Hi Chao, On Wed, Oct 30, 2019 at 10:39:18AM +0800, Chao Yu wrote: > On 2019/10/28 22:23, Gao Xiang wrote: > > From: Pratik Shinde <[email protected]> > > > > Added code for calculating crc of erofs blocks (4K size). > > For now it calculates checksum of first block. but it can > > be modified to calculate crc for any no. of blocks. > > > > Note that the first 1024 bytes are not checksumed to allow > > for the installation of x86 boot sectors and other oddities. > > > > Fill 'feature_compat' field of erofs_super_block so that it > > can be used on kernel side. also fixing one typo. > > > > Signed-off-by: Pratik Shinde <[email protected]> > > Signed-off-by: Gao Xiang <[email protected]> > > --- > > > > changes since v7: > > - get rid of `chksum_blocks' pointed out by Chao. > > > > > > include/erofs/internal.h | 1 + > > include/erofs/io.h | 8 +++++ > > include/erofs_fs.h | 3 +- > > lib/io.c | 27 ++++++++++++++++ > > mkfs/main.c | 68 ++++++++++++++++++++++++++++++++++++++++ > > 5 files changed, 106 insertions(+), 1 deletion(-) > > > > diff --git a/include/erofs/internal.h b/include/erofs/internal.h > > index 25ce7b54442d..9e2bb9ce33b6 100644 > > --- a/include/erofs/internal.h > > +++ b/include/erofs/internal.h > > @@ -52,6 +52,7 @@ struct erofs_sb_info { > > erofs_blk_t meta_blkaddr; > > erofs_blk_t xattr_blkaddr; > > > > + u32 feature_compat; > > u32 feature_incompat; > > u64 build_time; > > u32 build_time_nsec; > > diff --git a/include/erofs/io.h b/include/erofs/io.h > > index 97750478b5ab..e0ca8d949130 100644 > > --- a/include/erofs/io.h > > +++ b/include/erofs/io.h > > @@ -19,6 +19,7 @@ > > int dev_open(const char *devname); > > void dev_close(void); > > int dev_write(const void *buf, u64 offset, size_t len); > > +int dev_read(void *buf, u64 offset, size_t len); > > int dev_fillzero(u64 offset, size_t len, bool padding); > > int dev_fsync(void); > > int dev_resize(erofs_blk_t nblocks); > > @@ -31,5 +32,12 @@ static inline int blk_write(const void *buf, erofs_blk_t > > blkaddr, > > blknr_to_addr(nblocks)); > > } > > > > +static inline int blk_read(void *buf, erofs_blk_t start, > > + u32 nblocks) > > +{ > > + return dev_read(buf, blknr_to_addr(start), > > + blknr_to_addr(nblocks)); > > +} > > + > > #endif > > > > diff --git a/include/erofs_fs.h b/include/erofs_fs.h > > index f29aa2516a99..bcc4f0c630ad 100644 > > --- a/include/erofs_fs.h > > +++ b/include/erofs_fs.h > > @@ -13,6 +13,8 @@ > > #define EROFS_SUPER_MAGIC_V1 0xE0F5E1E2 > > #define EROFS_SUPER_OFFSET 1024 > > > > +#define EROFS_FEATURE_COMPAT_SB_CHKSUM 0x00000001 > > + > > /* > > * Any bits that aren't in EROFS_ALL_FEATURE_INCOMPAT should > > * be incompatible with this kernel version. > > @@ -39,7 +41,6 @@ struct erofs_super_block { > > __u8 uuid[16]; /* 128-bit uuid for volume */ > > __u8 volume_name[16]; /* volume name */ > > __le32 feature_incompat; > > - > > __u8 reserved2[44]; > > }; > > > > diff --git a/lib/io.c b/lib/io.c > > index 7f5f94dd6b1e..52f9424d201b 100644 > > --- a/lib/io.c > > +++ b/lib/io.c > > @@ -207,3 +207,30 @@ int dev_resize(unsigned int blocks) > > return dev_fillzero(st.st_size, length, true); > > } > > > > +int dev_read(void *buf, u64 offset, size_t len) > > +{ > > + int ret; > > + > > + if (cfg.c_dry_run) > > + return 0; > > + > > + if (!buf) { > > + erofs_err("buf is NULL"); > > + return -EINVAL; > > + } > > + if (offset >= erofs_devsz || len > erofs_devsz || > > + offset > erofs_devsz - len) { > > + erofs_err("read posion[%" PRIu64 ", %zd] is too large beyond" > > + "the end of device(%" PRIu64 ").", > > + offset, len, erofs_devsz); > > + return -EINVAL; > > + } > > + > > + ret = pread64(erofs_devfd, buf, len, (off64_t)offset); > > + if (ret != (int)len) { > > + erofs_err("Failed to read data from device - %s:[%" PRIu64 ", > > %zd].", > > + erofs_devname, offset, len); > > + return -errno; > > Minor thing, I notice caller wrap this errno to EIO, so we'd better print > errno > here or by caller? Other part looks good to me anyway.
Oops, I didn't notice that... that's a good point, let me resend with fix later... > > Reviewed-by: Chao Yu <[email protected]> Thanks for taking time on utils as well :-) Thanks, Gao Xiang > > Thanks, > > > + } > > + return 0; > > +} > > diff --git a/mkfs/main.c b/mkfs/main.c > > index ab57896e9ca8..eeb6ccc55b82 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 +248,62 @@ 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_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 fill checksum"); > > + return -EIO; > > + } > > + > > + /* > > + * 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 checksumed 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 +319,7 @@ 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 +402,9 @@ 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_superblock_csum_set(); > > exit: > > z_erofs_compress_exit(); > > dev_close(); > >
