--- /dev/null
+/*
+ * 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);
+ 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 = 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;
+
+ 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);
+ }
+ }
+
+ 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;
+}
Code Review / kvmfornfv.git / blobdiff