C++ EXT2_INODES_PER_GROUP函数代码示例

static int ext2_setup_super (struct super_block * sb,
			      struct ext2_super_block * es,
			      int read_only)
{
	int res = 0;
	struct ext2_sb_info *sbi = EXT2_SB(sb);

	if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
		printk ("EXT2-fs warning: revision level too high, "
			"forcing read-only mode\n");
		res = MS_RDONLY;
	}
	if (read_only)
		return res;
	if (!(sbi->s_mount_state & EXT2_VALID_FS))
		printk ("EXT2-fs warning: mounting unchecked fs, "
			"running e2fsck is recommended\n");
	else if ((sbi->s_mount_state & EXT2_ERROR_FS))
		printk ("EXT2-fs warning: mounting fs with errors, "
			"running e2fsck is recommended\n");
	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
		 le16_to_cpu(es->s_mnt_count) >=
		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
		printk ("EXT2-fs warning: maximal mount count reached, "
			"running e2fsck is recommended\n");
	else if (le32_to_cpu(es->s_checkinterval) &&
		(le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds()))
		printk ("EXT2-fs warning: checktime reached, "
			"running e2fsck is recommended\n");
	if (!le16_to_cpu(es->s_max_mnt_count))
		es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
	le16_add_cpu(&es->s_mnt_count, 1);
	ext2_write_super(sb);
	if (test_opt (sb, DEBUG))
		printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
			"bpg=%lu, ipg=%lu, mo=%04lx]\n",
			EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
			sbi->s_frag_size,
			sbi->s_groups_count,
			EXT2_BLOCKS_PER_GROUP(sb),
			EXT2_INODES_PER_GROUP(sb),
			sbi->s_mount_opt);
	return res;
}

static void check_inode_end(e2fsck_t ctx)
{
	ext2_filsys fs = ctx->fs;
	ext2_ino_t	end, save_inodes_count, i;
	struct problem_context	pctx;

	clear_problem_context(&pctx);

	end = EXT2_INODES_PER_GROUP(fs->super) * fs->group_desc_count;
	pctx.errcode = ext2fs_fudge_inode_bitmap_end(fs->inode_map, end,
						     &save_inodes_count);
	if (pctx.errcode) {
		pctx.num = 1;
		fix_problem(ctx, PR_5_FUDGE_BITMAP_ERROR, &pctx);
		ctx->flags |= E2F_FLAG_ABORT; /* fatal */
		return;
	}
	if (save_inodes_count == end)
		return;

	/* protect loop from wrap-around if end is maxed */
	for (i = save_inodes_count + 1; i <= end && i > save_inodes_count; i++) {
		if (!ext2fs_test_inode_bitmap(fs->inode_map, i)) {
			if (fix_problem(ctx, PR_5_INODE_BMAP_PADDING, &pctx)) {
				for (; i <= end; i++)
					ext2fs_mark_inode_bitmap(fs->inode_map,
								 i);
				ext2fs_mark_ib_dirty(fs);
			} else
				ext2fs_unmark_valid(fs);
			break;
		}
	}

	pctx.errcode = ext2fs_fudge_inode_bitmap_end(fs->inode_map,
						     save_inodes_count, 0);
	if (pctx.errcode) {
		pctx.num = 2;
		fix_problem(ctx, PR_5_FUDGE_BITMAP_ERROR, &pctx);
		ctx->flags |= E2F_FLAG_ABORT; /* fatal */
		return;
	}
}

errcode_t ext2fs_write_inode_bitmap(ext2_filsys fs)
{
	dgrp_t		i;
	size_t		nbytes;
	errcode_t	retval;
	char * inode_bitmap = fs->inode_map->bitmap;
	char * bitmap_block = NULL;
	blk_t		blk;

	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

	if (!(fs->flags & EXT2_FLAG_RW))
		return EXT2_ET_RO_FILSYS;
	if (!inode_bitmap)
		return 0;
	nbytes = (size_t) ((EXT2_INODES_PER_GROUP(fs->super)+7) / 8);

	retval = ext2fs_get_mem(fs->blocksize, &bitmap_block);
	if (retval)
		return retval;
	memset(bitmap_block, 0xff, fs->blocksize);
	for (i = 0; i < fs->group_desc_count; i++) {
		memcpy(bitmap_block, inode_bitmap, nbytes);
		blk = fs->group_desc[i].bg_inode_bitmap;
		if (blk) {
#ifdef EXT2_BIG_ENDIAN_BITMAPS
			if (!((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
			      (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE)))
				ext2fs_swap_bitmap(fs, bitmap_block, nbytes);
#endif
			retval = io_channel_write_blk(fs->io, blk, 1,
						      bitmap_block);
			if (retval)
				return EXT2_ET_INODE_BITMAP_WRITE;
		}
		inode_bitmap += nbytes;
	}
	fs->flags &= ~EXT2_FLAG_IB_DIRTY;
	ext2fs_free_mem(&bitmap_block);
	return 0;
}

