[821] | 1 | /*
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| 2 | * initialize.c --- initialize a filesystem handle given superblock
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| 3 | * parameters. Used by mke2fs when initializing a filesystem.
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| 4 | *
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| 5 | * Copyright (C) 1994, 1995, 1996 Theodore Ts'o.
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| 6 | *
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| 7 | * %Begin-Header%
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| 8 | * This file may be redistributed under the terms of the GNU Public
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| 9 | * License.
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| 10 | * %End-Header%
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| 11 | */
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| 12 |
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| 13 | #include <stdio.h>
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| 14 | #include <string.h>
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| 15 | #if HAVE_UNISTD_H
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| 16 | #include <unistd.h>
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| 17 | #endif
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| 18 | #include <fcntl.h>
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| 19 | #include <time.h>
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| 20 | #if HAVE_SYS_STAT_H
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| 21 | #include <sys/stat.h>
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| 22 | #endif
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| 23 | #if HAVE_SYS_TYPES_H
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| 24 | #include <sys/types.h>
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| 25 | #endif
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| 26 |
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| 27 | #include "ext2_fs.h"
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| 28 | #include "ext2fs.h"
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| 29 |
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| 30 | #if defined(__linux__) && defined(EXT2_OS_LINUX)
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| 31 | #define CREATOR_OS EXT2_OS_LINUX
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| 32 | #else
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| 33 | #if defined(__GNU__) && defined(EXT2_OS_HURD)
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| 34 | #define CREATOR_OS EXT2_OS_HURD
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| 35 | #else
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| 36 | #if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD)
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| 37 | #define CREATOR_OS EXT2_OS_FREEBSD
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| 38 | #else
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| 39 | #if defined(LITES) && defined(EXT2_OS_LITES)
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| 40 | #define CREATOR_OS EXT2_OS_LITES
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| 41 | #else
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| 42 | #define CREATOR_OS EXT2_OS_LINUX /* by default */
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| 43 | #endif /* defined(LITES) && defined(EXT2_OS_LITES) */
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| 44 | #endif /* defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) */
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| 45 | #endif /* defined(__GNU__) && defined(EXT2_OS_HURD) */
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| 46 | #endif /* defined(__linux__) && defined(EXT2_OS_LINUX) */
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| 47 |
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| 48 | /*
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| 49 | * Note we override the kernel include file's idea of what the default
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| 50 | * check interval (never) should be. It's a good idea to check at
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| 51 | * least *occasionally*, specially since servers will never rarely get
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| 52 | * to reboot, since Linux is so robust these days. :-)
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| 53 | *
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| 54 | * 180 days (six months) seems like a good value.
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| 55 | */
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| 56 | #ifdef EXT2_DFL_CHECKINTERVAL
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| 57 | #undef EXT2_DFL_CHECKINTERVAL
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| 58 | #endif
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| 59 | #define EXT2_DFL_CHECKINTERVAL (86400L * 180L)
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| 60 |
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| 61 | /*
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| 62 | * Calculate the number of GDT blocks to reserve for online filesystem growth.
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| 63 | * The absolute maximum number of GDT blocks we can reserve is determined by
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| 64 | * the number of block pointers that can fit into a single block.
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| 65 | */
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| 66 | static int calc_reserved_gdt_blocks(ext2_filsys fs)
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| 67 | {
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| 68 | struct ext2_super_block *sb = fs->super;
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| 69 | unsigned long bpg = sb->s_blocks_per_group;
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| 70 | unsigned int gdpb = fs->blocksize / sizeof(struct ext2_group_desc);
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| 71 | unsigned long max_blocks = 0xffffffff;
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| 72 | unsigned long rsv_groups;
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| 73 | int rsv_gdb;
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| 74 |
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| 75 | /* We set it at 1024x the current filesystem size, or
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| 76 | * the upper block count limit (2^32), whichever is lower.
