path: root/fs/xfs/scrub/agheader.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_btree.h"
#include "xfs_sb.h"
#include "xfs_alloc.h"
#include "xfs_ialloc.h"
#include "xfs_rmap.h"
#include "xfs_ag.h"
#include "xfs_inode.h"
#include "scrub/scrub.h"
#include "scrub/common.h"

int
xchk_setup_agheader(
	struct xfs_scrub	*sc)
{
	if (xchk_need_intent_drain(sc))
		xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
	return xchk_setup_fs(sc);
}

/* Superblock */

/* Cross-reference with the other btrees. */
STATIC void
xchk_superblock_xref(
	struct xfs_scrub	*sc,
	struct xfs_buf		*bp)
{
	struct xfs_mount	*mp = sc->mp;
	xfs_agnumber_t		agno = sc->sm->sm_agno;
	xfs_agblock_t		agbno;
	int			error;

	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
		return;

	agbno = XFS_SB_BLOCK(mp);

	error = xchk_ag_init_existing(sc, agno, &sc->sa);
	if (!xchk_xref_process_error(sc, agno, agbno, &error))
		return;

	xchk_xref_is_used_space(sc, agbno, 1);
	xchk_xref_is_not_inode_chunk(sc, agbno, 1);
	xchk_xref_is_only_owned_by(sc, agbno, 1, &XFS_RMAP_OINFO_FS);
	xchk_xref_is_not_shared(sc, agbno, 1);
	xchk_xref_is_not_cow_staging(sc, agbno, 1);

	/* scrub teardown will take care of sc->sa for us */
}

/*
 * Calculate the ondisk superblock size in bytes given the feature set of the
 * mounted filesystem (aka the primary sb).  This is subtlely different from
 * the logic in xfs_repair, which computes the size of a secondary sb given the
 * featureset listed in the secondary sb.
 */
STATIC size_t
xchk_superblock_ondisk_size(
	struct xfs_mount	*mp)
{
	if (xfs_has_metauuid(mp))
		return offsetofend(struct xfs_dsb, sb_meta_uuid);
	if (xfs_has_crc(mp))
		return offsetofend(struct xfs_dsb, sb_lsn);
	if (xfs_sb_version_hasmorebits(&mp->m_sb))
		return offsetofend(struct xfs_dsb, sb_bad_features2);
	if (xfs_has_logv2(mp))
		return offsetofend(struct xfs_dsb, sb_logsunit);
	if (xfs_has_sector(mp))
		return offsetofend(struct xfs_dsb, sb_logsectsize);
	/* only support dirv2 or more recent */
	return offsetofend(struct xfs_dsb, sb_dirblklog);
}

/*
 * Scrub the filesystem superblock.
 *
 * Note: We do /not/ attempt to check AG 0's superblock.  Mount is
 * responsible for validating all the geometry information in sb 0, so
 * if the filesystem is capable of initiating online scrub, then clearly
 * sb 0 is ok and we can use its information to check everything else.
 */
int
xchk_superblock(
	struct xfs_scrub	*sc)
{
	struct xfs_mount	*mp = sc->mp;
	struct xfs_buf		*bp;
	struct xfs_dsb		*sb;
	struct xfs_perag	*pag;
	size_t			sblen;
	xfs_agnumber_t		agno;
	uint32_t		v2_ok;
	__be32			features_mask;
	int			error;
	__be16			vernum_mask;

	agno = sc->sm->sm_agno;
	if (agno == 0)
		return 0;

	/*
	 * Grab an active reference to the perag structure.  If we can't get
	 * it, we're racing with something that's tearing down the AG, so
	 * signal that the AG no longer exists.
	 */
	pag = xfs_perag_get(mp, agno);
	if (!pag)
		return -ENOENT;

	error = xfs_sb_read_secondary(mp, sc->tp, agno, &bp);
	/*
	 * The superblock verifier can return several different error codes
	 * if it thinks the superblock doesn't look right.  For a mount these
	 * would all get bounced back to userspace, but if we're here then the
	 * fs mounted successfully, which means that this secondary superblock
	 * is simply incorrect.  Treat all these codes the same way we treat
	 * any corruption.
	 */
	switch (error) {
	case -EINVAL:	/* also -EWRONGFS */
	case -ENOSYS:
	case -EFBIG:
		error = -EFSCORRUPTED;
		fallthrough;
	default:
		break;
	}
	if (!xchk_process_error(sc, agno, XFS_SB_BLOCK(mp), &error))
		goto out_pag;

	sb = bp->b_addr;

	/*
	 * Verify the geometries match.  Fields that are permanently
	 * set by mkfs are checked; fields that can be updated later
	 * (and are not propagated to backup superblocks) are preen
	 * checked.
	 */
	if (sb->sb_blocksize != cpu_to_be32(mp->m_sb.sb_blocksize))
		xchk_block_set_corrupt(sc, bp);

	if (sb->sb_dblocks != cpu_to_be64(mp->m_sb.sb_dblocks))
		xchk_block_set_corrupt(sc, bp);

	if (sb->sb_rblocks != cpu_to_be64(mp->m_sb.sb_rblocks))
		xchk_block_set_corrupt(sc, bp);

	if (sb->sb_rextents != cpu_to_be64(mp->m_sb.sb_rextents))
		xchk_block_set_corrupt(sc, bp);

	if (!uuid_equal(&sb->sb_uuid, &mp->m_sb.sb_uuid))
		xchk_block_set_preen(sc, bp);

	if (sb->sb_logstart != cpu_to_be64(mp->m_sb.sb_logstart))
		xchk_block_set_corrupt(sc, bp);

	if (sb->sb_rootino != cpu_to_be64(mp->m_sb.sb_rootino))
		xchk_block_set_preen(sc, bp);

	if (sb->sb_rbmino != cpu_to_be64(mp->m_sb.sb_rbmino))
		xchk_block_set_preen(sc, bp);

	if (sb->sb_rsumino != cpu_to_be64(mp->m_sb.sb_rsumino))
		xchk_block_set_preen(sc, bp);

	if (sb->sb_rextsize != cpu_to_be32(mp->m_sb.sb_rextsize))
		xchk_block_set_corrupt(sc, bp);

	if (sb->sb_agblocks != cpu_to_be32(mp->m_sb.sb_agblocks))
		xchk_block_set_corrupt(sc, bp);

	if (sb->sb_agcount != cpu_to_be32(mp->m_sb.sb_agcount