#include "disk-io.h"
#include "print-tree.h"
-int split_node(struct ctree_root *root, struct ctree_path *path, int level);
-int split_leaf(struct ctree_root *root, struct ctree_path *path, int data_size);
-int push_node_left(struct ctree_root *root, struct ctree_path *path, int level);
-int push_node_right(struct ctree_root *root,
- struct ctree_path *path, int level);
-int del_ptr(struct ctree_root *root, struct ctree_path *path, int level);
+static int split_node(struct ctree_root *root, struct ctree_path *path,
+ int level);
+static int split_leaf(struct ctree_root *root, struct ctree_path *path,
+ int data_size);
+static int push_node_left(struct ctree_root *root, struct tree_buffer *dst,
+ struct tree_buffer *src);
+static int balance_node_right(struct ctree_root *root,
+ struct tree_buffer *dst_buf,
+ struct tree_buffer *src_buf);
+static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level,
+ int slot);
inline void init_path(struct ctree_path *p)
{
break;
tree_block_release(root, p->nodes[i]);
}
+ 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;
}
/*
return 0;
}
+int check_node(struct ctree_path *path, int level)
+{
+ int i;
+ struct node *parent = NULL;
+ struct node *node = &path->nodes[level]->node;
+ int parent_slot;
+
+ if (path->nodes[level + 1])
+ parent = &path->nodes[level + 1]->node;
+ parent_slot = path->slots[level + 1];
+ if (parent && node->header.nritems > 0) {
+ struct key *parent_key;
+ parent_key = &parent->keys[parent_slot];
+ BUG_ON(memcmp(parent_key, node->keys, sizeof(struct key)));
+ BUG_ON(parent->blockptrs[parent_slot] != node->header.blocknr);
+ }
+ BUG_ON(node->header.nritems > NODEPTRS_PER_BLOCK);
+ for (i = 0; i < node->header.nritems - 2; i++) {
+ BUG_ON(comp_keys(&node->keys[i], &node->keys[i+1]) >= 0);
+ }
+ return 0;
+}
+
+int check_leaf(struct ctree_path *path, int level)
+{
+ int i;
+ struct leaf *leaf = &path->nodes[level]->leaf;
+ struct node *parent = NULL;
+ int parent_slot;
+
+ if (path->nodes[level + 1])
+ parent = &path->nodes[level + 1]->node;
+ parent_slot = path->slots[level + 1];
+ if (parent && leaf->header.nritems > 0) {
+ struct key *parent_key;
+ parent_key = &parent->keys[parent_slot];
+ BUG_ON(memcmp(parent_key, &leaf->items[0].key,
+ sizeof(struct key)));
+ BUG_ON(parent->blockptrs[parent_slot] != leaf->header.blocknr);
+ }
+ for (i = 0; i < leaf->header.nritems - 2; i++) {
+ BUG_ON(comp_keys(&leaf->items[i].key,
+ &leaf->items[i+1].key) >= 0);
+ BUG_ON(leaf->items[i].offset != leaf->items[i + 1].offset +
+ leaf->items[i + 1].size);
+ if (i == 0) {
+ BUG_ON(leaf->items[i].offset + leaf->items[i].size !=
+ LEAF_DATA_SIZE);
+ }
+ }
+ BUG_ON(leaf_free_space(leaf) < 0);
+ return 0;
+}
+
+int check_block(struct ctree_path *path, int level)
+{
+ if (level == 0)
+ return check_leaf(path, level);
+ return check_node(path, level);
+}
+
/*
* search for key in the array p. items p are item_size apart
* and there are 'max' items in p
return 1;
}
+/*
+ * simple bin_search frontend that does the right thing for
+ * leaves vs nodes
+ */
int bin_search(struct node *c, struct key *key, int *slot)
{
if (is_leaf(c->header.flags)) {
return -1;
}
+struct tree_buffer *read_node_slot(struct ctree_root *root,
+ struct tree_buffer *parent_buf,
+ int slot)
+{
+ struct node *node = &parent_buf->node;
+ if (slot < 0)
+ return NULL;
+ if (slot >= node->header.nritems)
+ return NULL;
+ return read_tree_block(root, node->blockptrs[slot]);
+}
+
+static int balance_level(struct ctree_root *root, struct ctree_path *path,
+ int level)
+{
+ struct tree_buffer *right_buf;
+ struct tree_buffer *mid_buf;
+ struct tree_buffer *left_buf;
+ struct tree_buffer *parent_buf = NULL;
+ struct node *right = NULL;
+ struct node *mid;
+ struct node *left = NULL;
+ struct node *parent = NULL;
