/*
 * Copyright (C) 2017 Oracle.  All Rights Reserved.
 *
 * Author: Darrick J. Wong <darrick.wong@oracle.com>
 *
 * 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 would 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 the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
 */
#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_defer.h"
#include "xfs_btree.h"
#include "xfs_bit.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_inode.h"
#include "scrub/xfs_scrub.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/trace.h"

/*
 * Set up scrub to check all the static metadata in each AG.
 * This means the SB, AGF, AGI, and AGFL headers.
 */
int
xfs_scrub_setup_ag_header(
	struct xfs_scrub_context	*sc,
	struct xfs_inode		*ip)
{
	struct xfs_mount		*mp = sc->mp;

	if (sc->sm->sm_agno >= mp->m_sb.sb_agcount ||
	    sc->sm->sm_ino || sc->sm->sm_gen)
		return -EINVAL;
	return xfs_scrub_setup_fs(sc, ip);
}

/* Superblock */

/*
 * 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
xfs_scrub_superblock(
	struct xfs_scrub_context	*sc)
{
	struct xfs_mount		*mp = sc->mp;
	struct xfs_buf			*bp;
	struct xfs_dsb			*sb;
	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;

	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
		  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
		  XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_sb_buf_ops);
	if (!xfs_scrub_process_error(sc, agno, XFS_SB_BLOCK(mp), &error))
		return error;

	sb = XFS_BUF_TO_SBP(bp);

	/*
	 * 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))
		xfs_scrub_block_set_corrupt(sc, bp);

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

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

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

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

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

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

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

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

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

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

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

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

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

	/* Check sb_versionnum bits that are set at mkfs time. */
	vernum_mask = cpu_to_be16(~XFS_SB_VERSION_OKBITS |
				  XFS_SB_VERSION_NUMBITS |
				  XFS_SB_VERSION_ALIGNBIT |
				  XFS_SB_VERSION_DALIGNBIT |
				  XFS_SB_VERSION_SHAREDBIT |
				  XFS_SB_VERSION_LOGV2BIT |
				  XFS_SB_VERSION_SECTORBIT |
				  XFS_SB_VERSION_EXTFLGBIT |
				  XFS_SB_VERSION_DIRV2BIT);
	if ((sb->sb_versionnum & vernum_mask) !=
	    (cpu_to_be16(mp->m_sb.sb_versionnum) & vernum_mask))
		xfs_scrub_block_set_corrupt(sc, bp);

	/* Check sb_versionnum bits that can be set after mkfs time. */
	vernum_mask = cpu_to_be16(XFS_SB_VERSION_ATTRBIT |
				  XFS_SB_VERSION_NLINKBIT |
				  XFS_SB_VERSION_QUOTABIT);
	if ((sb->sb_versionnum & vernum_mask) !=
	    (cpu_to_be16(mp->m_sb.sb_versionnum) & vernum_mask))
		xfs_scrub_block_set_preen(sc, bp);

	if (sb->sb_sectsize != cpu_to_be16(mp->m_sb.sb_sectsize))
		xfs_scrub_block_set_corrupt(sc, bp);

	if (sb->sb_inodesize != cpu_to_be16(mp->m_sb.sb_inodesize))
		xfs_scrub_block_set_corrupt(sc, bp);

	if (sb->sb_inopblock != cpu_to_be16(mp->m_sb.sb_inopblock))
		xfs_scrub_block_set_corrupt(sc, bp);

	if (memcmp(sb->sb_fname, mp->m_sb.sb_fname, sizeof(sb->sb_fname)))
		xfs_scrub_block_set_preen(sc, bp);

	if (sb->sb_blocklog != mp->m_sb.sb_blocklog)
		xfs_scrub_block_set_corrupt(sc, bp);

	if (sb->sb_sectlog != mp->m_sb.sb_sectlog)
		xfs_scrub_block_set_corrupt(sc, bp);

	if (sb->sb_inodelog != mp->m_sb.sb_inodelog)
		xfs_scrub_block_set_corrupt(sc, bp);

	if (sb->sb_inopblog != mp->m_sb.sb_inopblog)
		xfs_scrub_block_set_corrupt(sc, bp);

	if (sb->sb_agblklog != mp->m_sb.sb_agblklog)
		xfs_scrub_block_set_corrupt(sc, bp);

	if (sb->sb_rextslog != mp->m_sb.sb_rextslog)
		xfs_scrub_block_set_corrupt(sc, bp);

	if (sb->sb_imax_pct != mp->m_sb.sb_imax_pct)
		xfs_scrub_block_set_preen(sc, bp);

	/*
	 * Skip the summary counters since we track them in memory anyway.
	 * sb_icount, sb_ifree, sb_fdblocks, sb_frexents
	 */

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

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

	/*
	 * Skip the quota flags since repair will force quotacheck.
	 * sb_qflags
	 */

	if (sb->sb_flags != mp->m_sb.sb_flags)
		xfs_scrub_block_set_corrupt(sc, bp);

	if (sb->sb_shared_vn != mp->m_sb.sb_shared_vn)
		xfs_scrub_block_set_corrupt(sc, bp);

