1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 2017-2018 HUAWEI, Inc.
24 	 * on-disk error, let's only BUG_ON in the debugging mode.  in erofs_dirnamecmp()
25 	 * otherwise, it will return 1 to just skip the invalid name  in erofs_dirnamecmp()
28 	DBG_BUGON(qd->name > qd->end);  in erofs_dirnamecmp()
31 	/* However it is absolutely safe if < qd->end */  in erofs_dirnamecmp()
32 	while (qd->name + i < qd->end && qd->name[i] != '\0') {  in erofs_dirnamecmp()
33 		if (qn->name[i] != qd->name[i]) {  in erofs_dirnamecmp()
35 			return qn->name[i] > qd->name[i] ? 1 : -1;  in erofs_dirnamecmp()
41 	return qn->name[i] == '\0' ? 0 : 1;  in erofs_dirnamecmp()
44 #define nameoff_from_disk(off, sz)	(le16_to_cpu(off) & ((sz) - 1))
51 	int head, back;  in find_target_dirent()  local
57 	back = ndirents - 1;  in find_target_dirent()
60 	while (head <= back) {  in find_target_dirent()
61 		const int mid = head + (back - head) / 2;  in find_target_dirent()
67 			.end = mid >= ndirents - 1 ?  in find_target_dirent()
82 			back = mid - 1;  in find_target_dirent()
87 	return ERR_PTR(-ENOENT);  in find_target_dirent()
95 	int head, back;  in find_target_block_classic()  local
96 	struct address_space *const mapping = dir->i_mapping;  in find_target_block_classic()
97 	struct page *candidate = ERR_PTR(-ENOENT);  in find_target_block_classic()
101 	back = erofs_inode_datablocks(dir) - 1;  in find_target_block_classic()
103 	while (head <= back) {  in find_target_block_classic()
104 		const int mid = head + (back - head) / 2;  in find_target_block_classic()
109 			const int nameoff = nameoff_from_disk(de->nameoff,  in find_target_block_classic()
119 				erofs_err(dir->i_sb,  in find_target_block_classic()
121 					  mid, EROFS_I(dir)->nid);  in find_target_block_classic()
123 				page = ERR_PTR(-EFSCORRUPTED);  in find_target_block_classic()
155 				back = mid - 1;  in find_target_block_classic()
178 	if (!dir->i_size)  in erofs_namei()
179 		return -ENOENT;  in erofs_namei()
181 	qn.name = name->name;  in erofs_namei()
182 	qn.end = name->name + name->len;  in erofs_namei()
198 		*nid = le64_to_cpu(de->nid);  in erofs_namei()
199 		*d_type = de->file_type;  in erofs_namei()
219 	/* dentry must be unhashed in lookup, no need to worry about */  in erofs_lookup()
225 	if (dentry->d_name.len > EROFS_NAME_LEN)  in erofs_lookup()
226 		return ERR_PTR(-ENAMETOOLONG);  in erofs_lookup()
229 	err = erofs_namei(dir, &dentry->d_name, &nid, &d_type);  in erofs_lookup()
231 	if (err == -ENOENT) {  in erofs_lookup()
238 			  dentry->d_name.name, nid, d_type);  in erofs_lookup()
239 		inode = erofs_iget(dir->i_sb, nid, d_type == FT_DIR);  in erofs_lookup()