+ int ret = 0;
+ int wret;
+ int pslot;
+ int orig_slot = path->slots[level];
+ u64 orig_ptr;
+
+ if (level == 0)
+ return 0;
+
+ mid_buf = path->nodes[level];
+ mid = &mid_buf->node;
+ orig_ptr = mid->blockptrs[orig_slot];
+
+ if (level < MAX_LEVEL - 1)
+ parent_buf = path->nodes[level + 1];
+ pslot = path->slots[level + 1];
+
+ if (!parent_buf) {
+ struct tree_buffer *child;
+ u64 blocknr = mid_buf->blocknr;
+
+ if (mid->header.nritems != 1)
+ return 0;
+
+ /* promote the child to a root */
+ child = read_node_slot(root, mid_buf, 0);
+ BUG_ON(!child);
+ root->node = child;
+ path->nodes[level] = NULL;
+ /* once for the path */
+ tree_block_release(root, mid_buf);
+ /* once for the root ptr */
+ tree_block_release(root, mid_buf);
+ clean_tree_block(root, mid_buf);
+ return free_extent(root, blocknr, 1);
+ }
+ parent = &parent_buf->node;
+
+ if (mid->header.nritems > NODEPTRS_PER_BLOCK / 4)
+ return 0;
+
+ left_buf = read_node_slot(root, parent_buf, pslot - 1);
+ right_buf = read_node_slot(root, parent_buf, pslot + 1);
+
+ /* 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);
+ if (wret < 0)
+ ret = wret;
+ }
+
+ /*
+ * 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)
+ ret = wret;
+ if (right->header.nritems == 0) {
+ u64 blocknr = right_buf->blocknr;
+ tree_block_release(root, right_buf);
+ clean_tree_block(root, right_buf);
+ right_buf = NULL;
+ right = NULL;
+ wret = del_ptr(root, path, level + 1, pslot + 1);
+ if (wret)
+ ret = wret;
+ wret = free_extent(root, blocknr, 1);
+ if (wret)
+ ret = wret;
+ } else {
+ memcpy(parent->keys + pslot + 1, right->keys,
+ sizeof(struct key));
+ BUG_ON(list_empty(&parent_buf->dirty));
+ }
+ }
+ if (mid->header.nritems == 1) {
+ /*
+ * we're not allowed to leave a node with one item in the
+ * tree during a delete. A deletion from lower in the tree
+ * could try to delete the only pointer in this node.
+ * So, pull some keys from the left.
+ * There has to be a left pointer at this point because
+ * otherwise we would have pulled some pointers from the
+ * right
+ */
+ BUG_ON(!left_buf);
+ wret = balance_node_right(root, mid_buf, left_buf);
+ if (wret < 0)
+ ret = wret;
+ BUG_ON(wret == 1);
+ }
+ if (mid->header.nritems == 0) {
+ /* we've managed to empty the middle node, drop it */
+ u64 blocknr = mid_buf->blocknr;
+ tree_block_release(root, mid_buf);
+ clean_tree_block(root, mid_buf);
+ mid_buf = NULL;
+ mid = NULL;
+ wret = del_ptr(root, path, level + 1, pslot);
+ if (wret)
+ ret = wret;
+ wret = free_extent(root, blocknr, 1);
+ if (wret)
+ ret = wret;
+ } else {
+ /* update the parent key to reflect our changes */
+ memcpy(parent->keys + pslot, mid->keys, sizeof(struct key));
+ BUG_ON(list_empty(&parent_buf->dirty));
+ }
+
+ /* update the path */
+ if (left_buf) {
+ if (left->header.nritems > orig_slot) {
+ left_buf->count++; // released below
+ path->nodes[level] = left_buf;
+ path->slots[level + 1] -= 1;
+ path->slots[level] = orig_slot;
+ if (mid_buf)
+ tree_block_release(root, mid_buf);
+ } else {
+ orig_slot -= left->header.nritems;
+ path->slots[level] = orig_slot;
+ }
+ }
+ /* double check we haven't messed things up */
+ check_block(path, level);
+ if (orig_ptr != path->nodes[level]->node.blockptrs[path->slots[level]])
+ BUG();
+
+ if (right_buf)
+ tree_block_release(root, right_buf);
+ if (left_buf)
+ tree_block_release(root, left_buf);
+ return ret;
+}
+
/*
* look for key in the tree. path is filled in with nodes along the way
* if key is found, we return zero and you can find the item in the leaf
* level of the path (level 0)
*
* If the key isn't found, the path points to the slot where it should
- * be inserted.
+ * be inserted, and 1 is returned. If there are other errors during the
+ * search a negative error number is returned.
