mirror of https://github.com/vitalif/e2fsprogs
289 lines
6.6 KiB
C
289 lines
6.6 KiB
C
/*
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* closefs.c --- close an ext2 filesystem
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*
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* Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
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*
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* %Begin-Header%
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* This file may be redistributed under the terms of the GNU Public
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* License.
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* %End-Header%
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*/
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#include <stdio.h>
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#if HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#include <time.h>
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#include <string.h>
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#include "ext2_fs.h"
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#include "ext2fsP.h"
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static int test_root(int a, int b)
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{
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if (a == 0)
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return 1;
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while (1) {
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if (a == 1)
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return 1;
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if (a % b)
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return 0;
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a = a / b;
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}
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}
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int ext2fs_bg_has_super(ext2_filsys fs, int group_block)
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{
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if (!(fs->super->s_feature_ro_compat &
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EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER))
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return 1;
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if (test_root(group_block, 3) || (test_root(group_block, 5)) ||
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test_root(group_block, 7))
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return 1;
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return 0;
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}
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/*
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* This function forces out the primary superblock. We need to only
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* write out those fields which we have changed, since if the
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* filesystem is mounted, it may have changed some of the other
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* fields.
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*
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* It takes as input a superblock which has already been byte swapped
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* (if necessary).
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*
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*/
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static errcode_t write_primary_superblock(ext2_filsys fs,
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struct ext2_super_block *super)
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{
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__u16 *old_super, *new_super;
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int check_idx, write_idx, size;
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errcode_t retval;
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if (!fs->io->manager->write_byte || !fs->orig_super) {
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io_channel_set_blksize(fs->io, SUPERBLOCK_OFFSET);
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retval = io_channel_write_blk(fs->io, 1, -SUPERBLOCK_SIZE,
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super);
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io_channel_set_blksize(fs->io, fs->blocksize);
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return retval;
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}
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old_super = (__u16 *) fs->orig_super;
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new_super = (__u16 *) super;
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for (check_idx = 0; check_idx < SUPERBLOCK_SIZE/2; check_idx++) {
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if (old_super[check_idx] == new_super[check_idx])
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continue;
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write_idx = check_idx;
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for (check_idx++; check_idx < SUPERBLOCK_SIZE/2; check_idx++)
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if (old_super[check_idx] == new_super[check_idx])
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break;
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size = 2 * (check_idx - write_idx);
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#if 0
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printf("Writing %d bytes starting at %d\n",
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size, write_idx*2);
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#endif
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retval = io_channel_write_byte(fs->io,
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SUPERBLOCK_OFFSET + (2 * write_idx), size,
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new_super + write_idx);
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if (retval)
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return retval;
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}
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return 0;
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}
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/*
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* Updates the revision to EXT2_DYNAMIC_REV
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*/
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void ext2fs_update_dynamic_rev(ext2_filsys fs)
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{
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struct ext2_super_block *sb = fs->super;
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if (sb->s_rev_level > EXT2_GOOD_OLD_REV)
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return;
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sb->s_rev_level = EXT2_DYNAMIC_REV;
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sb->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
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sb->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
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/* s_uuid is handled by e2fsck already */
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/* other fields should be left alone */
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}
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errcode_t ext2fs_flush(ext2_filsys fs)
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{
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dgrp_t i,j,maxgroup,sgrp;
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blk_t group_block;
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errcode_t retval;
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char *group_ptr;
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unsigned long fs_state;
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struct ext2_super_block *super_shadow = 0;
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struct ext2_group_desc *group_shadow = 0;
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struct ext2_group_desc *s, *t;
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EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
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fs_state = fs->super->s_state;
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fs->super->s_wtime = time(NULL);
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fs->super->s_block_group_nr = 0;
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#ifdef EXT2FS_ENABLE_SWAPFS
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if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
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retval = EXT2_ET_NO_MEMORY;
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retval = ext2fs_get_mem(SUPERBLOCK_SIZE,
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(void **) &super_shadow);
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if (retval)
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goto errout;
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retval = ext2fs_get_mem((size_t)(fs->blocksize *
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fs->desc_blocks),
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(void **) &group_shadow);
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if (retval)
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goto errout;
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memset(group_shadow, 0, (size_t) fs->blocksize *
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fs->desc_blocks);
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/* swap the superblock */
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*super_shadow = *fs->super;
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ext2fs_swap_super(super_shadow);
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/* swap the group descriptors */
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for (j=0, s=fs->group_desc, t=group_shadow;
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j < fs->group_desc_count; j++, t++, s++) {
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*t = *s;
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ext2fs_swap_group_desc(t);
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}
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} else {
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super_shadow = fs->super;
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group_shadow = fs->group_desc;
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}
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#else
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super_shadow = fs->super;
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group_shadow = fs->group_desc;
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#endif
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/*
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* Write out master superblock. This has to be done
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* separately, since it is located at a fixed location
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* (SUPERBLOCK_OFFSET).
