Commit 19956c7e authored Jun 22, 2012 by Jan Schmidt

Btrfs: fix tree mod log rewind of ADD operations

When a MOD_LOG_KEY_ADD operation is rewinded, we remove the key from the
tree block. If its not the last key, removal involves a move operation.
This move operation was explicitly done before this commit.

However, at insertion time, there's a move operation before the actual
addition to make room for the new key, which is recorded in the tree mod
log as well. This means, we must drop the move operation when rewinding the
add operation, because the next operation we'll be rewinding will be the
corresponding MOD_LOG_MOVE_KEYS operation.

Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>

parent 155725c9

fs/btrfs/ctree.c

+1 −5

Original line number	Diff line number	Diff line
		@@ -1094,11 +1094,7 @@ __tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq,
		tm->generation);
		break;
		case MOD_LOG_KEY_ADD:
		if (tm->slot != n - 1) {
		o_dst = btrfs_node_key_ptr_offset(tm->slot);
		o_src = btrfs_node_key_ptr_offset(tm->slot + 1);
		memmove_extent_buffer(eb, o_dst, o_src, p_size);
		}
		/* if a move operation is needed it's in the log */
		n--;
		break;
		case MOD_LOG_MOVE_KEYS:

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