+ *
+ * if ins_len > 0, nodes and leaves will be split as we walk down the
+ * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if
+ * 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 = root->node;
+ struct tree_buffer *b;
+ struct tree_buffer *cow_buf;
struct node *c;
int slot;
int ret;
int level;
+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)
+ return -1;
ret = bin_search(c, key, &slot);
if (!is_leaf(c->header.flags)) {
if (ret && slot > 0)
b = p->nodes[level];
c = &b->node;
slot = p->slots[level];
- } else if (ins_len < 0 &&
- c->header.nritems <= NODEPTRS_PER_BLOCK/4) {
- u64 blocknr = b->blocknr;
- slot = p->slots[level +1];
- b->count++;
- if (push_node_left(root, p, level))
- push_node_right(root, p, level);
- if (c->header.nritems == 0 &&
- level < MAX_LEVEL - 1 &&
- p->nodes[level + 1]) {
- int tslot = p->slots[level + 1];
-
- p->slots[level + 1] = slot;
- del_ptr(root, p, level + 1);
- p->slots[level + 1] = tslot;
- tree_block_release(root, b);
- free_extent(root, blocknr, 1);
- } else {
- tree_block_release(root, b);
- }
+ } else if (ins_len < 0) {
+ int sret = balance_level(root, p, level);
+ if (sret)
+ return sret;
b = p->nodes[level];
+ if (!b)
+ goto again;
c = &b->node;
slot = p->slots[level];
+ BUG_ON(c->header.nritems == 1);
}
b = read_tree_block(root, c->blockptrs[slot]);
- continue;
} else {
struct leaf *l = (struct leaf *)c;
p->slots[level] = slot;
if (sret)
return sret;
}
+ BUG_ON(root->node->count == 1);
return ret;
}
}
- return -1;
+ BUG_ON(root->node->count == 1);
+ return 1;
}
/*
* This is used after shifting pointers to the left, so it stops
* fixing up pointers when a given leaf/node is not in slot 0 of the
* higher levels
+ *
+ * If this fails to write a tree block, it returns -1, but continues
+ * fixing up the blocks in ram so the tree is consistent.
*/
-static void fixup_low_keys(struct ctree_root *root,
+static int fixup_low_keys(struct ctree_root *root,
struct ctree_path *path, struct key *key,
int level)
{
int i;
+ int ret = 0;
for (i = level; i < MAX_LEVEL; i++) {
struct node *t;
int tslot = path->slots[i];
break;
t = &path->nodes[i]->node;
memcpy(t->keys + tslot, key, sizeof(*key));
- write_tree_block(root, path->nodes[i]);
+ BUG_ON(list_empty(&path->nodes[i]->dirty));
if (tslot != 0)
break;
}
+ return ret;
}
/*
* try to push data from one node into the next node left in the
- * tree. The src node is found at specified level in the path.
- * If some bytes were pushed, return 0, otherwise return 1.
- *
- * Lower nodes/leaves in the path are not touched, higher nodes may
- * be modified to reflect the push.
+ * tree.
*
- * The path is altered to reflect the push.
+ * returns 0 if some ptrs were pushed left, < 0 if there was some horrible
+ * error, and > 0 if there was no room in the left hand block.
*/
-int push_node_left(struct ctree_root *root, struct ctree_path *path, int level)
+static int push_node_left(struct ctree_root *root, struct tree_buffer *dst_buf,
+ struct tree_buffer *src_buf)
{
- int slot;
- struct node *left;
- struct node *right;
+ struct node *src = &src_buf->node;
+ struct node *dst = &dst_buf->node;
int push_items = 0;
- int left_nritems;
- int right_nritems;
- struct tree_buffer *t;
- struct tree_buffer *right_buf;
-
- if (level == MAX_LEVEL - 1 || path->nodes[level + 1] == 0)
- return 1;
- slot = path->slots[level + 1];
- if (slot == 0)
- return 1;
+ int src_nritems;
+ int dst_nritems;
+ int ret = 0;
- t = read_tree_block(root,
- path->nodes[level + 1]->node.blockptrs[slot - 1]);
- left = &t->node;
- right_buf = path->nodes[level];
- right = &right_buf->node;
- left_nritems = left->header.nritems;
- right_nritems = right->header.nritems;
- push_items = NODEPTRS_PER_BLOCK - (left_nritems + 1);
+ src_nritems = src->header.nritems;
+ dst_nritems = dst->header.nritems;
+ push_items = NODEPTRS_PER_BLOCK - dst_nritems;
if (push_items <= 0) {
- tree_block_release(root, t);
return 1;
}
- if (right_nritems < push_items)
- push_items = right_nritems;
- memcpy(left->keys + left_nritems, right->keys,
+ if (src_nritems < push_items)
+ push_items = src_nritems;
+
+ memcpy(dst->keys + dst_nritems, src->keys,
push_items * sizeof(struct key));
- memcpy(left->blockptrs + left_nritems, right->blockptrs,
+ memcpy(dst->blockptrs + dst_nritems, src->blockptrs,
push_items * sizeof(u64));
- memmove(right->keys, right->keys + push_items,
- (right_nritems - push_items) * sizeof(struct key));
