Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc

[powerpc.git] / fs / jffs2 / nodelist.c

diff --git a/fs/jffs2/nodelist.c b/fs/jffs2/nodelist.c
index ac2a4c4..4bf8608 100644 (file)
--- a/fs/jffs2/nodelist.c
+++ b/fs/jffs2/nodelist.c
@@ -52,7 +52,7 @@ void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new
        *prev = new;
 }
 
-void jffs2_truncate_fragtree(struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
+uint32_t jffs2_truncate_fragtree(struct jffs2_sb_info *c, struct rb_root *list, uint32_t size)
 {
        struct jffs2_node_frag *frag = jffs2_lookup_node_frag(list, size);
 
@@ -74,18 +74,24 @@ void jffs2_truncate_fragtree(struct jffs2_sb_info *c, struct rb_root *list, uint
        }
 
        if (size == 0)
-               return;
+               return 0;
 
-       /*
-        * If the last fragment starts at the RAM page boundary, it is
-        * REF_PRISTINE irrespective of its size.
-        */
        frag = frag_last(list);
+
+       /* Sanity check for truncation to longer than we started with... */
+       if (!frag)
+               return 0;
+       if (frag->ofs + frag->size < size)
+               return frag->ofs + frag->size;
+
+       /* If the last fragment starts at the RAM page boundary, it is
+        * REF_PRISTINE irrespective of its size. */
        if (frag->node && (frag->ofs & (PAGE_CACHE_SIZE - 1)) == 0) {
                dbg_fragtree2("marking the last fragment 0x%08x-0x%08x REF_PRISTINE.\n",
                        frag->ofs, frag->ofs + frag->size);
                frag->node->raw->flash_offset = ref_offset(frag->node->raw) | REF_PRISTINE;
        }
+       return size;
 }
 
 static void jffs2_obsolete_node_frag(struct jffs2_sb_info *c,