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-rw-r--r--fs/hfsplus/bfind.c294
1 files changed, 294 insertions, 0 deletions
diff --git a/fs/hfsplus/bfind.c b/fs/hfsplus/bfind.c
new file mode 100644
index 000000000..ca2ba8c9f
--- /dev/null
+++ b/fs/hfsplus/bfind.c
@@ -0,0 +1,294 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/hfsplus/bfind.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Search routines for btrees
+ */
+
+#include <linux/slab.h>
+#include "hfsplus_fs.h"
+
+int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd)
+{
+ void *ptr;
+
+ fd->tree = tree;
+ fd->bnode = NULL;
+ ptr = kmalloc(tree->max_key_len * 2 + 4, GFP_KERNEL);
+ if (!ptr)
+ return -ENOMEM;
+ fd->search_key = ptr;
+ fd->key = ptr + tree->max_key_len + 2;
+ hfs_dbg(BNODE_REFS, "find_init: %d (%p)\n",
+ tree->cnid, __builtin_return_address(0));
+ switch (tree->cnid) {
+ case HFSPLUS_CAT_CNID:
+ mutex_lock_nested(&tree->tree_lock, CATALOG_BTREE_MUTEX);
+ break;
+ case HFSPLUS_EXT_CNID:
+ mutex_lock_nested(&tree->tree_lock, EXTENTS_BTREE_MUTEX);
+ break;
+ case HFSPLUS_ATTR_CNID:
+ mutex_lock_nested(&tree->tree_lock, ATTR_BTREE_MUTEX);
+ break;
+ default:
+ BUG();
+ }
+ return 0;
+}
+
+void hfs_find_exit(struct hfs_find_data *fd)
+{
+ hfs_bnode_put(fd->bnode);
+ kfree(fd->search_key);
+ hfs_dbg(BNODE_REFS, "find_exit: %d (%p)\n",
+ fd->tree->cnid, __builtin_return_address(0));
+ mutex_unlock(&fd->tree->tree_lock);
+ fd->tree = NULL;
+}
+
+int hfs_find_1st_rec_by_cnid(struct hfs_bnode *bnode,
+ struct hfs_find_data *fd,
+ int *begin,
+ int *end,
+ int *cur_rec)
+{
+ __be32 cur_cnid;
+ __be32 search_cnid;
+
+ if (bnode->tree->cnid == HFSPLUS_EXT_CNID) {
+ cur_cnid = fd->key->ext.cnid;
+ search_cnid = fd->search_key->ext.cnid;
+ } else if (bnode->tree->cnid == HFSPLUS_CAT_CNID) {
+ cur_cnid = fd->key->cat.parent;
+ search_cnid = fd->search_key->cat.parent;
+ } else if (bnode->tree->cnid == HFSPLUS_ATTR_CNID) {
+ cur_cnid = fd->key->attr.cnid;
+ search_cnid = fd->search_key->attr.cnid;
+ } else {
+ cur_cnid = 0; /* used-uninitialized warning */
+ search_cnid = 0;
+ BUG();
+ }
+
+ if (cur_cnid == search_cnid) {
+ (*end) = (*cur_rec);
+ if ((*begin) == (*end))
+ return 1;
+ } else {
+ if (be32_to_cpu(cur_cnid) < be32_to_cpu(search_cnid))
+ (*begin) = (*cur_rec) + 1;
+ else
+ (*end) = (*cur_rec) - 1;
+ }
+
+ return 0;
+}
+
+int hfs_find_rec_by_key(struct hfs_bnode *bnode,
+ struct hfs_find_data *fd,
+ int *begin,
+ int *end,
+ int *cur_rec)
+{
+ int cmpval;
+
+ cmpval = bnode->tree->keycmp(fd->key, fd->search_key);
+ if (!cmpval) {
+ (*end) = (*cur_rec);
+ return 1;
+ }
+ if (cmpval < 0)
+ (*begin) = (*cur_rec) + 1;
+ else
+ *(end) = (*cur_rec) - 1;
+
+ return 0;
+}
+
+/* Find the record in bnode that best matches key (not greater than...)*/
+int __hfs_brec_find(struct hfs_bnode *bnode, struct hfs_find_data *fd,
+ search_strategy_t rec_found)
+{
+ u16 off, len, keylen;
+ int rec;
+ int b, e;
+ int res;
+
+ BUG_ON(!rec_found);
+ b = 0;
+ e = bnode->num_recs - 1;
+ res = -ENOENT;
+ do {
+ rec = (e + b) / 2;
+ len = hfs_brec_lenoff(bnode, rec, &off);
+ keylen = hfs_brec_keylen(bnode, rec);
+ if (keylen == 0) {
+ res = -EINVAL;
+ goto fail;
+ }
+ hfs_bnode_read(bnode, fd->key, off, keylen);
+ if (rec_found(bnode, fd, &b, &e, &rec)) {
+ res = 0;
+ goto done;
