1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 2017-2018 HUAWEI, Inc.
12 	const unsigned char *end;  member
15 /* based on the end of qn is accurate and it must have the trailing '\0' */
23 	 * on-disk error, let's only BUG_ON in the debugging mode.  in erofs_dirnamecmp()
27 	DBG_BUGON(qd->name > qd->end);  in erofs_dirnamecmp()
30 	/* However it is absolutely safe if < qd->end */  in erofs_dirnamecmp()
31 	while (qd->name + i < qd->end && qd->name[i] != '\0') {  in erofs_dirnamecmp()
32 		if (qn->name[i] != qd->name[i]) {  in erofs_dirnamecmp()
34 			return qn->name[i] > qd->name[i] ? 1 : -1;  in erofs_dirnamecmp()
40 	return qn->name[i] == '\0' ? 0 : 1;  in erofs_dirnamecmp()
43 #define nameoff_from_disk(off, sz)	(le16_to_cpu(off) & ((sz) - 1))
50 	int head, back;  in find_target_dirent()  local
56 	back = ndirents - 1;  in find_target_dirent()
59 	while (head <= back) {  in find_target_dirent()
60 		const int mid = head + (back - head) / 2;  in find_target_dirent()
66 			.end = mid >= ndirents - 1 ?  in find_target_dirent()
81 			back = mid - 1;  in find_target_dirent()
86 	return ERR_PTR(-ENOENT);  in find_target_dirent()
93 	int head = 0, back = erofs_iblks(dir) - 1;  in erofs_find_target_block()  local
95 	void *candidate = ERR_PTR(-ENOENT);  in erofs_find_target_block()
97 	while (head <= back) {  in erofs_find_target_block()
98 		const int mid = head + (back - head) / 2;  in erofs_find_target_block()
102 		buf.mapping = dir->i_mapping;  in erofs_find_target_block()
103 		de = erofs_bread(&buf, erofs_pos(dir->i_sb, mid), EROFS_KMAP);  in erofs_find_target_block()
105 			const int nameoff = nameoff_from_disk(de->nameoff, bsz);  in erofs_find_target_block()
113 				erofs_err(dir->i_sb,  in erofs_find_target_block()
115 					  mid, EROFS_I(dir)->nid);  in erofs_find_target_block()
117 				de = ERR_PTR(-EFSCORRUPTED);  in erofs_find_target_block()
125 				dname.end = (u8 *)de + bsz;  in erofs_find_target_block()
127 				dname.end = (u8 *)de +  in erofs_find_target_block()
135 				back = mid - 1;  in erofs_find_target_block()
169 	if (!dir->i_size)  in erofs_namei()
170 		return -ENOENT;  in erofs_namei()
172 	qn.name = name->name;  in erofs_namei()
173 	qn.end = name->name + name->len;  in erofs_namei()
174 	buf.mapping = dir->i_mapping;  in erofs_namei()
186 		*nid = le64_to_cpu(de->nid);  in erofs_namei()
187 		*d_type = de->file_type;  in erofs_namei()
203 	if (dentry->d_name.len > EROFS_NAME_LEN)  in erofs_lookup()
204 		return ERR_PTR(-ENAMETOOLONG);  in erofs_lookup()
206 	err = erofs_namei(dir, &dentry->d_name, &nid, &d_type);  in erofs_lookup()
208 	if (err == -ENOENT)  in erofs_lookup()
214 		inode = erofs_iget(dir->i_sb, nid);  in erofs_lookup()