fs/exfat/repair.c

/*
	repair.c (09.03.17)
	exFAT file system implementation library.

	Free exFAT implementation.
	Copyright (C) 2010-2023  Andrew Nayenko

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 2 of the License, or
	(at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License along
	with this program; if not, write to the Free Software Foundation, Inc.,
	51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "exfat.h"
#include <strings.h>

int exfat_errors_fixed;

bool exfat_ask_to_fix(const struct exfat* ef)
{
	const char* question = "Fix (Y/N)?";
	char answer[8];
	bool yeah, nope;

	switch (ef->repair)
	{
	case EXFAT_REPAIR_NO:
		return false;
	case EXFAT_REPAIR_YES:
		printf("%s %s", question, "Y\n");
		return true;
	case EXFAT_REPAIR_ASK:
		do
		{
			printf("%s ", question);
			fflush(stdout);
			if (fgets(answer, sizeof(answer), stdin))
			{
				yeah = strcasecmp(answer, "Y\n") == 0;
				nope = strcasecmp(answer, "N\n") == 0;
			}
			else
			{
				yeah = false;
				nope = true;
			}
		}
		while (!yeah && !nope);
		return yeah;
	}
	exfat_bug("invalid repair option value: %d", ef->repair);
}

bool exfat_fix_invalid_vbr_checksum(const struct exfat* ef, void* sector,
		uint32_t vbr_checksum)
{
	size_t i;
	off_t sector_size = SECTOR_SIZE(*ef->sb);

	for (i = 0; i < sector_size / sizeof(vbr_checksum); i++)
		((le32_t*) sector)[i] = cpu_to_le32(vbr_checksum);
	if (exfat_pwrite(ef->dev, sector, sector_size, 11 * sector_size) < 0)
	{
		exfat_error("failed to write correct VBR checksum");
		return false;
	}
	exfat_errors_fixed++;
	return true;
}

bool exfat_fix_invalid_node_checksum(UNUSED const struct exfat* ef,
		struct exfat_node* node)
{
	/* checksum will be rewritten by exfat_flush_node() */
	node->is_dirty = true;

	exfat_errors_fixed++;
	return true;
}

bool exfat_fix_unknown_entry(struct exfat* ef, struct exfat_node* dir,
		const struct exfat_entry* entry, off_t offset)
{
	struct exfat_entry deleted = *entry;

	deleted.type &= ~EXFAT_ENTRY_VALID;
	if (exfat_generic_pwrite(ef, dir, &deleted, sizeof(struct exfat_entry),
			offset) != sizeof(struct exfat_entry))
		return false;

	exfat_errors_fixed++;
	return true;
}