc.buffer->offset= new_buff_beginning;
   log_descriptor.bc.write_counter= write_counter;
   log_descriptor.bc.previous_offset= previous_offset;

storage/maria/ma_pagecache.c

@@ -184,7 +184,6 @@ static const char *page_cache_page_type_str[]=
 static const char *page_cache_page_write_mode_str[]=
 {
   "DELAY",
-  "NOW",
   "DONE"
 };
 
@@ -2929,7 +2928,14 @@ uchar *pagecache_valid_read(PAGECACHE *pagecache,
 
     status= block->status;
     if (!buff)
+    {
       buff=  block->buffer;
+      /* if we lock for write we must link the block to changed blocks */
+      if ((lock == PAGECACHE_LOCK_WRITE ||
+           lock == PAGECACHE_LOCK_LEFT_WRITELOCKED) &&
+          !(block->status & PCBLOCK_CHANGED))
+          link_to_changed_list(pagecache, block);
+    }
     else
     {
       if (!(status & PCBLOCK_ERROR))