diff options
Diffstat (limited to 'mkfs/main.c')
| -rw-r--r-- | mkfs/main.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/mkfs/main.c b/mkfs/main.c index ab57896..9187c43 100644 --- a/mkfs/main.c +++ b/mkfs/main.c @@ -109,6 +109,12 @@ static int parse_extended_opts(const char *opts) return -EINVAL; cfg.c_force_inodeversion = FORCE_INODE_EXTENDED; } + + if (MATCH_EXTENTED_OPT("nosbcrc", token, keylen)) { + if (vallen) + return -EINVAL; + sbi.feature_compat &= ~EROFS_FEATURE_COMPAT_SB_CHKSUM; + } } return 0; } @@ -218,6 +224,8 @@ int erofs_mkfs_update_super_block(struct erofs_buffer_head *bh, .meta_blkaddr = sbi.meta_blkaddr, .xattr_blkaddr = sbi.xattr_blkaddr, .feature_incompat = cpu_to_le32(sbi.feature_incompat), + .feature_compat = cpu_to_le32(sbi.feature_compat & + ~EROFS_FEATURE_COMPAT_SB_CHKSUM), }; const unsigned int sb_blksize = round_up(EROFS_SUPER_END, EROFS_BLKSIZ); @@ -240,6 +248,63 @@ int erofs_mkfs_update_super_block(struct erofs_buffer_head *bh, return 0; } +#define CRC32C_POLY_LE 0x82F63B78 +static inline u32 crc32c(u32 crc, const u8 *in, size_t len) +{ + int i; + + while (len--) { + crc ^= *in++; + for (i = 0; i < 8; i++) + crc = (crc >> 1) ^ ((crc & 1) ? CRC32C_POLY_LE : 0); + } + return crc; +} + +static int erofs_mkfs_superblock_csum_set(void) +{ + int ret; + u8 buf[EROFS_BLKSIZ]; + u32 crc; + struct erofs_super_block *sb; + + ret = blk_read(buf, 0, 1); + if (ret) { + erofs_err("failed to read superblock to set checksum: %s", + erofs_strerror(ret)); + return ret; + } + + /* + * skip the first 1024 bytes, to allow for the installation + * of x86 boot sectors and other oddities. + */ + sb = (struct erofs_super_block *)(buf + EROFS_SUPER_OFFSET); + + if (le32_to_cpu(sb->magic) != EROFS_SUPER_MAGIC_V1) { + erofs_err("internal error: not an erofs valid image"); + return -EFAULT; + } + + /* turn on checksum feature */ + sb->feature_compat = cpu_to_le32(le32_to_cpu(sb->feature_compat) | + EROFS_FEATURE_COMPAT_SB_CHKSUM); + crc = crc32c(~0, (u8 *)sb, EROFS_BLKSIZ - EROFS_SUPER_OFFSET); + + /* set up checksum field to erofs_super_block */ + sb->checksum = cpu_to_le32(crc); + + ret = blk_write(buf, 0, 1); + if (ret) { + erofs_err("failed to write checksummed superblock: %s", + erofs_strerror(ret)); + return ret; + } + + erofs_info("superblock checksum 0x%08x written", crc); + return 0; +} + int main(int argc, char **argv) { int err = 0; @@ -255,6 +320,7 @@ int main(int argc, char **argv) cfg.c_legacy_compress = false; sbi.feature_incompat = EROFS_FEATURE_INCOMPAT_LZ4_0PADDING; + sbi.feature_compat = EROFS_FEATURE_COMPAT_SB_CHKSUM; err = mkfs_parse_options_cfg(argc, argv); if (err) { @@ -337,6 +403,9 @@ int main(int argc, char **argv) err = -EIO; else err = dev_resize(nblocks); + + if (!err && (sbi.feature_compat & EROFS_FEATURE_COMPAT_SB_CHKSUM)) + err = erofs_mkfs_superblock_csum_set(); exit: z_erofs_compress_exit(); dev_close(); |