Merge pull request #6355 from vcaputo/journal_avoid_mmap_cache_get_calls

journal: avoid unnecessary mmap_cache_get() calls

diff --cc src/journal/mmap-cache.c
index 3e076f8fea31ed2d0191271b13ded0aa09062b0e,546710cdc9f16e98c4fe97cf802a47e4ec884544..6e60d24dcf34a41476f56d5804b73e06bae542ef
--- 1/src/journal/mmap-cache.c
--- 2/src/journal/mmap-cache.c
+++ b/src/journal/mmap-cache.c
@@@ -510,9 -512,14 +519,12 @@@ static int add_mmap
          if (!w)
                  goto outofmem;
  
 -        context_detach_window(c);
 -        c->window = w;
 -        LIST_PREPEND(by_window, w->contexts, c);
 +        context_attach_window(c, w);
  
          *ret = (uint8_t*) w->ptr + (offset - w->offset);
+         if (ret_size)
+                 *ret_size = w->size - (offset - w->offset);
+ 
          return 1;
  
  outofmem: