From 01763a2e37425ae3f37a3dc051e0703fdade5956 Mon Sep 17 00:00:00 2001 From: Jan Schmidt Date: Tue, 23 Oct 2012 15:02:12 +0200 Subject: [PATCH] Btrfs: comment for loop in tree_mod_log_insert_move Emphasis the way tree_mod_log_insert_move avoids adding MOD_LOG_KEY_REMOVE_WHILE_MOVING operations, depending on the direction of the move operation. Signed-off-by: Jan Schmidt --- fs/btrfs/ctree.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index f673990..eba44b0 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -596,6 +596,11 @@ tree_mod_log_insert_move(struct btrfs_fs_info *fs_info, if (tree_mod_dont_log(fs_info, eb)) return 0; + /* + * When we override something during the move, we log these removals. + * This can only happen when we move towards the beginning of the + * buffer, i.e. dst_slot < src_slot. + */ for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { ret = tree_mod_log_insert_key_locked(fs_info, eb, i + dst_slot, MOD_LOG_KEY_REMOVE_WHILE_MOVING); -- 2.7.4