Merge tag 'repair-quotacheck-6.9_2024-02-23' of...

Merge tag 'repair-quotacheck-6.9_2024-02-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-6.9-mergeC

xfs: online repair of quota counters

This series uses the inode scanner and live update hook functionality
introduced in the last patchset to implement quotacheck on a live
filesystem.  The quotacheck scrubber builds an incore copy of the
dquot resource usage counters and compares it to the live dquots to
report discrepancies.

If the user chooses to repair the quota counters, the repair function
visits each incore dquot to update the counts from the live information.
The live update hooks are key to keeping the incore copy up to date.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

* tag 'repair-quotacheck-6.9_2024-02-23' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
  xfs: repair dquots based on live quotacheck results
  xfs: repair cannot update the summary counters when logging quota flags
  xfs: track quota updates during live quotacheck
  xfs: implement live quotacheck inode scan
  xfs: create a sparse load xfarray function
  xfs: create a helper to count per-device inode block usage
  xfs: create a xchk_trans_alloc_empty helper for scrub
  xfs: report the health of quota counts

fs/xfs/Makefile

@@ -180,6 +180,7 @@ xfs-$(CONFIG_XFS_RT)		+= $(addprefix scrub/, \
 xfs-$(CONFIG_XFS_QUOTA)		+= $(addprefix scrub/, \
 				   dqiterate.o \
 				   quota.o \
+				   quotacheck.o \
 				   )
 
 # online repair
@@ -203,6 +204,7 @@ xfs-$(CONFIG_XFS_RT)		+= $(addprefix scrub/, \
 
 xfs-$(CONFIG_XFS_QUOTA)		+= $(addprefix scrub/, \
 				   quota_repair.o \
+				   quotacheck_repair.o \
 				   )
 endif
 endif

fs/xfs/libxfs/xfs_fs.h

@@ -195,6 +195,7 @@ struct xfs_fsop_geom {
 #define XFS_FSOP_GEOM_SICK_PQUOTA	(1 << 3)  /* project quota */
 #define XFS_FSOP_GEOM_SICK_RT_BITMAP	(1 << 4)  /* realtime bitmap */
 #define XFS_FSOP_GEOM_SICK_RT_SUMMARY	(1 << 5)  /* realtime summary */
+#define XFS_FSOP_GEOM_SICK_QUOTACHECK	(1 << 6)  /* quota counts */
 
 /* Output for XFS_FS_COUNTS */
 typedef struct xfs_fsop_counts {
@@ -709,9 +710,10 @@ struct xfs_scrub_metadata {
 #define XFS_SCRUB_TYPE_GQUOTA	22	/* group quotas */
 #define XFS_SCRUB_TYPE_PQUOTA	23	/* project quotas */
 #define XFS_SCRUB_TYPE_FSCOUNTERS 24	/* fs summary counters */
+#define XFS_SCRUB_TYPE_QUOTACHECK 25	/* quota counters */
 
 /* Number of scrub subcommands. */
-#define XFS_SCRUB_TYPE_NR	25
+#define XFS_SCRUB_TYPE_NR	26
 
 /* i: Repair this metadata. */
 #define XFS_SCRUB_IFLAG_REPAIR		(1u << 0)

fs/xfs/libxfs/xfs_health.h

@@ -41,6 +41,7 @@ struct xfs_fsop_geom;
 #define XFS_SICK_FS_UQUOTA	(1 << 1)  /* user quota */
 #define XFS_SICK_FS_GQUOTA	(1 << 2)  /* group quota */
 #define XFS_SICK_FS_PQUOTA	(1 << 3)  /* project quota */
+#define XFS_SICK_FS_QUOTACHECK	(1 << 4)  /* quota counts */
 
 /* Observable health issues for realtime volume metadata. */
 #define XFS_SICK_RT_BITMAP	(1 << 0)  /* realtime bitmap */
@@ -77,7 +78,8 @@ struct xfs_fsop_geom;
 #define XFS_SICK_FS_PRIMARY	(XFS_SICK_FS_COUNTERS | \
 				 XFS_SICK_FS_UQUOTA | \
 				 XFS_SICK_FS_GQUOTA | \
-				 XFS_SICK_FS_PQUOTA)
+				 XFS_SICK_FS_PQUOTA | \
+				 XFS_SICK_FS_QUOTACHECK)
 
 #define XFS_SICK_RT_PRIMARY	(XFS_SICK_RT_BITMAP | \
 				 XFS_SICK_RT_SUMMARY)

fs/xfs/scrub/common.c

@@ -29,6 +29,8 @@
 #include "xfs_attr.h"
 #include "xfs_reflink.h"
 #include "xfs_ag.h"
+#include "xfs_error.h"
+#include "xfs_quota.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/trace.h"
@@ -82,6 +84,15 @@ __xchk_process_error(
 				sc->ip ? sc->ip : XFS_I(file_inode(sc->file)),
 				sc->sm, *error);
 		break;
+	case -ECANCELED:
+		/*
+		 * ECANCELED here means that the caller set one of the scrub
+		 * outcome flags (corrupt, xfail, xcorrupt) and wants to exit
+		 * quickly.  Set error to zero and do not continue.
+		 */
+		trace_xchk_op_error(sc, agno, bno, *error, ret_ip);
+		*error = 0;
+		break;
 	case -EFSBADCRC:
 	case -EFSCORRUPTED:
 		/* Note the badness but don't abort. */
@@ -89,8 +100,7 @@ __xchk_process_error(
 		*error = 0;
 		fallthrough;
 	default:
-		trace_xchk_op_error(sc, agno, bno, *error,
-				ret_ip);
+		trace_xchk_op_error(sc, agno, bno, *error, ret_ip);
 		break;
 	}
 	return false;
@@ -136,6 +146,16 @@ __xchk_fblock_process_error(
 		/* Used to restart an op with deadlock avoidance. */
 		trace_xchk_deadlock_retry(sc->ip, sc->sm, *error);
 		break;
+	case -ECANCELED:
+		/*
+		 * ECANCELED here means that the caller set one of the scrub
+		 * outcome flags (corrupt, xfail, xcorrupt) and wants to exit
+		 * quickly.  Set error to zero and do not continue.
+		 */
+		trace_xchk_file_op_error(sc, whichfork, offset, *error,
+				ret_ip);
+		*error = 0;
+		break;
 	case -EFSBADCRC:
 	case -EFSCORRUPTED:
 		/* Note the badness but don't abort. */
@@ -227,6 +247,19 @@ xchk_block_set_corrupt(
 	trace_xchk_block_error(sc, xfs_buf_daddr(bp), __return_address);
 }
 
+#ifdef CONFIG_XFS_QUOTA
+/* Record a corrupt quota counter. */
+void
+xchk_qcheck_set_corrupt(
+	struct xfs_scrub	*sc,
+	unsigned int		dqtype,
+	xfs_dqid_t		id)
+{
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+	trace_xchk_qcheck_error(sc, dqtype, id, __return_address);
+}
+#endif
+
 /* Record a corruption while cross-referencing. */
 void
 xchk_block_xref_set_corrupt(
@@ -653,6 +686,13 @@ xchk_trans_cancel(
 	sc->tp = NULL;
 }
 
+int
+xchk_trans_alloc_empty(
+	struct xfs_scrub	*sc)
+{
+	return xfs_trans_alloc_empty(sc->mp, &sc->tp);
+}
+
 /*
  * Grab an empty transaction so that we can re-grab locked buffers if
  * one of our btrees turns out to be cyclic.
@@ -672,7 +712,7 @@ xchk_trans_alloc(
 		return xfs_trans_alloc(sc->mp, &M_RES(sc->mp)->tr_itruncate,
 				resblks, 0, 0, &sc->tp);
 
-	return xfs_trans_alloc_empty(sc->mp, &sc->tp);
+	return xchk_trans_alloc_empty(sc);
 }
 
 /* Set us up with a transaction and an empty context. */
@@ -1259,6 +1299,9 @@ xchk_fsgates_enable(
 	if (scrub_fsgates & XCHK_FSGATES_DRAIN)
 		xfs_drain_wait_enable();
 
+	if (scrub_fsgates & XCHK_FSGATES_QUOTA)
+		xfs_dqtrx_hook_enable();
+
 	sc->flags |= scrub_fsgates;
 }
 

fs/xfs/scrub/common.h

@@ -32,6 +32,7 @@ xchk_should_terminate(
 }
 
 int xchk_trans_alloc(struct xfs_scrub *sc, uint resblks);
+int xchk_trans_alloc_empty(struct xfs_scrub *sc);
 void xchk_trans_cancel(struct xfs_scrub *sc);
 
 bool xchk_process_error(struct xfs_scrub *sc, xfs_agnumber_t agno,
@@ -54,6 +55,10 @@ void xchk_block_set_corrupt(struct xfs_scrub *sc,
 void xchk_ino_set_corrupt(struct xfs_scrub *sc, xfs_ino_t ino);
 void xchk_fblock_set_corrupt(struct xfs_scrub *sc, int whichfork,
 		xfs_fileoff_t offset);
+#ifdef CONFIG_XFS_QUOTA
+void xchk_qcheck_set_corrupt(struct xfs_scrub *sc, unsigned int dqtype,
+		xfs_dqid_t id);
+#endif
 
 void xchk_block_xref_set_corrupt(struct xfs_scrub *sc,
 		struct xfs_buf *bp);
@@ -105,6 +110,7 @@ xchk_setup_rtsummary(struct xfs_scrub *sc)
 #ifdef CONFIG_XFS_QUOTA
 int xchk_ino_dqattach(struct xfs_scrub *sc);
 int xchk_setup_quota(struct xfs_scrub *sc);
+int xchk_setup_quotacheck(struct xfs_scrub *sc);
 #else
 static inline int
 xchk_ino_dqattach(struct xfs_scrub *sc)
@@ -116,6 +122,11 @@ xchk_setup_quota(struct xfs_scrub *sc)
 {
 	return -ENOENT;
 }
+static inline int
+xchk_setup_quotacheck(struct xfs_scrub *sc)
+{
+	return -ENOENT;
+}
 #endif
 int xchk_setup_fscounters(struct xfs_scrub *sc);
 

fs/xfs/scrub/fscounters.c

@@ -242,7 +242,7 @@ xchk_setup_fscounters(
 			return error;
 	}
 
-	return xfs_trans_alloc_empty(sc->mp, &sc->tp);
+	return xchk_trans_alloc_empty(sc);
 }
 
