xfs: scrub quota information

Perform some quick sanity testing of the disk quota information.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/Makefile

@@ -161,4 +161,5 @@ xfs-y				+= $(addprefix scrub/, \
 				   )
 
 xfs-$(CONFIG_XFS_RT)		+= scrub/rtbitmap.o
+xfs-$(CONFIG_XFS_QUOTA)		+= scrub/quota.o
 endif

fs/xfs/libxfs/xfs_fs.h

@@ -504,9 +504,12 @@ struct xfs_scrub_metadata {
 #define XFS_SCRUB_TYPE_PARENT	18	/* parent pointers */
 #define XFS_SCRUB_TYPE_RTBITMAP	19	/* realtime bitmap */
 #define XFS_SCRUB_TYPE_RTSUM	20	/* realtime summary */
+#define XFS_SCRUB_TYPE_UQUOTA	21	/* user quotas */
+#define XFS_SCRUB_TYPE_GQUOTA	22	/* group quotas */
+#define XFS_SCRUB_TYPE_PQUOTA	23	/* project quotas */
 
 /* Number of scrub subcommands. */
-#define XFS_SCRUB_TYPE_NR	21
+#define XFS_SCRUB_TYPE_NR	24
 
 /* i: Repair this metadata. */
 #define XFS_SCRUB_IFLAG_REPAIR		(1 << 0)

fs/xfs/scrub/common.h

@@ -110,6 +110,15 @@ xfs_scrub_setup_rt(struct xfs_scrub_context *sc, struct xfs_inode *ip)
 	return -ENOENT;
 }
 #endif
+#ifdef CONFIG_XFS_QUOTA
+int xfs_scrub_setup_quota(struct xfs_scrub_context *sc, struct xfs_inode *ip);
+#else
+static inline int
+xfs_scrub_setup_quota(struct xfs_scrub_context *sc, struct xfs_inode *ip)
+{
+	return -ENOENT;
+}
+#endif
 
 void xfs_scrub_ag_free(struct xfs_scrub_context *sc, struct xfs_scrub_ag *sa);
 int xfs_scrub_ag_init(struct xfs_scrub_context *sc, xfs_agnumber_t agno,

