2874c5fd28426 (Thomas Gleixner 2019-05-27 08:55:01 +0200 1) // SPDX-License-Identifier: GPL-2.0-or-later
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 2) /* RomFS storage access routines
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 3) *
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 4) * Copyright © 2007 Red Hat, Inc. All Rights Reserved.
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 5) * Written by David Howells (dhowells@redhat.com)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 6) */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 7)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 8) #include <linux/fs.h>
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 9) #include <linux/mtd/super.h>
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 10) #include <linux/buffer_head.h>
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 11) #include "internal.h"
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 12)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 13) #if !defined(CONFIG_ROMFS_ON_MTD) && !defined(CONFIG_ROMFS_ON_BLOCK)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 14) #error no ROMFS backing store interface configured
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 15) #endif
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 16)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 17) #ifdef CONFIG_ROMFS_ON_MTD
c382fb43df342 (Artem Bityutskiy 2012-01-30 15:11:44 +0200 18) #define ROMFS_MTD_READ(sb, ...) mtd_read((sb)->s_mtd, ##__VA_ARGS__)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 19)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 20) /*
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 21) * read data from an romfs image on an MTD device
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 22) */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 23) static int romfs_mtd_read(struct super_block *sb, unsigned long pos,
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 24) void *buf, size_t buflen)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 25) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 26) size_t rlen;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 27) int ret;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 28)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 29) ret = ROMFS_MTD_READ(sb, pos, buflen, &rlen, buf);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 30) return (ret < 0 || rlen != buflen) ? -EIO : 0;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 31) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 32)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 33) /*
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 34) * determine the length of a string in a romfs image on an MTD device
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 35) */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 36) static ssize_t romfs_mtd_strnlen(struct super_block *sb,
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 37) unsigned long pos, size_t maxlen)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 38) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 39) ssize_t n = 0;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 40) size_t segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 41) u_char buf[16], *p;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 42) size_t len;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 43) int ret;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 44)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 45) /* scan the string up to 16 bytes at a time */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 46) while (maxlen > 0) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 47) segment = min_t(size_t, maxlen, 16);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 48) ret = ROMFS_MTD_READ(sb, pos, segment, &len, buf);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 49) if (ret < 0)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 50) return ret;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 51) p = memchr(buf, 0, len);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 52) if (p)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 53) return n + (p - buf);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 54) maxlen -= len;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 55) pos += len;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 56) n += len;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 57) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 58)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 59) return n;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 60) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 61)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 62) /*
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 63) * compare a string to one in a romfs image on MTD
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 64) * - return 1 if matched, 0 if differ, -ve if error
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 65) */
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 66) static int romfs_mtd_strcmp(struct super_block *sb, unsigned long pos,
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 67) const char *str, size_t size)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 68) {
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 69) u_char buf[17];
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 70) size_t len, segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 71) int ret;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 72)
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 73) /* scan the string up to 16 bytes at a time, and attempt to grab the
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 74) * trailing NUL whilst we're at it */
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 75) buf[0] = 0xff;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 76)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 77) while (size > 0) {
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 78) segment = min_t(size_t, size + 1, 17);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 79) ret = ROMFS_MTD_READ(sb, pos, segment, &len, buf);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 80) if (ret < 0)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 81) return ret;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 82) len--;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 83) if (memcmp(buf, str, len) != 0)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 84) return 0;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 85) buf[0] = buf[len];
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 86) size -= len;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 87) pos += len;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 88) str += len;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 89) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 90)
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 91) /* check the trailing NUL was */
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 92) if (buf[0])
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 93) return 0;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 94)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 95) return 1;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 96) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 97) #endif /* CONFIG_ROMFS_ON_MTD */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 98)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 99) #ifdef CONFIG_ROMFS_ON_BLOCK
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 100) /*
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 101) * read data from an romfs image on a block device
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 102) */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 103) static int romfs_blk_read(struct super_block *sb, unsigned long pos,
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 104) void *buf, size_t buflen)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 105) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 106) struct buffer_head *bh;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 107) unsigned long offset;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 108) size_t segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 109)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 110) /* copy the string up to blocksize bytes at a time */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 111) while (buflen > 0) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 112) offset = pos & (ROMBSIZE - 1);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 113) segment = min_t(size_t, buflen, ROMBSIZE - offset);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 114) bh = sb_bread(sb, pos >> ROMBSBITS);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 115) if (!bh)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 116) return -EIO;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 117) memcpy(buf, bh->b_data + offset, segment);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 118) brelse(bh);
4b2b0b9753194 (David Howells 2009-04-23 16:41:18 +0100 119) buf += segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 120) buflen -= segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 121) pos += segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 122) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 123)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 124) return 0;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 125) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 126)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 127) /*
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 128) * determine the length of a string in romfs on a block device
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 129) */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 130) static ssize_t romfs_blk_strnlen(struct super_block *sb,
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 131) unsigned long pos, size_t limit)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 132) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 133) struct buffer_head *bh;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 134) unsigned long offset;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 135) ssize_t n = 0;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 136) size_t segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 137) u_char *buf, *p;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 138)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 139) /* scan the string up to blocksize bytes at a time */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 140) while (limit > 0) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 141) offset = pos & (ROMBSIZE - 1);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 142) segment = min_t(size_t, limit, ROMBSIZE - offset);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 143) bh = sb_bread(sb, pos >> ROMBSBITS);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 144) if (!bh)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 145) return -EIO;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 146) buf = bh->b_data + offset;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 147) p = memchr(buf, 0, segment);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 148) brelse(bh);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 149) if (p)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 150) return n + (p - buf);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 151) limit -= segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 152) pos += segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 153) n += segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 154) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 155)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 156) return n;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 157) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 158)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 159) /*