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

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

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

	if (sb->sb_dirblklog != mp->m_sb.sb_dirblklog)
		xfs_scrub_block_set_corrupt(sc, bp);

	if (sb->sb_logsectlog != mp->m_sb.sb_logsectlog)
		xfs_scrub_block_set_corrupt(sc, bp);

	if (sb->sb_logsectsize != cpu_to_be16(mp->m_sb.sb_logsectsize))
		xfs_scrub_block_set_corrupt(sc, bp);

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

	/* Do we see any invalid bits in sb_features2? */
	if (!xfs_sb_version_hasmorebits(&mp->m_sb)) {
		if (sb->sb_features2 != 0)
			xfs_scrub_block_set_corrupt(sc, bp);
	} else {
		v2_ok = XFS_SB_VERSION2_OKBITS;
		if (XFS_SB_VERSION_NUM(&mp->m_sb) >= XFS_SB_VERSION_5)
			v2_ok |= XFS_SB_VERSION2_CRCBIT;

		if (!!(sb->sb_features2 & cpu_to_be32(~v2_ok)))
			xfs_scrub_block_set_corrupt(sc, bp);

		if (sb->sb_features2 != sb->sb_bad_features2)
			xfs_scrub_block_set_preen(sc, bp);
	}

	/* Check sb_features2 flags that are set at mkfs time. */
	features_mask = cpu_to_be32(XFS_SB_VERSION2_LAZYSBCOUNTBIT |
				    XFS_SB_VERSION2_PROJID32BIT |
				    XFS_SB_VERSION2_CRCBIT |
				    XFS_SB_VERSION2_FTYPE);
	if ((sb->sb_features2 & features_mask) !=
	    (cpu_to_be32(mp->m_sb.sb_features2) & features_mask))
		xfs_scrub_block_set_corrupt(sc, bp);

	/* Check sb_features2 flags that can be set after mkfs time. */
	features_mask = cpu_to_be32(XFS_SB_VERSION2_ATTR2BIT);
	if ((sb->sb_features2 & features_mask) !=
	    (cpu_to_be32(mp->m_sb.sb_features2) & features_mask))
		xfs_scrub_block_set_corrupt(sc, bp);

	if (!xfs_sb_version_hascrc(&mp->m_sb)) {
		/* all v5 fields must be zero */
		if (memchr_inv(&sb->sb_features_compat, 0,
				sizeof(struct xfs_dsb) -
				offsetof(struct xfs_dsb, sb_features_compat)))
			xfs_scrub_block_set_corrupt(sc, bp);
	} else {
		/* Check compat flags; all are set at mkfs time. */
		features_mask = cpu_to_be32(XFS_SB_FEAT_COMPAT_UNKNOWN);
		if ((sb->sb_features_compat & features_mask) !=
		    (cpu_to_be32(mp->m_sb.sb_features_compat) & features_mask))
			xfs_scrub_block_set_corrupt(sc, bp);

		/* Check ro compat flags; all are set at mkfs time. */
		features_mask = cpu_to_be32(XFS_SB_FEAT_RO_COMPAT_UNKNOWN |
					    XFS_SB_FEAT_RO_COMPAT_FINOBT |
					    XFS_SB_FEAT_RO_COMPAT_RMAPBT |
					    XFS_SB_FEAT_RO_COMPAT_REFLINK);
		if ((sb->sb_features_ro_compat & features_mask) !=
		    (cpu_to_be32(mp->m_sb.sb_features_ro_compat) &
		     features_mask))
			xfs_scrub_block_set_corrupt(sc, bp);

		/* Check incompat flags; all are set at mkfs time. */
		features_mask = cpu_to_be32(XFS_SB_FEAT_INCOMPAT_UNKNOWN |
					    XFS_SB_FEAT_INCOMPAT_FTYPE |
					    XFS_SB_FEAT_INCOMPAT_SPINODES |
					    XFS_SB_FEAT_INCOMPAT_META_UUID);
		if ((sb->sb_features_incompat & features_mask) !=
		    (cpu_to_be32(mp->m_sb.sb_features_incompat) &
		     features_mask))
			xfs_scrub_block_set_corrupt(sc, bp);

		/* Check log incompat flags; all are set at mkfs time. */
		features_mask = cpu_to_be32(XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN);
		if ((sb->sb_features_log_incompat & features_mask) !=
		    (cpu_to_be32(mp->m_sb.sb_features_log_incompat) &
		     features_mask))
			xfs_scrub_block_set_corrupt(sc, bp);

		/* Don't care about sb_crc */

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

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

		/* Don't care about sb_lsn */
	}

	if (xfs_sb_version_hasmetauuid(&mp->m_sb)) {
		/* The metadata UUID must be the same for all supers */
		if (!uuid_equal(&sb->sb_meta_uuid, &mp->m_sb.sb_meta_uuid))
			xfs_scrub_block_set_corrupt(sc, bp);
	}

	/* Everything else must be zero. */
	if (memchr_inv(sb + 1, 0,
			BBTOB(bp->b_length) - sizeof(struct xfs_dsb)))
		xfs_scrub_block_set_corrupt(sc, bp);

	return error;
}