Btrfs: early reference counting
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
committed by
David Woodhouse
David Woodhouse
parent
77ce6846c4
commit
02217ed299
153
fs/btrfs/ctree.c
153
fs/btrfs/ctree.c
@ -34,6 +34,37 @@ void release_path(struct ctree_root *root, struct ctree_path *p)
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memset(p, 0, sizeof(*p));
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}
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int btrfs_cow_block(struct ctree_root *root,
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struct tree_buffer *buf,
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struct tree_buffer *parent,
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int parent_slot,
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struct tree_buffer **cow_ret)
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{
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struct tree_buffer *cow;
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if (!list_empty(&buf->dirty)) {
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*cow_ret = buf;
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return 0;
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}
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cow = alloc_free_block(root);
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memcpy(&cow->node, &buf->node, sizeof(buf->node));
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cow->node.header.blocknr = cow->blocknr;
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*cow_ret = cow;
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if (buf == root->node) {
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root->node = cow;
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cow->count++;
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tree_block_release(root, buf);
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} else {
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parent->node.blockptrs[parent_slot] = cow->blocknr;
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BUG_ON(list_empty(&parent->dirty));
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}
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if (0 && root != root->extent_root && !is_leaf(cow->node.header.flags)) {
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btrfs_inc_ref(root, cow);
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}
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tree_block_release(root, buf);
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return 0;
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}
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/*
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* The leaf data grows from end-to-front in the node.
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* this returns the address of the start of the last item,
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@ -263,6 +294,8 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
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/* first, try to make some room in the middle buffer */
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if (left_buf) {
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btrfs_cow_block(root, left_buf, parent_buf,
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pslot - 1, &left_buf);
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left = &left_buf->node;
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orig_slot += left->header.nritems;
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wret = push_node_left(root, left_buf, mid_buf);
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@ -274,6 +307,8 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
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* then try to empty the right most buffer into the middle
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*/
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if (right_buf) {
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btrfs_cow_block(root, right_buf, parent_buf,
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pslot + 1, &right_buf);
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right = &right_buf->node;
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wret = push_node_left(root, mid_buf, right_buf);
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if (wret < 0)
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@ -293,9 +328,7 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
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} else {
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memcpy(parent->keys + pslot + 1, right->keys,
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sizeof(struct key));
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wret = dirty_tree_block(root, parent_buf);
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if (wret)
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ret = wret;
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BUG_ON(list_empty(&parent_buf->dirty));
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}
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}
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if (mid->header.nritems == 1) {
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@ -330,9 +363,7 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
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} else {
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/* update the parent key to reflect our changes */
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memcpy(parent->keys + pslot, mid->keys, sizeof(struct key));
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wret = dirty_tree_block(root, parent_buf);
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if (wret)
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ret = wret;
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BUG_ON(list_empty(&parent_buf->dirty));
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}
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/* update the path */
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@ -375,9 +406,10 @@ static int balance_level(struct ctree_root *root, struct ctree_path *path,
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* possible)
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*/
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int search_slot(struct ctree_root *root, struct key *key,
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struct ctree_path *p, int ins_len)
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struct ctree_path *p, int ins_len, int cow)
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{
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struct tree_buffer *b;
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struct tree_buffer *cow_buf;
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struct node *c;
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int slot;
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int ret;
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@ -387,8 +419,15 @@ again:
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b = root->node;
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b->count++;
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while (b) {
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level = node_level(b->node.header.flags);
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if (cow) {
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int wret;
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wret = btrfs_cow_block(root, b, p->nodes[level + 1],
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p->slots[level + 1], &cow_buf);
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b = cow_buf;
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}
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BUG_ON(!cow && ins_len);
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c = &b->node;
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level = node_level(c->header.flags);
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p->nodes[level] = b;
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ret = check_block(p, level);
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if (ret)
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@ -453,7 +492,6 @@ static int fixup_low_keys(struct ctree_root *root,
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{
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int i;
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int ret = 0;
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int wret;
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for (i = level; i < MAX_LEVEL; i++) {
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struct node *t;
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int tslot = path->slots[i];
