1 // SPDX-License-Identifier: GPL-2.0-or-later
18 #define ROMFS_MTD_READ(sb, ...) mtd_read((sb)->s_mtd, ##__VA_ARGS__)
30 	return (ret < 0 || rlen != buflen) ? -EIO : 0;  in romfs_mtd_read()
34  * determine the length of a string in a romfs image on an MTD device
40 	size_t segment;  in romfs_mtd_strnlen()  local
45 	/* scan the string up to 16 bytes at a time */  in romfs_mtd_strnlen()
47 		segment = min_t(size_t, maxlen, 16);  in romfs_mtd_strnlen()
48 		ret = ROMFS_MTD_READ(sb, pos, segment, &len, buf);  in romfs_mtd_strnlen()
53 			return n + (p - buf);  in romfs_mtd_strnlen()
54 		maxlen -= len;  in romfs_mtd_strnlen()
63  * compare a string to one in a romfs image on MTD
64  * - return 1 if matched, 0 if differ, -ve if error
70 	size_t len, segment;  in romfs_mtd_strcmp()  local
73 	/* scan the string up to 16 bytes at a time, and attempt to grab the  in romfs_mtd_strcmp()
78 		segment = min_t(size_t, size + 1, 17);  in romfs_mtd_strcmp()
79 		ret = ROMFS_MTD_READ(sb, pos, segment, &len, buf);  in romfs_mtd_strcmp()
82 		len--;  in romfs_mtd_strcmp()
86 		size -= len;  in romfs_mtd_strcmp()
95 	return 1;  in romfs_mtd_strcmp()
101  * read data from an romfs image on a block device
108 	size_t segment;  in romfs_blk_read()  local
110 	/* copy the string up to blocksize bytes at a time */  in romfs_blk_read()
112 		offset = pos & (ROMBSIZE - 1);  in romfs_blk_read()
113 		segment = min_t(size_t, buflen, ROMBSIZE - offset);  in romfs_blk_read()
116 			return -EIO;  in romfs_blk_read()
117 		memcpy(buf, bh->b_data + offset, segment);  in romfs_blk_read()
119 		buf += segment;  in romfs_blk_read()
120 		buflen -= segment;  in romfs_blk_read()
121 		pos += segment;  in romfs_blk_read()
128  * determine the length of a string in romfs on a block device
136 	size_t segment;  in romfs_blk_strnlen()  local
139 	/* scan the string up to blocksize bytes at a time */  in romfs_blk_strnlen()
141 		offset = pos & (ROMBSIZE - 1);  in romfs_blk_strnlen()
142 		segment = min_t(size_t, limit, ROMBSIZE - offset);  in romfs_blk_strnlen()
145 			return -EIO;  in romfs_blk_strnlen()
146 		buf = bh->b_data + offset;  in romfs_blk_strnlen()
147 		p = memchr(buf, 0, segment);  in romfs_blk_strnlen()
150 			return n + (p - buf);  in romfs_blk_strnlen()
151 		limit -= segment;  in romfs_blk_strnlen()
152 		pos += segment;  in romfs_blk_strnlen()
153 		n += segment;  in romfs_blk_strnlen()
160  * compare a string to one in a romfs image on a block device
161  * - return 1 if matched, 0 if differ, -ve if error
168 	size_t segment;  in romfs_blk_strcmp()  local
171 	/* compare string up to a block at a time */  in romfs_blk_strcmp()
173 		offset = pos & (ROMBSIZE - 1);  in romfs_blk_strcmp()
174 		segment = min_t(size_t, size, ROMBSIZE - offset);  in romfs_blk_strcmp()
177 			return -EIO;  in romfs_blk_strcmp()
178 		matched = (memcmp(bh->b_data + offset, str, segment) == 0);  in romfs_blk_strcmp()
180 		size -= segment;  in romfs_blk_strcmp()
181 		pos += segment;  in romfs_blk_strcmp()
182 		str += segment;  in romfs_blk_strcmp()
183 		if (matched && size == 0 && offset + segment < ROMBSIZE) {  in romfs_blk_strcmp()
184 			if (!bh->b_data[offset + segment])  in romfs_blk_strcmp()
197 		BUG_ON((pos & (ROMBSIZE - 1)) != 0);  in romfs_blk_strcmp()
200 			return -EIO;  in romfs_blk_strcmp()
201 		matched = !bh->b_data[0];  in romfs_blk_strcmp()
207 	return 1;  in romfs_blk_strcmp()
220 	if (pos >= limit || buflen > limit - pos)  in romfs_dev_read()
221 		return -EIO;  in romfs_dev_read()
224 	if (sb->s_mtd)  in romfs_dev_read()
228 	if (sb->s_bdev)  in romfs_dev_read()
231 	return -EIO;  in romfs_dev_read()
235  * determine the length of a string in romfs
244 		return -EIO;  in romfs_dev_strnlen()
245 	if (maxlen > limit - pos)  in romfs_dev_strnlen()
246 		maxlen = limit - pos;  in romfs_dev_strnlen()
249 	if (sb->s_mtd)  in romfs_dev_strnlen()
253 	if (sb->s_bdev)  in romfs_dev_strnlen()
256 	return -EIO;  in romfs_dev_strnlen()
260  * compare a string to one in romfs
261  * - the string to be compared to, str, may not be NUL-terminated; instead the
263  * - return 1 if matched, 0 if differ, -ve if error
272 		return -EIO;  in romfs_dev_strcmp()
274 		return -ENAMETOOLONG;  in romfs_dev_strcmp()
275 	if (size + 1 > limit - pos)  in romfs_dev_strcmp()
276 		return -EIO;  in romfs_dev_strcmp()
279 	if (sb->s_mtd)  in romfs_dev_strcmp()
283 	if (sb->s_bdev)  in romfs_dev_strcmp()
286 	return -EIO;  in romfs_dev_strcmp()