Btrfs: Add BH_Defrag to mark buffers that are in need of defragging
This allows the tree walking code to defrag only the newly allocated
buffers, it seems to be a good balance between perfect defragging and the
performance hit of repeatedly reallocating blocks.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/tree-defrag.c b/fs/btrfs/tree-defrag.c
index a09064a..35fd20d 100644
--- a/fs/btrfs/tree-defrag.c
+++ b/fs/btrfs/tree-defrag.c
@@ -86,7 +86,7 @@
if (cache_only) {
next = btrfs_find_tree_block(root, blocknr);
if (!next || !buffer_uptodate(next) ||
- buffer_locked(next)) {
+ buffer_locked(next) || !buffer_defrag(next)) {
brelse(next);
path->slots[*level]++;
continue;
@@ -142,6 +142,7 @@
root->defrag_level = i;
return 0;
} else {
+ clear_buffer_defrag(path->nodes[*level]);
btrfs_block_release(root, path->nodes[*level]);
path->nodes[*level] = NULL;
*level = i + 1;