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@ -461,9 +499,7 @@ static int fixup_low_keys(struct ctree_root *root,
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break;
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t = &path->nodes[i]->node;
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memcpy(t->keys + tslot, key, sizeof(*key));
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wret = dirty_tree_block(root, path->nodes[i]);
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if (wret)
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ret = wret;
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BUG_ON(list_empty(&path->nodes[i]->dirty));
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if (tslot != 0)
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break;
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}
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@ -486,7 +522,6 @@ static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf,
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int src_nritems;
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int dst_nritems;
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int ret = 0;
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int wret;
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src_nritems = src->header.nritems;
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dst_nritems = dst->header.nritems;
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@ -511,13 +546,8 @@ static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf,
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src->header.nritems -= push_items;
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dst->header.nritems += push_items;
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wret = dirty_tree_block(root, src_buf);
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if (wret < 0)
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ret = wret;
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wret = dirty_tree_block(root, dst_buf);
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if (wret < 0)
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ret = wret;
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BUG_ON(list_empty(&src_buf->dirty));
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BUG_ON(list_empty(&dst_buf->dirty));
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return ret;
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}
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@ -541,7 +571,6 @@ static int balance_node_right(struct ctree_root *root,
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int src_nritems;
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int dst_nritems;
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int ret = 0;
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int wret;
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src_nritems = src->header.nritems;
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dst_nritems = dst->header.nritems;
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@ -569,13 +598,8 @@ static int balance_node_right(struct ctree_root *root,
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src->header.nritems -= push_items;
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dst->header.nritems += push_items;
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wret = dirty_tree_block(root, src_buf);
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if (wret < 0)
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ret = wret;
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wret = dirty_tree_block(root, dst_buf);
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if (wret < 0)
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ret = wret;
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BUG_ON(list_empty(&src_buf->dirty));
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BUG_ON(list_empty(&dst_buf->dirty));
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return ret;
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}
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@ -615,7 +639,6 @@ static int insert_new_root(struct ctree_root *root,
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tree_block_release(root, root->node);
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root->node = t;
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t->count++;
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dirty_tree_block(root, t);
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path->nodes[level] = t;
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path->slots[level] = 0;
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return 0;
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@ -655,7 +678,7 @@ static int insert_ptr(struct ctree_root *root,
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lower->header.nritems++;
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if (lower->keys[1].objectid == 0)
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BUG();
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dirty_tree_block(root, path->nodes[level]);
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BUG_ON(list_empty(&path->nodes[level]->dirty));
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return 0;
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}
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@ -701,12 +724,7 @@ static int split_node(struct ctree_root *root, struct ctree_path *path,
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c->header.nritems = mid;
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ret = 0;
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wret = dirty_tree_block(root, t);
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if (wret)
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ret = wret;
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wret = dirty_tree_block(root, split_buffer);
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if (wret)
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ret = wret;
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BUG_ON(list_empty(&t->dirty));
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wret = insert_ptr(root, path, split->keys, split_buffer->blocknr,
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path->slots[level + 1] + 1, level + 1);
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if (wret)
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@ -778,6 +796,15 @@ static int push_leaf_right(struct ctree_root *root, struct ctree_path *path,
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tree_block_release(root, right_buf);
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return 1;
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}
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/* cow and double check */
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btrfs_cow_block(root, right_buf, upper, slot + 1, &right_buf);
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right = &right_buf->leaf;
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free_space = leaf_free_space(right);
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if (free_space < data_size + sizeof(struct item)) {
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tree_block_release(root, right_buf);
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return 1;
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}
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for (i = left->header.nritems - 1; i >= 0; i--) {
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item = left->items + i;
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if (path->slots[0] == i)
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@ -818,11 +845,12 @@ static int push_leaf_right(struct ctree_root *root, struct ctree_path *path,
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}
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left->header.nritems -= push_items;
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dirty_tree_block(root, left_buf);
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dirty_tree_block(root, right_buf);
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BUG_ON(list_empty(&left_buf->dirty));
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BUG_ON(list_empty(&right_buf->dirty));
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memcpy(upper->node.keys + slot + 1,
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&right->items[0].key, sizeof(struct key));
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dirty_tree_block(root, upper);
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BUG_ON(list_empty(&upper->dirty));
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/* then fixup the leaf pointer in the path */
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if (path->slots[0] >= left->header.nritems) {
