1 files changed, 343 insertions, 0 deletions
diff --git a/fs/xfs/scrub/quota.c b/fs/xfs/scrub/quota.c
new file mode 100644
index 000000000000..5c5374c44c5a
--- /dev/null
+++ b/fs/xfs/scrub/quota.c
@@ -0,0 +1,343 @@
+// 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_bit.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_quota.h"
+#include "xfs_qm.h"
+#include "xfs_bmap.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/quota.h"
+
+/* Convert a scrub type code to a DQ flag, or return 0 if error. */
+xfs_dqtype_t
+xchk_quota_to_dqtype(
+	struct xfs_scrub	*sc)
+{
+	switch (sc->sm->sm_type) {
+	case XFS_SCRUB_TYPE_UQUOTA:
+		return XFS_DQTYPE_USER;
+	case XFS_SCRUB_TYPE_GQUOTA:
+		return XFS_DQTYPE_GROUP;
+	case XFS_SCRUB_TYPE_PQUOTA:
+		return XFS_DQTYPE_PROJ;
+	default:
+		return 0;
+	}
+}
+
+/* Set us up to scrub a quota. */
+int
+xchk_setup_quota(
+	struct xfs_scrub	*sc)
+{
+	xfs_dqtype_t		dqtype;
+	int			error;
+
+	if (!XFS_IS_QUOTA_ON(sc->mp))
+		return -ENOENT;
+
+	dqtype = xchk_quota_to_dqtype(sc);
+	if (dqtype == 0)
+		return -EINVAL;
+
+	if (!xfs_this_quota_on(sc->mp, dqtype))
+		return -ENOENT;
+
+	if (xchk_need_intent_drain(sc))
+		xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
+
+	error = xchk_setup_fs(sc);
+	if (error)
+		return error;
+
+	error = xchk_install_live_inode(sc, xfs_quota_inode(sc->mp, dqtype));
+	if (error)
+		return error;
+
+	xchk_ilock(sc, XFS_ILOCK_EXCL);
+	return 0;
+}
+
+/* Quotas. */
+
+struct xchk_quota_info {
+	struct xfs_scrub	*sc;
+	xfs_dqid_t		last_id;
+};
+
+/* There's a written block backing this dquot, right? */
+STATIC int
+xchk_quota_item_bmap(
+	struct xfs_scrub	*sc,
+	struct xfs_dquot	*dq,
+	xfs_fileoff_t		offset)
+{
+	struct xfs_bmbt_irec	irec;
+	struct xfs_mount	*mp = sc->mp;
+	int			nmaps = 1;
+	int			error;
+
+	if (!xfs_verify_fileoff(mp, offset)) {
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+		return 0;
+	}
+
+	if (dq->q_fileoffset != offset) {
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+		return 0;
+	}
+
+	error = xfs_bmapi_read(sc->ip, offset, 1, &irec, &nmaps, 0);
+	if (error)
+		return error;
+
+	if (nmaps != 1) {
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+		return 0;
+	}
+
+	if (!xfs_verify_fsbno(mp, irec.br_startblock))
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+	if (XFS_FSB_TO_DADDR(mp, irec.br_startblock) != dq->q_blkno)
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+	if (!xfs_bmap_is_written_extent(&irec))
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	return 0;
+}
+
+/* Complain if a quota timer is incorrectly set. */
+static inline void
+xchk_quota_item_timer(
+	struct xfs_scrub		*sc,
+	xfs_fileoff_t			offset,
+	const struct xfs_dquot_res	*res)
+{
+	if ((res->softlimit && res->count > res->softlimit) ||
+	    (res->hardlimit && res->count > res->hardlimit)) {
+		if (!res->timer)
+			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+	} else {
+		if (res->timer)
+			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+	}
+}
+
+/* Scrub the fields in an individual quota item. */
+STATIC int
+xchk_quota_item(
+	struct xchk_quota_info	*sqi,
+	struct xfs_dquot	*dq)
+{
+	struct xfs_scrub	*sc = sqi->sc;
+	struct xfs_mount	*mp = sc->mp;
+	struct xfs_quotainfo	*qi = mp->m_quotainfo;
+	xfs_fileoff_t		offset;
+	xfs_ino_t		fs_icount;
+	int			error = 0;
+
+	if (xchk_should_terminate(sc, &error))
+		return error;
+
+	/*
+	 * We want to validate the bmap record for the storage backing this
+	 * dquot, so we need to lock the dquot and the quota file.  For quota
+	 * operations, the locking order is first the ILOCK and then the dquot.
+	 */
+	xchk_ilock(sc, XFS_ILOCK_SHARED);
+	mutex_lock(&dq->q_qlock);
+
+	/*
+	 * Except for the root dquot, the actual dquot we got must either have
+	 * the same or higher id as we saw before.
+	 */
+	offset = dq->q_id / qi->qi_dqperchunk;
+	if (dq->q_id && dq->q_id <= sqi->last_id)
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	sqi->last_id = dq->q_id;
+
+	error = xchk_quota_item_bmap(sc, dq, offset);
+	xchk_iunlock(sc, XFS_ILOCK_SHARED);
+	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, offset, &error))
+		return error;
+
+	/*
+	 * Warn if the hard limits are larger than the fs.
+	 * Administrators can do this, though in production this seems
+	 * suspect, which is why we flag it for review.
+	 *
+	 * Complain about corruption if the soft limit is greater than
+	 * the hard limit.
