Commit 95c80bb1 authored Oct 19, 2012 by Liu Bo Committed by Josef Bacik Dec 11, 2012

Btrfs: MOD_LOG_KEY_REMOVE_WHILE_MOVING never change node's nritems



Key MOD_LOG_KEY_REMOVE_WHILE_MOVING means that we're doing memmove inside
an extent buffer node, and the node's number of items remains unchanged
(unless we are inserting a single pointer, but we have MOD_LOG_KEY_ADD for that).

So we don't need to increase node's number of items during rewinding,
otherwise we may get an node larger than leafsize and cause general protection
errors later.

Here is the details,
- If we do memory move for inserting a single pointer, we need to
  add node's nritems by one, and we honor MOD_LOG_KEY_ADD for adding.

- If we do memory move for deleting a single pointer, we need to
  decrease node's nritems by one, and we honor MOD_LOG_KEY_REMOVE for
  deleting.

- If we do memory move for balance left/right, we need to decrease
  node's nritems, and we honor MOD_LOG_KEY_REMOVE for balaning.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

parent de6c4115

fs/btrfs/ctree.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1140,13 +1140,13 @@ __tree_mod_log_rewind(struct extent_buffer *eb, u64 time_seq,
		switch (tm->op) {
		case MOD_LOG_KEY_REMOVE_WHILE_FREEING:
		BUG_ON(tm->slot < n);
		case MOD_LOG_KEY_REMOVE_WHILE_MOVING:
		case MOD_LOG_KEY_REMOVE:
		n++;
		case MOD_LOG_KEY_REMOVE_WHILE_MOVING:
		btrfs_set_node_key(eb, &tm->key, tm->slot);
		btrfs_set_node_blockptr(eb, tm->slot, tm->blockptr);
		btrfs_set_node_ptr_generation(eb, tm->slot,
		tm->generation);
		n++;
		break;
		case MOD_LOG_KEY_REPLACE:
		BUG_ON(tm->slot >= n);

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