fs/xfs/scrub/quota.c

+/*
+ * 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 "xfs_inode_fork.h"
+#include "xfs_alloc.h"
+#include "xfs_bmap.h"
+#include "xfs_quota.h"
+#include "xfs_qm.h"
+#include "xfs_dquot.h"
+#include "xfs_dquot_item.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+
+/* Convert a scrub type code to a DQ flag, or return 0 if error. */
+static inline uint
+xfs_scrub_quota_to_dqtype(
+	struct xfs_scrub_context	*sc)
+{
+	switch (sc->sm->sm_type) {
+	case XFS_SCRUB_TYPE_UQUOTA:
+		return XFS_DQ_USER;
+	case XFS_SCRUB_TYPE_GQUOTA:
+		return XFS_DQ_GROUP;
+	case XFS_SCRUB_TYPE_PQUOTA:
+		return XFS_DQ_PROJ;
+	default:
+		return 0;
+	}
+}
+
+/* Set us up to scrub a quota. */
+int
+xfs_scrub_setup_quota(
+	struct xfs_scrub_context	*sc,
+	struct xfs_inode		*ip)
+{
+	uint				dqtype;
+
+	/*
+	 * If userspace gave us an AG number or inode data, they don't
+	 * know what they're doing.  Get out.
+	 */
+	if (sc->sm->sm_agno || sc->sm->sm_ino || sc->sm->sm_gen)
+		return -EINVAL;
+
+	dqtype = xfs_scrub_quota_to_dqtype(sc);
+	if (dqtype == 0)
+		return -EINVAL;
+	if (!xfs_this_quota_on(sc->mp, dqtype))
+		return -ENOENT;
+	return 0;
+}
+
+/* Quotas. */
+
+/* Scrub the fields in an individual quota item. */
+STATIC void
+xfs_scrub_quota_item(
+	struct xfs_scrub_context	*sc,
+	uint				dqtype,
+	struct xfs_dquot		*dq,
+	xfs_dqid_t			id)
+{
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_disk_dquot		*d = &dq->q_core;
+	struct xfs_quotainfo		*qi = mp->m_quotainfo;
+	xfs_fileoff_t			offset;
+	unsigned long long		bsoft;
+	unsigned long long		isoft;
+	unsigned long long		rsoft;
+	unsigned long long		bhard;
+	unsigned long long		ihard;
+	unsigned long long		rhard;
+	unsigned long long		bcount;
+	unsigned long long		icount;
+	unsigned long long		rcount;
+	xfs_ino_t			fs_icount;
+
+	offset = id * qi->qi_dqperchunk;
+
+	/*
+	 * We fed $id and DQNEXT into the xfs_qm_dqget call, which means
+	 * that the actual dquot we got must either have the same id or
+	 * the next higher id.
+	 */
+	if (id > be32_to_cpu(d->d_id))
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	/* Did we get the dquot type we wanted? */
+	if (dqtype != (d->d_flags & XFS_DQ_ALLTYPES))
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	if (d->d_pad0 != cpu_to_be32(0) || d->d_pad != cpu_to_be16(0))
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	/* Check the limits. */
+	bhard = be64_to_cpu(d->d_blk_hardlimit);
+	ihard = be64_to_cpu(d->d_ino_hardlimit);
+	rhard = be64_to_cpu(d->d_rtb_hardlimit);
+
+	bsoft = be64_to_cpu(d->d_blk_softlimit);
+	isoft = be64_to_cpu(d->d_ino_softlimit);
+	rsoft = be64_to_cpu(d->d_rtb_softlimit);
+
+	/*
+	 * 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 (bhard > mp->m_sb.sb_dblocks)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (bsoft > bhard)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	if (ihard > mp->m_maxicount)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (isoft > ihard)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	if (rhard > mp->m_sb.sb_rblocks)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (rsoft > rhard)
+		xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
+
+	/* Check the resource counts. */
+	bcount = be64_to_cpu(d->d_bcount);
+	icount = be64_to_cpu(d->d_icount);
+	rcount = be64_to_cpu(d->d_rtbcount);
+	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_sb_version_hasreflink(&mp->m_sb)) {
+		if (mp->m_sb.sb_dblocks < bcount)
+			xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK,
+					offset);
+	} else {
+		if (mp->m_sb.sb_dblocks < bcount)
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK,
+					offset);
+	}
+	if (icount > fs_icount || rcount > mp->m_sb.sb_rblocks)
+		xfs_scrub_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 (id != 0 && bhard != 0 && bcount > bhard)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (id != 0 && ihard != 0 && icount > ihard)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+	if (id != 0 && rhard != 0 && rcount > rhard)
+		xfs_scrub_fblock_set_warning(sc, XFS_DATA_FORK, offset);
+}
+
+/* Scrub all of a quota type's items. */
+int
+xfs_scrub_quota(
+	struct xfs_scrub_context	*sc)
+{
+	struct xfs_bmbt_irec		irec = { 0 };
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_inode		*ip;
+	struct xfs_quotainfo		*qi = mp->m_quotainfo;
+	struct xfs_dquot		*dq;
+	xfs_fileoff_t			max_dqid_off;
+	xfs_fileoff_t			off = 0;
+	xfs_dqid_t			id = 0;
+	uint				dqtype;
+	int				nimaps;
+	int				error;
+
+	if (!XFS_IS_QUOTA_RUNNING(mp) || !XFS_IS_QUOTA_ON(mp))
+		return -ENOENT;
+
+	mutex_lock(&qi->qi_quotaofflock);
+	dqtype = xfs_scrub_quota_to_dqtype(sc);
+	if (!xfs_this_quota_on(sc->mp, dqtype)) {
+		error = -ENOENT;
+		goto out_unlock_quota;
+	}
+
+	/* Attach to the quota inode and set sc->ip so that reporting works. */
+	ip = xfs_quota_inode(sc->mp, dqtype);
+	sc->ip = ip;
+
+	/* Look for problem extents. */
+	xfs_ilock(ip, XFS_ILOCK_EXCL);
+	if (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) {
+		xfs_scrub_ino_set_corrupt(sc, sc->ip->i_ino, NULL);
+		goto out_unlock_inode;
+	}
+	max_dqid_off = ((xfs_dqid_t)-1) / qi->qi_dqperchunk;
+	while (1) {
+		if (xfs_scrub_should_terminate(sc, &error))
+			break;
+
+		off = irec.br_startoff + irec.br_blockcount;
+		nimaps = 1;
+		error = xfs_bmapi_read(ip, off, -1, &irec, &nimaps,
+				XFS_BMAPI_ENTIRE);
+		if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, off,
+				&error))
+			goto out_unlock_inode;
+		if (!nimaps)
+			break;
+		if (irec.br_startblock == HOLESTARTBLOCK)
+			continue;
+
+		/* Check the extent record doesn't point to crap. */
+		if (irec.br_startblock + irec.br_blockcount <=
+		    irec.br_startblock)
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK,
+					irec.br_startoff);
+		if (!xfs_verify_fsbno(mp, irec.br_startblock) ||
+		    !xfs_verify_fsbno(mp, irec.br_startblock +
+					irec.br_blockcount - 1))
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK,
+					irec.br_startoff);
+
+		/*
+		 * Unwritten extents or blocks mapped above the highest
+		 * quota id shouldn't happen.
+		 */
+		if (isnullstartblock(irec.br_startblock) ||
+		    irec.br_startoff > max_dqid_off ||
+		    irec.br_startoff + irec.br_blockcount > max_dqid_off + 1)
+			xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, off);
+	}
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		goto out;
+
+	/* Check all the quota items. */
+	while (id < ((xfs_dqid_t)-1ULL)) {
+		if (xfs_scrub_should_terminate(sc, &error))
+			break;
+
+		error = xfs_qm_dqget(mp, NULL, id, dqtype, XFS_QMOPT_DQNEXT,
+				&dq);
+		if (error == -ENOENT)
+			break;
+		if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK,
+				id * qi->qi_dqperchunk, &error))
+			break;
+
+		xfs_scrub_quota_item(sc, dqtype, dq, id);
+
+		id = be32_to_cpu(dq->q_core.d_id) + 1;
+		xfs_qm_dqput(dq);
+		if (!id)
+			break;
+	}
+
+out:
+	/* We set sc->ip earlier, so make sure we clear it now. */
+	sc->ip = NULL;
+out_unlock_quota:
+	mutex_unlock(&qi->qi_quotaofflock);
+	return error;
+
+out_unlock_inode:
+	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	goto out;
+}

