path: root/fs/xfs/scrub/dir.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2017-2023 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <djwong@kernel.org>
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_inode.h"
#include "xfs_icache.h"
#include "xfs_dir2.h"
#include "xfs_dir2_priv.h"
#include "xfs_health.h"
#include "xfs_attr.h"
#include "xfs_parent.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/dabtree.h"
#include "scrub/readdir.h"
#include "scrub/health.h"
#include "scrub/repair.h"
#include "scrub/trace.h"
#include "scrub/xfile.h"
#include "scrub/xfarray.h"
#include "scrub/xfblob.h"

/* Set us up to scrub directories. */
int
xchk_setup_directory(
	struct xfs_scrub	*sc)
{
	int			error;

	if (xchk_could_repair(sc)) {
		error = xrep_setup_directory(sc);
		if (error)
			return error;
	}

	return xchk_setup_inode_contents(sc, 0);
}

/* Directories */

/* Deferred directory entry that we saved for later. */
struct xchk_dirent {
	/* Cookie for retrieval of the dirent name. */
	xfblob_cookie		name_cookie;

	/* Child inode number. */
	xfs_ino_t		ino;

	/* Length of the pptr name. */
	uint8_t			namelen;
};

struct xchk_dir {
	struct xfs_scrub	*sc;

	/* information for parent pointer validation. */
	struct xfs_parent_rec	pptr_rec;
	struct xfs_da_args	pptr_args;

	/* Fixed-size array of xchk_dirent structures. */
	struct xfarray		*dir_entries;

	/* Blobs containing dirent names. */
	struct xfblob		*dir_names;

	/* If we've cycled the ILOCK, we must revalidate deferred dirents. */
	bool			need_revalidate;

	/* Name buffer for dirent revalidation. */
	struct xfs_name		xname;
	uint8_t			namebuf[MAXNAMELEN];
};

/* Scrub a directory entry. */

/* Check that an inode's mode matches a given XFS_DIR3_FT_* type. */
STATIC void
xchk_dir_check_ftype(
	struct xfs_scrub	*sc,
	xfs_fileoff_t		offset,
	struct xfs_inode	*ip,
	int			ftype)
{
	struct xfs_mount	*mp = sc->mp;

	if (!xfs_has_ftype(mp)) {
		if (ftype != XFS_DIR3_FT_UNKNOWN && ftype != XFS_DIR3_FT_DIR)
			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
		return;
	}

	if (xfs_mode_to_ftype(VFS_I(ip)->i_mode) != ftype)
		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
}

/*
 * Try to lock a child file for checking parent pointers.  Returns the inode
 * flags for the locks we now hold, or zero if we failed.
 */
STATIC unsigned int
xchk_dir_lock_child(
	struct xfs_scrub	*sc,
	struct xfs_inode	*ip)
{
	if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
		return 0;

	if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) {
		xfs_iunlock(ip, XFS_IOLOCK_SHARED);
		return 0;
	}

	if (!xfs_inode_has_attr_fork(ip) || !xfs_need_iread_extents(&ip->i_af))
		return XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED;

	xfs_iunlock(ip, XFS_ILOCK_SHARED);

	if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
		xfs_iunlock(ip, XFS_IOLOCK_SHARED);
		return 0;
	}

	return XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL;
}

/* Check the backwards link (parent pointer) associated with this dirent. */
STATIC int
xchk_dir_parent_pointer(
	struct xchk_dir		*sd,
	const struct xfs_name	*name,
	struct xfs_inode	*ip)
{
	struct xfs_scrub	*sc = sd->sc;
	int			error;

	xfs_inode_to_parent_rec(&sd->pptr_rec, sc->ip);
	error = xfs_parent_lookup(sc->tp, ip, name, &sd->pptr_rec,
			&sd->pptr_args);
	if (error == -ENOATTR)
		xchk_fblock_xref_set_corrupt(sc, XFS_DATA_FORK, 0);

	return 0;
}

/* Look for a parent pointer matching this dirent, if the child isn't busy. */
STATIC int
xchk_dir_check_pptr_fast(
	struct xchk_dir		*sd,
	xfs_dir2_dataptr_t	dapos,
	const struct xfs_name	*name,
	struct xfs_inode	*ip)
{
	struct xfs_scrub	*sc = sd->sc;
	unsigned int		lockmode;
	int			error;

	/* dot and dotdot entries do not have parent pointers */
	if (xfs_dir2_samename(name, &xfs_name_dot) ||
	    xfs_dir2_samename(name, &xfs_name_dotdot))
		return 0;

	/* No self-referential non-dot or dotdot dirents. */
	if (ip == sc->ip) {
		xchk_fblock_