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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /fs/hfsplus/bfind.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/hfsplus/bfind.c')
-rw-r--r-- | fs/hfsplus/bfind.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/fs/hfsplus/bfind.c b/fs/hfsplus/bfind.c new file mode 100644 index 0000000000..ca2ba8c9f8 --- /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; +} |