 /*

fs/xfs/scrub/health.c

@@ -105,6 +105,7 @@ static const struct xchk_health_map type_to_health_flag[XFS_SCRUB_TYPE_NR] = {
 	[XFS_SCRUB_TYPE_GQUOTA]		= { XHG_FS,  XFS_SICK_FS_GQUOTA },
 	[XFS_SCRUB_TYPE_PQUOTA]		= { XHG_FS,  XFS_SICK_FS_PQUOTA },
 	[XFS_SCRUB_TYPE_FSCOUNTERS]	= { XHG_FS,  XFS_SICK_FS_COUNTERS },
+	[XFS_SCRUB_TYPE_QUOTACHECK]	= { XHG_FS,  XFS_SICK_FS_QUOTACHECK },
 };
 
 /* Return the health status mask for this scrub type. */

fs/xfs/scrub/quotacheck.c

+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2020-2024 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_quota.h"
+#include "xfs_qm.h"
+#include "xfs_icache.h"
+#include "xfs_bmap_util.h"
+#include "xfs_ialloc.h"
+#include "xfs_ag.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/repair.h"
+#include "scrub/xfile.h"
+#include "scrub/xfarray.h"
+#include "scrub/iscan.h"
+#include "scrub/quota.h"
+#include "scrub/quotacheck.h"
+#include "scrub/trace.h"
+
+/*
+ * Live Quotacheck
+ * ===============
+ *
+ * Quota counters are "summary" metadata, in the sense that they are computed
+ * as the summation of the block usage counts for every file on the filesystem.
+ * Therefore, we compute the correct icount, bcount, and rtbcount values by
+ * creating a shadow quota counter structure and walking every inode.
+ */
+
+/* Track the quota deltas for a dquot in a transaction. */
+struct xqcheck_dqtrx {
+	xfs_dqtype_t		q_type;
+	xfs_dqid_t		q_id;
+
+	int64_t			icount_delta;
+
+	int64_t			bcount_delta;
+	int64_t			delbcnt_delta;
+
+	int64_t			rtbcount_delta;
+	int64_t			delrtb_delta;
+};
+
+#define XQCHECK_MAX_NR_DQTRXS	(XFS_QM_TRANS_DQTYPES * XFS_QM_TRANS_MAXDQS)
+
+/*
+ * Track the quota deltas for all dquots attached to a transaction if the
+ * quota deltas are being applied to an inode that we already scanned.
+ */
+struct xqcheck_dqacct {
+	struct rhash_head	hash;
+	uintptr_t		tx_id;
+	struct xqcheck_dqtrx	dqtrx[XQCHECK_MAX_NR_DQTRXS];
+	unsigned int		refcount;
+};
+
+/* Free a shadow dquot accounting structure. */
+static void
+xqcheck_dqacct_free(
+	void			*ptr,
+	void			*arg)
+{
+	struct xqcheck_dqacct	*dqa = ptr;
+
+	kfree(dqa);
+}
+
+/* Set us up to scrub quota counters. */
+int
+xchk_setup_quotacheck(
+	struct xfs_scrub	*sc)
+{
+	if (!XFS_IS_QUOTA_ON(sc->mp))
+		return -ENOENT;
+
+	xchk_fsgates_enable(sc, XCHK_FSGATES_QUOTA);
+
+	sc->buf = kzalloc(sizeof(struct xqcheck), XCHK_GFP_FLAGS);
+	if (!sc->buf)
+		return -ENOMEM;
+
+	return xchk_setup_fs(sc);
+}
+
+/*
+ * Part 1: Collecting dquot resource usage counts.  For each xfs_dquot attached
+ * to each inode, we create a shadow dquot, and compute the inode count and add
+ * the data/rt block usage from what we see.
+ *
+ * To avoid false corruption reports in part 2, any failure in this part must
+ * set the INCOMPLETE flag even when a negative errno is returned.  This care
+ * must be taken with certain errno values (i.e. EFSBADCRC, EFSCORRUPTED,
+ * ECANCELED) that are absorbed into a scrub state flag update by
+ * xchk_*_process_error.  Scrub and repair share the same incore data
+ * structures, so the INCOMPLETE flag is critical to prevent a repair based on
+ * insufficient information.
+ *
+ * Because we are scanning a live filesystem, it's possible that another thread
+ * will try to update the quota counters for an inode that we've already
+ * scanned.  This will cause our counts to be incorrect.  Therefore, we hook
+ * the live transaction code in two places: (1) when the callers update the
+ * per-transaction dqtrx structure to log quota counter updates; and (2) when
+ * transaction commit actually logs those updates to the incore dquot.  By
+ * shadowing transaction updates in this manner, live quotacheck can ensure
+ * by locking the dquot and the shadow structure that its own copies are not
+ * out of date.  Because the hook code runs in a different process context from
+ * the scrub code and the scrub state flags are not accessed atomically,
+ * failures in the hook code must abort the iscan and the scrubber must notice
+ * the aborted scan and set the incomplete flag.
+ *
+ * Note that we use srcu notifier hooks to minimize the overhead when live
+ * quotacheck is /not/ running.
+ */
+
+/* Update an incore dquot counter information from a live update. */
+static int
+xqcheck_update_incore_counts(
+	struct xqcheck		*xqc,
+	struct xfarray		*counts,
+	xfs_dqid_t		id,
+	int64_t			inodes,
+	int64_t			nblks,
+	int64_t			rtblks)
+{
+	struct xqcheck_dquot	xcdq;
+	int			error;
+
+	error = xfarray_load_sparse(counts, id, &xcdq);
+	if (error)
+		return error;
+
+	xcdq.flags |= XQCHECK_DQUOT_WRITTEN;
+	xcdq.icount += inodes;
+	xcdq.bcount += nblks;
+	xcdq.rtbcount += rtblks;
+
+	error = xfarray_store(counts, id, &xcdq);
+	if (error == -EFBIG) {
+		/*
+		 * EFBIG means we tried to store data at too high a byte offset
+		 * in the sparse array.  IOWs, we cannot complete the check and
+		 * must notify userspace that the check was incomplete.
+		 */
+		error = -ECANCELED;
+	}
+	return error;
+}
+
+/* Decide if this is the shadow dquot accounting structure for a transaction. */
+static int
+xqcheck_dqacct_obj_cmpfn(
+	struct rhashtable_compare_arg	*arg,
+	const void			*obj)
+{
+	const uintptr_t			*tx_idp = arg->key;
+	const struct xqcheck_dqacct	*dqa = obj;
+
+	if (dqa->tx_id != *tx_idp)
+		return 1;
+	return 0;
+}
+
+static const struct rhashtable_params xqcheck_dqacct_hash_params = {
+	.min_size		= 32,
+	.key_len		= sizeof(uintptr_t),
+	.key_offset		= offsetof(struct xqcheck_dqacct, tx_id),
+	.head_offset		= offsetof(struct xqcheck_dqacct, hash),
+	.automatic_shrinking	= true,
+	.obj_cmpfn		= xqcheck_dqacct_obj_cmpfn,
+};
+
+/* Find a shadow dqtrx slot for the given dquot. */
+STATIC struct xqcheck_dqtrx *
+xqcheck_get_dqtrx(
+	struct xqcheck_dqacct	*dqa,
+	xfs_dqtype_t		q_type,
+	xfs_dqid_t		q_id)
+{
+	int			i;
+
+	for (i = 0; i < XQCHECK_MAX_NR_DQTRXS; i++) {
+		if (dqa->dqtrx[i].q_type == 0 ||
+		    (dqa->dqtrx[i].q_type == q_type &&
+		     dqa->dqtrx[i].q_id == q_id))
+			return &dqa->dqtrx[i];
+	}
+
+	return NULL;
+}
+
+/*
+ * Create and fill out a quota delta tracking structure to shadow the updates
+ * going on in the regular quota code.
+ */
+static int
+xqcheck_mod_live_ino_dqtrx(
+	struct notifier_block		*nb,
+	unsigned long			action,
+	void				*data)
+{
+	struct xfs_mod_ino_dqtrx_params *p = data;
+	struct xqcheck			*xqc;
+	struct xqcheck_dqacct		*dqa;
+	struct xqcheck_dqtrx		*dqtrx;
+	int				error;
+
+	xqc = container_of(nb, struct xqcheck, qhook.mod_hook.nb);
+
+	/* Skip quota reservation fields. */
+	switch (action) {
+	case XFS_TRANS_DQ_BCOUNT:
+	case XFS_TRANS_DQ_DELBCOUNT:
+	case XFS_TRANS_DQ_ICOUNT:
+	case XFS_TRANS_DQ_RTBCOUNT:
+	case XFS_TRANS_DQ_DELRTBCOUNT:
+		break;
+	default:
+		return NOTIFY_DONE;
+	}
+
+	/* Ignore dqtrx updates for quota types we don't care about. */
+	switch (p->q_type) {
+	case XFS_DQTYPE_USER:
+		if (!xqc->ucounts)
+			return NOTIFY_DONE;
+		break;
+	case XFS_DQTYPE_GROUP:
+		if (!xqc->gcounts)
+			return NOTIFY_DONE;
+		break;
+	case XFS_DQTYPE_PROJ:
+		if (!xqc->pcounts)
+			return NOTIFY_DONE;
+		break;
+	default:
+		return NOTIFY_DONE;
+	}
+
+	/* Skip inodes that haven't been scanned yet. */
+	if (!xchk_iscan_want_live_update(&xqc->iscan, p->ino))
+		return NOTIFY_DONE;
+
+	/* Make a shadow quota accounting tracker for this transaction. */
+	mutex_lock(&xqc->lock);
+	dqa = rhashtable_lookup_fast(&xqc->shadow_dquot_acct, &p->tx_id,
+			xqcheck_dqacct_hash_params);
+	if (!dqa) {
+		dqa = kzalloc(sizeof(struct xqcheck_dqacct), XCHK_GFP_FLAGS);
+		if (!dqa)
+			goto out_abort;
+
+		dqa->tx_id = p->tx_id;
+		error = rhashtable_insert_fast(&xqc->shadow_dquot_acct,
+				&dqa->hash, xqcheck_dqacct_hash_params);
+		if (error)
+			goto out_abort;
+	}
+
+	/* Find the shadow dqtrx (or an empty slot) here. */
+	dqtrx = xqcheck_get_dqtrx(dqa, p->q_type, p->q_id);