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| 77 | */
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| 78 | if (sb->s_blocks_count < max_blocks / 1024)
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| 79 | max_blocks = sb->s_blocks_count * 1024;
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| 80 | rsv_groups = (max_blocks - sb->s_first_data_block + bpg - 1) / bpg;
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| 81 | rsv_gdb = (rsv_groups + gdpb - 1) / gdpb - fs->desc_blocks;
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| 82 | if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb))
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| 83 | rsv_gdb = EXT2_ADDR_PER_BLOCK(sb);
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| 84 | #ifdef RES_GDT_DEBUG
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| 85 | printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %lu\n",
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| 86 | max_blocks, rsv_groups, rsv_gdb);
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| 87 | #endif
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| 88 |
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| 89 | return rsv_gdb;
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| 90 | }
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| 91 |
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| 92 | errcode_t ext2fs_initialize(const char *name, int flags,
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| 93 | struct ext2_super_block *param,
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| 94 | io_manager manager, ext2_filsys *ret_fs)
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| 95 | {
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| 96 | ext2_filsys fs;
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| 97 | errcode_t retval;
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| 98 | struct ext2_super_block *super;
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| 99 | int frags_per_block;
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| 100 | unsigned int rem;
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| 101 | unsigned int overhead = 0;
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| 102 | blk_t group_block;
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| 103 | unsigned int ipg;
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| 104 | dgrp_t i;
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| 105 | blk_t numblocks;
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| 106 | int rsv_gdt;
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| 107 | char *buf;
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| 108 |
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| 109 | if (!param || !param->s_blocks_count)
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| 110 | return EXT2_ET_INVALID_ARGUMENT;
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| 111 |
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| 112 | retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs);
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| 113 | if (retval)
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| 114 | return retval;
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| 115 |
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| 116 | memset(fs, 0, sizeof(struct struct_ext2_filsys));
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| 117 | fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
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| 118 | fs->flags = flags | EXT2_FLAG_RW;
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| 119 | fs->umask = 022;
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| 120 | #ifdef WORDS_BIGENDIAN
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| 121 | fs->flags |= EXT2_FLAG_SWAP_BYTES;
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| 122 | #endif
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| 123 | retval = manager->open(name, IO_FLAG_RW, &fs->io);
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| 124 | if (retval)
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| 125 | goto cleanup;
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| 126 | fs->image_io = fs->io;
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| 127 | fs->io->app_data = fs;
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| 128 | retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name);
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| 129 | if (retval)
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| 130 | goto cleanup;
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| 131 |
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| 132 | strcpy(fs->device_name, name);
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| 133 | retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super);
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| 134 | if (retval)
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| 135 | goto cleanup;
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| 136 | fs->super = super;
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| 137 |
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| 138 | memset(super, 0, SUPERBLOCK_SIZE);
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| 139 |
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| 140 | #define set_field(field, default) (super->field = param->field ? \
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| 141 | param->field : (default))
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| 142 |
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| 143 | super->s_magic = EXT2_SUPER_MAGIC;
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| 144 | super->s_state = EXT2_VALID_FS;
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| 145 |
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| 146 | set_field(s_log_block_size, 0); /* default blocksize: 1024 bytes */
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| 147 | set_field(s_log_frag_size, 0); /* default fragsize: 1024 bytes */
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| 148 | set_field(s_first_data_block, super->s_log_block_size ? 0 : 1);
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| 149 | set_field(s_max_mnt_count, EXT2_DFL_MAX_MNT_COUNT);
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| 150 | set_field(s_errors, EXT2_ERRORS_DEFAULT);
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| 151 | set_field(s_feature_compat, 0);
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| 152 | set_field(s_feature_incompat, 0);
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| 153 | set_field(s_feature_ro_compat, 0);
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| 154 | set_field(s_first_meta_bg, 0);
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| 155 | if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
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| 156 | retval = EXT2_ET_UNSUPP_FEATURE;
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| 157 | goto cleanup;
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| 158 | }
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| 159 | if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) {
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| 160 | retval = EXT2_ET_RO_UNSUPP_FEATURE;
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| 161 | goto cleanup;
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| 162 | }
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| 163 |
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| 164 | set_field(s_rev_level, EXT2_GOOD_OLD_REV);
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| 165 | if (super->s_rev_level >= EXT2_DYNAMIC_REV) {
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| 166 | set_field(s_first_ino, EXT2_GOOD_OLD_FIRST_INO);
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| 167 | set_field(s_inode_size, EXT2_GOOD_OLD_INODE_SIZE);
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| 168 | }
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| 169 |
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| 170 | set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL);
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| 171 | super->s_mkfs_time = super->s_lastcheck = time(NULL);
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| 172 |
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| 173 | super->s_creator_os = CREATOR_OS;
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| 174 |
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| 175 | fs->blocksize = EXT2_BLOCK_SIZE(super);
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| 176 | fs->fragsize = EXT2_FRAG_SIZE(super);
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| 177 | frags_per_block = fs->blocksize / fs->fragsize;
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| 178 |
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| 179 | /* default: (fs->blocksize*8) blocks/group, up to 2^16 (GDT limit) */
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| 180 | set_field(s_blocks_per_group, fs->blocksize * 8);
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| 181 | if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super))
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| 182 | super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super);
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| 183 | super->s_frags_per_group = super->s_blocks_per_group * frags_per_block;
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| 184 |
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| 185 | super->s_blocks_count = param->s_blocks_count;
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| 186 | super->s_r_blocks_count = param->s_r_blocks_count;
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| 187 | if (super->s_r_blocks_count >= param->s_blocks_count) {
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| 188 | retval = EXT2_ET_INVALID_ARGUMENT;
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| 189 | goto cleanup;
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| 190 | }
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| 191 |
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| 192 | /*
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| 193 | * If we're creating an external journal device, we don't need
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| 194 | * to bother with the rest.
