[LogFS] Prevent memory corruption on large deletes

Removing sufficiently large files would create aliases for a large
number of segments.  This in turn results in a large number of journal
entries and an overflow of s_je_array.

Cheap fix is to add a BUG_ON, turning memory corruption into something
annoying, but less dangerous.  Real fix is to count the number of
affected segments and prevent the problem completely.

Signed-off-by: Joern Engel <joern@logfs.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/logfs/super.c b/fs/logfs/super.c
index 9d856c49afc5..d6e1f4fc3115 100644
--- a/fs/logfs/super.c
+++ b/fs/logfs/super.c
@@ -451,6 +451,8 @@ static int logfs_read_sb(struct super_block *sb, int read_only)
 
         btree_init_mempool64(&super->s_shadow_tree.new, super->s_btree_pool);
         btree_init_mempool64(&super->s_shadow_tree.old, super->s_btree_pool);
+        btree_init_mempool32(&super->s_shadow_tree.segment_map,
+                        super->s_btree_pool);
 
         ret = logfs_init_mapping(sb);
         if (ret)