static void ext2_setup_super (struct super_block * sb,
			      struct ext2_super_block * es)
{
	if (!(sb->s_flags & MS_RDONLY)) {
		if (!(sb->u.ext2_sb.s_mount_state & EXT2_VALID_FS))
			printk ("EXT2-fs warning: mounting unchecked fs, "
				"running e2fsck is recommended\n");
		else if ((sb->u.ext2_sb.s_mount_state & EXT2_ERROR_FS))
			printk ("EXT2-fs warning: mounting fs with errors, "
				"running e2fsck is recommended\n");
		else if (es->s_max_mnt_count >= 0 &&
		         es->s_mnt_count >= (unsigned short) es->s_max_mnt_count)
			printk ("EXT2-fs warning: maximal mount count reached, "
				"running e2fsck is recommended\n");
		else if (es->s_checkinterval &&
			(es->s_lastcheck + es->s_checkinterval <= CURRENT_TIME))
			printk ("EXT2-fs warning: checktime reached, "
				"running e2fsck is recommended\n");
		es->s_state &= ~EXT2_VALID_FS;
		if (!es->s_max_mnt_count)
			es->s_max_mnt_count = EXT2_DFL_MAX_MNT_COUNT;
		es->s_mnt_count++;
		es->s_mtime = CURRENT_TIME;
		sb->u.ext2_sb.s_sbh->b_dirt = 1;
		sb->s_dirt = 1;
		if (test_opt (sb, DEBUG))
			printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
				"bpg=%lu, ipg=%lu, mo=%04lx]\n",
				EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
				sb->u.ext2_sb.s_frag_size,
				sb->u.ext2_sb.s_groups_count,
				EXT2_BLOCKS_PER_GROUP(sb),
				EXT2_INODES_PER_GROUP(sb),
				sb->u.ext2_sb.s_mount_opt);
		if (test_opt (sb, CHECK)) {
			ext2_check_blocks_bitmap (sb);
			ext2_check_inodes_bitmap (sb);
		}
	}
}

unsigned long ext2_count_free_inodes (struct super_block * sb)
{
#ifdef EXT2FS_DEBUG
	struct ext2_super_block * es;
	unsigned long desc_count, bitmap_count, x;
	int bitmap_nr;
	struct ext2_group_desc * gdp;
	int i, bs;

	lock_super (sb);
	es = sb->u.ext2_sb.s_es;
	bs = BYTE_SWAP(sb->u.ext2_sb.s_byte_swapped);
	desc_count = 0;
	bitmap_count = 0;
	gdp = NULL;
	for (i = 0; i < sb->u.ext2_sb.s_groups_count; i++) {
		gdp = get_group_desc (sb, i, NULL);
		desc_count += e_swab (bs, gdp->bg_free_inodes_count);
		bitmap_nr = load_inode_bitmap (sb, i);
		if (bitmap_nr < 0)
			continue;
		
		x = ext2_count_free (sb->u.ext2_sb.s_inode_bitmap[bitmap_nr],
				     EXT2_INODES_PER_GROUP(sb) / 8);
		printk ("group %d: stored = %d, counted = %lu\n",
			i, e_swab (bs, gdp->bg_free_inodes_count), x);
		bitmap_count += x;
	}
	printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
		e_swab (bs, es->s_free_inodes_count), desc_count, bitmap_count);
	unlock_super (sb);
	return desc_count;
#else
	return e_swab (BYTE_SWAP(sb->u.ext2_sb.s_byte_swapped),
		       sb->u.ext2_sb.s_es->s_free_inodes_count);
#endif
}

static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block)
{
	dgrp_t 		i;
	unsigned int	j;
	int		block_nbytes, inode_nbytes;
	unsigned int	nbits;
	errcode_t	retval;
	char 		*block_bitmap, *inode_bitmap;
	char 		*block_buf, *inode_buf;
	int		lazy_flag = 0;
	blk_t		blk;

	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

	if (!(fs->flags & EXT2_FLAG_RW))
		return EXT2_ET_RO_FILSYS;
	if (EXT2_HAS_COMPAT_FEATURE(fs->super, 
				    EXT2_FEATURE_COMPAT_LAZY_BG))
		lazy_flag = 1;
	inode_nbytes = block_nbytes = 0;
	block_bitmap = inode_bitmap = 0;
	if (do_block) {
		block_bitmap = fs->block_map->bitmap;
		block_nbytes = EXT2_BLOCKS_PER_GROUP(fs->super) / 8;
		retval = ext2fs_get_mem(fs->blocksize, &block_buf);
		if (retval)
			return retval;
		memset(block_buf, 0xff, fs->blocksize);
	}
	if (do_inode) {
		inode_bitmap = fs->inode_map->bitmap;
		inode_nbytes = (size_t) 
			((EXT2_INODES_PER_GROUP(fs->super)+7) / 8);
		retval = ext2fs_get_mem(fs->blocksize, &inode_buf);
		if (retval)
			return retval;
		memset(inode_buf, 0xff, fs->blocksize);
	}

	for (i = 0; i < fs->group_desc_count; i++) {
		if (!block_bitmap || !do_block)
			goto skip_block_bitmap;

		if (lazy_flag && fs->group_desc[i].bg_flags &
		    EXT2_BG_BLOCK_UNINIT) 
			goto skip_this_block_bitmap;
 
