int hfs_brec_insert(struct hfs_find_data *fd, void *entry, int entry_len)
{
struct hfs_btree *tree;
struct hfs_bnode *node, *new_node;
int size, key_len, rec;
int data_off, end_off;
int idx_rec_off, data_rec_off, end_rec_off;
__be32 cnid;
tree = fd->tree;
if (!fd->bnode) {
if (!tree->root)
hfs_btree_inc_height(tree);
fd->bnode = hfs_bnode_find(tree, tree->leaf_head);
if (IS_ERR(fd->bnode))
return PTR_ERR(fd->bnode);
fd->record = -1;
}
new_node = NULL;
key_len = (fd->search_key->key_len | 1) + 1;
again:
/* new record idx and complete record size */
rec = fd->record + 1;
size = key_len + entry_len;
node = fd->bnode;
hfs_bnode_dump(node);
/* get last offset */
end_rec_off = tree->node_size - (node->num_recs + 1) * 2;
end_off = hfs_bnode_read_u16(node, end_rec_off);
end_rec_off -= 2;
dprint(DBG_BNODE_MOD, "insert_rec: %d, %d, %d, %d\n", rec, size, end_off, end_rec_off);
if (size > end_rec_off - end_off) {
if (new_node)
panic("not enough room!\n");
new_node = hfs_bnode_split(fd);
if (IS_ERR(new_node))
return PTR_ERR(new_node);
goto again;
}
if (node->type == HFS_NODE_LEAF) {
tree->leaf_count++;
mark_inode_dirty(tree->inode);
}
node->num_recs++;
/* write new last offset */
hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs);
hfs_bnode_write_u16(node, end_rec_off, end_off + size);
data_off = end_off;
data_rec_off = end_rec_off + 2;
idx_rec_off = tree->node_size - (rec + 1) * 2;
if (idx_rec_off == data_rec_off)
goto skip;
/* move all following entries */
do {
data_off = hfs_bnode_read_u16(node, data_rec_off + 2);
hfs_bnode_write_u16(node, data_rec_off, data_off + size);
data_rec_off += 2;
} while (data_rec_off < idx_rec_off);
/* move data away */
hfs_bnode_move(node, data_off + size, data_off,
end_off - data_off);
skip:
hfs_bnode_write(node, fd->search_key, data_off, key_len);
hfs_bnode_write(node, entry, data_off + key_len, entry_len);
hfs_bnode_dump(node);
if (new_node) {
/* update parent key if we inserted a key
* at the start of the first node
*/
if (!rec && new_node != node)
hfs_brec_update_parent(fd);
hfs_bnode_put(fd->bnode);
if (!new_node->parent) {
hfs_btree_inc_height(tree);
new_node->parent = tree->root;
}
fd->bnode = hfs_bnode_find(tree, new_node->parent);
/* create index data entry */
cnid = cpu_to_be32(new_node->this);
entry = &cnid;
entry_len = sizeof(cnid);
/* get index key */
hfs_bnode_read_key(new_node, fd->search_key, 14);
__hfs_brec_find(fd->bnode, fd);
hfs_bnode_put(new_node);
new_node = NULL;
if (tree->attributes & HFS_TREE_VARIDXKEYS)
key_len = fd->search_key->key_len + 1;
else {
fd->search_key->key_len = tree->max_key_len;
key_len = tree->max_key_len + 1;
}
goto again;
}
if (!rec)
hfs_brec_update_parent(fd);
return 0;
}
/*
* del_root()
*
* Description:
* Delete the current root bnode.
* Input Variable(s):
* struct hfs_bnode_ref *root: reference to the root bnode
* Output Variable(s):
* NONE
* Returns:
* int: 0 on success, error code on failure
* Preconditions:
* 'root' refers to the root bnode with HFS_LOCK_WRITE access.
* None of 'root's children are held with HFS_LOCK_WRITE access.
* Postconditions:
* The current 'root' node is removed from the tree and the depth
* of the tree is reduced by one.
* If 'root' is an index node with exactly one child, then that
* child becomes the new root of the tree.
* If 'root' is an empty leaf node the tree becomes empty.
* Upon return access to 'root' is relinquished.