+	if (!dqtrx)
+		goto out_abort;
+	if (dqtrx->q_type == 0) {
+		dqtrx->q_type = p->q_type;
+		dqtrx->q_id = p->q_id;
+		dqa->refcount++;
+	}
+
+	/* Update counter */
+	switch (action) {
+	case XFS_TRANS_DQ_BCOUNT:
+		dqtrx->bcount_delta += p->delta;
+		break;
+	case XFS_TRANS_DQ_DELBCOUNT:
+		dqtrx->delbcnt_delta += p->delta;
+		break;
+	case XFS_TRANS_DQ_ICOUNT:
+		dqtrx->icount_delta += p->delta;
+		break;
+	case XFS_TRANS_DQ_RTBCOUNT:
+		dqtrx->rtbcount_delta += p->delta;
+		break;
+	case XFS_TRANS_DQ_DELRTBCOUNT:
+		dqtrx->delrtb_delta += p->delta;
+		break;
+	}
+
+	mutex_unlock(&xqc->lock);
+	return NOTIFY_DONE;
+
+out_abort:
+	xchk_iscan_abort(&xqc->iscan);
+	mutex_unlock(&xqc->lock);
+	return NOTIFY_DONE;
+}
+
+/*
+ * Apply the transaction quota deltas to our shadow quota accounting info when
+ * the regular quota code are doing the same.
+ */
+static int
+xqcheck_apply_live_dqtrx(
+	struct notifier_block		*nb,
+	unsigned long			action,
+	void				*data)
+{
+	struct xfs_apply_dqtrx_params	*p = data;
+	struct xqcheck			*xqc;
+	struct xqcheck_dqacct		*dqa;
+	struct xqcheck_dqtrx		*dqtrx;
+	struct xfarray			*counts;
+	int				error;
+
+	xqc = container_of(nb, struct xqcheck, qhook.apply_hook.nb);
+
+	/* Map the dquot type to an incore counter object. */
+	switch (p->q_type) {
+	case XFS_DQTYPE_USER:
+		counts = xqc->ucounts;
+		break;
+	case XFS_DQTYPE_GROUP:
+		counts = xqc->gcounts;
+		break;
+	case XFS_DQTYPE_PROJ:
+		counts = xqc->pcounts;
+		break;
+	default:
+		return NOTIFY_DONE;
+	}
+
+	if (xchk_iscan_aborted(&xqc->iscan) || counts == NULL)
+		return NOTIFY_DONE;
+
+	/*
+	 * Find the shadow dqtrx for this transaction and dquot, if any deltas
+	 * need to be applied here.  If not, we're finished early.
+	 */
+	mutex_lock(&xqc->lock);
+	dqa = rhashtable_lookup_fast(&xqc->shadow_dquot_acct, &p->tx_id,
+			xqcheck_dqacct_hash_params);
+	if (!dqa)
+		goto out_unlock;
+	dqtrx = xqcheck_get_dqtrx(dqa, p->q_type, p->q_id);
+	if (!dqtrx || dqtrx->q_type == 0)
+		goto out_unlock;
+
+	/* Update our shadow dquot if we're committing. */
+	if (action == XFS_APPLY_DQTRX_COMMIT) {
+		error = xqcheck_update_incore_counts(xqc, counts, p->q_id,
+				dqtrx->icount_delta,
+				dqtrx->bcount_delta + dqtrx->delbcnt_delta,
+				dqtrx->rtbcount_delta + dqtrx->delrtb_delta);
+		if (error)
+			goto out_abort;
+	}
+
+	/* Free the shadow accounting structure if that was the last user. */
+	dqa->refcount--;
+	if (dqa->refcount == 0) {
+		error = rhashtable_remove_fast(&xqc->shadow_dquot_acct,
+				&dqa->hash, xqcheck_dqacct_hash_params);
+		if (error)
+			goto out_abort;
+		xqcheck_dqacct_free(dqa, NULL);
+	}
+
+	mutex_unlock(&xqc->lock);
+	return NOTIFY_DONE;
+
+out_abort:
+	xchk_iscan_abort(&xqc->iscan);
+out_unlock:
+	mutex_unlock(&xqc->lock);
+	return NOTIFY_DONE;
+}
+
+/* Record this inode's quota usage in our shadow quota counter data. */
+STATIC int
+xqcheck_collect_inode(
+	struct xqcheck		*xqc,
+	struct xfs_inode	*ip)
+{
+	struct xfs_trans	*tp = xqc->sc->tp;
+	xfs_filblks_t		nblks, rtblks;
+	uint			ilock_flags = 0;
+	xfs_dqid_t		id;
+	bool			isreg = S_ISREG(VFS_I(ip)->i_mode);
+	int			error = 0;
+
+	if (xfs_is_quota_inode(&tp->t_mountp->m_sb, ip->i_ino)) {
+		/*
+		 * Quota files are never counted towards quota, so we do not
+		 * need to take the lock.
+		 */
+		xchk_iscan_mark_visited(&xqc->iscan, ip);
+		return 0;
+	}
+
+	/* Figure out the data / rt device block counts. */
+	xfs_ilock(ip, XFS_IOLOCK_SHARED);
+	if (isreg)
+		xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
+	if (XFS_IS_REALTIME_INODE(ip)) {
+		/*
+		 * Read in the data fork for rt files so that _count_blocks
+		 * can count the number of blocks allocated from the rt volume.
+		 * Inodes do not track that separately.
+		 */
+		ilock_flags = xfs_ilock_data_map_shared(ip);
+		error = xfs_iread_extents(tp, ip, XFS_DATA_FORK);
+		if (error)
+			goto out_abort;
+	} else {
+		ilock_flags = XFS_ILOCK_SHARED;
+		xfs_ilock(ip, XFS_ILOCK_SHARED);
+	}
+	xfs_inode_count_blocks(tp, ip, &nblks, &rtblks);
+
+	if (xchk_iscan_aborted(&xqc->iscan)) {
+		error = -ECANCELED;
+		goto out_incomplete;
+	}
+
+	/* Update the shadow dquot counters. */
+	mutex_lock(&xqc->lock);
+	if (xqc->ucounts) {
+		id = xfs_qm_id_for_quotatype(ip, XFS_DQTYPE_USER);
+		error = xqcheck_update_incore_counts(xqc, xqc->ucounts, id, 1,
+				nblks, rtblks);
+		if (error)
+			goto out_mutex;
+	}
+
+	if (xqc->gcounts) {
+		id = xfs_qm_id_for_quotatype(ip, XFS_DQTYPE_GROUP);
+		error = xqcheck_update_incore_counts(xqc, xqc->gcounts, id, 1,
+				nblks, rtblks);
+		if (error)
+			goto out_mutex;
+	}
+
+	if (xqc->pcounts) {
+		id = xfs_qm_id_for_quotatype(ip, XFS_DQTYPE_PROJ);
+		error = xqcheck_update_incore_counts(xqc, xqc->pcounts, id, 1,
+				nblks, rtblks);
+		if (error)
+			goto out_mutex;
+	}
+	mutex_unlock(&xqc->lock);
+
+	xchk_iscan_mark_visited(&xqc->iscan, ip);
+	goto out_ilock;
+
+out_mutex:
+	mutex_unlock(&xqc->lock);
+out_abort:
+	xchk_iscan_abort(&xqc->iscan);
+out_incomplete:
+	xchk_set_incomplete(xqc->sc);
+out_ilock:
+	xfs_iunlock(ip, ilock_flags);
+	if (isreg)
+		xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
+	return error;
+}
+
+/* Walk all the allocated inodes and run a quota scan on them. */
+STATIC int
+xqcheck_collect_counts(
+	struct xqcheck		*xqc)
+{
+	struct xfs_scrub	*sc = xqc->sc;
+	struct xfs_inode	*ip;
+	int			error;
+
+	/*
+	 * Set up for a potentially lengthy filesystem scan by reducing our
+	 * transaction resource usage for the duration.  Specifically:
+	 *
+	 * Cancel the transaction to release the log grant space while we scan
+	 * the filesystem.
+	 *
+	 * Create a new empty transaction to eliminate the possibility of the
+	 * inode scan deadlocking on cyclical metadata.
+	 *
+	 * We pass the empty transaction to the file scanning function to avoid
+	 * repeatedly cycling empty transactions.  This can be done without
+	 * risk of deadlock between sb_internal and the IOLOCK (we take the
+	 * IOLOCK to quiesce the file before scanning) because empty
+	 * transactions do not take sb_internal.
+	 */
+	xchk_trans_cancel(sc);
+	error = xchk_trans_alloc_empty(sc);
+	if (error)
+		return error;
+
+	while ((error = xchk_iscan_iter(&xqc->iscan, &ip)) == 1) {
+		error = xqcheck_collect_inode(xqc, ip);
+		xchk_irele(sc, ip);
+		if (error)
+			break;
+
+		if (xchk_should_terminate(sc, &error))
+			break;
+	}
+	xchk_iscan_iter_finish(&xqc->iscan);
+	if (error) {
+		xchk_set_incomplete(sc);
+		/*
+		 * If we couldn't grab an inode that was busy with a state
+		 * change, change the error code so that we exit to userspace
+		 * as quickly as possible.
+		 */
+		if (error == -EBUSY)
+			return -ECANCELED;
+		return error;
+	}
+
+	/*
+	 * Switch out for a real transaction in preparation for building a new
+	 * tree.
+	 */
+	xchk_trans_cancel(sc);
+	return xchk_setup_fs(sc);
+}
+
+/*
+ * Part 2: Comparing dquot resource counters.  Walk each xfs_dquot, comparing
+ * the resource usage counters against our shadow dquots; and then walk each
+ * shadow dquot (that wasn't covered in the first part), comparing it against
+ * the xfs_dquot.
+ */
+
+/*
+ * Check the dquot data against what we observed.  Caller must hold the dquot
+ * lock.
+ */
+STATIC int
+xqcheck_compare_dquot(
+	struct xqcheck		*xqc,
+	xfs_dqtype_t		dqtype,
+	struct xfs_dquot	*dq)
+{
+	struct xqcheck_dquot	xcdq;
+	struct xfarray		*counts = xqcheck_counters_for(xqc, dqtype);
+	int			error;
+
+	if (xchk_iscan_aborted(&xqc->iscan)) {
+		xchk_set_incomplete(xqc->sc);
+		return -ECANCELED;
+	}
+
+	mutex_lock(&xqc->lock);
+	error = xfarray_load_sparse(counts, dq->q_id, &xcdq);
+	if (error)
+		goto out_unlock;
+
+	if (xcdq.icount != dq->q_ino.count)
+		xchk_qcheck_set_corrupt(xqc->sc, dqtype, dq->q_id);
+
+	if (xcdq.bcount != dq->q_blk.count)
+		xchk_qcheck_set_corrupt(xqc->sc, dqtype, dq->q_id);
+
