| /* |
| * closefs.c --- close an ext2 filesystem |
| * |
| * Copyright (C) 1993, 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> |
| #if HAVE_UNISTD_H |
| #include <unistd.h> |
| #endif |
| #include <stdlib.h> |
| #include <time.h> |
| #include <string.h> |
| |
| #include <linux/ext2_fs.h> |
| |
| #include "ext2fsP.h" |
| |
| static int test_root(int a, int b) |
| { |
| if (a == 0) |
| return 1; |
| while (1) { |
| if (a == 1) |
| return 1; |
| if (a % b) |
| return 0; |
| a = a / b; |
| } |
| } |
| |
| int ext2fs_bg_has_super(ext2_filsys fs, int group_block) |
| { |
| #ifdef EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER |
| struct ext2fs_sb *s; |
| |
| s = (struct ext2fs_sb *) fs->super; |
| if (!(s->s_feature_ro_compat & EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)) |
| return 1; |
| |
| if (test_root(group_block, 3) || (test_root(group_block, 5)) || |
| test_root(group_block, 7)) |
| return 1; |
| |
| return 0; |
| #else |
| return 1; |
| #endif |
| } |
| |
| errcode_t ext2fs_flush(ext2_filsys fs) |
| { |
| dgrp_t i,j,maxgroup; |
| blk_t group_block; |
| errcode_t retval; |
| char *group_ptr; |
| unsigned long fs_state; |
| struct ext2_super_block *super_shadow = 0; |
| struct ext2_group_desc *group_shadow = 0; |
| struct ext2_group_desc *s, *t; |
| |
| EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
| |
| fs_state = fs->super->s_state; |
| |
| fs->super->s_wtime = time(NULL); |
| if (fs->flags & EXT2_FLAG_SWAP_BYTES) { |
| retval = EXT2_NO_MEMORY; |
| retval = ext2fs_get_mem(SUPERBLOCK_SIZE, |
| (void **) &super_shadow); |
| if (retval) |
| goto errout; |
| retval = ext2fs_get_mem((size_t)(fs->blocksize * |
| fs->desc_blocks), |
| (void **) &group_shadow); |
| if (retval) |
| goto errout; |
| memset(group_shadow, 0, (size_t) fs->blocksize * |
| fs->desc_blocks); |
| |
| /* swap the superblock */ |
| *super_shadow = *fs->super; |
| ext2fs_swap_super(super_shadow); |
| |
| /* swap the group descriptors */ |
| for (j=0, s=fs->group_desc, t=group_shadow; |
| j < fs->group_desc_count; j++, t++, s++) { |
| *t = *s; |
| ext2fs_swap_group_desc(t); |
| } |
| } else { |
| super_shadow = fs->super; |
| group_shadow = fs->group_desc; |
| } |
| |
| /* |
| * Write out master superblock. This has to be done |
| * separately, since it is located at a fixed location |
| * (SUPERBLOCK_OFFSET). |
| */ |
| io_channel_set_blksize(fs->io, SUPERBLOCK_OFFSET); |
| retval = io_channel_write_blk(fs->io, 1, -SUPERBLOCK_SIZE, |
| super_shadow); |
| if (retval) |
| goto errout; |
| io_channel_set_blksize(fs->io, fs->blocksize); |
| |
| /* |
| * Set the state of the FS to be non-valid. (The state has |
| * already been backed up earlier, and will be restored when |
| * we exit.) |
| */ |
| fs->super->s_state &= ~EXT2_VALID_FS; |
| if (fs->flags & EXT2_FLAG_SWAP_BYTES) { |
| *super_shadow = *fs->super; |
| ext2fs_swap_super(super_shadow); |
| } |
| |
| /* |
| * Write out the master group descriptors, and the backup |
| * superblocks and group descriptors. |
| */ |
| group_block = fs->super->s_first_data_block; |
| maxgroup = (fs->flags & EXT2_FLAG_MASTER_SB_ONLY) ? 1 : |
| fs->group_desc_count; |
| for (i = 0; i < maxgroup; i++) { |
| if (!ext2fs_bg_has_super(fs, i)) |
| goto next_group; |
| |
| if (i !=0 ) { |
| retval = io_channel_write_blk(fs->io, group_block, |
| -SUPERBLOCK_SIZE, |
| super_shadow); |
| if (retval) |
| goto errout; |
| } |
| group_ptr = (char *) group_shadow; |
| for (j=0; j < fs->desc_blocks; j++) { |
| retval = io_channel_write_blk(fs->io, |
| group_block+1+j, 1, |
| group_ptr); |
| if (retval) |
| goto errout; |
| group_ptr += fs->blocksize; |
| } |
| next_group: |
| group_block += EXT2_BLOCKS_PER_GROUP(fs->super); |
| } |
| |
| /* |
| * If the write_bitmaps() function is present, call it to |
| * flush the bitmaps. This is done this way so that a simple |
| * program that doesn't mess with the bitmaps doesn't need to |
| * drag in the bitmaps.c code. |
| */ |
| if (fs->write_bitmaps) { |
| retval = fs->write_bitmaps(fs); |
| if (retval) |
| goto errout; |
| } |
| retval = 0; |
| errout: |
| fs->super->s_state = fs_state; |
| if (fs->flags & EXT2_FLAG_SWAP_BYTES) { |
| if (super_shadow) |
| ext2fs_free_mem((void **) &super_shadow); |
| if (group_shadow) |
| ext2fs_free_mem((void **) &group_shadow); |
| } |
| return retval; |
| } |
| |
| errcode_t ext2fs_close(ext2_filsys fs) |
| { |
| errcode_t retval; |
| |
| EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); |
| |
| if (fs->flags & EXT2_FLAG_DIRTY) { |
| retval = ext2fs_flush(fs); |
| if (retval) |
| return retval; |
| } |
| if (fs->write_bitmaps) { |
| retval = fs->write_bitmaps(fs); |
| if (retval) |
| return retval; |
| } |
| ext2fs_free(fs); |
| return 0; |
| } |
| |