1 files changed, 491 insertions, 0 deletions

diff --git a/fs/hfsplus/brec.c b/fs/hfsplus/brec.c
new file mode 100644
index 000000000000..0ccef2ab790c
--- /dev/null
+++ b/fs/hfsplus/brec.c
@@ -0,0 +1,491 @@
+/*
+ *  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)) {
+                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 (node->tree->attributes & HFS_TREE_BIGKEYS)
+                        retval = hfs_bnode_read_u16(node, recoff) + 2;
+                else
+                        retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
+        }
+        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;
+        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 = 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;
+        }
+
+        if (!rec)
+                hfs_brec_update_parent(fd);
+
+        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);
+        dprint(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);
+                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;
+        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;
+
+        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);
+                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 (new_node->next) {
+                struct hfs_bnode *next_node = hfs_bnode_find(tree, new_node->next);
+                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_bnode_dump(parent);
+        rec = fd->record;
+
+        /* size difference between old and new key */
+        if (tree->attributes & HFS_TREE_VARIDXKEYS)
+                newkeylen = hfs_bnode_read_u16(node, 14) + 2;
+        else
+                fd->keylength = newkeylen = tree->max_key_len + 2;
+        dprint(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) {
+
+                        printk("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_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)
+                        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)) {
+                        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;
+}