		memcpy(block_buf, block_bitmap, block_nbytes);
		if (i == fs->group_desc_count - 1) {
			/* Force bitmap padding for the last group */
			nbits = ((fs->super->s_blocks_count
				  - fs->super->s_first_data_block)
				 % EXT2_BLOCKS_PER_GROUP(fs->super));
			if (nbits)
				for (j = nbits; j < fs->blocksize * 8; j++)
					ext2fs_set_bit(j, block_buf);
		}
		blk = fs->group_desc[i].bg_block_bitmap;
		if (blk) {
#ifdef EXT2_BIG_ENDIAN_BITMAPS
			if (!((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
			      (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE)))
				ext2fs_swap_bitmap(fs, block_buf, 
						   block_nbytes);
#endif
			retval = io_channel_write_blk(fs->io, blk, 1,
						      block_buf);
			if (retval)
				return EXT2_ET_BLOCK_BITMAP_WRITE;
		}
	skip_this_block_bitmap:
		block_bitmap += block_nbytes;
	skip_block_bitmap:

		if (!inode_bitmap || !do_inode)
			continue;

		if (lazy_flag && fs->group_desc[i].bg_flags &
		    EXT2_BG_INODE_UNINIT) 
			goto skip_this_inode_bitmap;
 
		memcpy(inode_buf, inode_bitmap, inode_nbytes);
		blk = fs->group_desc[i].bg_inode_bitmap;
		if (blk) {
#ifdef EXT2_BIG_ENDIAN_BITMAPS
			if (!((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
			      (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE)))
				ext2fs_swap_bitmap(fs, inode_buf, 
						   inode_nbytes);
#endif
			retval = io_channel_write_blk(fs->io, blk, 1,
						      inode_buf);
			if (retval)
				return EXT2_ET_INODE_BITMAP_WRITE;
		}
	skip_this_inode_bitmap:
		inode_bitmap += inode_nbytes;

	}
	if (do_block) {
//.........这里部分代码省略.........

//.........这里部分代码省略.........

	if (!ext2fs_has_feature_bigalloc(fs->super) &&
	    (fs->super->s_log_block_size != fs->super->s_log_cluster_size)) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->fragsize = fs->blocksize = EXT2_BLOCK_SIZE(fs->super);
	if (EXT2_INODE_SIZE(fs->super) < EXT2_GOOD_OLD_INODE_SIZE) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}

	/* Enforce the block group descriptor size */
	if (ext2fs_has_feature_64bit(fs->super)) {
		if (fs->super->s_desc_size < EXT2_MIN_DESC_SIZE_64BIT) {
			retval = EXT2_ET_BAD_DESC_SIZE;
			goto cleanup;
		}
	} else {
		if (fs->super->s_desc_size &&
		    fs->super->s_desc_size != EXT2_MIN_DESC_SIZE) {
			retval = EXT2_ET_BAD_DESC_SIZE;
			goto cleanup;
		}
	}

	fs->cluster_ratio_bits = fs->super->s_log_cluster_size -
		fs->super->s_log_block_size;
	if (EXT2_BLOCKS_PER_GROUP(fs->super) !=
	    EXT2_CLUSTERS_PER_GROUP(fs->super) << fs->cluster_ratio_bits) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	fs->inode_blocks_per_group = ((EXT2_INODES_PER_GROUP(fs->super) *
				       EXT2_INODE_SIZE(fs->super) +
				       EXT2_BLOCK_SIZE(fs->super) - 1) /
				      EXT2_BLOCK_SIZE(fs->super));
	if (block_size) {
		if (block_size != fs->blocksize) {
			retval = EXT2_ET_UNEXPECTED_BLOCK_SIZE;
			goto cleanup;
		}
	}
	/*
	 * Set the blocksize to the filesystem's blocksize.
	 */
	io_channel_set_blksize(fs->io, fs->blocksize);

	/*
	 * If this is an external journal device, don't try to read
	 * the group descriptors, because they're not there.
	 */
	if (ext2fs_has_feature_journal_dev(fs->super)) {
		fs->group_desc_count = 0;
		*ret_fs = fs;
		return 0;
	}

	if (EXT2_INODES_PER_GROUP(fs->super) == 0) {
		retval = EXT2_ET_CORRUPT_SUPERBLOCK;
		goto cleanup;
	}
	/* Precompute the FS UUID to seed other checksums */
	ext2fs_init_csum_seed(fs);

	/*

//.........这里部分代码省略.........
						i = j;
						gdp = tmp;
					}
				}
			}
		}
	}
	else
	{
		/*
		 * Try to place the inode in its parent directory
		 */
		i = dir->i_block_group;
		tmp = get_group_desc (ITOV(dir)->v_mount, i, &bh2);
		if (tmp->bg_free_inodes_count)
			gdp = tmp;
		else
		{
			/*
			 * Use a quadratic hash to find a group with a
			 * free inode
			 */
			for (j = 1; j < sb->s_groups_count; j <<= 1) {
				i += j;
				if (i >= sb->s_groups_count)
					i -= sb->s_groups_count;
				tmp = get_group_desc(ITOV(dir)->v_mount,i,&bh2);
				if (tmp->bg_free_inodes_count) {
					gdp = tmp;
					break;
				}
			}
		}
		if (!gdp) {
			/*
			 * That failed: try linear search for a free inode
			 */
			i = dir->i_block_group + 1;
			for (j = 2; j < sb->s_groups_count; j++) {
				if (++i >= sb->s_groups_count)
					i = 0;
				tmp = get_group_desc(ITOV(dir)->v_mount,i,&bh2);
				if (tmp->bg_free_inodes_count) {
					gdp = tmp;
					break;
				}
			}
		}
	}