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path->slots[0] -= left->header.nritems;
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@ -869,6 +897,16 @@ static int push_leaf_left(struct ctree_root *root, struct ctree_path *path,
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tree_block_release(root, t);
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return 1;
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}
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/* cow and double check */
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btrfs_cow_block(root, t, path->nodes[1], slot - 1, &t);
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left = &t->leaf;
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free_space = leaf_free_space(left);
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if (free_space < data_size + sizeof(struct item)) {
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tree_block_release(root, t);
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return 1;
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}
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for (i = 0; i < right->header.nritems; i++) {
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item = right->items + i;
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if (path->slots[0] == i)
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@ -912,12 +950,8 @@ static int push_leaf_left(struct ctree_root *root, struct ctree_path *path,
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push_space = right->items[i].offset;
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}
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wret = dirty_tree_block(root, t);
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if (wret)
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ret = wret;
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wret = dirty_tree_block(root, right_buf);
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if (wret)
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ret = wret;
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BUG_ON(list_empty(&t->dirty));
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BUG_ON(list_empty(&right_buf->dirty));
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wret = fixup_low_keys(root, path, &right->items[0].key, 1);
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if (wret)
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@ -968,6 +1002,7 @@ static int split_leaf(struct ctree_root *root, struct ctree_path *path,
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if (wret < 0)
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return wret;
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}
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l_buf = path->nodes[0];
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l = &l_buf->leaf;
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@ -1022,13 +1057,8 @@ static int split_leaf(struct ctree_root *root, struct ctree_path *path,
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right_buffer->blocknr, path->slots[1] + 1, 1);
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if (wret)
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ret = wret;
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wret = dirty_tree_block(root, right_buffer);
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if (wret)
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ret = wret;
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wret = dirty_tree_block(root, l_buf);
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if (wret)
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ret = wret;
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BUG_ON(list_empty(&right_buffer->dirty));
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BUG_ON(list_empty(&l_buf->dirty));
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BUG_ON(path->slots[0] != slot);
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if (mid <= slot) {
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tree_block_release(root, path->nodes[0]);
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@ -1049,7 +1079,6 @@ int insert_item(struct ctree_root *root, struct key *key,
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void *data, int data_size)
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{
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int ret = 0;
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int wret;
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int slot;
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int slot_orig;
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struct leaf *leaf;
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@ -1062,7 +1091,7 @@ int insert_item(struct ctree_root *root, struct key *key,
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if (!root->node)
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BUG();
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init_path(&path);
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ret = search_slot(root, key, &path, data_size);
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ret = search_slot(root, key, &path, data_size, 1);
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if (ret == 0) {
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release_path(root, &path);
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return -EEXIST;
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@ -1114,10 +1143,7 @@ int insert_item(struct ctree_root *root, struct key *key,
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if (slot == 0)
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ret = fixup_low_keys(root, &path, key, 1);
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wret = dirty_tree_block(root, leaf_buf);
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if (wret)
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ret = wret;
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BUG_ON(list_empty(&leaf_buf->dirty));
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if (leaf_free_space(leaf) < 0)
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BUG();
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check_leaf(&path, 0);
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@ -1162,9 +1188,7 @@ static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level,
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if (wret)
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ret = wret;
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}
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wret = dirty_tree_block(root, parent);
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if (wret)
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ret = wret;
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BUG_ON(list_empty(&parent->dirty));
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return ret;
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}
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@ -1205,7 +1229,7 @@ int del_item(struct ctree_root *root, struct ctree_path *path)
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if (leaf->header.nritems == 0) {
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if (leaf_buf == root->node) {
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leaf->header.flags = node_level(0);
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dirty_tree_block(root, leaf_buf);
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BUG_ON(list_empty(&leaf_buf->dirty));
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} else {
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clean_tree_block(root, leaf_buf);
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wret = del_ptr(root, path, 1, path->slots[1]);
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@ -1223,9 +1247,7 @@ int del_item(struct ctree_root *root, struct ctree_path *path)
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if (wret)
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ret = wret;
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}
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wret = dirty_tree_block(root, leaf_buf);
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if (wret)
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ret = wret;
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BUG_ON(list_empty(&leaf_buf->dirty));
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/* delete the leaf if it is mostly empty */
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if (used < LEAF_DATA_SIZE / 3) {
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@ -1304,3 +1326,4 @@ int next_leaf(struct ctree_root *root, struct ctree_path *path)
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return 0;
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}
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