- memmove(right->blockptrs, right->blockptrs + push_items,
- (right_nritems - push_items) * sizeof(u64));
- right->header.nritems -= push_items;
- left->header.nritems += push_items;
-
- /* adjust the pointers going up the tree */
- fixup_low_keys(root, path, right->keys, level + 1);
-
- write_tree_block(root, t);
- write_tree_block(root, right_buf);
-
- /* then fixup the leaf pointer in the path */
- if (path->slots[level] < push_items) {
- path->slots[level] += left_nritems;
- tree_block_release(root, path->nodes[level]);
- path->nodes[level] = t;
- path->slots[level + 1] -= 1;
- } else {
- path->slots[level] -= push_items;
- tree_block_release(root, t);
+ if (push_items < src_nritems) {
+ memmove(src->keys, src->keys + push_items,
+ (src_nritems - push_items) * sizeof(struct key));
+ memmove(src->blockptrs, src->blockptrs + push_items,
+ (src_nritems - push_items) * sizeof(u64));
}
- return 0;
+ src->header.nritems -= push_items;
+ dst->header.nritems += push_items;
+
+ BUG_ON(list_empty(&src_buf->dirty));
+ BUG_ON(list_empty(&dst_buf->dirty));
+ return ret;
}
/*
* try to push data from one node into the next node right in the
- * tree. The src node is found at specified level in the path.
- * If some bytes were pushed, return 0, otherwise return 1.
+ * tree.
*
- * Lower nodes/leaves in the path are not touched, higher nodes may
- * be modified to reflect the push.
+ * returns 0 if some ptrs were pushed, < 0 if there was some horrible
+ * error, and > 0 if there was no room in the right hand block.
*
- * The path is altered to reflect the push.
+ * this will only push up to 1/2 the contents of the left node over
*/
-int push_node_right(struct ctree_root *root, struct ctree_path *path, int level)
+static int balance_node_right(struct ctree_root *root,
+ struct tree_buffer *dst_buf,
+ struct tree_buffer *src_buf)
{
- int slot;
- struct tree_buffer *t;
- struct tree_buffer *src_buffer;
- struct node *dst;
- struct node *src;
+ struct node *src = &src_buf->node;
+ struct node *dst = &dst_buf->node;
int push_items = 0;
- int dst_nritems;
+ int max_push;
int src_nritems;
+ int dst_nritems;
+ int ret = 0;
- /* can't push from the root */
- if (level == MAX_LEVEL - 1 || path->nodes[level + 1] == 0)
- return 1;
-
- /* only try to push inside the node higher up */
- slot = path->slots[level + 1];
- if (slot == NODEPTRS_PER_BLOCK - 1)
- return 1;
-
- if (slot >= path->nodes[level + 1]->node.header.nritems -1)
- return 1;
-
- t = read_tree_block(root,
- path->nodes[level + 1]->node.blockptrs[slot + 1]);
- dst = &t->node;
- src_buffer = path->nodes[level];
- src = &src_buffer->node;
- dst_nritems = dst->header.nritems;
src_nritems = src->header.nritems;
- push_items = NODEPTRS_PER_BLOCK - (dst_nritems + 1);
+ dst_nritems = dst->header.nritems;
+ push_items = NODEPTRS_PER_BLOCK - dst_nritems;
if (push_items <= 0) {
- tree_block_release(root, t);
return 1;
}
- if (src_nritems < push_items)
- push_items = src_nritems;
+ max_push = src_nritems / 2 + 1;
+ /* don't try to empty the node */
+ if (max_push > src_nritems)
+ return 1;
+ if (max_push < push_items)
+ push_items = max_push;
+
memmove(dst->keys + push_items, dst->keys,
dst_nritems * sizeof(struct key));
- memcpy(dst->keys, src->keys + src_nritems - push_items,
- push_items * sizeof(struct key));
-
memmove(dst->blockptrs + push_items, dst->blockptrs,
dst_nritems * sizeof(u64));
+ memcpy(dst->keys, src->keys + src_nritems - push_items,
+ push_items * sizeof(struct key));
memcpy(dst->blockptrs, src->blockptrs + src_nritems - push_items,
push_items * sizeof(u64));
src->header.nritems -= push_items;
dst->header.nritems += push_items;
- /* adjust the pointers going up the tree */
- memcpy(path->nodes[level + 1]->node.keys + path->slots[level + 1] + 1,
- dst->keys, sizeof(struct key));
-
- write_tree_block(root, path->nodes[level + 1]);
- write_tree_block(root, t);
- write_tree_block(root, src_buffer);
-
- /* then fixup the pointers in the path */
- if (path->slots[level] >= src->header.nritems) {
- path->slots[level] -= src->header.nritems;
- tree_block_release(root, path->nodes[level]);
- path->nodes[level] = t;
- path->slots[level + 1] += 1;
- } else {
- tree_block_release(root, t);
- }
- return 0;
+ BUG_ON(list_empty(&src_buf->dirty));
+ BUG_ON(list_empty(&dst_buf->dirty));
+ return ret;
}
+/*
+ * helper function to insert a new root level in the tree.
