| /* |
| * initialize.c --- initialize a filesystem handle given superblock |
| * parameters. Used by mke2fs when initializing a filesystem. |
| * |
| * Copyright (C) 1994, 1995, 1996 Theodore Ts'o. |
| * |
| * %Begin-Header% |
| * This file may be redistributed under the terms of the GNU Public |
| * License. |
| * %End-Header% |
| */ |
| |
| #include <stdio.h> |
| #include <string.h> |
| #if HAVE_UNISTD_H |
| #include <unistd.h> |
| #endif |
| #include <stdlib.h> |
| #include <fcntl.h> |
| #include <time.h> |
| #if HAVE_SYS_STAT_H |
| #include <sys/stat.h> |
| #endif |
| #if HAVE_SYS_TYPES_H |
| #include <sys/types.h> |
| #endif |
| #if HAVE_ERRNO_H |
| #include <errno.h> |
| #endif |
| |
| #include <linux/ext2_fs.h> |
| |
| #include "ext2fs.h" |
| |
| #if defined(__linux__) && defined(EXT2_OS_LINUX) |
| #define CREATOR_OS EXT2_OS_LINUX |
| #elif defined(__gnu__) && defined(EXT2_OS_HURD) |
| #define CREATOR_OS EXT2_OS_HURD |
| #elif defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) |
| #define CREATOR_OS EXT2_OS_FREEBSD |
| #elif defined(LITES) && defined(EXT2_OS_LITES) |
| #define CREATOR_OS EXT2_OS_LITES |
| #else |
| #define CREATOR_OS EXT2_OS_LINUX /* by default */ |
| #endif |
| |
| /* |
| * Note we override the kernel include file's idea of what the default |
| * check interval (never) should be. It's a good idea to check at |
| * least *occasionally*, specially since servers will never rarely get |
| * to reboot, since Linux is so robust these days. :-) |
| * |
| * 180 days (six months) seems like a good value. |
| */ |
| #ifdef EXT2_DFL_CHECKINTERVAL |
| #undef EXT2_DFL_CHECKINTERVAL |
| #endif |
| #define EXT2_DFL_CHECKINTERVAL (86400L * 180L) |
| |
| errcode_t ext2fs_initialize(const char *name, int flags, |
| struct ext2_super_block *param, |
| io_manager manager, ext2_filsys *ret_fs) |
| { |
| ext2_filsys fs; |
| errcode_t retval; |
| struct ext2_super_block *super; |
| int frags_per_block; |
| int rem; |
| int overhead = 0; |
| blk_t group_block; |
| int i, j; |
| blk_t numblocks; |
| char *buf; |
| |
| if (!param || !param->s_blocks_count) |
| return EINVAL; |
| |
| fs = (ext2_filsys) malloc(sizeof(struct struct_ext2_filsys)); |
| if (!fs) |
| return ENOMEM; |
| |
| memset(fs, 0, sizeof(struct struct_ext2_filsys)); |
| fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS; |
| fs->flags = flags | EXT2_FLAG_RW | ext2fs_native_flag(); |
| retval = manager->open(name, IO_FLAG_RW, &fs->io); |
| if (retval) |
| goto cleanup; |
| fs->io->app_data = fs; |
| fs->device_name = malloc(strlen(name)+1); |
| if (!fs->device_name) { |
| retval = ENOMEM; |
| goto cleanup; |
| } |
| strcpy(fs->device_name, name); |
| fs->super = super = malloc(SUPERBLOCK_SIZE); |
| if (!super) { |
| retval = ENOMEM; |
| goto cleanup; |
| } |
| memset(super, 0, SUPERBLOCK_SIZE); |
| |
| #define set_field(field, default) (super->field = param->field ? \ |
| param->field : (default)) |
| |
| super->s_magic = EXT2_SUPER_MAGIC; |
| super->s_state = EXT2_VALID_FS; |
| |
| set_field(s_log_block_size, 0); /* default blocksize: 1024 bytes */ |
| set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */ |
| set_field(s_first_data_block, super->s_log_block_size ? 0 : 1); |
