From 6b7092fd084070daeef5aeb60b608a633d56f252 Mon Sep 17 00:00:00 2001 From: Rob Landley Date: Tue, 23 Jan 2007 19:54:01 -0500 Subject: More work on mke2fs. --- toys.h | 1 + toys/e2fs.h | 78 ++++++++++++++++++++++++++++++---------------------------- toys/mke2fs.c | 73 +++++++++++++++++++++++++++++++++++++++++------------- toys/toylist.h | 1 + 4 files changed, 98 insertions(+), 55 deletions(-) diff --git a/toys.h b/toys.h index ebd858e8..fea991b1 100644 --- a/toys.h +++ b/toys.h @@ -26,6 +26,7 @@ #include #include #include +#include #include #include "lib/lib.h" diff --git a/toys/e2fs.h b/toys/e2fs.h index fa3dd0d4..b50a8817 100644 --- a/toys/e2fs.h +++ b/toys/e2fs.h @@ -9,33 +9,7 @@ #define EXT2_SUPER_MAGIC 0xEF53 -struct ext2_inode { - uint16_t mode; // File mode - uint16_t uid; // Low 16 bits of Owner Uid - uint32_t size; // Size in bytes - uint32_t atime; // Access time - uint32_t ctime; // Creation time - uint32_t mtime; // Modification time - uint32_t dtime; // Deletion Time - uint16_t gid; // Low 16 bits of Group Id - uint16_t links_count; // Links count - uint32_t blocks; // Blocks count - uint32_t flags; // File flags - uint32_t reserved1; - uint32_t block[15]; // Pointers to blocks - uint32_t generation; // File version (for NFS) - uint32_t file_acl; // File ACL - uint32_t dir_acl; // Directory ACL - uint32_t faddr; // Fragment address - uint8_t frag; // Fragment number - uint8_t fsize; // Fragment size - uint16_t pad1; - uint16_t uid_high; // High bits of uid - uint16_t gid_high; // High bits of gid - uint32_t reserved2; -}; - -struct ext2_super_block { +struct ext2_superblock { uint32_t inodes_count; // Inodes count uint32_t blocks_count; // Blocks count uint32_t r_blocks_count; // Reserved blocks count @@ -44,9 +18,9 @@ struct ext2_super_block { uint32_t first_data_block; // First Data Block uint32_t log_block_size; // Block size uint32_t log_frag_size; // Fragment size - uint32_t blocks_per_group; // # Blocks per group - uint32_t frags_per_group; // # Fragments per group - uint32_t inodes_per_group; // # Inodes per group + uint32_t blocks_per_group; // Blocks per group + uint32_t frags_per_group; // Fragments per group + uint32_t inodes_per_group; // Inodes per group uint32_t mtime; // Mount time uint32_t wtime; // Write time uint16_t mnt_count; // Mount count @@ -90,6 +64,42 @@ struct ext2_super_block { uint32_t reserved[172]; // Padding to the end of the block }; +struct ext2_dentry { + uint32_t inode; // Inode number + uint16_t rec_len; // Directory entry length + uint8_t name_len; // Name length + uint8_t file_type; + char name[255]; // File name +}; + +struct ext2_inode { + uint16_t mode; // File mode + uint16_t uid; // Low 16 bits of Owner Uid + uint32_t size; // Size in bytes + uint32_t atime; // Access time + uint32_t ctime; // Creation time + uint32_t mtime; // Modification time + uint32_t dtime; // Deletion Time + uint16_t gid; // Low 16 bits of Group Id + uint16_t links_count; // Links count + uint32_t blocks; // Blocks count + uint32_t flags; // File flags + uint32_t reserved1; + uint32_t block[15]; // Pointers to blocks + uint32_t generation; // File version (for NFS) + uint32_t file_acl; // File ACL + uint32_t dir_acl; // Directory ACL + uint32_t faddr; // Fragment address + uint8_t frag; // Fragment number + uint8_t fsize; // Fragment size + uint16_t pad1; + uint16_t uid_high; // High bits of uid + uint16_t gid_high; // High bits of gid + uint32_t reserved2; +}; + + + #define EXT2_FEATURE_COMPAT_DIR_PREALLOC 0x0001 #define EXT2_FEATURE_COMPAT_IMAGIC_INODES 0x0002 #define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x0004 @@ -109,14 +119,6 @@ struct ext2_super_block { #define EXT2_NAME_LEN 255 -struct ext2_dentry { - uint32_t inode; // Inode number - uint16_t rec_len; // Directory entry length - uint8_t name_len; // Name length - uint8_t file_type; - char name[255]; // File name -}; - // Ext2 directory file types. Only the low 3 bits are used. The // other bits are reserved for now. diff --git a/toys/mke2fs.c b/toys/mke2fs.c index 8266cec4..464b8b50 100644 --- a/toys/mke2fs.c +++ b/toys/mke2fs.c @@ -7,6 +7,8 @@ #include "toys.h" +#define TT