+	if (xcdq.rtbcount != dq->q_rtb.count)
+		xchk_qcheck_set_corrupt(xqc->sc, dqtype, dq->q_id);
+
+	xcdq.flags |= (XQCHECK_DQUOT_COMPARE_SCANNED | XQCHECK_DQUOT_WRITTEN);
+	error = xfarray_store(counts, dq->q_id, &xcdq);
+	if (error == -EFBIG) {
+		/*
+		 * EFBIG means we tried to store data at too high a byte offset
+		 * in the sparse array.  IOWs, we cannot complete the check and
+		 * must notify userspace that the check was incomplete.  This
+		 * should never happen outside of the collection phase.
+		 */
+		xchk_set_incomplete(xqc->sc);
+		error = -ECANCELED;
+	}
+	mutex_unlock(&xqc->lock);
+	if (error)
+		return error;
+
+	if (xqc->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return -ECANCELED;
+
+	return 0;
+
+out_unlock:
+	mutex_unlock(&xqc->lock);
+	return error;
+}
+
+/*
+ * Walk all the observed dquots, and make sure there's a matching incore
+ * dquot and that its counts match ours.
+ */
+STATIC int
+xqcheck_walk_observations(
+	struct xqcheck		*xqc,
+	xfs_dqtype_t		dqtype)
+{
+	struct xqcheck_dquot	xcdq;
+	struct xfs_dquot	*dq;
+	struct xfarray		*counts = xqcheck_counters_for(xqc, dqtype);
+	xfarray_idx_t		cur = XFARRAY_CURSOR_INIT;
+	int			error;
+
+	mutex_lock(&xqc->lock);
+	while ((error = xfarray_iter(counts, &cur, &xcdq)) == 1) {
+		xfs_dqid_t	id = cur - 1;
+
+		if (xcdq.flags & XQCHECK_DQUOT_COMPARE_SCANNED)
+			continue;
+
+		mutex_unlock(&xqc->lock);
+
+		error = xfs_qm_dqget(xqc->sc->mp, id, dqtype, false, &dq);
+		if (error == -ENOENT) {
+			xchk_qcheck_set_corrupt(xqc->sc, dqtype, id);
+			return 0;
+		}
+		if (error)
+			return error;
+
+		error = xqcheck_compare_dquot(xqc, dqtype, dq);
+		xfs_qm_dqput(dq);
+		if (error)
+			return error;
+
+		if (xchk_should_terminate(xqc->sc, &error))
+			return error;
+
+		mutex_lock(&xqc->lock);
+	}
+	mutex_unlock(&xqc->lock);
+
+	return error;
+}
+
+/* Compare the quota counters we observed against the live dquots. */
+STATIC int
+xqcheck_compare_dqtype(
+	struct xqcheck		*xqc,
+	xfs_dqtype_t		dqtype)
+{
+	struct xchk_dqiter	cursor = { };
+	struct xfs_scrub	*sc = xqc->sc;
+	struct xfs_dquot	*dq;
+	int			error;
+
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return 0;
+
+	/* If the quota CHKD flag is cleared, we need to repair this quota. */
+	if (!(xfs_quota_chkd_flag(dqtype) & sc->mp->m_qflags)) {
+		xchk_qcheck_set_corrupt(xqc->sc, dqtype, 0);
+		return 0;
+	}
+
+	/* Compare what we observed against the actual dquots. */
+	xchk_dqiter_init(&cursor, sc, dqtype);
+	while ((error = xchk_dquot_iter(&cursor, &dq)) == 1) {
+		error = xqcheck_compare_dquot(xqc, dqtype, dq);
+		xfs_qm_dqput(dq);
+		if (error)
+			break;
+	}
+	if (error)
+		return error;
+
+	/* Walk all the observed dquots and compare to the incore ones. */
+	return xqcheck_walk_observations(xqc, dqtype);
+}
+
+/* Tear down everything associated with a quotacheck. */
+static void
+xqcheck_teardown_scan(
+	void			*priv)
+{
+	struct xqcheck		*xqc = priv;
+	struct xfs_quotainfo	*qi = xqc->sc->mp->m_quotainfo;
+
+	/* Discourage any hook functions that might be running. */
+	xchk_iscan_abort(&xqc->iscan);
+
+	/*
+	 * As noted above, the apply hook is responsible for cleaning up the
+	 * shadow dquot accounting data when a transaction completes.  The mod
+	 * hook must be removed before the apply hook so that we don't
+	 * mistakenly leave an active shadow account for the mod hook to get
+	 * its hands on.  No hooks should be running after these functions
+	 * return.
+	 */
+	xfs_dqtrx_hook_del(qi, &xqc->qhook);
+
+	if (xqc->shadow_dquot_acct.key_len) {
+		rhashtable_free_and_destroy(&xqc->shadow_dquot_acct,
+				xqcheck_dqacct_free, NULL);
+		xqc->shadow_dquot_acct.key_len = 0;
+	}
+
+	if (xqc->pcounts) {
+		xfarray_destroy(xqc->pcounts);
+		xqc->pcounts = NULL;
+	}
+
+	if (xqc->gcounts) {
+		xfarray_destroy(xqc->gcounts);
+		xqc->gcounts = NULL;
+	}
+
+	if (xqc->ucounts) {
+		xfarray_destroy(xqc->ucounts);
+		xqc->ucounts = NULL;
+	}
+
+	xchk_iscan_teardown(&xqc->iscan);
+	mutex_destroy(&xqc->lock);
+	xqc->sc = NULL;
+}
+
+/*
+ * Scan all inodes in the entire filesystem to generate quota counter data.
+ * If the scan is successful, the quota data will be left alive for a repair.
+ * If any error occurs, we'll tear everything down.
+ */
+STATIC int
+xqcheck_setup_scan(
+	struct xfs_scrub	*sc,
+	struct xqcheck		*xqc)
+{
+	char			*descr;
+	struct xfs_quotainfo	*qi = sc->mp->m_quotainfo;
+	unsigned long long	max_dquots = XFS_DQ_ID_MAX + 1ULL;
+	int			error;
+
+	ASSERT(xqc->sc == NULL);
+	xqc->sc = sc;
+
+	mutex_init(&xqc->lock);
+
+	/* Retry iget every tenth of a second for up to 30 seconds. */
+	xchk_iscan_start(sc, 30000, 100, &xqc->iscan);
+
+	error = -ENOMEM;
+	if (xfs_this_quota_on(sc->mp, XFS_DQTYPE_USER)) {
+		descr = xchk_xfile_descr(sc, "user dquot records");
+		error = xfarray_create(descr, max_dquots,
+				sizeof(struct xqcheck_dquot), &xqc->ucounts);
+		kfree(descr);
+		if (error)
+			goto out_teardown;
+	}
+
+	if (xfs_this_quota_on(sc->mp, XFS_DQTYPE_GROUP)) {
+		descr = xchk_xfile_descr(sc, "group dquot records");
+		error = xfarray_create(descr, max_dquots,
+				sizeof(struct xqcheck_dquot), &xqc->gcounts);
+		kfree(descr);
+		if (error)
+			goto out_teardown;
+	}
+
+	if (xfs_this_quota_on(sc->mp, XFS_DQTYPE_PROJ)) {
+		descr = xchk_xfile_descr(sc, "project dquot records");
+		error = xfarray_create(descr, max_dquots,
+				sizeof(struct xqcheck_dquot), &xqc->pcounts);
+		kfree(descr);
+		if (error)
+			goto out_teardown;
+	}
+
+	/*
+	 * Set up hash table to map transactions to our internal shadow dqtrx
+	 * structures.
+	 */
+	error = rhashtable_init(&xqc->shadow_dquot_acct,
+			&xqcheck_dqacct_hash_params);
+	if (error)
+		goto out_teardown;
+
+	/*
+	 * Hook into the quota code.  The hook only triggers for inodes that
+	 * were already scanned, and the scanner thread takes each inode's
+	 * ILOCK, which means that any in-progress inode updates will finish
+	 * before we can scan the inode.
+	 *
+	 * The apply hook (which removes the shadow dquot accounting struct)
+	 * must be installed before the mod hook so that we never fail to catch
+	 * the end of a quota update sequence and leave stale shadow data.
+	 */
+	ASSERT(sc->flags & XCHK_FSGATES_QUOTA);
+	xfs_dqtrx_hook_setup(&xqc->qhook, xqcheck_mod_live_ino_dqtrx,
+			xqcheck_apply_live_dqtrx);
+
+	error = xfs_dqtrx_hook_add(qi, &xqc->qhook);
+	if (error)
+		goto out_teardown;
+
+	/* Use deferred cleanup to pass the quota count data to repair. */
+	sc->buf_cleanup = xqcheck_teardown_scan;
+	return 0;
+
+out_teardown:
+	xqcheck_teardown_scan(xqc);
+	return error;
+}
+
+/* Scrub all counters for a given quota type. */
+int
+xchk_quotacheck(
+	struct xfs_scrub	*sc)
+{
+	struct xqcheck		*xqc = sc->buf;
+	int			error = 0;
+
+	/* Check quota counters on the live filesystem. */
+	error = xqcheck_setup_scan(sc, xqc);
+	if (error)
+		return error;
+
+	/* Walk all inodes, picking up quota information. */
+	error = xqcheck_collect_counts(xqc);
+	if (!xchk_xref_process_error(sc, 0, 0, &error))
+		return error;
+
+	/* Fail fast if we're not playing with a full dataset. */
+	if (xchk_iscan_aborted(&xqc->iscan))
+		xchk_set_incomplete(sc);
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_INCOMPLETE)
+		return 0;
+
+	/* Compare quota counters. */
+	if (xqc->ucounts) {
+		error = xqcheck_compare_dqtype(xqc, XFS_DQTYPE_USER);
+		if (!xchk_xref_process_error(sc, 0, 0, &error))
+			return error;
+	}
+	if (xqc->gcounts) {
+		error = xqcheck_compare_dqtype(xqc, XFS_DQTYPE_GROUP);
+		if (!xchk_xref_process_error(sc, 0, 0, &error))
+			return error;
+	}
+	if (xqc->pcounts) {
+		error = xqcheck_compare_dqtype(xqc, XFS_DQTYPE_PROJ);
+		if (!xchk_xref_process_error(sc, 0, 0, &error))
+			return error;
+	}
+
+	/* Check one last time for an incomplete dataset. */
+	if (xchk_iscan_aborted(&xqc->iscan))
+		xchk_set_incomplete(sc);
+
+	return 0;
+}

