From 7da449a2f634d1807a5aaa8cd8dceb360032343e Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Fri, 2 Mar 2007 16:08:05 -0500 Subject: early reference counting --- ctree.c | 153 +++++++++++++++++++++++++++++++++++++--------------------------- 1 file changed, 88 insertions(+), 65 deletions(-) (limited to 'ctree.c') diff --git a/ctree.c b/ctree.c index 3c5f4c2d..1118986d 100644 --- a/ctree.c +++ b/ctree.c @@ -34,6 +34,37 @@ void release_path(struct ctree_root *root, struct ctree_path *p) memset(p, 0, sizeof(*p)); } +int btrfs_cow_block(struct ctree_root *root, + struct tree_buffer *buf, + struct tree_buffer *parent, + int parent_slot, + struct tree_buffer **cow_ret) +{ + struct tree_buffer *cow; + + if (!list_empty(&buf->dirty)) { + *cow_ret = buf; + return 0; + } + cow = alloc_free_block(root); + memcpy(&cow->node, &buf->node, sizeof(buf->node)); + cow->node.header.blocknr = cow->blocknr; + *cow_ret = cow; + if (buf == root->node) { + root->node = cow; + cow->count++; + tree_block_release(root, buf); + } else { + parent->node.blockptrs[parent_slot] = cow->blocknr; + BUG_ON(list_empty(&parent->dirty)); + } + if (0 && root != root->extent_root && !is_leaf(cow->node.header.flags)) { + btrfs_inc_ref(root, cow); + } + tree_block_release(root, buf); + return 0; +} + /* * The leaf data grows from end-to-front in the node. * this returns the address of the start of the last item, @@ -263,6 +294,8 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path, /* first, try to make some room in the middle buffer */ if (left_buf) { + btrfs_cow_block(root, left_buf, parent_buf, + pslot - 1, &left_buf); left = &left_buf->node; orig_slot += left->header.nritems; wret = push_node_left(root, left_buf, mid_buf); @@ -274,6 +307,8 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path, * then try to empty the right most buffer into the middle */ if (right_buf) { + btrfs_cow_block(root, right_buf, parent_buf, + pslot + 1, &right_buf); right = &right_buf->node; wret = push_node_left(root, mid_buf, right_buf); if (wret < 0) @@ -293,9 +328,7 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path, } else { memcpy(parent->keys + pslot + 1, right->keys, sizeof(struct key)); - wret = dirty_tree_block(root, parent_buf); - if (wret) - ret = wret; + BUG_ON(list_empty(&parent_buf->dirty)); } } if (mid->header.nritems == 1) { @@ -330,9 +363,7 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path, } else { /* update the parent key to reflect our changes */ memcpy(parent->keys + pslot, mid->keys, sizeof(struct key)); - wret = dirty_tree_block(root, parent_buf); - if (wret) - ret = wret; + BUG_ON(list_empty(&parent_buf->dirty)); } /* update the path */ @@ -375,9 +406,10 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path, * possible) */ int search_slot(struct ctree_root *root, struct key *key, - struct ctree_path *p, int ins_len) + struct ctree_path *p, int ins_len, int cow) { struct tree_buffer *b; + struct tree_buffer *cow_buf; struct node *c; int slot; int ret; @@ -387,8 +419,15 @@ again: b = root->node; b->count++; while (b) { + level = node_level(b->node.header.flags); + if (cow) { + int wret; + wret = btrfs_cow_block(root, b, p->nodes[level + 1], + p->slots[level + 1], &cow_buf); + b = cow_buf; + } + BUG_ON(!cow && ins_len); c = &b->node; - level = node_level(c->header.flags); p->nodes[level] = b; ret = check_block(p, level); if (ret) @@ -453,7 +492,6 @@ static int fixup_low_keys(struct ctree_root *root, { int i; int ret = 0; - int wret; for (i = level; i < MAX_LEVEL; i++) { struct node *t; int tslot = path->slots[i]; @@ -461,9 +499,7 @@ static int fixup_low_keys(struct ctree_root *root, break; t = &path->nodes[i]->node; memcpy(t->keys + tslot, key, sizeof(*key)); - wret = dirty_tree_block(root, path->nodes[i]); - if (wret) - ret = wret; + BUG_ON(list_empty(&path->nodes[i]->dirty)); if (tslot != 0) break; } @@ -486,7 +522,6 @@ static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf, int src_nritems; int dst_nritems; int ret = 0; - int wret; src_nritems = src->header.nritems; dst_nritems = dst->header.nritems; @@ -511,13 +546,8 @@ static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf, src->header.nritems -= push_items; dst->header.nritems += push_items; - wret = dirty_tree_block(root, src_buf); - if (wret < 0) - ret = wret; - - wret = dirty_tree_block(root, dst_buf); - if (wret < 0) - ret = wret; + BUG_ON(list_empty(&src_buf->dirty)); + BUG_ON(list_empty(&dst_buf->dirty)); return ret; } @@ -541,7 +571,6 @@ static int balance_node_right(struct ctree_root *root, int src_nritems; int dst_nritems; int ret = 0; - int wret; src_nritems = src->header.nritems; dst_nritems = dst->header.nritems; @@ -569,13 +598,8 @@ static int balance_node_right(struct ctree_root *root, src->header.nritems -= push_items; dst->header.nritems += push_items; - wret = dirty_tree_block(root, src_buf); - if (wret < 0) - ret = wret; - - wret = dirty_tree_block(root, dst_buf); - if (wret < 0) - ret = wret; + BUG_ON(list_empty(&src_buf->dirty)); + BUG_ON(list_empty(&dst_buf->dirty)); return ret; } @@ -615,7 +639,6 @@ static int insert_new_root(struct ctree_root *root, tree_block_release(root, root->node); root->node = t; t->count++; - dirty_tree_block(root, t); path->nodes[level] = t; path->slots[level] = 0; return 0; @@ -655,7 +678,7 @@ static int insert_ptr(struct ctree_root *root, lower->header.nritems++; if (lower->keys[1].objectid == 0) BUG(); - dirty_tree_block(root, path->nodes[level]); + BUG_ON(list_empty(&path->nodes[level]->dirty)); return 0; } @@ -701,12 +724,7 @@ static int split_node(struct ctree_root *root, struct ctree_path *path, c->header.nritems = mid; ret = 0; - wret = dirty_tree_block(root, t); - if (wret) - ret = wret; - wret = dirty_tree_block(root, split_buffer); - if (wret) - ret = wret; + BUG_ON(list_empty(&t->dirty)); wret = insert_ptr(root, path, split->keys, split_buffer->blocknr, path->slots[level + 1] + 1, level + 1); if (wret) @@ -778,6 +796,15 @@ static int push_leaf_right(struct ctree_root *root, struct ctree_path *path, tree_block_release(root, right_buf); return 1; } + /* cow and double check */ + btrfs_cow_block(root, right_buf, upper, slot + 1, &right_buf); + right = &right_buf->leaf; + free_space = leaf_free_space(right); + if (free_space < data_size + sizeof(struct item)) { + tree_block_release(root, right_buf); + return 1; + } + for (i = left->header.nritems - 1; i >= 0; i--) { item = left->items + i; if (path->slots[0] == i) @@ -818,11 +845,12 @@ static int push_leaf_right(struct ctree_root *root, struct ctree_path *path, } left->header.nritems -= push_items; - dirty_tree_block(root, left_buf); - dirty_tree_block(root, right_buf); + BUG_ON(list_empty(&left_buf->dirty)); + BUG_ON(list_empty(&right_buf->dirty)); memcpy(upper->node.keys + slot + 1, &right->items[0].key, sizeof(struct key)); - dirty_tree_block(root, upper); + BUG_ON(list_empty(&upper->dirty)); + /* then