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| 195 | */
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| 196 | if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
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| 197 | fs->group_desc_count = 0;
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| 198 | ext2fs_mark_super_dirty(fs);
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| 199 | *ret_fs = fs;
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| 200 | return 0;
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| 201 | }
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| 202 |
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| 203 | retry:
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| 204 | fs->group_desc_count = (super->s_blocks_count -
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| 205 | super->s_first_data_block +
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| 206 | EXT2_BLOCKS_PER_GROUP(super) - 1)
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| 207 | / EXT2_BLOCKS_PER_GROUP(super);
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| 208 | if (fs->group_desc_count == 0) {
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| 209 | retval = EXT2_ET_TOOSMALL;
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| 210 | goto cleanup;
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| 211 | }
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| 212 | fs->desc_blocks = (fs->group_desc_count +
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| 213 | EXT2_DESC_PER_BLOCK(super) - 1)
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| 214 | / EXT2_DESC_PER_BLOCK(super);
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| 215 |
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| 216 | i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize;
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| 217 | set_field(s_inodes_count, super->s_blocks_count / i);
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| 218 |
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| 219 | /*
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| 220 | * Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
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| 221 | * that we have enough inodes for the filesystem(!)
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| 222 | */
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| 223 | if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1)
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| 224 | super->s_inodes_count = EXT2_FIRST_INODE(super)+1;
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| 225 |
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| 226 | /*
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| 227 | * There should be at least as many inodes as the user
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| 228 | * requested. Figure out how many inodes per group that
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| 229 | * should be. But make sure that we don't allocate more than
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| 230 | * one bitmap's worth of inodes each group.
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| 231 | */
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| 232 | ipg = (super->s_inodes_count + fs->group_desc_count - 1) /
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| 233 | fs->group_desc_count;
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| 234 | if (ipg > fs->blocksize * 8) {
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| 235 | if (super->s_blocks_per_group >= 256) {
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| 236 | /* Try again with slightly different parameters */
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| 237 | super->s_blocks_per_group -= 8;
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| 238 | super->s_blocks_count = param->s_blocks_count;
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| 239 | super->s_frags_per_group = super->s_blocks_per_group *
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| 240 | frags_per_block;
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| 241 | goto retry;
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| 242 | } else
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| 243 | return EXT2_ET_TOO_MANY_INODES;
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| 244 | }
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| 245 |
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| 246 | if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super))
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| 247 | ipg = EXT2_MAX_INODES_PER_GROUP(super);
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| 248 |
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| 249 | super->s_inodes_per_group = ipg;
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| 250 | if (super->s_inodes_count > ipg * fs->group_desc_count)
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| 251 | super->s_inodes_count = ipg * fs->group_desc_count;
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| 252 |
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| 253 | /*
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| 254 | * Make sure the number of inodes per group completely fills
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| 255 | * the inode table blocks in the descriptor. If not, add some
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| 256 | * additional inodes/group. Waste not, want not...
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| 257 | */
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| 258 | fs->inode_blocks_per_group = (((super->s_inodes_per_group *
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| 259 | EXT2_INODE_SIZE(super)) +
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| 260 | EXT2_BLOCK_SIZE(super) - 1) /
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| 261 | EXT2_BLOCK_SIZE(super));
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| 262 | super->s_inodes_per_group = ((fs->inode_blocks_per_group *
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| 263 | EXT2_BLOCK_SIZE(super)) /
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| 264 | EXT2_INODE_SIZE(super));
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| 265 | /*
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| 266 | * Finally, make sure the number of inodes per group is a
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| 267 | * multiple of 8. This is needed to simplify the bitmap
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| 268 | * splicing code.