fs/xfs/scrub/quotacheck.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2020-2024 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#ifndef __XFS_SCRUB_QUOTACHECK_H__
+#define __XFS_SCRUB_QUOTACHECK_H__
+
+/* Quota counters for live quotacheck. */
+struct xqcheck_dquot {
+	/* block usage count */
+	int64_t			bcount;
+
+	/* inode usage count */
+	int64_t			icount;
+
+	/* realtime block usage count */
+	int64_t			rtbcount;
+
+	/* Record state */
+	unsigned int		flags;
+};
+
+/*
+ * This incore dquot record has been written at least once.  We never want to
+ * store an xqcheck_dquot that looks uninitialized.
+ */
+#define XQCHECK_DQUOT_WRITTEN		(1U << 0)
+
+/* Already checked this dquot. */
+#define XQCHECK_DQUOT_COMPARE_SCANNED	(1U << 1)
+
+/* Already repaired this dquot. */
+#define XQCHECK_DQUOT_REPAIR_SCANNED	(1U << 2)
+
+/* Live quotacheck control structure. */
+struct xqcheck {
+	struct xfs_scrub	*sc;
+
+	/* Shadow dquot counter data. */
+	struct xfarray		*ucounts;
+	struct xfarray		*gcounts;
+	struct xfarray		*pcounts;
+
+	/* Lock protecting quotacheck count observations */
+	struct mutex		lock;
+
+	struct xchk_iscan	iscan;
+
+	/* Hooks into the quota code. */
+	struct xfs_dqtrx_hook	qhook;
+
+	/* Shadow quota delta tracking structure. */
+	struct rhashtable	shadow_dquot_acct;
+};
+
+/* Return the incore counter array for a given quota type. */
+static inline struct xfarray *
+xqcheck_counters_for(
+	struct xqcheck		*xqc,
+	xfs_dqtype_t		dqtype)
+{
+	switch (dqtype) {
+	case XFS_DQTYPE_USER:
+		return xqc->ucounts;
+	case XFS_DQTYPE_GROUP:
+		return xqc->gcounts;
+	case XFS_DQTYPE_PROJ:
+		return xqc->pcounts;
+	}
+
+	ASSERT(0);
+	return NULL;
+}
+
+#endif /* __XFS_SCRUB_QUOTACHECK_H__ */

