lib/ext2fs/initialize.c - platform/external/e2fsprogs_custom - Gitiles

 /*
  * 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

 #if EXT2_FLAT_INCLUDES
 #include "ext2_fs.h"
 #else
 #include <linux/ext2_fs.h>
 #endif

 #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 EXT2_ET_INVALID_ARGUMENT;

 	retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys),
 				(void **) &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 | ext2fs_native_flag();
 	retval = manager->open(name, IO_FLAG_RW, &fs->io);
 	if (retval)
 		goto cleanup;
 	fs->io->app_data = fs;
 	retval = ext2fs_get_mem(strlen(name)+1, (void **) &fs->device_name);
 	if (retval)
 		goto cleanup;

 	strcpy(fs->device_name, name);
 	retval = ext2fs_get_mem(SUPERBLOCK_SIZE, (void **) &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);
 #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 = EXT2_ET_INVALID_ARGUMENT;
 		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);

 	/* n.b., fs->blocksize is <= 4096 */
 	set_field(s_inodes_count, super->s_blocks_count/(4096/fs->blocksize));

 	/*
 	 * 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
 	 */
 	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.
 	 */

 	retval = ext2fs_get_mem(strlen(fs->device_name) + 80,
 				(void **) &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((void **) &buf);

 	retval = ext2fs_get_mem((size_t) fs->desc_blocks * fs->blocksize,
 				(void **) &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++) {
 		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;
 }
	/*
	* 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

	#if EXT2_FLAT_INCLUDES
	#include "ext2_fs.h"
	#else
	#include <linux/ext2_fs.h>
	#endif

	#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 EXT2_ET_INVALID_ARGUMENT;

	retval = ext2fs_get_mem(sizeof(struct struct_ext2_filsys),
	(void **) &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 \| ext2fs_native_flag();
	retval = manager->open(name, IO_FLAG_RW, &fs->io);
	if (retval)
	goto cleanup;
	fs->io->app_data = fs;
	retval = ext2fs_get_mem(strlen(name)+1, (void **) &fs->device_name);
	if (retval)
	goto cleanup;

	strcpy(fs->device_name, name);
	retval = ext2fs_get_mem(SUPERBLOCK_SIZE, (void **) &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);
	#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->blocksize8) 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 = EXT2_ET_INVALID_ARGUMENT;
	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);

	/* n.b., fs->blocksize is <= 4096 */
	set_field(s_inodes_count, super->s_blocks_count/(4096/fs->blocksize));

	/*
	* 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
	*/
	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.
	*/

	retval = ext2fs_get_mem(strlen(fs->device_name) + 80,
	(void **) &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((void **) &buf);

	retval = ext2fs_get_mem((size_t) fs->desc_blocks * fs->blocksize,
	(void **) &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++) {
	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;
	}