+ * A new node is allocated, and a single item is inserted to
+ * point to the existing root
+ *
+ * returns zero on success or < 0 on failure.
+ */
static int insert_new_root(struct ctree_root *root,
struct ctree_path *path, int level)
{
tree_block_release(root, root->node);
root->node = t;
t->count++;
- write_tree_block(root, t);
path->nodes[level] = t;
path->slots[level] = 0;
return 0;
/*
* worker function to insert a single pointer in a node.
* the node should have enough room for the pointer already
+ *
* slot and level indicate where you want the key to go, and
* blocknr is the block the key points to.
+ *
+ * returns zero on success and < 0 on any error
*/
-int insert_ptr(struct ctree_root *root,
+static int insert_ptr(struct ctree_root *root,
struct ctree_path *path, struct key *key,
u64 blocknr, int slot, int level)
{
lower->header.nritems++;
if (lower->keys[1].objectid == 0)
BUG();
- write_tree_block(root, path->nodes[level]);
+ BUG_ON(list_empty(&path->nodes[level]->dirty));
return 0;
}
-int split_node(struct ctree_root *root, struct ctree_path *path, int level)
+/*
+ * split the node at the specified level in path in two.
+ * The path is corrected to point to the appropriate node after the split
+ *
+ * Before splitting this tries to make some room in the node by pushing
+ * left and right, if either one works, it returns right away.
+ *
+ * returns 0 on success and < 0 on failure
+ */
+static int split_node(struct ctree_root *root, struct ctree_path *path,
+ int level)
{
struct tree_buffer *t;
struct node *c;
struct node *split;
int mid;
int ret;
+ int wret;
- ret = push_node_left(root, path, level);
- if (!ret)
- return 0;
- ret = push_node_right(root, path, level);
- if (!ret)
- return 0;
t = path->nodes[level];
c = &t->node;
if (t == root->node) {
(c->header.nritems - mid) * sizeof(u64));
split->header.nritems = c->header.nritems - mid;
c->header.nritems = mid;
- write_tree_block(root, t);
- write_tree_block(root, split_buffer);
- insert_ptr(root, path, split->keys, split_buffer->blocknr,
- path->slots[level + 1] + 1, level + 1);
+ ret = 0;
+
+ 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)
+ ret = wret;
+
if (path->slots[level] >= mid) {
path->slots[level] -= mid;
tree_block_release(root, t);
} else {
tree_block_release(root, split_buffer);
}
- return 0;
+ return ret;
}
/*
* and nr indicate which items in the leaf to check. This totals up the
* space used both by the item structs and the item data
*/
-int leaf_space_used(struct leaf *l, int start, int nr)
+static int leaf_space_used(struct leaf *l, int start, int nr)
{
int data_len;
int end = start + nr - 1;
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
+ *
+ * returns 1 if the push failed because the other node didn't have enough
+ * room, 0 if everything worked out and < 0 if there were major errors.
+ */
+static 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;
+ }
+ /* 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)
+ 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;
+
+ 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));
+ 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;
+ 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
*/
-int push_leaf_left(struct ctree_root *root, struct ctree_path *path,
- int data_size)
+static int push_leaf_left(struct ctree_root *root, struct ctree_path *path,
+ int data_size)
{
struct tree_buffer *right_buf = path->nodes[0];
struct leaf *right = &right_buf->leaf;
int push_items = 0;
struct item *item;
int old_left_nritems;
+ int ret = 0;
+ int wret;
slot = path->slots[1];
if (slot == 0) {
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)
push_space = right->items[i].offset;
}
- write_tree_block(root, t);
- write_tree_block(root, right_buf);
+ BUG_ON(list_empty(&t->dirty));
+ BUG_ON(list_empty(&right_buf->dirty));
- fixup_low_keys(root, path, &right->items[0].key, 1);
+ wret = fixup_low_keys(root, path, &right->items[0].key, 1);
+ if (wret)
+ ret = wret;
/* then fixup the leaf pointer in the path */
if (path->slots[0] < push_items) {
path->slots[0] -= push_items;
}
BUG_ON(path->slots[0] < 0);
- return 0;
+ return ret;
}
/*
* split the path's leaf in two, making sure there is at least data_size
* available for the resulting leaf level of the path.