toy.mke2fs + // b - block size (1024, 2048, 4096) // F - force (run on mounted device or non-block device) // i - bytes per inode @@ -54,39 +56,76 @@ void create_uuid(char *uuid) int mke2fs_main(void) { - struct ext2_super_block *sb = xzalloc(sizeof(struct ext2_super_block)); - int temp; + struct ext2_superblock *sb = xzalloc(sizeof(struct ext2_superblock)); + uint32_t temp; off_t length; // Handle command line arguments. if (toys.optargs[1]) { - sscanf(toys.optargs[1], "%u", &(sb->inodes_count)); + sscanf(toys.optargs[1], "%u", &TT.blocks); temp = O_RDWR|O_CREAT; } else temp = O_RDWR; - // Check if filesystem is mounted + // TODO: Check if filesystem is mounted here // For mke?fs, open file. For gene?fs, create file. - length = fdlength(toy.mke2fs.fsfd = xcreate(*toys.optargs, temp, 0777)); + length = fdlength(TT.fsfd = xcreate(*toys.optargs, temp, 0777)); + + // TODO: collect gene2fs list, calculate requirements. - if (toy.mke2fs.blocksize && toy.mke2fs.blocksize!=1024 - && toy.mke2fs.blocksize!=2048 && toy.mke2fs.blocksize!=4096) - error_exit("bad blocksize"); + // Fill out superblock structure - // Determine block size. If unspecified, use simple heuristic. - if (toy.mke2fs.blocksize) - sb->log_block_size = (length && length < 1<<24) ? 1024 : 4096; - else sb->log_block_size = toy.mke2fs.blocksize; + // Determine appropriate block size, set log_block_size and log_frag_size. - if (!sb->inodes_count) sb->inodes_count = length/toy.mke2fs.blocksize; + if (!TT.blocksize) TT.blocksize = (length && length < 1<<29) ? 1024 : 4096; + if (TT.blocksize == 1024) temp = 0; + else if (TT.blocksize == 2048) temp = 1; + else if (TT.blocksize == 4096) temp = 2; + else error_exit("bad blocksize"); + sb->log_block_size = sb->log_frag_size = SWAP_LE32(temp); - // Fill out superblock structure + // Fill out blocks_count, inodes_count, r_blocks_count + + if (!TT.blocks) TT.blocks = length/TT.blocksize; + sb->blocks_count = SWAP_LE32(TT.blocks); + + if (!TT.inodes) { + if (!TT.bytes_per_inode) TT.bytes_per_inode = 8192; + TT.inodes = (TT.blocks * (uint64_t)TT.blocksize) / TT.bytes_per_inode; + } + sb->inodes_count = SWAP_LE32(TT.inodes); + + if (!TT.reserved_percent) TT.reserved_percent = 5; + temp = (TT.blocks * (uint64_t)TT.reserved_percent) /100; + sb->r_blocks_count = SWAP_LE32(temp); + + // Set blocks_per_group and frags_per_group, which is the size of an + // allocation bitmap that fits in one block (I.E. how many bits per block)? + + temp = TT.blocksize*8; + sb->blocks_per_group = sb->frags_per_group = SWAP_LE32(temp); + + // Set inodes_per_group + + TT.groups = (TT.blocks)/temp; + if (TT.blocks & (temp-1)) TT.groups++; // Round up without int overflow. + temp = TT.inodes/TT.groups; + if (TT.blocks & (TT.groups-1)) TT.blocks++; + sb->inodes_per_group = SWAP_LE32(temp); + + sb->max_mnt_count=0xFFFF; + sb->wtime = sb->lastcheck = sb->mkfs_time = SWAP_LE32(time(NULL)); + sb->magic = SWAP_LE32(0xEF53); + sb->state = sb->errors = SWAP_LE16(1); sb->rev_level = SWAP_LE32(1); + sb->inode_size = sizeof(struct ext2_inode); sb->feature_incompat = SWAP_LE32(EXT2_FEATURE_INCOMPAT_FILETYPE); sb->feature_ro_compat = SWAP_LE32(EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER); + create_uuid(sb->uuid); + // If we're called as mke3fs or mkfs.ext3, do a journal. //if (strchr(toys.which->name,'3')) @@ -94,11 +133,11 @@ int mke2fs_main(void) // We skip the first 1k (to avoid the boot sector, if any). Use this to // figure out if this file is seekable. - if(-1 == lseek(toy.mke2fs.fsfd, 1024, SEEK_SET)) perror_exit("lseek"); - //{ toy.mke2fs.noseek=1; xwrite(toy.mke2fs.fsfd, sb, 1024); } + if(-1 == lseek(TT.fsfd, 1024, SEEK_SET)) perror_exit("lseek"); + //{ TT.noseek=1; xwrite(TT.fsfd, sb, 1024); } // Write superblock to disk. - xwrite(toy.mke2fs.fsfd, sb, 3072); // 4096-1024 + xwrite(TT.fsfd, sb, sizeof(struct ext2_superblock)); // 4096-1024 return 0; } diff --git a/toys/toylist.h b/toys/toylist.h index 126c1700..76787f21 100644 --- a/toys/toylist.h +++ b/toys/toylist.h @@ -32,6 +32,7 @@ struct mke2fs_data { long inodes; long reserved_percent; + unsigned blocks, groups; int fsfd, noseek; }; -- cgit v1.2.3