	if (!gdp) {
		unlock_super (DEVVP(dir));
		return 0;
	}
	bitmap_nr = load_inode_bitmap (ITOV(dir)->v_mount, i);
	bh = sb->s_inode_bitmap[bitmap_nr];
	if ((j = find_first_zero_bit ((unsigned long *) bh->b_data,
				      EXT2_INODES_PER_GROUP(sb))) <
	    EXT2_INODES_PER_GROUP(sb)) {
		if (set_bit (j, bh->b_data)) {
			kprintf ( "ext2_new_inode:"
				      "bit already set for inode %d", j);
			goto repeat;
		}
/* Linux now does the following:
		mark_buffer_dirty(bh);
		if (sb->s_flags & MS_SYNCHRONOUS) {
			ll_rw_block (WRITE, 1, &bh);
			wait_on_buffer (bh);
		}
*/
		mark_buffer_dirty(bh);
	} else {
		if (gdp->bg_free_inodes_count != 0) {
			kprintf ( "ext2_new_inode:"
				    "Free inodes count corrupted in group %d",
				    i);
			unlock_super (DEVVP(dir));
			return 0;
		}
		goto repeat;
	}
	j += i * EXT2_INODES_PER_GROUP(sb) + 1;
	if (j < EXT2_FIRST_INO(sb) || j > es->s_inodes_count) {
		kprintf ( "ext2_new_inode:"
			    "reserved inode or inode > inodes count - "
			    "block_group = %d,inode=%d", i, j);
		unlock_super (DEVVP(dir));
		return 0;
	}
	gdp->bg_free_inodes_count--;
	if (S_ISDIR(mode))
		gdp->bg_used_dirs_count++;
	mark_buffer_dirty(bh2);
	es->s_free_inodes_count--;
	/* mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1); */
	sb->s_dirt = 1;
	unlock_super (DEVVP(dir));
	return j;
}

static errcode_t read_bitmaps(ext2_filsys fs, int do_inode, int do_block)
{
	dgrp_t i;
	char *block_bitmap = 0, *inode_bitmap = 0;
	char *buf;
	errcode_t retval;
	int block_nbytes = (int) EXT2_BLOCKS_PER_GROUP(fs->super) / 8;
	int inode_nbytes = (int) EXT2_INODES_PER_GROUP(fs->super) / 8;
	int lazy_flag = 0;
	blk_t	blk;

	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

	fs->write_bitmaps = ext2fs_write_bitmaps;

	if (EXT2_HAS_COMPAT_FEATURE(fs->super, 
				    EXT2_FEATURE_COMPAT_LAZY_BG))
		lazy_flag = 1;

	retval = ext2fs_get_mem(strlen(fs->device_name) + 80, &buf);
	if (retval)
		return retval;
	if (do_block) {
		if (fs->block_map)
			ext2fs_free_block_bitmap(fs->block_map);
		sprintf(buf, "block bitmap for %s", fs->device_name);
		retval = ext2fs_allocate_block_bitmap(fs, buf, &fs->block_map);
		if (retval)
			goto cleanup;
		block_bitmap = fs->block_map->bitmap;
	}
	if (do_inode) {
		if (fs->inode_map)
			ext2fs_free_inode_bitmap(fs->inode_map);
		sprintf(buf, "inode bitmap for %s", fs->device_name);
		retval = ext2fs_allocate_inode_bitmap(fs, buf, &fs->inode_map);
		if (retval)
			goto cleanup;
		inode_bitmap = fs->inode_map->bitmap;
	}
	ext2fs_free_mem(&buf);

	if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
		if (inode_bitmap) {
			blk = (fs->image_header->offset_inodemap /
			       fs->blocksize);
			retval = io_channel_read_blk(fs->image_io, blk,
			     -(inode_nbytes * fs->group_desc_count),
			     inode_bitmap);
			if (retval)
				goto cleanup;
		}
		if (block_bitmap) {
			blk = (fs->image_header->offset_blockmap /
			       fs->blocksize);
			retval = io_channel_read_blk(fs->image_io, blk, 
			     -(block_nbytes * fs->group_desc_count),
			     block_bitmap);
			if (retval)
				goto cleanup;
		}
		return 0;
	}

