emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
f246dc7f57
busybox/e2fsprogs/ext2fs/initialize.c
Mike Frysinger 1fd98e039d import ext2fs lib to prep for new e2fsprogs
2005-05-09 22:10:42 +00:00

388 lines
11 KiB
C
Raw Blame History

/*
* 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 <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
#include "ext2_fs.h"
#include "ext2fs.h"
#if defined(__linux__) && defined(EXT2_OS_LINUX)
#define CREATOR_OS EXT2_OS_LINUX
#else
#if defined(__GNU__) && defined(EXT2_OS_HURD)
#define CREATOR_OS EXT2_OS_HURD
#else
#if defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD)
#define CREATOR_OS EXT2_OS_FREEBSD
#else
#if defined(LITES) && defined(EXT2_OS_LITES)
#define CREATOR_OS EXT2_OS_LITES
#else
#define CREATOR_OS EXT2_OS_LINUX /* by default */
#endif /* defined(LITES) && defined(EXT2_OS_LITES) */
#endif /* defined(__FreeBSD__) && defined(EXT2_OS_FREEBSD) */
#endif /* defined(__GNU__) && defined(EXT2_OS_HURD) */
#endif /* defined(__linux__) && defined(EXT2_OS_LINUX) */
/*
* 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)
/*
* Calculate the number of GDT blocks to reserve for online filesystem growth.
* The absolute maximum number of GDT blocks we can reserve is determined by
* the number of block pointers that can fit into a single block.
*/
static int calc_reserved_gdt_blocks(ext2_filsys fs)
{
struct ext2_super_block *sb = fs->super;
unsigned long bpg = sb->s_blocks_per_group;
unsigned int gdpb = fs->blocksize / sizeof(struct ext2_group_desc);
unsigned long max_blocks = 0xffffffff;
unsigned long rsv_groups;
int rsv_gdb;
/* We set it at 1024x the current filesystem size, or
* the upper block count limit (2^32), whichever is lower.
*/
if (sb->s_blocks_count < max_blocks / 1024)
max_blocks = sb->s_blocks_count * 1024;
rsv_groups = (max_blocks - sb->s_first_data_block + bpg - 1) / bpg;
rsv_gdb = (rsv_groups + gdpb - 1) / gdpb - fs->desc_blocks;
if (rsv_gdb > EXT2_ADDR_PER_BLOCK(sb))
rsv_gdb = EXT2_ADDR_PER_BLOCK(sb);
#ifdef RES_GDT_DEBUG
printf("max_blocks %lu, rsv_groups = %lu, rsv_gdb = %lu\n",
max_blocks, rsv_groups, rsv_gdb);
#endif
return rsv_gdb;
}
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;
unsigned int rem;
unsigned int overhead = 0;
blk_t group_block;
unsigned int ipg;
dgrp_t i;
blk_t numblocks;
int rsv_gdt;
char *buf;
if (!param || !param->s_blocks_count)
return EXT2_ET_INVALID_ARGUMENT;
retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys), &fs);
if (retval)
return retval;
memset(fs, 0, sizeof(struct struct_ext2_filsys));
fs->magic = EXT2_ET_MAGIC_EXT2FS_FILSYS;
fs->flags = flags | EXT2_FLAG_RW;
fs->umask = 022;
#ifdef WORDS_BIGENDIAN
fs->flags |= EXT2_FLAG_SWAP_BYTES;
#endif
retval = manager->open(name, IO_FLAG_RW, &fs->io);
if (retval)
goto cleanup;
fs->image_io = fs->io;
fs->io->app_data = fs;
retval = ext2fs_get_mem(strlen(name)+1, &fs->device_name);
if (retval)
goto cleanup;
strcpy(fs->device_name, name);
retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super);
if (retval)
goto cleanup;
fs->super = super;
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);
set_field(s_feature_compat, 0);
set_field(s_feature_incompat, 0);
set_field(s_feature_ro_compat, 0);
set_field(s_first_meta_bg, 0);
if (super->s_feature_incompat & ~EXT2_LIB_FEATURE_INCOMPAT_SUPP) {
retval = EXT2_ET_UNSUPP_FEATURE;
goto cleanup;
}
if (super->s_feature_ro_compat & ~EXT2_LIB_FEATURE_RO_COMPAT_SUPP) {
retval = EXT2_ET_RO_UNSUPP_FEATURE;
goto cleanup;
}
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);
}
set_field(s_checkinterval, EXT2_DFL_CHECKINTERVAL);
super->s_mkfs_time = 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, up to 2^16 (GDT limit) */
set_field(s_blocks_per_group, fs->blocksize * 8);
if (super->s_blocks_per_group > EXT2_MAX_BLOCKS_PER_GROUP(super))
super->s_blocks_per_group = EXT2_MAX_BLOCKS_PER_GROUP(super);
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 = EXT2_ET_INVALID_ARGUMENT;
goto cleanup;
}
/*
* If we're creating an external journal device, we don't need
* to bother with the rest.
