Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /* RomFS storage access routines
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright © 2007 Red Hat, Inc. All Rights Reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Written by David Howells (dhowells@redhat.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/mtd/super.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/buffer_head.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include "internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #if !defined(CONFIG_ROMFS_ON_MTD) && !defined(CONFIG_ROMFS_ON_BLOCK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #error no ROMFS backing store interface configured
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #ifdef CONFIG_ROMFS_ON_MTD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #define ROMFS_MTD_READ(sb, ...) mtd_read((sb)->s_mtd, ##__VA_ARGS__)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)  * read data from an romfs image on an MTD device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) static int romfs_mtd_read(struct super_block *sb, unsigned long pos,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) 			  void *buf, size_t buflen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) 	size_t rlen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 	ret = ROMFS_MTD_READ(sb, pos, buflen, &rlen, buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 	return (ret < 0 || rlen != buflen) ? -EIO : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34)  * determine the length of a string in a romfs image on an MTD device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) static ssize_t romfs_mtd_strnlen(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 				 unsigned long pos, size_t maxlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	ssize_t n = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	size_t segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	u_char buf[16], *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	size_t len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	/* scan the string up to 16 bytes at a time */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	while (maxlen > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 		segment = min_t(size_t, maxlen, 16);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 		ret = ROMFS_MTD_READ(sb, pos, segment, &len, buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 		if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 			return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 		p = memchr(buf, 0, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		if (p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 			return n + (p - buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 		maxlen -= len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 		pos += len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 		n += len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	return n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63)  * compare a string to one in a romfs image on MTD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64)  * - return 1 if matched, 0 if differ, -ve if error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) static int romfs_mtd_strcmp(struct super_block *sb, unsigned long pos,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 			    const char *str, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	u_char buf[17];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	size_t len, segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	/* scan the string up to 16 bytes at a time, and attempt to grab the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	 * trailing NUL whilst we're at it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	buf[0] = 0xff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	while (size > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		segment = min_t(size_t, size + 1, 17);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 		ret = ROMFS_MTD_READ(sb, pos, segment, &len, buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 		if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 			return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		len--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 		if (memcmp(buf, str, len) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 			return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 		buf[0] = buf[len];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 		size -= len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 		pos += len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		str += len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	/* check the trailing NUL was */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	if (buf[0])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) #endif /* CONFIG_ROMFS_ON_MTD */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) #ifdef CONFIG_ROMFS_ON_BLOCK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)  * read data from an romfs image on a block device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) static int romfs_blk_read(struct super_block *sb, unsigned long pos,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 			  void *buf, size_t buflen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	struct buffer_head *bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	unsigned long offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	size_t segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	/* copy the string up to blocksize bytes at a time */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	while (buflen > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 		offset = pos & (ROMBSIZE - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 		segment = min_t(size_t, buflen, ROMBSIZE - offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 		bh = sb_bread(sb, pos >> ROMBSBITS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 		if (!bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 			return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 		memcpy(buf, bh->b_data + offset, segment);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 		brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 		buf += segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 		buflen -= segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 		pos += segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)  * determine the length of a string in romfs on a block device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) static ssize_t romfs_blk_strnlen(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 				 unsigned long pos, size_t limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	struct buffer_head *bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	unsigned long offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	ssize_t n = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	size_t segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	u_char *buf, *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	/* scan the string up to blocksize bytes at a time */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	while (limit > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 		offset = pos & (ROMBSIZE - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 		segment = min_t(size_t, limit, ROMBSIZE - offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 		bh = sb_bread(sb, pos >> ROMBSBITS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		if (!bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 			return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 		buf = bh->b_data + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		p = memchr(buf, 0, segment);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 		brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 		if (p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 			return n + (p - buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 		limit -= segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 		pos += segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 		n += segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	return n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160)  * compare a string to one in a romfs image on a block device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)  * - return 1 if matched, 0 if differ, -ve if error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) static int romfs_blk_strcmp(struct super_block *sb, unsigned long pos,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 			    const char *str, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	struct buffer_head *bh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	unsigned long offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	size_t segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	bool matched, terminated = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	/* compare string up to a block at a time */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	while (size > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		offset = pos & (ROMBSIZE - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 		segment = min_t(size_t, size, ROMBSIZE - offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 		bh = sb_bread(sb, pos >> ROMBSBITS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 		if (!bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 			return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 		matched = (memcmp(bh->b_data + offset, str, segment) == 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 		size -= segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		pos += segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 		str += segment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		if (matched && size == 0 && offset + segment < ROMBSIZE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 			if (!bh->b_data[offset + segment])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 				terminated = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 			else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 				matched = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 		brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		if (!matched)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 			return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	if (!terminated) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		/* the terminating NUL must be on the first byte of the next
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 		 * block */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		BUG_ON((pos & (ROMBSIZE - 1)) != 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 		bh = sb_bread(sb, pos >> ROMBSBITS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 		if (!bh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 			return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 		matched = !bh->b_data[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 		brelse(bh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 		if (!matched)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 			return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) #endif /* CONFIG_ROMFS_ON_BLOCK */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)  * read data from the romfs image
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) int romfs_dev_read(struct super_block *sb, unsigned long pos,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 		   void *buf, size_t buflen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	size_t limit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	limit = romfs_maxsize(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	if (pos >= limit || buflen > limit - pos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) #ifdef CONFIG_ROMFS_ON_MTD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 	if (sb->s_mtd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		return romfs_mtd_read(sb, pos, buf, buflen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) #ifdef CONFIG_ROMFS_ON_BLOCK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	if (sb->s_bdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 		return romfs_blk_read(sb, pos, buf, buflen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)  * determine the length of a string in romfs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) ssize_t romfs_dev_strnlen(struct super_block *sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 			  unsigned long pos, size_t maxlen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	size_t limit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	limit = romfs_maxsize(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	if (pos >= limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	if (maxlen > limit - pos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 		maxlen = limit - pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) #ifdef CONFIG_ROMFS_ON_MTD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	if (sb->s_mtd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 		return romfs_mtd_strnlen(sb, pos, maxlen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) #ifdef CONFIG_ROMFS_ON_BLOCK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	if (sb->s_bdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 		return romfs_blk_strnlen(sb, pos, maxlen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)  * compare a string to one in romfs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)  * - the string to be compared to, str, may not be NUL-terminated; instead the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262)  *   string is of the specified size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263)  * - return 1 if matched, 0 if differ, -ve if error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) int romfs_dev_strcmp(struct super_block *sb, unsigned long pos,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 		     const char *str, size_t size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	size_t limit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	limit = romfs_maxsize(sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	if (pos >= limit)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 	if (size > ROMFS_MAXFN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 		return -ENAMETOOLONG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 	if (size + 1 > limit - pos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 		return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) #ifdef CONFIG_ROMFS_ON_MTD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	if (sb->s_mtd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 		return romfs_mtd_strcmp(sb, pos, str, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) #ifdef CONFIG_ROMFS_ON_BLOCK
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 	if (sb->s_bdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 		return romfs_blk_strcmp(sb, pos, str, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) }