| set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT); |
| set_field(s_errors, EXT2_ERRORS_DEFAULT); |
| #ifdef EXT2_DYNAMIC_REV |
| set_field(s_feature_compat, 0); |
| set_field(s_feature_incompat, 0); |
| set_field(s_feature_ro_compat, 0); |
| if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) |
| return EXT2_ET_UNSUPP_FEATURE; |
| if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) |
| return EXT2_ET_RO_UNSUPP_FEATURE; |
| |
| set_field(s_rev_level, EXT2_GOOD_OLD_REV); |
| if (super->s_rev_level >= EXT2_DYNAMIC_REV) { |
| set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO); |
| set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE); |
| } |
| #endif |
| |
| set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL); |
| super->s_lastcheck = time(NULL); |
| |
| super->s_creator_os = CREATOR_OS; |
| |
| fs->blocksize = EXT2_BLOCK_SIZE(super); |
| fs->fragsize = EXT2_FRAG_SIZE(super); |
| frags_per_block = fs->blocksize / fs->fragsize; |
| |
| /* default: (fs->blocksize*8) blocks/group */ |
| set_field(s_blocks_per_group, fs->blocksize*8); |
| super->s_frags_per_group = super->s_blocks_per_group * frags_per_block; |
| |
| super->s_blocks_count = param->s_blocks_count; |
| super->s_r_blocks_count = param->s_r_blocks_count; |
| if (super->s_r_blocks_count >= param->s_blocks_count) { |
| retval = EINVAL; |
| goto cleanup; |
| } |
| |
| retry: |
| fs->group_desc_count = (super->s_blocks_count - |
| super->s_first_data_block + |
| EXT2_BLOCKS_PER_GROUP(super) - 1) |
| / EXT2_BLOCKS_PER_GROUP(super); |
| if (fs->group_desc_count == 0) |
| return EXT2_ET_TOOSMALL; |
| fs->desc_blocks = (fs->group_desc_count + |
| EXT2_DESC_PER_BLOCK(super) - 1) |
| / EXT2_DESC_PER_BLOCK(super); |
| |
| set_field(s_inodes_count, (super->s_blocks_count*fs->blocksize)/4096); |
| |
| /* |
| * There should be at least as many inodes as the user |
| * requested. Figure out how many inodes per group that |
| * should be. But make sure that we don't allocate more than |
| * one bitmap's worth of inodes |
| */ |
| super->s_inodes_per_group = (super->s_inodes_count + |
| fs->group_desc_count - 1) / |
| fs->group_desc_count; |
| if (super->s_inodes_per_group > fs->blocksize*8) |
| super->s_inodes_per_group = fs->blocksize*8; |
| |
| /* |
| * Make sure the number of inodes per group completely fills |
| * the inode table blocks in the descriptor. If not, add some |
| * additional inodes/group. Waste not, want not... |
| */ |
| fs->inode_blocks_per_group = (((super->s_inodes_per_group * |
| EXT2_INODE_SIZE(super)) + |
| EXT2_BLOCK_SIZE(super) - 1) / |
| EXT2_BLOCK_SIZE(super)); |
| super->s_inodes_per_group = ((fs->inode_blocks_per_group * |
| EXT2_BLOCK_SIZE(super)) / |
| EXT2_INODE_SIZE(super)); |
| /* |
| * Finally, make sure the number of inodes per group is a |
| * multiple of 8. This is needed to simplify the bitmap |
| * splicing code. |
| */ |
| super->s_inodes_per_group &= ~7; |
| fs->inode_blocks_per_group = (((super->s_inodes_per_group * |
| EXT2_INODE_SIZE(super)) + |
| EXT2_BLOCK_SIZE(super) - 1) / |
| EXT2_BLOCK_SIZE(super)); |
| |
| /* |
| * adjust inode count to reflect the adjusted inodes_per_group |
| */ |
| super->s_inodes_count = super->s_inodes_per_group * |
| fs->group_desc_count; |
