// SPDX-License-Identifier: GPL-2.0 /* * linux/fs/hfsplus/brec.c * * Copyright (C) 2001 * Brad Boyer (flar@allandria.com) * (C) 2003 Ardis Technologies <roman@ardistech.com> * * Handle individual btree records */ #include "hfsplus_fs.h" #include "hfsplus_raw.h" static struct hfs_bnode *hfs_bnode_split(struct hfs_find_data *fd); static int hfs_brec_update_parent(struct hfs_find_data *fd); static int hfs_btree_inc_height(struct hfs_btree *); /* Get the length and offset of the given record in the given node */ u16 hfs_brec_lenoff(struct hfs_bnode *node, u16 rec, u16 *off) { __be16 retval[2]; u16 dataoff; dataoff = node->tree->node_size - (rec + 2) * 2; hfs_bnode_read(node, retval, dataoff, 4); *off = be16_to_cpu(retval[1]); return be16_to_cpu(retval[0]) - *off; } /* Get the length of the key from a keyed record */ u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec) { u16 retval, recoff; if (node->type != HFS_NODE_INDEX && node->type != HFS_NODE_LEAF) return 0; if ((node->type == HFS_NODE_INDEX) && !(node->tree->attributes & HFS_TREE_VARIDXKEYS) && (node->tree->cnid != HFSPLUS_ATTR_CNID)) { retval = node->tree->max_key_len + 2; } else { recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec + 1) * 2); if (!recoff) return 0; if (recoff > node->tree->node_size - 2) { pr_err("recoff %d too large\n", recoff); return 0; } retval = hfs_bnode_read_u16(node, recoff) + 2; if (retval > node->tree->max_key_len + 2) { pr_err("keylen %d too large\n", retval); retval = 0; } } return retval; } 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); node = hfs_bnode_find(tree, tree->leaf_head); if (IS_ERR(node)) return PTR_ERR(node); fd->bnode = node; fd->record = -1; } new_node = NULL; key_len = be16_to_cpu(fd->search_key->key_len) + 2; 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; hfs_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); /* * update parent key if we inserted a key * at the start of the node and it is not the new node */ if (!rec && new_node != node) { hfs_bnode_read_key(node, fd->search_key, data_off + size); hfs_brec_update_parent(fd); } if (new_node) { 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_find_rec_by_key); hfs_bnode_put(new_node); new_node = NULL; if ((tree->attributes & HFS_TREE_VARIDXKEYS) || (tree->cnid == HFSPLUS_ATTR_CNID)) key_len = be16_to_cpu(fd->search_key->key_len) + 2; else { fd->search_key->key_len = cpu_to_be16(tree->max_key_len); key_len = tree->max_key_len + 2; } goto again; } return 0; } int hfs_brec_remove(struct hfs_find_data *fd) { struct hfs_btree *tree; struct hfs_bnode *node, *parent; int end_off, rec_off, data_off, size; tree = fd->tree; node = fd->bnode; again: rec_off = tree->node_size - (fd->record + 2) * 2; end_off = tree->node_size - (node->num_recs + 1) * 2; if (node->type == HFS_NODE_LEAF) { tree->leaf_count--; mark_inode_dirty(tree->inode); } hfs_bnode_dump(node); hfs_dbg(BNODE_MOD, "remove_rec: %d, %d\n", fd->record, fd->keylength + fd->entrylength); if (!--node->num_recs) { hfs_bnode_unlink(node); if (!node->parent) return 0; parent = hfs_bnode_find(tree, node->parent); if (IS_ERR(parent)) return PTR_ERR(parent); hfs_bnode_put(node); node = fd->bnode = parent; __hfs_brec_find(node, fd, hfs_find_rec_by_key); goto again; } hfs_bnode_write_u16(node, offsetof(struct hfs_bnode_desc, num_recs), node->num_recs); if (rec_off == end_off) goto skip; size = fd->keylength + fd->entrylength; do { data_off = hfs_bnode_read_u16(node, rec_off); hfs_bnode_write_u16(node, rec_off + 2, data_off - size); rec_off -= 2; } while (rec_off >= end_off); /* fill hole */ hfs_bnode_move(node, fd->keyoffset, fd->keyoffset + size, data_off - fd->keyoffset - size); skip: hfs_bnode_dump(node); if (!fd->record) hfs_brec_update_parent(fd); return 0; } 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); hfs_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) { /* if there is no next node, this might be the new tail */ tree->leaf_tail = new_node->this; mark_inode_dirty(tree->inode); } hfs_bnode_dump(node); hfs_bnode_dump(new_node); hfs_bnode_put(node); return