fixup the leaf pointer in the path */ if (path->slots[0] >= left->header.nritems) { path->slots[0] -= left->header.nritems; @@ -869,6 +897,16 @@ static int push_leaf_left(struct ctree_root *root, struct ctree_path *path, tree_block_release(root, t); return 1; } + + /* cow and double check */ + btrfs_cow_block(root, t, path->nodes[1], slot - 1, &t); + left = &t->leaf; + free_space = leaf_free_space(left); + if (free_space < data_size + sizeof(struct item)) { + tree_block_release(root, t); + return 1; + } + for (i = 0; i < right->header.nritems; i++) { item = right->items + i; if (path->slots[0] == i) @@ -912,12 +950,8 @@ static int push_leaf_left(struct ctree_root *root, struct ctree_path *path, push_space = right->items[i].offset; } - wret = dirty_tree_block(root, t); - if (wret) - ret = wret; - wret = dirty_tree_block(root, right_buf); - if (wret) - ret = wret; + BUG_ON(list_empty(&t->dirty)); + BUG_ON(list_empty(&right_buf->dirty)); wret = fixup_low_keys(root, path, &right->items[0].key, 1); if (wret) @@ -968,6 +1002,7 @@ static int split_leaf(struct ctree_root *root, struct ctree_path *path, if (wret < 0) return wret; } + l_buf = path->nodes[0]; l = &l_buf->leaf; @@ -1022,13 +1057,8 @@ static int split_leaf(struct ctree_root *root, struct ctree_path *path, right_buffer->blocknr, path->slots[1] + 1, 1); if (wret) ret = wret; - wret = dirty_tree_block(root, right_buffer); - if (wret) - ret = wret; - wret = dirty_tree_block(root, l_buf); - if (wret) - ret = wret; - + BUG_ON(list_empty(&right_buffer->dirty)); + BUG_ON(list_empty(&l_buf->dirty)); BUG_ON(path->slots[0] != slot); if (mid <= slot) { tree_block_release(root, path->nodes[0]); @@ -1049,7 +1079,6 @@ int insert_item(struct ctree_root *root, struct key *key, void *data, int data_size) { int ret = 0; - int wret; int slot; int slot_orig; struct leaf *leaf; @@ -1062,7 +1091,7 @@ int insert_item(struct ctree_root *root, struct key *key, if (!root->node) BUG(); init_path(&path); - ret = search_slot(root, key, &path, data_size); + ret = search_slot(root, key, &path, data_size, 1); if (ret == 0) { release_path(root, &path); return -EEXIST; @@ -1114,10 +1143,7 @@ int insert_item(struct ctree_root *root, struct key *key, if (slot == 0) ret = fixup_low_keys(root, &path, key, 1); - wret = dirty_tree_block(root, leaf_buf); - if (wret) - ret = wret; - + BUG_ON(list_empty(&leaf_buf->dirty)); if (leaf_free_space(leaf) < 0) BUG(); check_leaf(&path, 0); @@ -1162,9 +1188,7 @@ static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level, if (wret) ret = wret; } - wret = dirty_tree_block(root, parent); - if (wret) - ret = wret; + BUG_ON(list_empty(&parent->dirty)); return ret; } @@ -1205,7 +1229,7 @@ int del_item(struct ctree_root *root, struct ctree_path *path) if (leaf->header.nritems == 0) { if (leaf_buf == root->node) { leaf->header.flags = node_level(0); - dirty_tree_block(root, leaf_buf); + BUG_ON(list_empty(&leaf_buf->dirty)); } else { clean_tree_block(root, leaf_buf); wret = del_ptr(root, path, 1, path->slots[1]); @@ -1223,9 +1247,7 @@ int del_item(struct ctree_root *root, struct ctree_path *path) if (wret) ret = wret; } - wret = dirty_tree_block(root, leaf_buf); - if (wret) - ret = wret; + BUG_ON(list_empty(&leaf_buf->dirty)); /* delete the leaf if it is mostly empty */ if (used < LEAF_DATA_SIZE / 3) { @@ -1304,3 +1326,4 @@ int next_leaf(struct ctree_root *root, struct ctree_path *path) return 0; } + -- cgit v1.2.3