diff options
| -rw-r--r-- | util-linux/mkfs_ext2.c | 58 |
1 files changed, 39 insertions, 19 deletions
diff --git a/util-linux/mkfs_ext2.c b/util-linux/mkfs_ext2.c index de4c8b6c6..5cd923811 100644 --- a/util-linux/mkfs_ext2.c +++ b/util-linux/mkfs_ext2.c @@ -120,16 +120,45 @@ static uint32_t has_super(uint32_t x) } } -/* Standard mke2fs 1.41.9: - * Usage: mke2fs [-c|-l filename] [-b block-size] [-f fragment-size] - * [-i bytes-per-inode] [-I inode-size] [-J journal-options] - * [-G meta group size] [-N number-of-inodes] - * [-m reserved-blocks-percentage] [-o creator-os] - * [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory] - * [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]] - * [-T fs-type] [-U UUID] [-jnqvFSV] device [blocks-count] -*/ -// N.B. not commented below options are taken and silently ignored +#define fd 3 /* predefined output descriptor */ + +static void PUT(uint64_t off, void *buf, uint32_t size) +{ +// bb_info_msg("PUT[%llu]:[%u]", off, size); + xlseek(fd, off, SEEK_SET); + xwrite(fd, buf, size); +} + +// 128 and 256-byte inodes: +// 128-byte inode is described by struct ext2_inode. +// 256-byte one just has these fields appended: +// __u16 i_extra_isize; +// __u16 i_pad1; +// __u32 i_ctime_extra; /* extra Change time (nsec << 2 | epoch) */ +// __u32 i_mtime_extra; /* extra Modification time (nsec << 2 | epoch) */ +// __u32 i_atime_extra; /* extra Access time (nsec << 2 | epoch) */ +// __u32 i_crtime; /* File creation time */ +// __u32 i_crtime_extra; /* extra File creation time (nsec << 2 | epoch)*/ +// __u32 i_version_hi; /* high 32 bits for 64-bit version */ +// the rest is padding. +// +// linux/ext2_fs.h has "#define i_size_high i_dir_acl" which suggests that even +// 128-byte inode is capable of describing large files (i_dir_acl is meaningful +// only for directories, which never need i_size_high). +// +// Standard mke2fs creates a filesystem with 256-byte inodes if it is +// bigger than 0.5GB. So far, we do not do this. + +// Standard mke2fs 1.41.9: +// Usage: mke2fs [-c|-l filename] [-b block-size] [-f fragment-size] +// [-i bytes-per-inode] [-I inode-size] [-J journal-options] +// [-G meta group size] [-N number-of-inodes] +// [-m reserved-blocks-percentage] [-o creator-os] +// [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory] +// [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]] +// [-T fs-type] [-U UUID] [-jnqvFSV] device [blocks-count] +// +// Options not commented below are taken but silently ignored: enum { OPT_c = 1 << 0, OPT_l = 1 << 1, @@ -159,15 +188,6 @@ enum { //OPT_V = 1 << 25, // -V version. bbox applets don't support that }; -#define fd 3 /* predefined output descriptor */ - -static void PUT(uint64_t off, void *buf, uint32_t size) -{ -// bb_info_msg("PUT[%llu]:[%u]", off, size); - xlseek(fd, off, SEEK_SET); - xwrite(fd, buf, size); -} - int mkfs_ext2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int mkfs_ext2_main(int argc UNUSED_PARAM, char **argv) { |