	for (i = 0; i < fs->group_desc_count; i++) {
		if (block_bitmap) {
			blk = fs->group_desc[i].bg_block_bitmap;
			if (lazy_flag && fs->group_desc[i].bg_flags &
			    EXT2_BG_BLOCK_UNINIT)
				blk = 0;
			if (blk) {
				retval = io_channel_read_blk(fs->io, blk,
					     -block_nbytes, block_bitmap);
				if (retval) {
					retval = EXT2_ET_BLOCK_BITMAP_READ;
					goto cleanup;
				}
#ifdef EXT2_BIG_ENDIAN_BITMAPS
				if (!((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
				      (fs->flags & EXT2_FLAG_SWAP_BYTES_READ)))
					ext2fs_swap_bitmap(fs, block_bitmap, block_nbytes);
#endif
			} else
				memset(block_bitmap, 0xff, block_nbytes);
			block_bitmap += block_nbytes;
		}
		if (inode_bitmap) {
			blk = fs->group_desc[i].bg_inode_bitmap;
			if (lazy_flag && fs->group_desc[i].bg_flags &
			    EXT2_BG_INODE_UNINIT)
				blk = 0;
			if (blk) {
				retval = io_channel_read_blk(fs->io, blk,
					     -inode_nbytes, inode_bitmap);
				if (retval) {
					retval = EXT2_ET_INODE_BITMAP_READ;
					goto cleanup;
				}
#ifdef EXT2_BIG_ENDIAN_BITMAPS
				if (!((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
//.........这里部分代码省略.........

static void ext2_setup_super (struct super_block * sb,
                              struct ext2_super_block * es)
{
#ifdef OS2
        if (Errors_Panic) {
            clear_opt(sb->u.ext2_sb.s_mount_opt, ERRORS_CONT);
            clear_opt(sb->u.ext2_sb.s_mount_opt, ERRORS_RO);
            set_opt(sb->u.ext2_sb.s_mount_opt, ERRORS_PANIC);
        } else {
            clear_opt(sb->u.ext2_sb.s_mount_opt, ERRORS_PANIC);
            clear_opt(sb->u.ext2_sb.s_mount_opt, ERRORS_RO);
            set_opt(sb->u.ext2_sb.s_mount_opt, ERRORS_CONT);
        }
#endif

        if (es->s_rev_level > EXT2_CURRENT_REV) {
                        printk ("EXT2-fs warning: revision level too high, "
                                "forcing read/only mode\n");
                        sb->s_flags |= MS_RDONLY;
        }
        if (!(sb->s_flags & MS_RDONLY)) {
                if (!(sb->u.ext2_sb.s_mount_state & EXT2_VALID_FS))
                        printk ("EXT2-fs warning: mounting unchecked fs, "
                                "running e2fsck is recommended\n");
                else if ((sb->u.ext2_sb.s_mount_state & EXT2_ERROR_FS))
                        printk ("EXT2-fs warning: mounting fs with errors, "
                                "running e2fsck is recommended\n");
                else if (es->s_max_mnt_count >= 0 &&
                         es->s_mnt_count >= (unsigned short) es->s_max_mnt_count)
                        printk ("EXT2-fs warning: maximal mount count reached, "
                                "running e2fsck is recommended\n");
                else if (es->s_checkinterval &&
                        (es->s_lastcheck + es->s_checkinterval <= CURRENT_TIME))
                        printk ("EXT2-fs warning: checktime reached, "
                                "running e2fsck is recommended\n");
                es->s_state &= ~EXT2_VALID_FS;
                if (!es->s_max_mnt_count)
                        es->s_max_mnt_count = EXT2_DFL_MAX_MNT_COUNT;
#ifndef OS2
                es->s_mnt_count++;
#else
                //
                // This is to force Linux to autocheck the ext2fs partition "touched" by OS/2
                // this autocheck is enabled unless -no_auto_fsck is specified on the IFS cmd
                // line
                //
                if (auto_fsck) {
                    kernel_printf("e2fsck will be forced next time Linux will mount this partition");
                      es->s_mnt_count = EXT2_DFL_MAX_MNT_COUNT;
                } else {
                    es->s_mnt_count++;
                }
#endif
                es->s_mtime = CURRENT_TIME;
                mark_buffer_dirty(sb->u.ext2_sb.s_sbh, 1);
                sb->s_dirt = 1;
#ifndef OS2 // For the moment .....
                if (test_opt (sb, DEBUG))
#endif
                        printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
                                "bpg=%lu, ipg=%lu, mo=%04lx]\n",
                                EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
                                sb->u.ext2_sb.s_frag_size,
                                sb->u.ext2_sb.s_groups_count,
                                EXT2_BLOCKS_PER_GROUP(sb),
                                EXT2_INODES_PER_GROUP(sb),
                                sb->u.ext2_sb.s_mount_opt);
#ifndef OS2 // For the moment .....
                if (test_opt (sb, CHECK)) {
#endif
                        ext2_check_blocks_bitmap (sb);
                        ext2_check_inodes_bitmap (sb);
#ifndef OS2 // For the moment .....
                }
#endif
        }
}

static errcode_t write_bitmaps(ext2_filsys fs, int do_inode, int do_block)
{
	dgrp_t 		i;
	unsigned int	j;
	int		block_nbytes, inode_nbytes;
	unsigned int	nbits;
	errcode_t	retval;
	char		*block_buf = NULL, *inode_buf = NULL;
	int		csum_flag = 0;
	blk64_t		blk;
	blk64_t		blk_itr = EXT2FS_B2C(fs, fs->super->s_first_data_block);
	ext2_ino_t	ino_itr = 1;

	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

	if (!(fs->flags & EXT2_FLAG_RW))
		return EXT2_ET_RO_FILSYS;