+ *
+ * returns 0 if all went well and < 0 on failure.
*/
-int split_leaf(struct ctree_root *root, struct ctree_path *path, int data_size)
+static int split_leaf(struct ctree_root *root, struct ctree_path *path,
+ int data_size)
{
- struct tree_buffer *l_buf = path->nodes[0];
- struct leaf *l = &l_buf->leaf;
+ struct tree_buffer *l_buf;
+ struct leaf *l;
int nritems;
int mid;
int slot;
int rt_data_off;
int i;
int ret;
-
- if (push_leaf_left(root, path, data_size) == 0) {
- l_buf = path->nodes[0];
- l = &l_buf->leaf;
- if (leaf_free_space(l) >= sizeof(struct item) + data_size)
- return 0;
+ int wret;
+
+ wret = push_leaf_left(root, path, data_size);
+ if (wret < 0)
+ return wret;
+ if (wret) {
+ wret = push_leaf_right(root, path, data_size);
+ if (wret < 0)
+ return wret;
}
+
+ l_buf = path->nodes[0];
+ l = &l_buf->leaf;
+
+ /* did the pushes work? */
+ if (leaf_free_space(l) >= sizeof(struct item) + data_size)
+ return 0;
+
if (!path->nodes[1]) {
ret = insert_new_root(root, path, 1);
if (ret)
right = &right_buffer->leaf;
memset(right, 0, sizeof(*right));
if (mid <= slot) {
+ /* FIXME, just alloc a new leaf here */
if (leaf_space_used(l, mid, nritems - mid) + space_needed >
LEAF_DATA_SIZE)
BUG();
} else {
+ /* FIXME, just alloc a new leaf here */
if (leaf_space_used(l, 0, mid + 1) + space_needed >
LEAF_DATA_SIZE)
BUG();
right->items[i].offset += rt_data_off;
l->header.nritems = mid;
- ret = insert_ptr(root, path, &right->items[0].key,
+ ret = 0;
+ wret = insert_ptr(root, path, &right->items[0].key,
right_buffer->blocknr, path->slots[1] + 1, 1);
- write_tree_block(root, right_buffer);
- write_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]);
int insert_item(struct ctree_root *root, struct key *key,
void *data, int data_size)
{
- int ret;
+ int ret = 0;
int slot;
int slot_orig;
struct leaf *leaf;
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;
}
+ if (ret < 0)
+ goto out;
slot_orig = path.slots[0];
leaf_buf = path.nodes[0];
slot = path.slots[0];
BUG_ON(slot < 0);
- if (slot == 0)
- fixup_low_keys(root, &path, key, 1);
if (slot != nritems) {
int i;
unsigned int old_data = leaf->items[slot].offset +
leaf->items[slot].size = data_size;
memcpy(leaf->data + data_end - data_size, data, data_size);
leaf->header.nritems += 1;
- write_tree_block(root, leaf_buf);
+
+ ret = 0;
+ if (slot == 0)
+ ret = fixup_low_keys(root, &path, key, 1);
+
+ BUG_ON(list_empty(&leaf_buf->dirty));
if (leaf_free_space(leaf) < 0)
BUG();
+ check_leaf(&path, 0);
+out:
release_path(root, &path);
- return 0;
+ return ret;
}
/*
* continuing all the way the root if required. The root is converted into
* a leaf if all the nodes are emptied.