fs/xfs/scrub/quotacheck_repair.c

+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2020-2024 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_quota.h"
+#include "xfs_qm.h"
+#include "xfs_icache.h"
+#include "xfs_bmap_util.h"
+#include "xfs_iwalk.h"
+#include "xfs_ialloc.h"
+#include "xfs_sb.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/repair.h"
+#include "scrub/xfile.h"
+#include "scrub/xfarray.h"
+#include "scrub/iscan.h"
+#include "scrub/quota.h"
+#include "scrub/quotacheck.h"
+#include "scrub/trace.h"
+
+/*
+ * Live Quotacheck Repair
+ * ======================
+ *
+ * Use the live quota counter information that we collected to replace the
+ * counter values in the incore dquots.  A scrub->repair cycle should have left
+ * the live data and hooks active, so this is safe so long as we make sure the
+ * dquot is locked.
+ */
+
+/* Commit new counters to a dquot. */
+static int
+xqcheck_commit_dquot(
+	struct xqcheck		*xqc,
+	xfs_dqtype_t		dqtype,
+	struct xfs_dquot	*dq)
+{
+	struct xqcheck_dquot	xcdq;
+	struct xfarray		*counts = xqcheck_counters_for(xqc, dqtype);
+	int64_t			delta;
+	bool			dirty = false;
+	int			error = 0;
+
+	/* Unlock the dquot just long enough to allocate a transaction. */
+	xfs_dqunlock(dq);
+	error = xchk_trans_alloc(xqc->sc, 0);
+	xfs_dqlock(dq);
+	if (error)
+		return error;
+
+	xfs_trans_dqjoin(xqc->sc->tp, dq);
+
+	if (xchk_iscan_aborted(&xqc->iscan)) {
+		error = -ECANCELED;
+		goto out_cancel;
+	}
+
+	mutex_lock(&xqc->lock);
+	error = xfarray_load_sparse(counts, dq->q_id, &xcdq);
+	if (error)
+		goto out_unlock;
+
+	/* Adjust counters as needed. */
+	delta = (int64_t)xcdq.icount - dq->q_ino.count;
+	if (delta) {
+		dq->q_ino.reserved += delta;
+		dq->q_ino.count += delta;
+		dirty = true;
+	}
+
+	delta = (int64_t)xcdq.bcount - dq->q_blk.count;
+	if (delta) {
+		dq->q_blk.reserved += delta;
+		dq->q_blk.count += delta;
+		dirty = true;
+	}
+
+	delta = (int64_t)xcdq.rtbcount - dq->q_rtb.count;
+	if (delta) {
+		dq->q_rtb.reserved += delta;
+		dq->q_rtb.count += delta;
+		dirty = true;
+	}
+
+	xcdq.flags |= (XQCHECK_DQUOT_REPAIR_SCANNED | XQCHECK_DQUOT_WRITTEN);
+	error = xfarray_store(counts, dq->q_id, &xcdq);
+	if (error == -EFBIG) {
+		/*
+		 * EFBIG means we tried to store data at too high a byte offset
+		 * in the sparse array.  IOWs, we cannot complete the repair
+		 * and must cancel the whole operation.  This should never
+		 * happen, but we need to catch it anyway.
+		 */
+		error = -ECANCELED;
+	}
+	mutex_unlock(&xqc->lock);
+	if (error || !dirty)
+		goto out_cancel;
+
+	trace_xrep_quotacheck_dquot(xqc->sc->mp, dq->q_type, dq->q_id);
+
+	/* Commit the dirty dquot to disk. */
+	dq->q_flags |= XFS_DQFLAG_DIRTY;
+	if (dq->q_id)
+		xfs_qm_adjust_dqtimers(dq);
+	xfs_trans_log_dquot(xqc->sc->tp, dq);
+
+	/*
+	 * Transaction commit unlocks the dquot, so we must re-lock it so that
+	 * the caller can put the reference (which apparently requires a locked
+	 * dquot).
+	 */
+	error = xrep_trans_commit(xqc->sc);
+	xfs_dqlock(dq);
+	return error;
+
+out_unlock:
+	mutex_unlock(&xqc->lock);
+out_cancel:
+	xchk_trans_cancel(xqc->sc);
+
+	/* Re-lock the dquot so the caller can put the reference. */
+	xfs_dqlock(dq);
+	return error;
+}
+
+/* Commit new quota counters for a particular quota type. */
+STATIC int
+xqcheck_commit_dqtype(
+	struct xqcheck		*xqc,
+	unsigned int		dqtype)
+{
+	struct xchk_dqiter	cursor = { };
+	struct xqcheck_dquot	xcdq;
+	struct xfs_scrub	*sc = xqc->sc;
+	struct xfs_mount	*mp = sc->mp;
+	struct xfarray		*counts = xqcheck_counters_for(xqc, dqtype);
+	struct xfs_dquot	*dq;
+	xfarray_idx_t		cur = XFARRAY_CURSOR_INIT;
+	int			error;
+
+	/*
+	 * Update the counters of every dquot that the quota file knows about.
+	 */
+	xchk_dqiter_init(&cursor, sc, dqtype);
+	while ((error = xchk_dquot_iter(&cursor, &dq)) == 1) {
+		error = xqcheck_commit_dquot(xqc, dqtype, dq);
+		xfs_qm_dqput(dq);
+		if (error)
+			break;
+	}
+	if (error)
+		return error;
+
+	/*
+	 * Make a second pass to deal with the dquots that we know about but
+	 * the quota file previously did not know about.
+	 */
+	mutex_lock(&xqc->lock);
+	while ((error = xfarray_iter(counts, &cur, &xcdq)) == 1) {
+		xfs_dqid_t	id = cur - 1;
+
+		if (xcdq.flags & XQCHECK_DQUOT_REPAIR_SCANNED)
+			continue;
+
+		mutex_unlock(&xqc->lock);
+
+		/*
+		 * Grab the dquot, allowing for dquot block allocation in a
+		 * separate transaction.  We committed the scrub transaction
+		 * in a previous step, so we will not be creating nested
+		 * transactions here.
+		 */
+		error = xfs_qm_dqget(mp, id, dqtype, true, &dq);
+		if (error)
+			return error;
+
+		error = xqcheck_commit_dquot(xqc, dqtype, dq);
+		xfs_qm_dqput(dq);
+		if (error)
+			return error;
+
+		mutex_lock(&xqc->lock);
+	}
+	mutex_unlock(&xqc->lock);
+
+	return error;
+}
+
+/* Figure out quota CHKD flags for the running quota types. */
+static inline unsigned int
+xqcheck_chkd_flags(
+	struct xfs_mount	*mp)
+{
+	unsigned int		ret = 0;
+
+	if (XFS_IS_UQUOTA_ON(mp))
+		ret |= XFS_UQUOTA_CHKD;
+	if (XFS_IS_GQUOTA_ON(mp))
+		ret |= XFS_GQUOTA_CHKD;
+	if (XFS_IS_PQUOTA_ON(mp))
+		ret |= XFS_PQUOTA_CHKD;
+	return ret;
+}
+
+/* Commit the new dquot counters. */
+int
+xrep_quotacheck(
+	struct xfs_scrub	*sc)
+{
+	struct xqcheck		*xqc = sc->buf;
+	unsigned int		qflags = xqcheck_chkd_flags(sc->mp);
+	int			error;
+
+	/*
+	 * Clear the CHKD flag for the running quota types and commit the scrub
+	 * transaction so that we can allocate new quota block mappings if we
+	 * have to.  If we crash after this point, the sb still has the CHKD
+	 * flags cleared, so mount quotacheck will fix all of this up.
+	 */
+	xrep_update_qflags(sc, qflags, 0);
+	error = xrep_trans_commit(sc);
+	if (error)
+		return error;
+
+	/* Commit the new counters to the dquots. */
+	if (xqc->ucounts) {
+		error = xqcheck_commit_dqtype(xqc, XFS_DQTYPE_USER);
+		if (error)
+			return error;
+	}
+	if (xqc->gcounts) {
+		error = xqcheck_commit_dqtype(xqc, XFS_DQTYPE_GROUP);
+		if (error)
+			return error;
+	}
+	if (xqc->pcounts) {
+		error = xqcheck_commit_dqtype(xqc, XFS_DQTYPE_PROJ);
+		if (error)
+			return error;
+	}
+
+	/* Set the CHKD flags now that we've fixed quota counts. */
+	error = xchk_trans_alloc(sc, 0);
+	if (error)
+		return error;
+
+	xrep_update_qflags(sc, 0, qflags);
+	return xrep_trans_commit(sc);
+}

fs/xfs/scrub/repair.c

@@ -687,6 +687,44 @@ xrep_find_ag_btree_roots(
 }
 
 #ifdef CONFIG_XFS_QUOTA
+/* Update some quota flags in the superblock. */
+void
+xrep_update_qflags(
+	struct xfs_scrub	*sc,
+	unsigned int		clear_flags,
+	unsigned int		set_flags)
+{
+	struct xfs_mount	*mp = sc->mp;
+	struct xfs_buf		*bp;
+
+	mutex_lock(&mp->m_quotainfo->qi_quotaofflock);
+	if ((mp->m_qflags & clear_flags) == 0 &&
+	    (mp->m_qflags & set_flags) == set_flags)
+		goto no_update;
+
+	mp->m_qflags &= ~clear_flags;
+	mp->m_qflags |= set_flags;
+
+	spin_lock(&mp->m_sb_lock);
+	mp->m_sb.sb_qflags &= ~clear_flags;
+	mp->m_sb.sb_qflags |= set_flags;
+	spin_unlock(&mp->m_sb_lock);
+
+	/*
+	 * Update the quota flags in the ondisk superblock without touching
+	 * the summary counters.  We have not quiesced inode chunk allocation,
+	 * so we cannot coordinate with updates to the icount and ifree percpu
+	 * counters.
+	 */
+	bp = xfs_trans_getsb(sc->tp);
+	xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
+	xfs_trans_buf_set_type(sc->tp, bp, XFS_BLFT_SB_BUF);
+	xfs_trans_log_buf(sc->tp, bp, 0, sizeof(struct xfs_dsb) - 1);
+
+no_update:
+	mutex_unlock(&sc->mp->m_quotainfo->qi_quotaofflock);
+}
+
 /* Force a quotacheck the next time we mount. */
 void
 xrep_force_quotacheck(
@@ -699,13 +737,7 @@ xrep_force_quotacheck(
 	if (!(flag & sc->mp->m_qflags))
 		return;
 
-	mutex_lock(&sc->mp->m_quotainfo->qi_quotaofflock);
-	sc->mp->m_qflags &= ~flag;
-	spin_lock(&sc->mp->m_sb_lock);
-	sc->mp->m_sb.sb_qflags &= ~flag;
-	spin_unlock(&sc->mp->m_sb_lock);
-	xfs_log_sb(sc->tp);
-	mutex_unlock(&sc->mp->m_quotainfo->qi_quotaofflock);
+	xrep_update_qflags(sc, flag, 0);
 }
 
 /*

fs/xfs/scrub/repair.h

@@ -72,6 +72,8 @@ int xrep_find_ag_btree_roots(struct xfs_scrub *sc, struct xfs_buf *agf_bp,
 		struct xrep_find_ag_btree *btree_info, struct xfs_buf *agfl_bp);
 
 #ifdef CONFIG_XFS_QUOTA
+void xrep_update_qflags(struct xfs_scrub *sc, unsigned int clear_flags,
+		unsigned int set_flags);
 void xrep_force_quotacheck(struct xfs_scrub *sc, xfs_dqtype_t type);
 int xrep_ino_dqattach(struct xfs_scrub *sc);
 #else
@@ -123,8 +125,10 @@ int xrep_rtbitmap(struct xfs_scrub *sc);
 
 #ifdef CONFIG_XFS_QUOTA
 int xrep_quota(struct xfs_scrub *sc);
+int xrep_quotacheck(struct xfs_scrub *sc);
 #else
 # define xrep_quota			xrep_notsupported
+# define xrep_quotacheck		xrep_notsupported
 #endif /* CONFIG_XFS_QUOTA */
 
 int xrep_reinit_pagf(struct xfs_scrub *sc);
@@ -191,6 +195,7 @@ xrep_setup_nothing(
 #define xrep_bmap_cow			xrep_notsupported
 #define xrep_rtbitmap			xrep_notsupported
 #define xrep_quota			xrep_notsupported
+#define xrep_quotacheck			xrep_notsupported
 
 #endif /* CONFIG_XFS_ONLINE_REPAIR */
 

fs/xfs/scrub/scrub.c

@@ -157,6 +157,9 @@ xchk_fsgates_disable(
 	if (sc->flags & XCHK_FSGATES_DRAIN)
 		xfs_drain_wait_disable();
 
+	if (sc->flags & XCHK_FSGATES_QUOTA)
+		xfs_dqtrx_hook_disable();
+
 	sc->flags &= ~XCHK_FSGATES_ALL;
 }
 
