From 00ec4c5161e0adcf8be3cd844cb40239dc393d70 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Sat, 24 Feb 2007 12:47:20 -0500 Subject: [PATCH] Btrfs: push_leaf_right Signed-off-by: Chris Mason --- fs/btrfs/ctree.c | 109 ++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 102 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index e497fd963118..ef8bfa837532 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -517,6 +517,97 @@ int leaf_space_used(struct leaf *l, int start, int nr) return data_len; } +/* + * push some data in the path leaf to the right, trying to free up at + * least data_size bytes. returns zero if the push worked, nonzero otherwise + */ +int push_leaf_right(struct ctree_root *root, struct ctree_path *path, + int data_size) +{ + struct tree_buffer *left_buf = path->nodes[0]; + struct leaf *left = &left_buf->leaf; + struct leaf *right; + struct tree_buffer *right_buf; + struct tree_buffer *upper; + int slot; + int i; + int free_space; + int push_space = 0; + int push_items = 0; + struct item *item; + + slot = path->slots[1]; + if (!path->nodes[1]) { + return 1; + } + upper = path->nodes[1]; + if (slot >= upper->node.header.nritems - 1) { + return 1; + } + right_buf = read_tree_block(root, upper->node.blockptrs[slot + 1]); + 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) + push_space += data_size + sizeof(*item); + if (item->size + sizeof(*item) + push_space > free_space) + break; + push_items++; + push_space += item->size + sizeof(*item); + } + if (push_items == 0) { + tree_block_release(root, right_buf); + return 1; + } + /* push left to right */ + push_space = left->items[left->header.nritems - push_items].offset + + left->items[left->header.nritems - push_items].size; + push_space -= leaf_data_end(left); + /* make room in the right data area */ + memmove(right->data + leaf_data_end(right) - push_space, + right->data + leaf_data_end(right), + LEAF_DATA_SIZE - leaf_data_end(right)); + /* copy from the left data area */ + memcpy(right->data + LEAF_DATA_SIZE - push_space, + left->data + leaf_data_end(left), + push_space); + memmove(right->items + push_items, right->items, + right->header.nritems * sizeof(struct item)); + /* copy the items from left to right */ + memcpy(right->items, left->items + left->header.nritems - push_items, + push_items * sizeof(struct item)); + + /* update the item pointers */ + right->header.nritems += push_items; + push_space = LEAF_DATA_SIZE; + for (i = 0; i < right->header.nritems; i++) { + right->items[i].offset = push_space - right->items[i].size; + push_space = right->items[i].offset; + } + left->header.nritems -= push_items; + + write_tree_block(root, left_buf); + write_tree_block(root, right_buf); + memcpy(upper->node.keys + slot + 1, + &right->items[0].key, sizeof(struct key)); + write_tree_block(root, upper); + /* then fixup the leaf pointer in the path */ + // FIXME use nritems in here somehow + if (path->slots[0] >= left->header.nritems) { + path->slots[0] -= left->header.nritems; + tree_block_release(root, path->nodes[0]); + path->nodes[0] = right_buf; + path->slots[1] += 1; + } else { + tree_block_release(root, right_buf); + } + return 0; +} /* * push some data in the path leaf to the left, trying to free up at * least data_size bytes. returns zero if the push worked, nonzero otherwise @@ -631,7 +722,8 @@ int split_leaf(struct ctree_root *root, struct ctree_path *path, int data_size) int i; int ret; - if (push_leaf_left(root, path, data_size) == 0) { + if (push_leaf_left(root, path, data_size) == 0 || + push_leaf_right(root, path, data_size) == 0) { l_buf = path->nodes[0]; l = &l_buf->leaf; if (leaf_free_space(l) >= sizeof(struct item) + data_size) @@ -875,6 +967,8 @@ int del_item(struct ctree_root *root, struct ctree_path *path) slot = path->slots[1]; leaf_buf->count++; push_leaf_left(root, path, 1); + if (leaf->header.nritems) + push_leaf_right(root, path, 1); if (leaf->header.nritems == 0) { u64 blocknr = leaf_buf->blocknr; path->slots[1] = slot; @@ -929,7 +1023,7 @@ int next_leaf(struct ctree_root *root, struct ctree_path *path) /* for testing only */ int next_key(int i, int max_key) { return rand() % max_key; - // return i; + //return i; } int main() { @@ -958,7 +1052,7 @@ int main() { // num = i; sprintf(buf, "string-%d", num); if (i % 10000 == 0) - printf("insert %d:%d\n", num, i); + fprintf(stderr, "insert %d:%d\n", num, i); ins.objectid = num; ins.offset = 0; ins.flags = 0; @@ -978,7 +1072,7 @@ int main() { ins.objectid = num; init_path(&path); if (i % 10000 == 0) - printf("search %d:%d\n", num, i); + fprintf(stderr, "search %d:%d\n", num, i); ret = search_slot(root, &ins, &path, 0); if (ret) { print_tree(root, root->node); @@ -1004,7 +1098,7 @@ int main() { ret = search_slot(root, &ins, &path, -1); if (!ret) { if (i % 10000 == 0) - printf("del %d:%d\n", num, i); + fprintf(stderr, "del %d:%d\n", num, i); ret = del_item(root, &path); if (ret != 0) BUG(); @@ -1022,7 +1116,7 @@ int main() { sprintf(buf, "string-%d", num); ins.objectid = num; if (i % 10000 == 0) - printf("insert %d:%d\n", num, i); + fprintf(stderr, "insert %d:%d\n", num, i); ret = insert_item(root, &ins, buf, strlen(buf)); if (!ret) tree_size++; @@ -1038,7 +1132,7 @@ int main() { ins.objectid = num; init_path(&path); if (i % 10000 == 0) - printf("search %d:%d\n", num, i); + fprintf(stderr, "search %d:%d\n", num, i); ret = search_slot(root, &ins, &path, 0); if (ret) { print_tree(root, root->node); @@ -1082,6 +1176,7 @@ int main() { } printf("tree size is now %d\n", tree_size); printf("map tree\n"); + print_tree(root->extent_root, root->extent_root->node); write_ctree_super(root, &super); close_ctree(root); return 0; -- GitLab