/* vi: set sw=4 ts=4: *//* * 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;}