@@ -360,6 +363,12 @@ static const struct xchk_meta_ops meta_scrub_ops[] = {
 		.scrub	= xchk_fscounters,
 		.repair	= xrep_notsupported,
 	},
+	[XFS_SCRUB_TYPE_QUOTACHECK] = {	/* quota counters */
+		.type	= ST_FS,
+		.setup	= xchk_setup_quotacheck,
+		.scrub	= xchk_quotacheck,
+		.repair	= xrep_quotacheck,
+	},
 };
 
 static int

fs/xfs/scrub/scrub.h

@@ -121,6 +121,7 @@ struct xfs_scrub {
 #define XCHK_HAVE_FREEZE_PROT	(1U << 1)  /* do we have freeze protection? */
 #define XCHK_FSGATES_DRAIN	(1U << 2)  /* defer ops draining enabled */
 #define XCHK_NEED_DRAIN		(1U << 3)  /* scrub needs to drain defer ops */
+#define XCHK_FSGATES_QUOTA	(1U << 4)  /* quota live update enabled */
 #define XREP_RESET_PERAG_RESV	(1U << 30) /* must reset AG space reservation */
 #define XREP_ALREADY_FIXED	(1U << 31) /* checking our repair work */
 
@@ -130,7 +131,8 @@ struct xfs_scrub {
  * features are gated off via dynamic code patching, which is why the state
  * must be enabled during scrub setup and can only be torn down afterwards.
  */
-#define XCHK_FSGATES_ALL	(XCHK_FSGATES_DRAIN)
+#define XCHK_FSGATES_ALL	(XCHK_FSGATES_DRAIN | \
+				 XCHK_FSGATES_QUOTA)
 
 /* Metadata scrubbers */
 int xchk_tester(struct xfs_scrub *sc);
@@ -167,12 +169,18 @@ xchk_rtsummary(struct xfs_scrub *sc)
 #endif
 #ifdef CONFIG_XFS_QUOTA
 int xchk_quota(struct xfs_scrub *sc);
+int xchk_quotacheck(struct xfs_scrub *sc);
 #else
 static inline int
 xchk_quota(struct xfs_scrub *sc)
 {
 	return -ENOENT;
 }
+static inline int
+xchk_quotacheck(struct xfs_scrub *sc)
+{
+	return -ENOENT;
+}
 #endif
 int xchk_fscounters(struct xfs_scrub *sc);
 

fs/xfs/scrub/stats.c

@@ -77,6 +77,7 @@ static const char *name_map[XFS_SCRUB_TYPE_NR] = {
 	[XFS_SCRUB_TYPE_GQUOTA]		= "grpquota",
 	[XFS_SCRUB_TYPE_PQUOTA]		= "prjquota",
 	[XFS_SCRUB_TYPE_FSCOUNTERS]	= "fscounters",
+	[XFS_SCRUB_TYPE_QUOTACHECK]	= "quotacheck",
 };
 
 /* Format the scrub stats into a text buffer, similar to pcp style. */

fs/xfs/scrub/trace.h

@@ -15,6 +15,7 @@
 
 #include <linux/tracepoint.h>
 #include "xfs_bit.h"
+#include "xfs_quota_defs.h"
 
 struct xfs_scrub;
 struct xfile;
@@ -65,6 +66,7 @@ TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_UQUOTA);
 TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_GQUOTA);
 TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_PQUOTA);
 TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_FSCOUNTERS);
+TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_QUOTACHECK);
 
 #define XFS_SCRUB_TYPE_STRINGS \
 	{ XFS_SCRUB_TYPE_PROBE,		"probe" }, \
@@ -91,7 +93,8 @@ TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_FSCOUNTERS);
 	{ XFS_SCRUB_TYPE_UQUOTA,	"usrquota" }, \
 	{ XFS_SCRUB_TYPE_GQUOTA,	"grpquota" }, \
 	{ XFS_SCRUB_TYPE_PQUOTA,	"prjquota" }, \
-	{ XFS_SCRUB_TYPE_FSCOUNTERS,	"fscounters" }
+	{ XFS_SCRUB_TYPE_FSCOUNTERS,	"fscounters" }, \
+	{ XFS_SCRUB_TYPE_QUOTACHECK,	"quotacheck" }
 
 #define XFS_SCRUB_FLAG_STRINGS \
 	{ XFS_SCRUB_IFLAG_REPAIR,		"repair" }, \
@@ -109,6 +112,7 @@ TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_FSCOUNTERS);
 	{ XCHK_HAVE_FREEZE_PROT,		"nofreeze" }, \
 	{ XCHK_FSGATES_DRAIN,			"fsgates_drain" }, \
 	{ XCHK_NEED_DRAIN,			"need_drain" }, \
+	{ XCHK_FSGATES_QUOTA,			"fsgates_quota" }, \
 	{ XREP_RESET_PERAG_RESV,		"reset_perag_resv" }, \
 	{ XREP_ALREADY_FIXED,			"already_fixed" }
 
@@ -397,6 +401,29 @@ DEFINE_SCRUB_DQITER_EVENT(xchk_dquot_iter_revalidate_bmap);
 DEFINE_SCRUB_DQITER_EVENT(xchk_dquot_iter_advance_bmap);
 DEFINE_SCRUB_DQITER_EVENT(xchk_dquot_iter_advance_incore);
 DEFINE_SCRUB_DQITER_EVENT(xchk_dquot_iter);
+
+TRACE_EVENT(xchk_qcheck_error,
+	TP_PROTO(struct xfs_scrub *sc, xfs_dqtype_t dqtype, xfs_dqid_t id,
+		 void *ret_ip),
+	TP_ARGS(sc, dqtype, id, ret_ip),
+	TP_STRUCT__entry(
+		__field(dev_t, dev)
+		__field(xfs_dqtype_t, dqtype)
+		__field(xfs_dqid_t, id)
+		__field(void *, ret_ip)
+	),
+	TP_fast_assign(
+		__entry->dev = sc->mp->m_super->s_dev;
+		__entry->dqtype = dqtype;
+		__entry->id = id;
+		__entry->ret_ip = ret_ip;
+	),
+	TP_printk("dev %d:%d dquot type %s id 0x%x ret_ip %pS",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __print_symbolic(__entry->dqtype, XFS_DQTYPE_STRINGS),
+		  __entry->id,
+		  __entry->ret_ip)
+);
 #endif /* CONFIG_XFS_QUOTA */
 
 TRACE_EVENT(xchk_incomplete,
@@ -1977,6 +2004,7 @@ DEFINE_EVENT(xrep_dquot_class, name, \
 DEFINE_XREP_DQUOT_EVENT(xrep_dquot_item);
 DEFINE_XREP_DQUOT_EVENT(xrep_disk_dquot);
 DEFINE_XREP_DQUOT_EVENT(xrep_dquot_item_fill_bmap_hole);
+DEFINE_XREP_DQUOT_EVENT(xrep_quotacheck_dquot);
 #endif /* CONFIG_XFS_QUOTA */
 
 #endif /* IS_ENABLED(CONFIG_XFS_ONLINE_REPAIR) */

fs/xfs/scrub/xfarray.h

@@ -45,6 +45,25 @@ int xfarray_store(struct xfarray *array, xfarray_idx_t idx, const void *ptr);
 int xfarray_store_anywhere(struct xfarray *array, const void *ptr);
 bool xfarray_element_is_null(struct xfarray *array, const void *ptr);
 
+/*
+ * Load an array element, but zero the buffer if there's no data because we
+ * haven't stored to that array element yet.
+ */
+static inline int
+xfarray_load_sparse(
+	struct xfarray	*array,
+	uint64_t	idx,
+	void		*rec)
+{
+	int		error = xfarray_load(array, idx, rec);
+
+	if (error == -ENODATA) {
+		memset(rec, 0, array->obj_size);
+		return 0;
+	}
+	return error;
+}
+
 /* Append an element to the array. */
 static inline int xfarray_append(struct xfarray *array, const void *ptr)
 {

fs/xfs/xfs_health.c

@@ -280,6 +280,7 @@ static const struct ioctl_sick_map fs_map[] = {
 	{ XFS_SICK_FS_UQUOTA,	XFS_FSOP_GEOM_SICK_UQUOTA },
 	{ XFS_SICK_FS_GQUOTA,	XFS_FSOP_GEOM_SICK_GQUOTA },
 	{ XFS_SICK_FS_PQUOTA,	XFS_FSOP_GEOM_SICK_PQUOTA },
+	{ XFS_SICK_FS_QUOTACHECK, XFS_FSOP_GEOM_SICK_QUOTACHECK },
 	{ 0, 0 },
 };
 

fs/xfs/xfs_inode.c

@@ -3755,3 +3755,19 @@ xfs_ifork_zapped(
 		return false;
 	}
 }
+
+/* Compute the number of data and realtime blocks used by a file. */
+void
+xfs_inode_count_blocks(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	xfs_filblks_t		*dblocks,
+	xfs_filblks_t		*rblocks)
+{
+	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
+
+	*rblocks = 0;
+	if (XFS_IS_REALTIME_INODE(ip))
+		xfs_bmap_count_leaves(ifp, rblocks);
+	*dblocks = ip->i_nblocks - *rblocks;
+}

fs/xfs/xfs_inode.h

@@ -623,5 +623,7 @@ int xfs_inode_reload_unlinked_bucket(struct xfs_trans *tp, struct xfs_inode *ip)
 int xfs_inode_reload_unlinked(struct xfs_inode *ip);
 
 bool xfs_ifork_zapped(const struct xfs_inode *ip, int whichfork);
+void xfs_inode_count_blocks(struct xfs_trans *tp, struct xfs_inode *ip,
+		xfs_filblks_t *dblocks, xfs_filblks_t *rblocks);
 
 #endif	/* __XFS_INODE_H__ */

fs/xfs/xfs_qm.c

@@ -26,6 +26,7 @@
 #include "xfs_ag.h"
 #include "xfs_ialloc.h"
 #include "xfs_log_priv.h"
+#include "xfs_health.h"
 
 /*
  * The global quota manager. There is only one of these for the entire
@@ -692,6 +693,9 @@ xfs_qm_init_quotainfo(
 
 	shrinker_register(qinf->qi_shrinker);
 