*/
static int del_root(struct hfs_bnode_ref *root)
{
struct hfs_btree *tree = root->bn->tree;
struct hfs_bnode_ref child;
hfs_u32 node;
if (root->bn->ndNRecs > 1) {
return 0;
} else if (root->bn->ndNRecs == 0) {
/* tree is empty */
tree->bthRoot = 0;
tree->root = NULL;
tree->bthRoot = 0;
tree->bthFNode = 0;
tree->bthLNode = 0;
--tree->bthDepth;
tree->dirt = 1;
if (tree->bthDepth) {
hfs_warn("hfs_bdelete: empty tree with bthDepth=%d\n",
tree->bthDepth);
goto bail;
}
return hfs_bnode_free(root);
} else if (root->bn->ndType == ndIndxNode) {
/* tree is non-empty */
node = hfs_get_hl(bkey_record(bnode_datastart(root->bn)));
child = hfs_bnode_find(tree, node, HFS_LOCK_READ);
if (!child.bn) {
hfs_warn("hfs_bdelete: can't read child node.\n");
goto bail;
}
child.bn->sticky = HFS_STICKY;
if (child.bn->next) {
child.bn->next->prev = child.bn->prev;
}
if (child.bn->prev) {
child.bn->prev->next = child.bn->next;
}
if (bhash(tree, child.bn->node) == child.bn) {
bhash(tree, child.bn->node) = child.bn->next;
}
child.bn->next = NULL;
child.bn->prev = NULL;
tree->bthRoot = child.bn->node;
tree->root = child.bn;
/* re-assign bthFNode and bthLNode if the new root is
a leaf node. */
if (child.bn->ndType == ndLeafNode) {
tree->bthFNode = node;
tree->bthLNode = node;
}
hfs_bnode_relse(&child);
tree->bthRoot = node;
--tree->bthDepth;
tree->dirt = 1;
if (!tree->bthDepth) {
hfs_warn("hfs_bdelete: non-empty tree with "
"bthDepth == 0\n");
goto bail;
}
return hfs_bnode_free(root); /* marks tree dirty */
}
hfs_bnode_relse(root);
return 0;
bail:
hfs_bnode_relse(root);
return -EIO;
}
static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd)
{
struct hfs_btree *tree;
struct hfs_bnode *node, *new_node, *next_node;
struct hfs_bnode_desc node_desc;
int num_recs, new_rec_off, new_off, old_rec_off;
int data_start, data_end, size;
tree = fd->tree;
node = fd->bnode;
new_node = hfs_bmap_alloc(tree);
if (IS_ERR(new_node))
return new_node;
hfs_bnode_get(node);
dprint(DBG_BNODE_MOD, "split_nodes: %d - %d - %d\n",
node->this, new_node->this, node->next);
new_node->next = node->next;
new_node->prev = node->this;
new_node->parent = node->parent;
new_node->type = node->type;
new_node->height = node->height;
if (node->next)
next_node = hfs_bnode_find(tree, node->next);
else
next_node = NULL;
if (IS_ERR(next_node)) {
hfs_bnode_put(node);
hfs_bnode_put(new_node);
return next_node;
}
size = tree->node_size / 2 - node->num_recs * 2 - 14;
old_rec_off = tree->node_size - 4;
num_recs = 1;
for (;;) {
data_start = hfs_bnode_read_u16(node, old_rec_off);
if (data_start > size)
break;
old_rec_off -= 2;
if (++num_recs < node->num_recs)
continue;
/* panic? */
hfs_bnode_put(node);
hfs_bnode_put(new_node);
if (next_node)
hfs_bnode_put(next_node);
return ERR_PTR(-ENOSPC);
}
if (fd->record + 1 < num_recs) {
/* new record is in the lower half,
* so leave some more space there
*/
old_rec_off += 2;
num_recs--;
data_start = hfs_bnode_read_u16(node, old_rec_off);
} else {
hfs_bnode_put(node);
hfs_bnode_get(new_node);
fd->bnode = new_node;
fd->record -= num_recs;
fd->keyoffset -= data_start - 14;
fd->entryoffset -= data_start - 14;
}
new_node->num_recs = node->num_recs - num_recs;
node->num_recs = num_recs;
new_rec_off = tree->node_size - 2;
new_off = 14;
size = data_start - new_off;
num_recs = new_node->num_recs;
data_end = data_start;
while (num_recs) {
hfs_bnode_write_u16(new_node, new_rec_off, new_off);
old_rec_off -= 2;
new_rec_off -= 2;
data_end = hfs_bnode_read_u16(node, old_rec_off);
new_off = data_end - size;
num_recs--;
}
hfs_bnode_write_u16(new_node, new_rec_off, new_off);
hfs_bnode_copy(new_node, 14, node, data_start, data_end - data_start);
/* update new bnode header */
node_desc.next = cpu_to_be32(new_node->next);
node_desc.prev = cpu_to_be32(new_node->prev);
node_desc.type = new_node->type;
node_desc.height = new_node->height;
node_desc.num_recs = cpu_to_be16(new_node->num_recs);
node_desc.reserved = 0;
hfs_bnode_write(new_node, &node_desc, 0, sizeof(node_desc));
/* update previous bnode header */
node->next = new_node->this;
hfs_bnode_read(node, &node_desc, 0, sizeof(node_desc));
node_desc.next = cpu_to_be32(node->next);
node_desc.num_recs = cpu_to_be16(node->num_recs);
hfs_bnode_write(node, &node_desc, 0, sizeof(node_desc));
/* update next bnode header */
if (next_node) {
next_node->prev = new_node->this;
hfs_bnode_read(next_node, &node_desc, 0, sizeof(node_desc));
node_desc.prev = cpu_to_be32(next_node->prev);
hfs_bnode_write(next_node, &node_desc, 0, sizeof(node_desc));
hfs_bnode_put(next_node);
} else if (node->this == tree->leaf_tail) {
/*
* bdelete()
*
* Delete the given record from a B-tree.