+	 */
+	if (dq->q_blk.hardlimit > mp->m_sb.sb_dblocks)
+		xchk_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (dq->q_blk.softlimit > dq->q_blk.hardlimit)
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	if (dq->q_ino.hardlimit > M_IGEO(mp)->maxicount)
+		xchk_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (dq->q_ino.softlimit > dq->q_ino.hardlimit)
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	if (dq->q_rtb.hardlimit > mp->m_sb.sb_rblocks)
+		xchk_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (dq->q_rtb.softlimit > dq->q_rtb.hardlimit)
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	/* Check the resource counts. */
+	fs_icount = percpu_counter_sum(&mp->m_icount);
+
+	/*
+	 * Check that usage doesn't exceed physical limits.  However, on
+	 * a reflink filesystem we're allowed to exceed physical space
+	 * if there are no quota limits.
+	 */
+	if (xfs_has_reflink(mp)) {
+		if (mp->m_sb.sb_dblocks < dq->q_blk.count)
+			xchk_fblock_set_warning(sc, XFS_DATA_FORK,
+					offset);
+		if (mp->m_sb.sb_rblocks < dq->q_rtb.count)
+			xchk_fblock_set_warning(sc, XFS_DATA_FORK,
+					offset);
+	} else {
+		if (mp->m_sb.sb_dblocks < dq->q_blk.count)
+			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
+					offset);
+		if (mp->m_sb.sb_rblocks < dq->q_rtb.count)
+			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
+					offset);
+	}
+	if (dq->q_ino.count > fs_icount)
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	/*
+	 * We can violate the hard limits if the admin suddenly sets a
+	 * lower limit than the actual usage.  However, we flag it for
+	 * admin review.
+	 */
+	if (dq->q_id == 0)
+		goto out;
+
+	if (dq->q_blk.hardlimit != 0 &&
+	    dq->q_blk.count > dq->q_blk.hardlimit)
+		xchk_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+
+	if (dq->q_ino.hardlimit != 0 &&
+	    dq->q_ino.count > dq->q_ino.hardlimit)
+		xchk_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+
+	if (dq->q_rtb.hardlimit != 0 &&
+	    dq->q_rtb.count > dq->q_rtb.hardlimit)
+		xchk_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+
+	xchk_quota_item_timer(sc, offset, &dq->q_blk);
+	xchk_quota_item_timer(sc, offset, &dq->q_ino);
+	xchk_quota_item_timer(sc, offset, &dq->q_rtb);
+
+out:
+	mutex_unlock(&dq->q_qlock);
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return -ECANCELED;
+
+	return 0;
+}
+
+/* Check the quota's data fork. */
+STATIC int
+xchk_quota_data_fork(
+	struct xfs_scrub	*sc)
+{
+	struct xfs_bmbt_irec	irec = { 0 };
+	struct xfs_iext_cursor	icur;
+	struct xfs_quotainfo	*qi = sc->mp->m_quotainfo;
+	struct xfs_ifork	*ifp;
+	xfs_fileoff_t		max_dqid_off;
+	int			error = 0;
+
+	/* Invoke the fork scrubber. */
+	error = xchk_metadata_inode_forks(sc);
+	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
+		return error;
+
+	/* Check for data fork problems that apply only to quota files. */
+	max_dqid_off = XFS_DQ_ID_MAX / qi->qi_dqperchunk;
+	ifp = xfs_ifork_ptr(sc->ip, XFS_DATA_FORK);
+	for_each_xfs_iext(ifp, &icur, &irec) {
+		if (xchk_should_terminate(sc, &error))
+			break;
+
+		/*
+		 * delalloc/unwritten extents or blocks mapped above the highest
+		 * quota id shouldn't happen.
+		 */
+		if (!xfs_bmap_is_written_extent(&irec) ||
+		    irec.br_startoff > max_dqid_off ||
+		    irec.br_startoff + irec.br_blockcount - 1 > max_dqid_off) {
+			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
+					irec.br_startoff);
+			break;
+		}
+	}
+
+	return error;
+}
+
+/* Scrub all of a quota type's items. */
+int
+xchk_quota(
+	struct xfs_scrub	*sc)
+{
+	struct xchk_dqiter	cursor = { };
+	struct xchk_quota_info	sqi = { .sc = sc };
+	struct xfs_mount	*mp = sc->mp;
+	struct xfs_quotainfo	*qi = mp->m_quotainfo;
+	struct xfs_dquot	*dq;
+	xfs_dqtype_t		dqtype;
+	int			error = 0;
+
+	dqtype = xchk_quota_to_dqtype(sc);
+
+	/* Look for problem extents. */
+	error = xchk_quota_data_fork(sc);
+	if (error)
+		goto out;
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		goto out;
+
+	/*
+	 * Check all the quota items.  Now that we've checked the quota inode
+	 * data fork we have to drop ILOCK_EXCL to use the regular dquot
+	 * functions.
+	 */
+	xchk_iunlock(sc, sc->ilock_flags);
+
+	/* Now look for things that the quota verifiers won't complain about. */
+	xchk_dqiter_init(&cursor, sc, dqtype);
+	while ((error = xchk_dquot_iter(&cursor, &dq)) == 1) {
+		error = xchk_quota_item(&sqi, dq);
+		xfs_qm_dqrele(dq);
+		if (error)
+			break;
+	}
+	if (error == -ECANCELED)
+		error = 0;
+	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK,
+			sqi.last_id * qi->qi_dqperchunk, &error))
+		goto out;
+
+out:
+	return error;
+}