| super->s_free_inodes_count = super->s_inodes_count; |
| |
| /* |
| * Overhead is the number of bookkeeping blocks per group. It |
| * includes the superblock backup, the group descriptor |
| * backups, the inode bitmap, the block bitmap, and the inode |
| * table. |
| * |
| * XXX Not all block groups need the descriptor blocks, but |
| * being clever is tricky... |
| */ |
| overhead = (int) (3 + fs->desc_blocks + fs->inode_blocks_per_group); |
| |
| /* |
| * See if the last group is big enough to support the |
| * necessary data structures. If not, we need to get rid of |
| * it. |
| */ |
| rem = (int) ((super->s_blocks_count - super->s_first_data_block) % |
| super->s_blocks_per_group); |
| if ((fs->group_desc_count == 1) && rem && (rem < overhead)) |
| return EXT2_ET_TOOSMALL; |
| if (rem && (rem < overhead+50)) { |
| super->s_blocks_count -= rem; |
| goto retry; |
| } |
| |
| /* |
| * At this point we know how big the filesystem will be. So |
| * we can do any and all allocations that depend on the block |
| * count. |
| */ |
| |
| buf = malloc(strlen(fs->device_name) + 80); |
| if (!buf) { |
| retval = ENOMEM; |
| goto cleanup; |
| } |
| |
| sprintf(buf, "block bitmap for %s", fs->device_name); |
| retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map); |
| if (retval) |
| goto cleanup; |
| |
| sprintf(buf, "inode bitmap for %s", fs->device_name); |
| retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map); |
| if (retval) |
| goto cleanup; |
| |
| free(buf); |
| |
| fs->group_desc = malloc((size_t) fs->desc_blocks * fs->blocksize); |
| if (!fs->group_desc) { |
| retval = ENOMEM; |
| goto cleanup; |
| } |
| memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize); |
| |
| /* |
| * Reserve the superblock and group descriptors for each |
| * group, and fill in the correct group statistics for group. |
| * Note that although the block bitmap, inode bitmap, and |
| * inode table have not been allocated (and in fact won't be |
| * by this routine), they are accounted for nevertheless. |
| */ |
| group_block = super->s_first_data_block; |
| super->s_free_blocks_count = 0; |
| for (i = 0; i < fs->group_desc_count; i++) { |
| if (i == fs->group_desc_count-1) { |
| numblocks = (fs->super->s_blocks_count - |
| fs->super->s_first_data_block) % |
| fs->super->s_blocks_per_group; |
| if (!numblocks) |
| numblocks = fs->super->s_blocks_per_group; |
| } else |
| numblocks = fs->super->s_blocks_per_group; |
| |
| if (ext2fs_bg_has_super(fs, i)) { |
| for (j=0; j < fs->desc_blocks+1; j++) |
| ext2fs_mark_block_bitmap(fs->block_map, |
| group_block + j); |
| numblocks -= 1 + fs->desc_blocks; |
| } |
| |
| numblocks -= 2 + fs->inode_blocks_per_group; |
| |
| super->s_free_blocks_count += numblocks; |
| fs->group_desc[i].bg_free_blocks_count = numblocks; |
| fs->group_desc[i].bg_free_inodes_count = |
| fs->super->s_inodes_per_group; |
| fs->group_desc[i].bg_used_dirs_count = 0; |
| |
| group_block += super->s_blocks_per_group; |
| } |
| |
| ext2fs_mark_super_dirty(fs); |
| ext2fs_mark_bb_dirty(fs); |
| ext2fs_mark_ib_dirty(fs); |
| |
| io_channel_set_blksize(fs->io, fs->blocksize); |
| |
| *ret_fs = fs; |
| return 0; |
| cleanup: |
| ext2fs_free(fs); |
| return retval; |
| } |
| |
| |
| |