	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
		csum_flag = 1;

	inode_nbytes = block_nbytes = 0;
	if (do_block) {
		block_nbytes = EXT2_CLUSTERS_PER_GROUP(fs->super) / 8;
		retval = io_channel_alloc_buf(fs->io, 0, &block_buf);
		if (retval)
			goto errout;
		memset(block_buf, 0xff, fs->blocksize);
	}
	if (do_inode) {
		inode_nbytes = (size_t)
			((EXT2_INODES_PER_GROUP(fs->super)+7) / 8);
		retval = io_channel_alloc_buf(fs->io, 0, &inode_buf);
		if (retval)
			goto errout;
		memset(inode_buf, 0xff, fs->blocksize);
	}

	for (i = 0; i < fs->group_desc_count; i++) {
		if (!do_block)
			goto skip_block_bitmap;

		if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_BLOCK_UNINIT)
		    )
			goto skip_this_block_bitmap;

		retval = ext2fs_get_block_bitmap_range2(fs->block_map,
				blk_itr, block_nbytes << 3, block_buf);
		if (retval)
			goto errout;

		if (i == fs->group_desc_count - 1) {
			/* Force bitmap padding for the last group */
			nbits = EXT2FS_NUM_B2C(fs,
				((ext2fs_blocks_count(fs->super)
				  - (__u64) fs->super->s_first_data_block)
				 % (__u64) EXT2_BLOCKS_PER_GROUP(fs->super)));
			if (nbits)
				for (j = nbits; j < fs->blocksize * 8; j++)
					ext2fs_set_bit(j, block_buf);
		}
		blk = ext2fs_block_bitmap_loc(fs, i);
		if (blk) {
			retval = io_channel_write_blk64(fs->io, blk, 1,
							block_buf);
			if (retval) {
				retval = EXT2_ET_BLOCK_BITMAP_WRITE;
				goto errout;
			}
		}
	skip_this_block_bitmap:
		blk_itr += block_nbytes << 3;
	skip_block_bitmap:

		if (!do_inode)
			continue;

		if (csum_flag && ext2fs_bg_flags_test(fs, i, EXT2_BG_INODE_UNINIT)
		    )
			goto skip_this_inode_bitmap;

		retval = ext2fs_get_inode_bitmap_range2(fs->inode_map,
				ino_itr, inode_nbytes << 3, inode_buf);
		if (retval)
			goto errout;

		blk = ext2fs_inode_bitmap_loc(fs, i);
		if (blk) {
			retval = io_channel_write_blk64(fs->io, blk, 1,
						      inode_buf);
			if (retval) {
				retval = EXT2_ET_INODE_BITMAP_WRITE;
				goto errout;
			}
		}
	skip_this_inode_bitmap:
		ino_itr += inode_nbytes << 3;

	}
//.........这里部分代码省略.........

/*
 * Functions to read and write a single inode.
 */
errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino,
				 struct ext2_inode * inode, int bufsize)
{
	blk64_t		block_nr;
	unsigned long 	group, block, offset;
	char 		*ptr;
	errcode_t	retval;
	unsigned	i;
	int		clen, inodes_per_block;
	io_channel	io;
	int		length = EXT2_INODE_SIZE(fs->super);
	struct ext2_inode_large	*iptr;
	int		cache_slot, fail_csum;

	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

	/* Check to see if user has an override function */
	if (fs->read_inode &&
	    ((bufsize == sizeof(struct ext2_inode)) ||
	     (EXT2_INODE_SIZE(fs->super) == sizeof(struct ext2_inode)))) {
		retval = (fs->read_inode)(fs, ino, inode);
		if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
			return retval;
	}
	if ((ino == 0) || (ino > fs->super->s_inodes_count))
		return EXT2_ET_BAD_INODE_NUM;
	/* Create inode cache if not present */
	if (!fs->icache) {
		retval = ext2fs_create_inode_cache(fs, 4);
		if (retval)
			return retval;
	}
	/* Check to see if it's in the inode cache */
	for (i = 0; i < fs->icache->cache_size; i++) {
		if (fs->icache->cache[i].ino == ino) {
			memcpy(inode, fs->icache->cache[i].inode,
			       (bufsize > length) ? length : bufsize);
			return 0;
		}
	}
	if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
		inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super);
		block_nr = fs->image_header->offset_inode / fs->blocksize;
		block_nr += (ino - 1) / inodes_per_block;
		offset = ((ino - 1) % inodes_per_block) *
			EXT2_INODE_SIZE(fs->super);
		io = fs->image_io;
	} else {
		group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
		if (group > fs->group_desc_count)
			return EXT2_ET_BAD_INODE_NUM;
		offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
			EXT2_INODE_SIZE(fs->super);
		block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
		if (!ext2fs_inode_table_loc(fs, (unsigned) group))
			return EXT2_ET_MISSING_INODE_TABLE;
		block_nr = ext2fs_inode_table_loc(fs, group) +
			block;
		io = fs->io;
	}
	offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);

	cache_slot = (fs->icache->cache_last + 1) % fs->icache->cache_size;
	iptr = (struct ext2_inode_large *)fs->icache->cache[cache_slot].inode;

	ptr = (char *) iptr;
	while (length) {
		clen = length;
		if ((offset + length) > fs->blocksize)
			clen = fs->blocksize - offset;

		if (block_nr != fs->icache->buffer_blk) {
			retval = io_channel_read_blk64(io, block_nr, 1,
						     fs->icache->buffer);
			if (retval)
				return retval;
			fs->icache->buffer_blk = block_nr;
		}

		memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset,
		       clen);

		offset = 0;
		length -= clen;
		ptr += clen;
		block_nr++;
	}
	length = EXT2_INODE_SIZE(fs->super);