*/
-int del_ptr(struct ctree_root *root, struct ctree_path *path, int level)
+static int del_ptr(struct ctree_root *root, struct ctree_path *path, int level,
+ int slot)
{
- int slot;
- struct tree_buffer *t;
struct node *node;
+ struct tree_buffer *parent = path->nodes[level];
int nritems;
- u64 blocknr;
-
- while(1) {
- t = path->nodes[level];
- if (!t)
- break;
- node = &t->node;
- slot = path->slots[level];
- nritems = node->header.nritems;
-
- if (slot != nritems -1) {
- memmove(node->keys + slot, node->keys + slot + 1,
- sizeof(struct key) * (nritems - slot - 1));
- memmove(node->blockptrs + slot,
- node->blockptrs + slot + 1,
- sizeof(u64) * (nritems - slot - 1));
- }
- node->header.nritems--;
- write_tree_block(root, t);
- blocknr = t->blocknr;
- if (node->header.nritems != 0) {
- if (slot == 0)
- fixup_low_keys(root, path, node->keys,
- level + 1);
- break;
- }
- if (t == root->node) {
- /* just turn the root into a leaf and break */
- root->node->node.header.flags = node_level(0);
- write_tree_block(root, t);
- break;
- }
- level++;
- free_extent(root, blocknr, 1);
- if (!path->nodes[level])
- BUG();
+ int ret = 0;
+ int wret;
+
+ node = &parent->node;
+ nritems = node->header.nritems;
+
+ if (slot != nritems -1) {
+ memmove(node->keys + slot, node->keys + slot + 1,
+ sizeof(struct key) * (nritems - slot - 1));
+ memmove(node->blockptrs + slot,
+ node->blockptrs + slot + 1,
+ sizeof(u64) * (nritems - slot - 1));
}
- return 0;
+ node->header.nritems--;
+ if (node->header.nritems == 0 && parent == root->node) {
+ BUG_ON(node_level(root->node->node.header.flags) != 1);
+ /* just turn the root into a leaf and break */
+ root->node->node.header.flags = node_level(0);
+ } else if (slot == 0) {
+ wret = fixup_low_keys(root, path, node->keys, level + 1);
+ if (wret)
+ ret = wret;
+ }
+ BUG_ON(list_empty(&parent->dirty));
+ return ret;
}
/*
struct tree_buffer *leaf_buf;
int doff;
int dsize;
+ int ret = 0;
+ int wret;
leaf_buf = path->nodes[0];
leaf = &leaf_buf->leaf;
if (leaf->header.nritems == 0) {
if (leaf_buf == root->node) {
leaf->header.flags = node_level(0);
- write_tree_block(root, leaf_buf);
+ BUG_ON(list_empty(&leaf_buf->dirty));
} else {
- del_ptr(root, path, 1);
- free_extent(root, leaf_buf->blocknr, 1);
+ clean_tree_block(root, leaf_buf);
+ wret = del_ptr(root, path, 1, path->slots[1]);
+ if (wret)
+ ret = wret;
+ wret = free_extent(root, leaf_buf->blocknr, 1);
+ if (wret)
+ ret = wret;
}
} else {
int used = leaf_space_used(leaf, 0, leaf->header.nritems);
- if (slot == 0)
- fixup_low_keys(root, path, &leaf->items[0].key, 1);
- write_tree_block(root, leaf_buf);
+ if (slot == 0) {
+ wret = fixup_low_keys(root, path,
+ &leaf->items[0].key, 1);
+ 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) {
/* push_leaf_left fixes the path.
*/
slot = path->slots[1];
leaf_buf->count++;
- push_leaf_left(root, path, 1);
+ wret = push_leaf_left(root, path, 1);
+ if (wret < 0)
+ ret = wret;
+ if (path->nodes[0] == leaf_buf &&
+ leaf->header.nritems) {
+ wret = push_leaf_right(root, path, 1);
+ if (wret < 0)
+ ret = wret;
+ }
if (leaf->header.nritems == 0) {
u64 blocknr = leaf_buf->blocknr;
- path->slots[1] = slot;
- del_ptr(root, path, 1);
+ clean_tree_block(root, leaf_buf);
+ wret = del_ptr(root, path, 1, slot);
+ if (wret)
+ ret = wret;
tree_block_release(root, leaf_buf);
- free_extent(root, blocknr, 1);
+ wret = free_extent(root, blocknr, 1);
+ if (wret)
+ ret = wret;
} else {
tree_block_release(root, leaf_buf);
}
}
}
- return 0;
+ return ret;
}
+/*
+ * walk up the tree as far as required to find the next leaf.
+ * returns 0 if it found something or 1 if there are no greater leaves.
+ * returns < 0 on io errors.