*/
static int bdelete(struct hfs_brec *brec)
{
struct hfs_btree *tree = brec->tree;
struct hfs_belem *belem = brec->bottom;
struct hfs_belem *parent = (belem-1);
struct hfs_bnode *bnode;
hfs_u32 left_node, right_node;
struct hfs_bnode_ref left, right;
int left_space, right_space, min_space;
int fix_right_key;
int fix_key;
while ((belem > brec->top) &&
(belem->flags & (HFS_BPATH_UNDERFLOW | HFS_BPATH_FIRST))) {
bnode = belem->bnr.bn;
fix_key = belem->flags & HFS_BPATH_FIRST;
fix_right_key = 0;
bdelete_nonempty(brec, belem);
if (bnode->node == tree->root->node) {
del_root(&belem->bnr);
--brec->bottom;
goto done;
}
/* check for btree corruption which could lead to deadlock */
left_node = bnode->ndBLink;
right_node = bnode->ndFLink;
if ((left_node && hfs_bnode_in_brec(left_node, brec)) ||
(right_node && hfs_bnode_in_brec(right_node, brec)) ||
(left_node == right_node)) {
hfs_warn("hfs_bdelete: corrupt btree\n");
hfs_brec_relse(brec, NULL);
return -EIO;
}
/* grab the left neighbor if it exists */
if (left_node) {
hfs_bnode_lock(&belem->bnr, HFS_LOCK_RESRV);
left = hfs_bnode_find(tree,left_node,HFS_LOCK_WRITE);
if (!left.bn) {
hfs_warn("hfs_bdelete: unable to read left "
"neighbor.\n");
hfs_brec_relse(brec, NULL);
return -EIO;
}
hfs_bnode_lock(&belem->bnr, HFS_LOCK_WRITE);
if (parent->record != 1) {
left_space = bnode_freespace(left.bn);
} else {
left_space = NO_SPACE;
}
} else {
left.bn = NULL;
left_space = NO_SPACE;
}
/* grab the right neighbor if it exists */
if (right_node) {
right = hfs_bnode_find(tree,right_node,HFS_LOCK_WRITE);
if (!right.bn) {
hfs_warn("hfs_bdelete: unable to read right "
"neighbor.\n");
hfs_bnode_relse(&left);
hfs_brec_relse(brec, NULL);
return -EIO;
}
if (parent->record < parent->bnr.bn->ndNRecs) {
right_space = bnode_freespace(right.bn);
} else {
right_space = NO_SPACE;
}
} else {
right.bn = NULL;
right_space = NO_SPACE;
}
if (left_space < right_space) {
min_space = left_space;
} else {
min_space = right_space;
}
if (min_space == NO_SPACE) {
hfs_warn("hfs_bdelete: no siblings?\n");
hfs_brec_relse(brec, NULL);
return -EIO;
}
if (bnode->ndNRecs == 0) {
delete_empty_bnode(left_node, &left, &belem->bnr,
right_node, &right);
} else if (min_space + bnode_freespace(bnode) >= FULL) {
if ((right_space == NO_SPACE) ||
((right_space == min_space) &&
(left_space != NO_SPACE))) {
hfs_bnode_shift_left(left.bn, bnode,
bnode->ndNRecs);
} else {
hfs_bnode_shift_right(bnode, right.bn, 1);
fix_right_key = 1;
}
delete_empty_bnode(left_node, &left, &belem->bnr,
right_node, &right);
} else if (min_space == right_space) {
balance(bnode, right.bn);
fix_right_key = 1;
} else {
balance(left.bn, bnode);
fix_key = 1;
}
if (fix_right_key) {
hfs_bnode_update_key(brec, belem, right.bn, 1);
}
hfs_bnode_relse(&left);
hfs_bnode_relse(&right);
if (bnode->ndNRecs) {
if (fix_key) {
hfs_bnode_update_key(brec, belem, bnode, 0);
}
goto done;
}
hfs_bnode_free(&belem->bnr);
--brec->bottom;
belem = parent;
--parent;
}
if (belem < brec->top) {
hfs_warn("hfs_bdelete: Missing parent.\n");
hfs_brec_relse(brec, NULL);
return -EIO;
}
bdelete_nonempty(brec, belem);
done:
hfs_brec_relse(brec, NULL);
return 0;
}