	/* Verify the inode checksum. */
	fail_csum = !ext2fs_inode_csum_verify(fs, ino, iptr);

#ifdef WORDS_BIGENDIAN
	ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) iptr,
			       (struct ext2_inode_large *) iptr,
			       0, length);
#endif
//.........这里部分代码省略.........

errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks,
				 ext2_inode_scan *ret_scan)
{
	ext2_inode_scan	scan;
	errcode_t	retval;
	errcode_t (*save_get_blocks)(ext2_filsys f, ext2_ino_t ino, blk_t *blocks);

	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

	/*
	 * If fs->badblocks isn't set, then set it --- since the inode
	 * scanning functions require it.
	 */
	if (fs->badblocks == 0) {
		/*
		 * Temporarly save fs->get_blocks and set it to zero,
		 * for compatibility with old e2fsck's.
		 */
		save_get_blocks = fs->get_blocks;
		fs->get_blocks = 0;
		retval = ext2fs_read_bb_inode(fs, &fs->badblocks);
		if (retval && fs->badblocks) {
			ext2fs_badblocks_list_free(fs->badblocks);
			fs->badblocks = 0;
		}
		fs->get_blocks = save_get_blocks;
	}

	retval = ext2fs_get_mem(sizeof(struct ext2_struct_inode_scan), &scan);
	if (retval)
		return retval;
	memset(scan, 0, sizeof(struct ext2_struct_inode_scan));

	scan->magic = EXT2_ET_MAGIC_INODE_SCAN;
	scan->fs = fs;
	scan->inode_size = EXT2_INODE_SIZE(fs->super);
	scan->bytes_left = 0;
	scan->current_group = 0;
	scan->groups_left = fs->group_desc_count - 1;
	scan->inode_buffer_blocks = buffer_blocks ? buffer_blocks :
				    EXT2_INODE_SCAN_DEFAULT_BUFFER_BLOCKS;
	scan->current_block = ext2fs_inode_table_loc(scan->fs,
						     scan->current_group);
	scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
	scan->blocks_left = scan->fs->inode_blocks_per_group;
	if (ext2fs_has_group_desc_csum(fs)) {
		__u32 unused = ext2fs_bg_itable_unused(fs, scan->current_group);
		if (scan->inodes_left > unused)
			scan->inodes_left -= unused;
		else
			scan->inodes_left = 0;
		scan->blocks_left =
			(scan->inodes_left +
			 (fs->blocksize / scan->inode_size - 1)) *
			scan->inode_size / fs->blocksize;
	}
	retval = io_channel_alloc_buf(fs->io, scan->inode_buffer_blocks,
				      &scan->inode_buffer);
	scan->done_group = 0;
	scan->done_group_data = 0;
	scan->bad_block_ptr = 0;
	if (retval) {
		ext2fs_free_mem(&scan);
		return retval;
	}
	retval = ext2fs_get_mem(scan->inode_size + scan->inode_buffer_blocks,
				&scan->temp_buffer);
	if (retval) {
		ext2fs_free_mem(&scan->inode_buffer);
		ext2fs_free_mem(&scan);
		return retval;
	}
	memset(SCAN_BLOCK_STATUS(scan), 0, scan->inode_buffer_blocks);
	if (scan->fs->badblocks && scan->fs->badblocks->num)
		scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS;
	if (ext2fs_has_group_desc_csum(fs))
		scan->scan_flags |= EXT2_SF_DO_LAZY;
	*ret_scan = scan;
	return 0;
}

errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks,
				 ext2_inode_scan *ret_scan)
{
	ext2_inode_scan	scan;
	errcode_t	retval;
	errcode_t (*save_get_blocks)(ext2_filsys f, ext2_ino_t ino, blk_t *blocks);

	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);

	/*
	 * If fs->badblocks isn't set, then set it --- since the inode
	 * scanning functions require it.
	 */
	if (fs->badblocks == 0) {
		/*
		 * Temporarly save fs->get_blocks and set it to zero,
		 * for compatibility with old e2fsck's.
		 */
		save_get_blocks = fs->get_blocks;
		fs->get_blocks = 0;
		retval = ext2fs_read_bb_inode(fs, &fs->badblocks);
		if (retval && fs->badblocks) {
			ext2fs_badblocks_list_free(fs->badblocks);
			fs->badblocks = 0;
		}
		fs->get_blocks = save_get_blocks;
	}

	retval = ext2fs_get_mem(sizeof(struct ext2_struct_inode_scan), &scan);
	if (retval)
		return retval;
	memset(scan, 0, sizeof(struct ext2_struct_inode_scan));

