[rtems commit] For PR 2163 - RFS File System - fix group search algorithm bug

[Chris Johns]

Module:    rtems
Branch:    master
Commit:    e60b7b1b4f19894dda0096b116bb0a21a5c51101
Changeset: http://git.rtems.org/rtems/commit/?id=e60b7b1b4f19894dda0096b116bb0a21a5c51101

Author:    Alan Cudmore <alan.cudmore at gmail.com>
Date:      Wed Dec 18 11:39:19 2013 -0500

For PR 2163 - RFS File System - fix group search algorithm bug

This is for the RFS file system. There is a bug in the group search
algorithm where it will skip groups, causing blocks to remain
unallocated. This is dependant on the size of the blocks and number
of blocks in a group, so it does not always show up. The fix corrects
the skipping of groups during the search, allowing all of the blocks
to be found.

---

 cpukit/libfs/src/rfs/rtems-rfs-group.c |   16 +++++++++++++++-
 1 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/cpukit/libfs/src/rfs/rtems-rfs-group.c b/cpukit/libfs/src/rfs/rtems-rfs-group.c
index b08e785..b096528 100644
--- a/cpukit/libfs/src/rfs/rtems-rfs-group.c
+++ b/cpukit/libfs/src/rfs/rtems-rfs-group.c
@@ -232,10 +232,24 @@ rtems_rfs_group_bitmap_alloc (rtems_rfs_file_system* fs,
       return 0;
     }
 
+    /*
+     * If we are still looking back and forth around the
+     * group_start, then alternate the direction and
+     * increment the offset on every other iteration.
+     * Otherwise we are marching through the groups, so just
+     * increment the offset.
+     */
     if (updown)
+    {
       direction = direction > 0 ? -1 : 1;
+      if ( direction == -1 )
+        offset++;
+    }
+    else
+    {
+       offset++;
+    }
 
-    offset++;
   }
 
   if (rtems_rfs_trace (RTEMS_RFS_TRACE_GROUP_BITMAPS))