*/
if (super->s_feature_incompat & EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
fs->group_desc_count = 0;
ext2fs_mark_super_dirty(fs);
*ret_fs = fs;
return 0;
}
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) {
retval = EXT2_ET_TOOSMALL;
goto cleanup;
}
fs->desc_blocks = (fs->group_desc_count +
EXT2_DESC_PER_BLOCK(super) - 1)
/ EXT2_DESC_PER_BLOCK(super);
i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize;
set_field(s_inodes_count, super->s_blocks_count / i);
/*
* Make sure we have at least EXT2_FIRST_INO + 1 inodes, so
* that we have enough inodes for the filesystem(!)
*/
if (super->s_inodes_count < EXT2_FIRST_INODE(super)+1)
super->s_inodes_count = EXT2_FIRST_INODE(super)+1;
/*
* 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 each group.
*/
ipg = (super->s_inodes_count + fs->group_desc_count - 1) /
fs->group_desc_count;
if (ipg > fs->blocksize * 8) {
if (super->s_blocks_per_group >= 256) {
/* Try again with slightly different parameters */
super->s_blocks_per_group -= 8;
super->s_blocks_count = param->s_blocks_count;
super->s_frags_per_group = super->s_blocks_per_group *
frags_per_block;
goto retry;
} else
return EXT2_ET_TOO_MANY_INODES;
}
if (ipg > (unsigned) EXT2_MAX_INODES_PER_GROUP(super))
ipg = EXT2_MAX_INODES_PER_GROUP(super);
super->s_inodes_per_group = ipg;
if (super->s_inodes_count > ipg * fs->group_desc_count)
super->s_inodes_count = ipg * fs->group_desc_count;
/*
* 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;
/*
* check the number of reserved group descriptor table blocks
*/
if (super->s_feature_compat & EXT2_FEATURE_COMPAT_RESIZE_INODE)
rsv_gdt = calc_reserved_gdt_blocks(fs);
else
rsv_gdt = 0;
set_field(s_reserved_gdt_blocks, rsv_gdt);
if (super->s_reserved_gdt_blocks > EXT2_ADDR_PER_BLOCK(super)) {
retval = EXT2_ET_RES_GDT_BLOCKS;
goto cleanup;
}
/*
* 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.
*/
overhead = (int) (2 + fs->inode_blocks_per_group);
if (ext2fs_bg_has_super(fs, fs->group_desc_count - 1))
overhead += 1 + fs->desc_blocks + super->s_reserved_gdt_blocks;
/* This can only happen if the user requested too many inodes */
if (overhead > super->s_blocks_per_group)
return EXT2_ET_TOO_MANY_INODES;
/*
* See if the last group is big enough to support the
* necessary data structures. If not, we need to get rid of
* it.
*/
rem = ((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.
*/
retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
if (retval)
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;
ext2fs_free_mem(&buf);
retval = ext2fs_get_mem((size_t) fs->desc_blocks * fs->blocksize,
&fs->group_desc);
if (retval)
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++) {
numblocks = ext2fs_reserve_super_and_bgd(fs, i, fs->block_map);
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;
}
Reference in New Issue View Git Blame Copy Permalink