+ */
int next_leaf(struct ctree_root *root, struct ctree_path *path)
{
int slot;
while(level < MAX_LEVEL) {
if (!path->nodes[level])
- return -1;
+ return 1;
slot = path->slots[level] + 1;
c = path->nodes[level];
if (slot >= c->node.header.nritems) {
return 0;
}
-/* for testing only */
-int next_key(int i, int max_key) {
- return rand() % max_key;
- // return i;
-}
-
-int main() {
- struct ctree_root *root;
- struct key ins;
- struct key last = { (u64)-1, 0, 0};
- char *buf;
- int i;
- int num;
- int ret;
- int run_size = 20000000;
- int max_key = 100000000;
- int tree_size = 0;
- struct ctree_path path;
- struct ctree_super_block super;
-
- radix_tree_init();
-
-
- root = open_ctree("dbfile", &super);
-
- srand(55);
- for (i = 0; i < run_size; i++) {
- buf = malloc(64);
- num = next_key(i, max_key);
- // num = i;
- sprintf(buf, "string-%d", num);
- if (i % 10000 == 0)
- printf("insert %d:%d\n", num, i);
- ins.objectid = num;
- ins.offset = 0;
- ins.flags = 0;
- ret = insert_item(root, &ins, buf, strlen(buf));
- if (!ret)
- tree_size++;
- free(buf);
- }
- write_ctree_super(root, &super);
- close_ctree(root);
-
- root = open_ctree("dbfile", &super);
- printf("starting search\n");
- srand(55);
- for (i = 0; i < run_size; i++) {
- num = next_key(i, max_key);
- ins.objectid = num;
- init_path(&path);
- if (i % 10000 == 0)
- printf("search %d:%d\n", num, i);
- ret = search_slot(root, &ins, &path, 0);
- if (ret) {
- print_tree(root, root->node);
- printf("unable to find %d\n", num);
- exit(1);
- }
- release_path(root, &path);
- }
- write_ctree_super(root, &super);
- close_ctree(root);
- root = open_ctree("dbfile", &super);
- printf("node %p level %d total ptrs %d free spc %lu\n", root->node,
- node_level(root->node->node.header.flags),
- root->node->node.header.nritems,
- NODEPTRS_PER_BLOCK - root->node->node.header.nritems);
- printf("all searches good, deleting some items\n");
- i = 0;
- srand(55);
- for (i = 0 ; i < run_size/4; i++) {
- num = next_key(i, max_key);
- ins.objectid = num;
- init_path(&path);
- ret = search_slot(root, &ins, &path, -1);
- if (!ret) {
- if (i % 10000 == 0)
- printf("del %d:%d\n", num, i);
- ret = del_item(root, &path);
- if (ret != 0)
- BUG();
- tree_size--;
- }
- release_path(root, &path);
- }
- write_ctree_super(root, &super);
- close_ctree(root);
- root = open_ctree("dbfile", &super);
- srand(128);
- for (i = 0; i < run_size; i++) {
- buf = malloc(64);
- num = next_key(i, max_key);
- sprintf(buf, "string-%d", num);
- ins.objectid = num;
- if (i % 10000 == 0)
- printf("insert %d:%d\n", num, i);
- ret = insert_item(root, &ins, buf, strlen(buf));
- if (!ret)
- tree_size++;
- free(buf);
- }
- write_ctree_super(root, &super);
- close_ctree(root);
- root = open_ctree("dbfile", &super);
- srand(128);
- printf("starting search2\n");
- for (i = 0; i < run_size; i++) {
- num = next_key(i, max_key);
- ins.objectid = num;
- init_path(&path);
- if (i % 10000 == 0)
- printf("search %d:%d\n", num, i);
- ret = search_slot(root, &ins, &path, 0);
- if (ret) {
- print_tree(root, root->node);
- printf("unable to find %d\n", num);
- exit(1);
- }
- release_path(root, &path);
- }
- printf("starting big long delete run\n");
- while(root->node && root->node->node.header.nritems > 0) {
- struct leaf *leaf;
- int slot;
- ins.objectid = (u64)-1;
- init_path(&path);
- ret = search_slot(root, &ins, &path, -1);
- if (ret == 0)
- BUG();
- leaf = &path.nodes[0]->leaf;
- slot = path.slots[0];
- if (slot != leaf->header.nritems)
- BUG();
- while(path.slots[0] > 0) {
- path.slots[0] -= 1;
- slot = path.slots[0];
- leaf = &path.nodes[0]->leaf;
-
- if (comp_keys(&last, &leaf->items[slot].key) <= 0)
- BUG();
- memcpy(&last, &leaf->items[slot].key, sizeof(last));
- if (tree_size % 10000 == 0)
- printf("big del %d:%d\n", tree_size, i);
- ret = del_item(root, &path);
- if (ret != 0) {
- printf("del_item returned %d\n", ret);
- BUG();
- }
- tree_size--;
- }
- release_path(root, &path);
- }
- printf("tree size is now %d\n", tree_size);
- printf("map tree\n");
- write_ctree_super(root, &super);
- close_ctree(root);
- return 0;
-}
projects / deliverable / linux.git / blobdiff