Btrfs: add del_ptr and insert_ptr modifications to the tree mod log
Record all relevant modifications to block pointers in the tree mod log so
that we can rewind them later on for backref walking.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 07c1a96..69ce3f7 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -38,7 +38,8 @@
struct extent_buffer *dst_buf,
struct extent_buffer *src_buf);
static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
- struct btrfs_path *path, int level, int slot);
+ struct btrfs_path *path, int level, int slot,
+ int tree_mod_log);
static void tree_mod_log_free_eb(struct btrfs_fs_info *fs_info,
struct extent_buffer *eb);
struct extent_buffer *read_old_tree_block(struct btrfs_root *root, u64 bytenr,
@@ -1465,7 +1466,7 @@
if (btrfs_header_nritems(right) == 0) {
clean_tree_block(trans, root, right);
btrfs_tree_unlock(right);
- del_ptr(trans, root, path, level + 1, pslot + 1);
+ del_ptr(trans, root, path, level + 1, pslot + 1, 1);
root_sub_used(root, right->len);
btrfs_free_tree_block(trans, root, right, 0, 1);
free_extent_buffer_stale(right);
@@ -1509,7 +1510,7 @@
if (btrfs_header_nritems(mid) == 0) {
clean_tree_block(trans, root, mid);
btrfs_tree_unlock(mid);
- del_ptr(trans, root, path, level + 1, pslot);
+ del_ptr(trans, root, path, level + 1, pslot, 1);
root_sub_used(root, mid->len);
btrfs_free_tree_block(trans, root, mid, 0, 1);
free_extent_buffer_stale(mid);
@@ -2626,10 +2627,11 @@
static void insert_ptr(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_path *path,
struct btrfs_disk_key *key, u64 bytenr,
- int slot, int level)
+ int slot, int level, int tree_mod_log)
{
struct extent_buffer *lower;
int nritems;
+ int ret;
BUG_ON(!path->nodes[level]);
btrfs_assert_tree_locked(path->nodes[level]);
@@ -2638,11 +2640,19 @@
BUG_ON(slot > nritems);
BUG_ON(nritems == BTRFS_NODEPTRS_PER_BLOCK(root));
if (slot != nritems) {
+ if (tree_mod_log && level)
+ tree_mod_log_eb_move(root->fs_info, lower, slot + 1,
+ slot, nritems - slot);
memmove_extent_buffer(lower,
btrfs_node_key_ptr_offset(slot + 1),
btrfs_node_key_ptr_offset(slot),
(nritems - slot) * sizeof(struct btrfs_key_ptr));
}
+ if (tree_mod_log && level) {
+ ret = tree_mod_log_insert_key(root->fs_info, lower, slot,
+ MOD_LOG_KEY_ADD);
+ BUG_ON(ret < 0);
+ }
btrfs_set_node_key(lower, key, slot);
btrfs_set_node_blockptr(lower, slot, bytenr);
WARN_ON(trans->transid == 0);
@@ -2726,7 +2736,7 @@
btrfs_mark_buffer_dirty(split);
insert_ptr(trans, root, path, &disk_key, split->start,
- path->slots[level + 1] + 1, level + 1);
+ path->slots[level + 1] + 1, level + 1, 1);
if (path->slots[level] >= mid) {
path->slots[level] -= mid;
@@ -3263,7 +3273,7 @@
btrfs_set_header_nritems(l, mid);
btrfs_item_key(right, &disk_key, 0);
insert_ptr(trans, root, path, &disk_key, right->start,
- path->slots[1] + 1, 1);
+ path->slots[1] + 1, 1, 0);
btrfs_mark_buffer_dirty(right);
btrfs_mark_buffer_dirty(l);
@@ -3470,7 +3480,7 @@
if (mid <= slot) {
btrfs_set_header_nritems(right, 0);
insert_ptr(trans, root, path, &disk_key, right->start,
- path->slots[1] + 1, 1);
+ path->slots[1] + 1, 1, 0);
btrfs_tree_unlock(path->nodes[0]);
free_extent_buffer(path->nodes[0]);
path->nodes[0] = right;
@@ -3479,7 +3489,7 @@
} else {
btrfs_set_header_nritems(right, 0);
insert_ptr(trans, root, path, &disk_key, right->start,
- path->slots[1], 1);
+ path->slots[1], 1, 0);
btrfs_tree_unlock(path->nodes[0]);
free_extent_buffer(path->nodes[0]);
path->nodes[0] = right;
@@ -4191,19 +4201,31 @@
* empty a node.
*/
static void del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
- struct btrfs_path *path, int level, int slot)
+ struct btrfs_path *path, int level, int slot,
+ int tree_mod_log)
{
struct extent_buffer *parent = path->nodes[level];
u32 nritems;
+ int ret;
nritems = btrfs_header_nritems(parent);
if (slot != nritems - 1) {
+ if (tree_mod_log && level)
+ tree_mod_log_eb_move(root->fs_info, parent, slot,
+ slot + 1, nritems - slot - 1);
memmove_extent_buffer(parent,
btrfs_node_key_ptr_offset(slot),
btrfs_node_key_ptr_offset(slot + 1),
sizeof(struct btrfs_key_ptr) *
(nritems - slot - 1));
}
+
+ if (tree_mod_log && level) {
+ ret = tree_mod_log_insert_key(root->fs_info, parent, slot,
+ MOD_LOG_KEY_REMOVE);
+ BUG_ON(ret < 0);
+ }
+
nritems--;
btrfs_set_header_nritems(parent, nritems);
if (nritems == 0 && parent == root->node) {
@@ -4235,7 +4257,7 @@
struct extent_buffer *leaf)
{
WARN_ON(btrfs_header_generation(leaf) != trans->transid);
- del_ptr(trans, root, path, 1, path->slots[1]);
+ del_ptr(trans, root, path, 1, path->slots[1], 1);
/*
* btrfs_free_extent is expensive, we want to make sure we