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*/
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retval = write_primary_superblock(fs, super_shadow);
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if (retval)
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goto errout;
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/*
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* If this is an external journal device, don't write out the
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* block group descriptors or any of the backup superblocks
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*/
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if (fs->super->s_feature_incompat &
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EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
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retval = 0;
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goto errout;
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}
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/*
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* Set the state of the FS to be non-valid. (The state has
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* already been backed up earlier, and will be restored when
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* we exit.)
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*/
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fs->super->s_state &= ~EXT2_VALID_FS;
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#ifdef EXT2FS_ENABLE_SWAPFS
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if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
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*super_shadow = *fs->super;
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ext2fs_swap_super(super_shadow);
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}
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#endif
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/*
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* Write out the master group descriptors, and the backup
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* superblocks and group descriptors.
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*/
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group_block = fs->super->s_first_data_block;
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maxgroup = (fs->flags & EXT2_FLAG_MASTER_SB_ONLY) ? 1 :
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fs->group_desc_count;
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for (i = 0; i < maxgroup; i++) {
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if (!ext2fs_bg_has_super(fs, i))
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goto next_group;
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sgrp = i;
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if (sgrp > ((1 << 16) - 1))
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sgrp = (1 << 16) - 1;
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#ifdef EXT2FS_ENABLE_SWAPFS
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if (fs->flags & EXT2_FLAG_SWAP_BYTES)
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super_shadow->s_block_group_nr = ext2fs_swab16(sgrp);
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else
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#endif
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fs->super->s_block_group_nr = sgrp;
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if (i !=0 ) {
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retval = io_channel_write_blk(fs->io, group_block,
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-SUPERBLOCK_SIZE,
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super_shadow);
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if (retval)
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goto errout;
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}
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if (fs->flags & EXT2_FLAG_SUPER_ONLY)
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goto next_group;
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group_ptr = (char *) group_shadow;
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for (j=0; j < fs->desc_blocks; j++) {
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retval = io_channel_write_blk(fs->io,
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group_block+1+j, 1,
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group_ptr);
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if (retval)
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goto errout;
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group_ptr += fs->blocksize;
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}
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next_group:
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group_block += EXT2_BLOCKS_PER_GROUP(fs->super);
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}
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fs->super->s_block_group_nr = 0;
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/*
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* If the write_bitmaps() function is present, call it to
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* flush the bitmaps. This is done this way so that a simple
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* program that doesn't mess with the bitmaps doesn't need to
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* drag in the bitmaps.c code.
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*/
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if (fs->write_bitmaps) {
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retval = fs->write_bitmaps(fs);
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if (retval)
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goto errout;
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}
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/*
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* Flush the blocks out to disk
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*/
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retval = io_channel_flush(fs->io);
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errout:
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fs->super->s_state = fs_state;
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if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
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if (super_shadow)
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ext2fs_free_mem((void **) &super_shadow);
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if (group_shadow)
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ext2fs_free_mem((void **) &group_shadow);
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}
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return retval;
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}
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errcode_t ext2fs_close(ext2_filsys fs)
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{
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errcode_t retval;
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EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
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if (fs->flags & EXT2_FLAG_DIRTY) {
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retval = ext2fs_flush(fs);
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if (retval)
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return retval;
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}
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if (fs->write_bitmaps) {
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retval = fs->write_bitmaps(fs);
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if (retval)
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return retval;
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}
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ext2fs_free(fs);
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return 0;
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}
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