+ }
+ } while (b <= e);
+
+ if (rec != e && e >= 0) {
+ len = hfs_brec_lenoff(bnode, e, &off);
+ keylen = hfs_brec_keylen(bnode, e);
+ if (keylen == 0) {
+ res = -EINVAL;
+ goto fail;
+ }
+ hfs_bnode_read(bnode, fd->key, off, keylen);
+ }
+
+done:
+ fd->record = e;
+ fd->keyoffset = off;
+ fd->keylength = keylen;
+ fd->entryoffset = off + keylen;
+ fd->entrylength = len - keylen;
+
+fail:
+ return res;
+}
+
+/* Traverse a B*Tree from the root to a leaf finding best fit to key */
+/* Return allocated copy of node found, set recnum to best record */
+int hfs_brec_find(struct hfs_find_data *fd, search_strategy_t do_key_compare)
+{
+ struct hfs_btree *tree;
+ struct hfs_bnode *bnode;
+ u32 nidx, parent;
+ __be32 data;
+ int height, res;
+
+ tree = fd->tree;
+ if (fd->bnode)
+ hfs_bnode_put(fd->bnode);
+ fd->bnode = NULL;
+ nidx = tree->root;
+ if (!nidx)
+ return -ENOENT;
+ height = tree->depth;
+ res = 0;
+ parent = 0;
+ for (;;) {
+ bnode = hfs_bnode_find(tree, nidx);
+ if (IS_ERR(bnode)) {
+ res = PTR_ERR(bnode);
+ bnode = NULL;
+ break;
+ }
+ if (bnode->height != height)
+ goto invalid;
+ if (bnode->type != (--height ? HFS_NODE_INDEX : HFS_NODE_LEAF))
+ goto invalid;
+ bnode->parent = parent;
+
+ res = __hfs_brec_find(bnode, fd, do_key_compare);
+ if (!height)
+ break;
+ if (fd->record < 0)
+ goto release;
+
+ parent = nidx;
+ hfs_bnode_read(bnode, &data, fd->entryoffset, 4);
+ nidx = be32_to_cpu(data);
+ hfs_bnode_put(bnode);
+ }
+ fd->bnode = bnode;
+ return res;
+
+invalid:
+ pr_err("inconsistency in B*Tree (%d,%d,%d,%u,%u)\n",
+ height, bnode->height, bnode->type, nidx, parent);
+ res = -EIO;
+release:
+ hfs_bnode_put(bnode);
+ return res;
+}
+
+int hfs_brec_read(struct hfs_find_data *fd, void *rec, int rec_len)
+{
+ int res;
+
+ res = hfs_brec_find(fd, hfs_find_rec_by_key);
+ if (res)
+ return res;
+ if (fd->entrylength > rec_len)
+ return -EINVAL;
+ hfs_bnode_read(fd->bnode, rec, fd->entryoffset, fd->entrylength);
+ return 0;
+}
+
+int hfs_brec_goto(struct hfs_find_data *fd, int cnt)
+{
+ struct hfs_btree *tree;
+ struct hfs_bnode *bnode;
+ int idx, res = 0;
+ u16 off, len, keylen;
+
+ bnode = fd->bnode;
+ tree = bnode->tree;
+
+ if (cnt < 0) {
+ cnt = -cnt;
+ while (cnt > fd->record) {
+ cnt -= fd->record + 1;
+ fd->record = bnode->num_recs - 1;
+ idx = bnode->prev;
+ if (!idx) {
+ res = -ENOENT;
+ goto out;
+ }
+ hfs_bnode_put(bnode);
+ bnode = hfs_bnode_find(tree, idx);
+ if (IS_ERR(bnode)) {
+ res = PTR_ERR(bnode);
+ bnode = NULL;
+ goto out;
+ }
+ }
+ fd->record -= cnt;
+ } else {
+ while (cnt >= bnode->num_recs - fd->record) {
+ cnt -= bnode->num_recs - fd->record;
+ fd->record = 0;
+ idx = bnode->next;
+ if (!idx) {
+ res = -ENOENT;
+ goto out;
+ }
+ hfs_bnode_put(bnode);
+ bnode = hfs_bnode_find(tree, idx);
+ if (IS_ERR(bnode)) {
+ res = PTR_ERR(bnode);
+ bnode = NULL;
+ goto out;
+ }
+ }
+ fd->record += cnt;
+ }
+
+ len = hfs_brec_lenoff(bnode, fd->record, &off);
+ keylen = hfs_brec_keylen(bnode, fd->record);
+ if (keylen == 0) {
+ res = -EINVAL;
+ goto out;
+ }
+ fd->keyoffset = off;
+ fd->keylength = keylen;
+ fd->entryoffset = off + keylen;
+ fd->entrylength = len - keylen;
+ hfs_bnode_read(bnode, fd->key, off, keylen);
+out:
+ fd->bnode = bnode;
+ return res;
+}
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