	scan->magic = EXT2_ET_MAGIC_INODE_SCAN;
	scan->fs = fs;
	scan->inode_size = EXT2_INODE_SIZE(fs->super);
	scan->bytes_left = 0;
	scan->current_group = 0;
	scan->groups_left = fs->group_desc_count - 1;
	scan->inode_buffer_blocks = buffer_blocks ? buffer_blocks : 8;
	scan->current_block = scan->fs->
		group_desc[scan->current_group].bg_inode_table;
	scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
	scan->blocks_left = scan->fs->inode_blocks_per_group;
	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
		scan->inodes_left -=
			fs->group_desc[scan->current_group].bg_itable_unused;
		scan->blocks_left =
			(scan->inodes_left +
			 (fs->blocksize / scan->inode_size - 1)) *
			scan->inode_size / fs->blocksize;
	}
	retval = ext2fs_get_memalign(scan->inode_buffer_blocks * fs->blocksize,
				     fs->blocksize, &scan->inode_buffer);
	scan->done_group = 0;
	scan->done_group_data = 0;
	scan->bad_block_ptr = 0;
	if (retval) {
		ext2fs_free_mem(&scan);
		return retval;
	}
	retval = ext2fs_get_mem(scan->inode_size, &scan->temp_buffer);
	if (retval) {
		ext2fs_free_mem(&scan->inode_buffer);
		ext2fs_free_mem(&scan);
		return retval;
	}
	if (scan->fs->badblocks && scan->fs->badblocks->num)
		scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS;
	if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
				       EXT4_FEATURE_RO_COMPAT_GDT_CSUM))
		scan->scan_flags |= EXT2_SF_DO_LAZY;
	*ret_scan = scan;
	return 0;
}

static int ext2_setup_super (struct super_block * sb,
			      struct ext2_super_block * es,
			      int read_only)
{
	int res = 0;
	struct ext2_sb_info *sbi = EXT2_SB(sb);

	if (le32_to_cpu(es->s_rev_level) > EXT2_MAX_SUPP_REV) {
		printk ("EXT2-fs warning: revision level too high, "
			"forcing read-only mode\n");
		res = MS_RDONLY;
	}
	if (read_only)
		return res;
	/* PR 28089 - Allow user to turn off a forced fsck in order
	 * to let user to mount a dirty FS RW
	 * Thus if FS is dirty and nocheck is the mount option, then
	 * FS is mounted RW.
	 */
	if (!(sbi->s_mount_state & EXT2_VALID_FS)) {
		if (!test_opt (sb, CHECK))
			printk ("EXT2-fs warning: mounting unclean fs with "
			"errors in RW mode.\nRunning e2fsck is strongly urged "
			"and recommended.\n");
		else {
			printk ("EXT2-fs warning: mounting unchecked fs read-only. "
			"Running e2fsck is recommended before re-mounting read-write.\n");
			sb->s_flags |= MS_RDONLY;
			return MS_RDONLY;
		}
	}
	/* PR 28089 - Allow user to turn off a forced fsck in order
	 * to let user to mount a dirty FS RW.
	 * Thus if FS is dirty and nocheck is the mount option, then
	 * FS is mounted RW.
	 */
	else if ((sbi->s_mount_state & EXT2_ERROR_FS)) {
		if (!test_opt (sb, CHECK))
			printk ("EXT2-fs warning: mounting unclean fs with "
			"errors in RW mode.\nRunning e2fsck is strongly urged "
			"and recommended.\n");
		else {
			printk ("EXT2-fs warning: mounting unchecked fs read-only. "
			"Running e2fsck is recommended before re-mounting read-write.\n");
			sb->s_flags |= MS_RDONLY;
			return MS_RDONLY;
		}
	}
	else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
		 le16_to_cpu(es->s_mnt_count) >=
		 (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count)) {
		printk ("EXT2-fs warning: maximal mount count reached. Mounting read-only. "
			"Running e2fsck is recommended before re-mounting read-write.\n");
		sb->s_flags |= MS_RDONLY;
		return MS_RDONLY;
	}
	else if (le32_to_cpu(es->s_checkinterval) &&
		(le32_to_cpu(es->s_lastcheck) + le32_to_cpu(es->s_checkinterval) <= get_seconds())) {
		printk ("EXT2-fs warning: checktime reached. Mounting read-only. "
			"Running e2fsck is recommended before re-mounting read-write.\n");
		sb->s_flags |= MS_RDONLY;
		return MS_RDONLY;
	}
	if (!le16_to_cpu(es->s_max_mnt_count))
		es->s_max_mnt_count = cpu_to_le16(EXT2_DFL_MAX_MNT_COUNT);
	es->s_mnt_count=cpu_to_le16(le16_to_cpu(es->s_mnt_count) + 1);
	ext2_write_super(sb);
	if (test_opt (sb, DEBUG))
		printk ("[EXT II FS %s, %s, bs=%lu, fs=%lu, gc=%lu, "
			"bpg=%lu, ipg=%lu, mo=%04lx]\n",
			EXT2FS_VERSION, EXT2FS_DATE, sb->s_blocksize,
			sbi->s_frag_size,
			sbi->s_groups_count,
			EXT2_BLOCKS_PER_GROUP(sb),
			EXT2_INODES_PER_GROUP(sb),
			sbi->s_mount_opt);
#ifdef CONFIG_EXT2_CHECK
	if (test_opt (sb, CHECK)) {
		ext2_check_blocks_bitmap (sb);
		ext2_check_inodes_bitmap (sb);
	}
#endif
	return res;
}