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| 269 | */
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| 270 | super->s_inodes_per_group &= ~7;
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| 271 | fs->inode_blocks_per_group = (((super->s_inodes_per_group *
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| 272 | EXT2_INODE_SIZE(super)) +
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| 273 | EXT2_BLOCK_SIZE(super) - 1) /
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| 274 | EXT2_BLOCK_SIZE(super));
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| 275 |
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| 276 | /*
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| 277 | * adjust inode count to reflect the adjusted inodes_per_group
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| 278 | */
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| 279 | super->s_inodes_count = super->s_inodes_per_group *
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| 280 | fs->group_desc_count;
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| 281 | super->s_free_inodes_count = super->s_inodes_count;
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| 282 |
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| 283 | /*
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| 284 | * check the number of reserved group descriptor table blocks
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| 285 | */
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| 286 | if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE)
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| 287 | rsv_gdt = calc_reserved_gdt_blocks(fs);
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| 288 | else
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| 289 | rsv_gdt = 0;
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| 290 | set_field(s_reserved_gdt_blocks, rsv_gdt);
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| 291 | if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) {
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| 292 | retval = EXT2_ET_RES_GDT_BLOCKS;
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| 293 | goto cleanup;
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| 294 | }
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| 295 |
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| 296 | /*
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| 297 | * Overhead is the number of bookkeeping blocks per group. It
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| 298 | * includes the superblock backup, the group descriptor
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| 299 | * backups, the inode bitmap, the block bitmap, and the inode
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| 300 | * table.
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| 301 | */
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| 302 |
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| 303 | overhead = (int) (2 + fs->inode_blocks_per_group);
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| 304 |
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| 305 | if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
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| 306 | overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
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| 307 |
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| 308 | /* This can only happen if the user requested too many inodes */
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| 309 | if (overhead > super->s_blocks_per_group)
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| 310 | return EXT2_ET_TOO_MANY_INODES;
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| 311 |
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| 312 | /*
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| 313 | * See if the last group is big enough to support the
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| 314 | * necessary data structures. If not, we need to get rid of
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| 315 | * it.
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| 316 | */
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| 317 | rem = ((super->s_blocks_count - super->s_first_data_block) %
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| 318 | super->s_blocks_per_group);
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| 319 | if ((fs->group_desc_count == 1) && rem && (rem < overhead))
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| 320 | return EXT2_ET_TOOSMALL;
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| 321 | if (rem && (rem < overhead+50)) {
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| 322 | super->s_blocks_count -= rem;
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| 323 | goto retry;
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| 324 | }
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| 325 |
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| 326 | /*
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| 327 | * At this point we know how big the filesystem will be. So
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| 328 | * we can do any and all allocations that depend on the block
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| 329 | * count.
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| 330 | */
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| 331 |
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| 332 | retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
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| 333 | if (retval)
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| 334 | goto cleanup;
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| 335 |
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| 336 | sprintf(buf, "block bitmap for %s", fs->device_name);
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| 337 | retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
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| 338 | if (retval)
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| 339 | goto cleanup;
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| 340 |
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| 341 | sprintf(buf, "inode bitmap for %s", fs->device_name);
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| 342 | retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
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| 343 | if (retval)
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| 344 | goto cleanup;
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| 345 |
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| 346 | ext2fs_free_mem(&buf);
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| 347 |
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| 348 | retval = ext2fs_get_mem((size_t) fs->desc_blocks * fs->blocksize,
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| 349 | &fs->group_desc);
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| 350 | if (retval)
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| 351 | goto cleanup;
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| 352 |
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| 353 | memset(fs->group_desc, 0, (size_t) fs->desc_blocks * fs->blocksize);
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| 354 |
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| 355 | /*
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| 356 | * Reserve the superblock and group descriptors for each
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| 357 | * group, and fill in the correct group statistics for group.
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| 358 | * Note that although the block bitmap, inode bitmap, and
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| 359 | * inode table have not been allocated (and in fact won't be
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| 360 | * by this routine), they are accounted for nevertheless.
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| 361 | */
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| 362 | group_block = super->s_first_data_block;
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| 363 | super->s_free_blocks_count = 0;
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| 364 | for (i = 0; i < fs->group_desc_count; i++) {
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| 365 | numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
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| 366 |
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| 367 | super->s_free_blocks_count += numblocks;
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| 368 | fs->group_desc[i].bg_free_blocks_count = numblocks;
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| 369 | fs->group_desc[i].bg_free_inodes_count =
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| 370 | fs->super->s_inodes_per_group;
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| 371 | fs->group_desc[i].bg_used_dirs_count = 0;
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| 372 |
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| 373 | group_block += super->s_blocks_per_group;
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| 374 | }
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| 375 |
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| 376 | ext2fs_mark_super_dirty(fs);
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| 377 | ext2fs_mark_bb_dirty(fs);
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| 378 | ext2fs_mark_ib_dirty(fs);
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| 379 |
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| 380 | io_channel_set_blksize(fs->io, fs->blocksize);
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| 381 |
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| 382 | *ret_fs = fs;
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| 383 | return 0;
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| 384 | cleanup:
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| 385 | ext2fs_free(fs);
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| 386 | return retval;
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| 387 | }
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