new_node; } static int hfs_brec_update_parent(struct hfs_find_data *fd) { struct hfs_btree *tree; struct hfs_bnode *node, *new_node, *parent; int newkeylen, diff; int rec, rec_off, end_rec_off; int start_off, end_off; tree = fd->tree; node = fd->bnode; new_node = NULL; if (!node->parent) return 0; again: parent = hfs_bnode_find(tree, node->parent); if (IS_ERR(parent)) return PTR_ERR(parent); __hfs_brec_find(parent, fd, hfs_find_rec_by_key); if (fd->record < 0) return -ENOENT; hfs_bnode_dump(parent); rec = fd->record; /* size difference between old and new key */ if ((tree->attributes & HFS_TREE_VARIDXKEYS) || (tree->cnid == HFSPLUS_ATTR_CNID)) newkeylen = hfs_bnode_read_u16(node, 14) + 2; else fd->keylength = newkeylen = tree->max_key_len + 2; hfs_dbg(BNODE_MOD, "update_rec: %d, %d, %d\n", rec, fd->keylength, newkeylen); rec_off = tree->node_size - (rec + 2) * 2; end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; diff = newkeylen - fd->keylength; if (!diff) goto skip; if (diff > 0) { end_off = hfs_bnode_read_u16(parent, end_rec_off); if (end_rec_off - end_off < diff) { hfs_dbg(BNODE_MOD, "splitting index node\n"); fd->bnode = parent; new_node = hfs_bnode_split(fd); if (IS_ERR(new_node)) return PTR_ERR(new_node); parent = fd->bnode; rec = fd->record; rec_off = tree->node_size - (rec + 2) * 2; end_rec_off = tree->node_size - (parent->num_recs + 1) * 2; } } end_off = start_off = hfs_bnode_read_u16(parent, rec_off); hfs_bnode_write_u16(parent, rec_off, start_off + diff); start_off -= 4; /* move previous cnid too */ while (rec_off > end_rec_off) { rec_off -= 2; end_off = hfs_bnode_read_u16(parent, rec_off); hfs_bnode_write_u16(parent, rec_off, end_off + diff); } hfs_bnode_move(parent, start_off + diff, start_off, end_off - start_off); skip: hfs_bnode_copy(parent, fd->keyoffset, node, 14, newkeylen); hfs_bnode_dump(parent); hfs_bnode_put(node); node = parent; if (new_node) { __be32 cnid; 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 key and entry */ hfs_bnode_read_key(new_node, fd->search_key, 14); cnid = cpu_to_be32(new_node->this); __hfs_brec_find(fd->bnode, fd, hfs_find_rec_by_key); hfs_brec_insert(fd, &cnid, sizeof(cnid)); hfs_bnode_put(fd->bnode); hfs_bnode_put(new_node); if (!rec) { if (new_node == node) goto out; /* restore search_key */ hfs_bnode_read_key(node, fd->search_key, 14); } new_node = NULL; } if (!rec && node->parent) goto again; out: fd->bnode = node; return 0; } static int hfs_btree_inc_height(struct hfs_btree *tree) { struct hfs_bnode *node, *new_node; struct hfs_bnode_desc node_desc; int key_size, rec; __be32 cnid; node = NULL; if (tree->root) { node = hfs_bnode_find(tree, tree->root); if (IS_ERR(node)) return PTR_ERR(node); } new_node = hfs_bmap_alloc(tree); if (IS_ERR(new_node)) { hfs_bnode_put(node); return PTR_ERR(new_node); } tree->root = new_node->this; if (!tree->depth) { tree->leaf_head = tree->leaf_tail = new_node->this; new_node->type = HFS_NODE_LEAF; new_node->num_recs = 0; } else { new_node->type = HFS_NODE_INDEX; new_node->num_recs = 1; } new_node->parent = 0; new_node->next = 0; new_node->prev = 0; new_node->height = ++tree->depth; 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)); rec = tree->node_size - 2; hfs_bnode_write_u16(new_node, rec, 14); if (node) { /* insert old root idx into new root */ node->parent = tree->root; if (node->type == HFS_NODE_LEAF || tree->attributes & HFS_TREE_VARIDXKEYS || tree->cnid == HFSPLUS_ATTR_CNID) key_size = hfs_bnode_read_u16(node, 14) + 2; else key_size = tree->max_key_len + 2; hfs_bnode_copy(new_node, 14, node, 14, key_size); if (!(tree->attributes & HFS_TREE_VARIDXKEYS) && (tree->cnid != HFSPLUS_ATTR_CNID)) { key_size = tree->max_key_len + 2; hfs_bnode_write_u16(new_node, 14, tree->max_key_len); } cnid = cpu_to_be32(node->this); hfs_bnode_write(new_node, &cnid, 14 + key_size, 4); rec -= 2; hfs_bnode_write_u16(new_node, rec, 14 + key_size + 4); hfs_bnode_put(node); } hfs_bnode_put(new_node); mark_inode_dirty(tree->inode); return 0; }