[LogFS] Prevent memory corruption on large deletes

[pandora-kernel.git] / fs / logfs / readwrite.c

diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
index 3659c37..7e0c39c 100644 (file)
--- a/fs/logfs/readwrite.c
+++ b/fs/logfs/readwrite.c
@@ -1219,6 +1219,18 @@ static void free_shadow(struct inode *inode, struct logfs_shadow *shadow)
        mempool_free(shadow, super->s_shadow_pool);
 }
 
+static void mark_segment(struct shadow_tree *tree, u32 segno)
+{
+       int err;
+
+       if (!btree_lookup32(&tree->segment_map, segno)) {
+               err = btree_insert32(&tree->segment_map, segno, (void *)1,
+                               GFP_NOFS);
+               BUG_ON(err);
+               tree->no_shadowed_segments++;
+       }
+}
+
 /**
  * fill_shadow_tree - Propagate shadow tree changes due to a write
  * @inode:     Inode owning the page
@@ -1266,6 +1278,8 @@ static void fill_shadow_tree(struct inode *inode, struct page *page,
 
                super->s_dirty_used_bytes += shadow->new_len;
                super->s_dirty_free_bytes += shadow->old_len;
+               mark_segment(tree, shadow->old_ofs >> super->s_segshift);
+               mark_segment(tree, shadow->new_ofs >> super->s_segshift);
        }
 }