Btrfs: Don't empty the middle buffer in push_nodes_for_insert
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index ac999f0..319f9f9 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -29,7 +29,7 @@
struct btrfs_path *path, int data_size, int extend);
static int push_node_left(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *dst,
- struct extent_buffer *src);
+ struct extent_buffer *src, int empty);
static int balance_node_right(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct extent_buffer *dst_buf,
@@ -789,7 +789,7 @@
/* first, try to make some room in the middle buffer */
if (left) {
orig_slot += btrfs_header_nritems(left);
- wret = push_node_left(trans, root, left, mid);
+ wret = push_node_left(trans, root, left, mid, 0);
if (wret < 0)
ret = wret;
if (btrfs_header_nritems(mid) < 2)
@@ -800,7 +800,7 @@
* then try to empty the right most buffer into the middle
*/
if (right) {
- wret = push_node_left(trans, root, mid, right);
+ wret = push_node_left(trans, root, mid, right, 1);
if (wret < 0 && wret != -ENOSPC)
ret = wret;
if (btrfs_header_nritems(right) == 0) {
@@ -941,7 +941,7 @@
wret = 1;
else {
wret = push_node_left(trans, root,
- left, mid);
+ left, mid, 0);
}
}
if (wret < 0)
@@ -1239,7 +1239,7 @@
*/
static int push_node_left(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *dst,
- struct extent_buffer *src)
+ struct extent_buffer *src, int empty)
{
int push_items = 0;
int src_nritems;
@@ -1252,12 +1252,17 @@
WARN_ON(btrfs_header_generation(src) != trans->transid);
WARN_ON(btrfs_header_generation(dst) != trans->transid);
+ if (!empty && src_nritems <= 2)
+ return 1;
+
if (push_items <= 0) {
return 1;
}
- if (src_nritems < push_items)
- push_items = src_nritems;
+ if (empty)
+ push_items = min(src_nritems, push_items);
+ else
+ push_items = min(src_nritems - 2, push_items);
copy_extent_buffer(dst, src,
btrfs_node_key_ptr_offset(dst_nritems),