Add semantic checks to btrfsck for files and directories

This patch makes btrfsck check more things, including
directory items, file extents, checksumming, inode link
counts etc.

The code for these checks is similar to the code verifies
extent back references. The main difference is that
shared tree blocks are treated specially. The partial
checking results(unresolved references and/or errors)
of shared sub-trees are cached. This avoids scanning
the shared blocks several times. Thank you,

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/extent-cache.h b/extent-cache.h
index 4c468ce..7f2f2a6 100644
--- a/extent-cache.h
+++ b/extent-cache.h
@@ -44,6 +44,11 @@ int insert_cache_extent(struct cache_tree *tree, u64 start, u64 size);
 int insert_existing_cache_extent(struct cache_tree *tree,
 				 struct cache_extent *pe);
 
+static inline int cache_tree_empty(struct cache_tree *tree)
+{
+	return RB_EMPTY_ROOT(&tree->root);
+}
+
 static inline void free_cache_extent(struct cache_extent *pe)
 {
 	free(pe);