fs/xfs/scrub/scrub.c

@@ -257,6 +257,18 @@ static const struct xfs_scrub_meta_ops meta_scrub_ops[] = {
 		.scrub	= xfs_scrub_rtsummary,
 		.has	= xfs_sb_version_hasrealtime,
 	},
+	{ /* user quota */
+		.setup = xfs_scrub_setup_quota,
+		.scrub = xfs_scrub_quota,
+	},
+	{ /* group quota */
+		.setup = xfs_scrub_setup_quota,
+		.scrub = xfs_scrub_quota,
+	},
+	{ /* project quota */
+		.setup = xfs_scrub_setup_quota,
+		.scrub = xfs_scrub_quota,
+	},
 };
 
 /* This isn't a stable feature, warn once per day. */

fs/xfs/scrub/scrub.h

@@ -102,5 +102,14 @@ xfs_scrub_rtsummary(struct xfs_scrub_context *sc)
 	return -ENOENT;
 }
 #endif
+#ifdef CONFIG_XFS_QUOTA
+int xfs_scrub_quota(struct xfs_scrub_context *sc);
+#else
+static inline int
+xfs_scrub_quota(struct xfs_scrub_context *sc)
+{
+	return -ENOENT;
+}
+#endif
 
 #endif	/* __XFS_SCRUB_SCRUB_H__ */