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 160) * compare a string to one in a romfs image on a block device
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 161) * - return 1 if matched, 0 if differ, -ve if error
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 162) */
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 163) static int romfs_blk_strcmp(struct super_block *sb, unsigned long pos,
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 164) const char *str, size_t size)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 165) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 166) struct buffer_head *bh;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 167) unsigned long offset;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 168) size_t segment;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 169) bool matched, terminated = false;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 170)
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 171) /* compare string up to a block at a time */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 172) while (size > 0) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 173) offset = pos & (ROMBSIZE - 1);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 174) segment = min_t(size_t, size, ROMBSIZE - offset);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 175) bh = sb_bread(sb, pos >> ROMBSBITS);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 176) if (!bh)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 177) return -EIO;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 178) matched = (memcmp(bh->b_data + offset, str, segment) == 0);
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 179)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 180) size -= segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 181) pos += segment;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 182) str += segment;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 183) if (matched && size == 0 && offset + segment < ROMBSIZE) {
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 184) if (!bh->b_data[offset + segment])
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 185) terminated = true;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 186) else
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 187) matched = false;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 188) }
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 189) brelse(bh);
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 190) if (!matched)
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 191) return 0;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 192) }
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 193)
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 194) if (!terminated) {
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 195) /* the terminating NUL must be on the first byte of the next
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 196) * block */
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 197) BUG_ON((pos & (ROMBSIZE - 1)) != 0);
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 198) bh = sb_bread(sb, pos >> ROMBSBITS);
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 199) if (!bh)
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 200) return -EIO;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 201) matched = !bh->b_data[0];
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 202) brelse(bh);
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 203) if (!matched)
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 204) return 0;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 205) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 206)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 207) return 1;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 208) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 209) #endif /* CONFIG_ROMFS_ON_BLOCK */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 210)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 211) /*
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 212) * read data from the romfs image
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 213) */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 214) int romfs_dev_read(struct super_block *sb, unsigned long pos,
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 215) void *buf, size_t buflen)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 216) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 217) size_t limit;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 218)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 219) limit = romfs_maxsize(sb);
bcf85fcedfdd1 (Jann Horn 2020-08-20 17:42:11 -0700 220) if (pos >= limit || buflen > limit - pos)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 221) return -EIO;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 222)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 223) #ifdef CONFIG_ROMFS_ON_MTD
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 224) if (sb->s_mtd)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 225) return romfs_mtd_read(sb, pos, buf, buflen);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 226) #endif
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 227) #ifdef CONFIG_ROMFS_ON_BLOCK
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 228) if (sb->s_bdev)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 229) return romfs_blk_read(sb, pos, buf, buflen);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 230) #endif
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 231) return -EIO;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 232) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 233)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 234) /*
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 235) * determine the length of a string in romfs
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 236) */
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 237) ssize_t romfs_dev_strnlen(struct super_block *sb,
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 238) unsigned long pos, size_t maxlen)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 239) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 240) size_t limit;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 241)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 242) limit = romfs_maxsize(sb);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 243) if (pos >= limit)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 244) return -EIO;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 245) if (maxlen > limit - pos)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 246) maxlen = limit - pos;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 247)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 248) #ifdef CONFIG_ROMFS_ON_MTD
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 249) if (sb->s_mtd)
ef1f7a7e878e4 (Bernd Schmidt 2009-10-06 09:55:26 +0100 250) return romfs_mtd_strnlen(sb, pos, maxlen);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 251) #endif
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 252) #ifdef CONFIG_ROMFS_ON_BLOCK
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 253) if (sb->s_bdev)
ef1f7a7e878e4 (Bernd Schmidt 2009-10-06 09:55:26 +0100 254) return romfs_blk_strnlen(sb, pos, maxlen);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 255) #endif
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 256) return -EIO;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 257) }
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 258)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 259) /*
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 260) * compare a string to one in romfs
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 261) * - the string to be compared to, str, may not be NUL-terminated; instead the
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 262) * string is of the specified size
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 263) * - return 1 if matched, 0 if differ, -ve if error
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 264) */
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 265) int romfs_dev_strcmp(struct super_block *sb, unsigned long pos,
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 266) const char *str, size_t size)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 267) {
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 268) size_t limit;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 269)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 270) limit = romfs_maxsize(sb);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 271) if (pos >= limit)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 272) return -EIO;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 273) if (size > ROMFS_MAXFN)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 274) return -ENAMETOOLONG;
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 275) if (size + 1 > limit - pos)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 276) return -EIO;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 277)
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 278) #ifdef CONFIG_ROMFS_ON_MTD
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 279) if (sb->s_mtd)
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 280) return romfs_mtd_strcmp(sb, pos, str, size);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 281) #endif
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 282) #ifdef CONFIG_ROMFS_ON_BLOCK
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 283) if (sb->s_bdev)
84baf74bf23bb (David Howells 2009-04-23 16:41:13 +0100 284) return romfs_blk_strcmp(sb, pos, str, size);
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 285) #endif
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 286) return -EIO;
da4458bda237a (David Howells 2009-02-12 10:40:10 +0000 287) }
VisionFive2 Linux kernel
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