Hi Guifu, On Tue, Oct 15, 2019 at 11:11:43PM +0800, Li Guifu wrote: > Hi Pratik, Gao Xiang > > Can sbi.fearture merge into sbi.feature_incompat ? > If not, it will has two feature parameter
Nope, please refer to https://lore.kernel.org/r/20190822142142.gb2...@mit.edu/ > > It has the blocks field in the super block, chksum_blocks duplicates it. > and chksum may be used to check whole erofs image file. Nope, chksum_blocks is used for checksuming given blocks, blocks field is designed to be used for statfs. Thanks, Gao Xiang > > > Added code for calculating crc of erofs blocks (4K size).for now it > > calculates > > checksum of first block. but can modified to calculate crc for any no. of > > blocks > > > > 1) Added 'chksum_blocks' field to erofs_super_block > > 2) removed unnecessary prints > > 3) moved EROFS_FEATURE_SB_CHKSUM include/erofs_fs.h > > > > Signed-off-by: Pratik Shinde <pratikshinde...@gmail.com> > > --- > > include/erofs/internal.h | 1 + > > include/erofs/io.h | 8 ++++++ > > include/erofs_fs.h | 3 ++- > > lib/io.c | 27 +++++++++++++++++++ > > mkfs/main.c | 70 > > ++++++++++++++++++++++++++++++++++++++++++++++++ > > 5 files changed, 108 insertions(+), 1 deletion(-) > > > > diff --git a/include/erofs/internal.h b/include/erofs/internal.h > > index 5384946..53335bc 100644 > > --- a/include/erofs/internal.h > > +++ b/include/erofs/internal.h > > @@ -55,6 +55,7 @@ struct erofs_sb_info { > > u32 feature_incompat; > > u64 build_time; > > u32 build_time_nsec; > > + u32 feature; > > }; > > /* global sbi */ > > diff --git a/include/erofs/io.h b/include/erofs/io.h > > index 9775047..e0ca8d9 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 f29aa25..8bd29d6 100644 > > --- a/include/erofs_fs.h > > +++ b/include/erofs_fs.h > > @@ -19,6 +19,7 @@ > > */ > > #define EROFS_FEATURE_INCOMPAT_LZ4_0PADDING 0x00000001 > > #define EROFS_ALL_FEATURE_INCOMPAT > > EROFS_FEATURE_INCOMPAT_LZ4_0PADDING > > +#define EROFS_FEATURE_SB_CHKSUM 0x0001 > > /* 128-byte erofs on-disk super block */ > > struct erofs_super_block { > > @@ -39,7 +40,7 @@ struct erofs_super_block { > > __u8 uuid[16]; /* 128-bit uuid for volume */ > > __u8 volume_name[16]; /* volume name */ > > __le32 feature_incompat; > > - > > + __le32 chksum_blocks; /* number of blocks used for checksum */ > > __u8 reserved2[44]; > > }; > > diff --git a/lib/io.c b/lib/io.c > > index 7f5f94d..52f9424 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; > > + } > > + return 0; > > +} > > diff --git a/mkfs/main.c b/mkfs/main.c > > index 91a018f..0633e83 100644 > > --- a/mkfs/main.c > > +++ b/mkfs/main.c > > @@ -22,6 +22,9 @@ > > #define EROFS_SUPER_END (EROFS_SUPER_OFFSET + sizeof(struct > > erofs_super_block)) > > +/* number of blocks for calculating checksum */ > > +#define EROFS_CKSUM_BLOCKS 1 > > + > > static void usage(void) > > { > > fprintf(stderr, "usage: [options] FILE DIRECTORY\n\n"); > > @@ -85,6 +88,10 @@ static int parse_extended_opts(const char *opts) > > return -EINVAL; > > cfg.c_force_inodeversion = FORCE_INODE_EXTENDED; > > } > > + > > + if (MATCH_EXTENTED_OPT("nocrc", token, keylen)) { > > + sbi.feature &= ~EROFS_FEATURE_SB_CHKSUM; > > + } > > } > > return 0; > > } > > @@ -180,6 +187,8 @@ int erofs_mkfs_update_super_block(struct > > erofs_buffer_head *bh, > > .meta_blkaddr = sbi.meta_blkaddr, > > .xattr_blkaddr = 0, > > .feature_incompat = cpu_to_le32(sbi.feature_incompat), > > + .checksum = 0, > > + .chksum_blocks = cpu_to_le32(EROFS_CKSUM_BLOCKS) > > }; > > const unsigned int sb_blksize = > > round_up(EROFS_SUPER_END, EROFS_BLKSIZ); > > @@ -202,6 +211,64 @@ int erofs_mkfs_update_super_block(struct > > erofs_buffer_head *bh, > > return 0; > > } > > +#define CRCPOLY 0x82F63B78 > > +static inline u32 crc32c(u32 seed, unsigned char const *in, size_t len) > > +{ > > + int i; > > + u32 crc = seed; > > + > > + while (len--) { > > + crc ^= *in++; > > + for (i = 0; i < 8; i++) { > > + crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY : 0); > > + } > > + } > > + return crc; > > +} > > + > > +/* calculate checksum for first n blocks */ > > +u32 erofs_calc_blk_checksum(erofs_blk_t nblks, u32 *crc) > > +{ > > + char *buf; > > + int err = 0; > > + > > + buf = malloc(nblks * EROFS_BLKSIZ); > > + err = blk_read(buf, 0, nblks); > > + if (err) { > > + return err; > > + } > > + *crc = crc32c(0, (const unsigned char *)buf, nblks * EROFS_BLKSIZ); > > + free(buf); > > + return 0; > > +} > > + > > +void erofs_write_sb_checksum() > > +{ > > + struct erofs_super_block *sb; > > + char buf[EROFS_BLKSIZ]; > > + int ret = 0; > > + u32 crc; > > + > > + ret = erofs_calc_blk_checksum(EROFS_CKSUM_BLOCKS, &crc); > > + if (ret) { > > + return; > > + } > > + ret = blk_read(buf, 0, 1); > > + if (ret) { > > + return; > > + } > > + > > + sb = (struct erofs_super_block *)((u8 *)buf + EROFS_SUPER_OFFSET); > > + if (le32_to_cpu(sb->magic) != EROFS_SUPER_MAGIC_V1) { > > + return; > > + } > > + sb->checksum = cpu_to_le32(crc); > > + ret = blk_write(buf, 0, 1); > > + if (ret) { > > + return; > > + } > > +} > > + > > int main(int argc, char **argv) > > { > > int err = 0; > > @@ -217,6 +284,7 @@ int main(int argc, char **argv) > > cfg.c_legacy_compress = false; > > sbi.feature_incompat = EROFS_FEATURE_INCOMPAT_LZ4_0PADDING; > > + sbi.feature = EROFS_FEATURE_SB_CHKSUM; > > err = mkfs_parse_options_cfg(argc, argv); > > if (err) { > > @@ -301,6 +369,8 @@ int main(int argc, char **argv) > > err = -EIO; > > else > > err = dev_resize(nblocks); > > + if (sbi.feature & EROFS_FEATURE_SB_CHKSUM) > > + erofs_write_sb_checksum(); > > exit: > > z_erofs_compress_exit(); > > dev_close(); > >