+	xfs_hooks_init(&qinf->qi_mod_ino_dqtrx_hooks);
+	xfs_hooks_init(&qinf->qi_apply_dqtrx_hooks);
+
 	return 0;
 
 out_free_inos:
@@ -1408,8 +1412,12 @@ xfs_qm_quotacheck(
 			xfs_warn(mp,
 				"Quotacheck: Failed to reset quota flags.");
 		}
-	} else
+		xfs_fs_mark_sick(mp, XFS_SICK_FS_QUOTACHECK);
+	} else {
 		xfs_notice(mp, "Quotacheck: Done.");
+		xfs_fs_mark_healthy(mp, XFS_SICK_FS_QUOTACHECK);
+	}
+
 	return error;
 
 error_purge:
@@ -1819,12 +1827,12 @@ xfs_qm_vop_chown(
 	ASSERT(prevdq);
 	ASSERT(prevdq != newdq);
 
-	xfs_trans_mod_dquot(tp, prevdq, bfield, -(ip->i_nblocks));
-	xfs_trans_mod_dquot(tp, prevdq, XFS_TRANS_DQ_ICOUNT, -1);
+	xfs_trans_mod_ino_dquot(tp, ip, prevdq, bfield, -(ip->i_nblocks));
+	xfs_trans_mod_ino_dquot(tp, ip, prevdq, XFS_TRANS_DQ_ICOUNT, -1);
 
 	/* the sparkling new dquot */
-	xfs_trans_mod_dquot(tp, newdq, bfield, ip->i_nblocks);
-	xfs_trans_mod_dquot(tp, newdq, XFS_TRANS_DQ_ICOUNT, 1);
+	xfs_trans_mod_ino_dquot(tp, ip, newdq, bfield, ip->i_nblocks);
+	xfs_trans_mod_ino_dquot(tp, ip, newdq, XFS_TRANS_DQ_ICOUNT, 1);
 
 	/*
 	 * Back when we made quota reservations for the chown, we reserved the
@@ -1906,22 +1914,21 @@ xfs_qm_vop_create_dqattach(
 		ASSERT(i_uid_read(VFS_I(ip)) == udqp->q_id);
 
 		ip->i_udquot = xfs_qm_dqhold(udqp);
-		xfs_trans_mod_dquot(tp, udqp, XFS_TRANS_DQ_ICOUNT, 1);
 	}
 	if (gdqp && XFS_IS_GQUOTA_ON(mp)) {
 		ASSERT(ip->i_gdquot == NULL);
 		ASSERT(i_gid_read(VFS_I(ip)) == gdqp->q_id);
 
 		ip->i_gdquot = xfs_qm_dqhold(gdqp);
-		xfs_trans_mod_dquot(tp, gdqp, XFS_TRANS_DQ_ICOUNT, 1);
 	}
 	if (pdqp && XFS_IS_PQUOTA_ON(mp)) {
 		ASSERT(ip->i_pdquot == NULL);
 		ASSERT(ip->i_projid == pdqp->q_id);
 
 		ip->i_pdquot = xfs_qm_dqhold(pdqp);
-		xfs_trans_mod_dquot(tp, pdqp, XFS_TRANS_DQ_ICOUNT, 1);
 	}
+
+	xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_ICOUNT, 1);
 }
 
 /* Decide if this inode's dquot is near an enforcement boundary. */

fs/xfs/xfs_qm.h

@@ -68,6 +68,10 @@ struct xfs_quotainfo {
 	/* Minimum and maximum quota expiration timestamp values. */
 	time64_t		qi_expiry_min;
 	time64_t		qi_expiry_max;
+
+	/* Hook to feed quota counter updates to an active online repair. */
+	struct xfs_hooks	qi_mod_ino_dqtrx_hooks;
+	struct xfs_hooks	qi_apply_dqtrx_hooks;
 };
 
 static inline struct radix_tree_root *
@@ -104,6 +108,18 @@ xfs_quota_inode(struct xfs_mount *mp, xfs_dqtype_t type)
 	return NULL;
 }
 
+/*
+ * Parameters for tracking dqtrx changes on behalf of an inode.  The hook
+ * function arg parameter is the field being updated.
+ */
+struct xfs_mod_ino_dqtrx_params {
+	uintptr_t		tx_id;
+	xfs_ino_t		ino;
+	xfs_dqtype_t		q_type;
+	xfs_dqid_t		q_id;
+	int64_t			delta;
+};
+
 extern void	xfs_trans_mod_dquot(struct xfs_trans *tp, struct xfs_dquot *dqp,
 				    uint field, int64_t delta);
 extern void	xfs_trans_dqjoin(struct xfs_trans *, struct xfs_dquot *);

fs/xfs/xfs_qm_bhv.c

@@ -9,6 +9,7 @@
 #include "xfs_format.h"
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
+#include "xfs_mount.h"
 #include "xfs_quota.h"
 #include "xfs_mount.h"
 #include "xfs_inode.h"

fs/xfs/xfs_quota.h

@@ -74,6 +74,22 @@ struct xfs_dqtrx {
 	int64_t		qt_icount_delta;  /* dquot inode count changes */
 };
 
+enum xfs_apply_dqtrx_type {
+	XFS_APPLY_DQTRX_COMMIT = 0,
+	XFS_APPLY_DQTRX_UNRESERVE,
+};
+
+/*
+ * Parameters for applying dqtrx changes to a dquot.  The hook function arg
+ * parameter is enum xfs_apply_dqtrx_type.
+ */
+struct xfs_apply_dqtrx_params {
+	uintptr_t		tx_id;
+	xfs_ino_t		ino;
+	xfs_dqtype_t		q_type;
+	xfs_dqid_t		q_id;
+};
+
 #ifdef CONFIG_XFS_QUOTA
 extern void xfs_trans_dup_dqinfo(struct xfs_trans *, struct xfs_trans *);
 extern void xfs_trans_free_dqinfo(struct xfs_trans *);
@@ -114,6 +130,30 @@ xfs_quota_reserve_blkres(struct xfs_inode *ip, int64_t blocks)
 	return xfs_trans_reserve_quota_nblks(NULL, ip, blocks, 0, false);
 }
 bool xfs_inode_near_dquot_enforcement(struct xfs_inode *ip, xfs_dqtype_t type);
+
+# ifdef CONFIG_XFS_LIVE_HOOKS
+void xfs_trans_mod_ino_dquot(struct xfs_trans *tp, struct xfs_inode *ip,
+		struct xfs_dquot *dqp, unsigned int field, int64_t delta);
+
+struct xfs_quotainfo;
+
+struct xfs_dqtrx_hook {
+	struct xfs_hook		mod_hook;
+	struct xfs_hook		apply_hook;
+};
+
+void xfs_dqtrx_hook_disable(void);
+void xfs_dqtrx_hook_enable(void);
+
+int xfs_dqtrx_hook_add(struct xfs_quotainfo *qi, struct xfs_dqtrx_hook *hook);
+void xfs_dqtrx_hook_del(struct xfs_quotainfo *qi, struct xfs_dqtrx_hook *hook);
+void xfs_dqtrx_hook_setup(struct xfs_dqtrx_hook *hook, notifier_fn_t mod_fn,
+		notifier_fn_t apply_fn);
+# else
+#  define xfs_trans_mod_ino_dquot(tp, ip, dqp, field, delta) \
+		xfs_trans_mod_dquot((tp), (dqp), (field), (delta))
+# endif /* CONFIG_XFS_LIVE_HOOKS */
+
 #else
 static inline int
 xfs_qm_vop_dqalloc(struct xfs_inode *ip, kuid_t kuid, kgid_t kgid,
@@ -173,6 +213,12 @@ xfs_trans_reserve_quota_icreate(struct xfs_trans *tp, struct xfs_dquot *udqp,
 #define xfs_qm_unmount(mp)
 #define xfs_qm_unmount_quotas(mp)
 #define xfs_inode_near_dquot_enforcement(ip, type)			(false)
+
+# ifdef CONFIG_XFS_LIVE_HOOKS
+#  define xfs_dqtrx_hook_enable()		((void)0)
+#  define xfs_dqtrx_hook_disable()		((void)0)
+# endif /* CONFIG_XFS_LIVE_HOOKS */
+
 #endif /* CONFIG_XFS_QUOTA */
 
 static inline int

fs/xfs/xfs_trans_dquot.c

@@ -17,6 +17,7 @@
 #include "xfs_qm.h"
 #include "xfs_trace.h"
 #include "xfs_error.h"
+#include "xfs_health.h"
 
 STATIC void	xfs_trans_alloc_dqinfo(xfs_trans_t *);
 
@@ -120,6 +121,116 @@ xfs_trans_dup_dqinfo(
 	}
 }
 
+#ifdef CONFIG_XFS_LIVE_HOOKS
+/*
+ * Use a static key here to reduce the overhead of quota live updates.  If the
+ * compiler supports jump labels, the static branch will be replaced by a nop
+ * sled when there are no hook users.  Online fsck is currently the only
+ * caller, so this is a reasonable tradeoff.
+ *
+ * Note: Patching the kernel code requires taking the cpu hotplug lock.  Other
+ * parts of the kernel allocate memory with that lock held, which means that
+ * XFS callers cannot hold any locks that might be used by memory reclaim or
+ * writeback when calling the static_branch_{inc,dec} functions.
+ */
+DEFINE_STATIC_XFS_HOOK_SWITCH(xfs_dqtrx_hooks_switch);
+
+void
+xfs_dqtrx_hook_disable(void)
+{
+	xfs_hooks_switch_off(&xfs_dqtrx_hooks_switch);
+}
+
+void
+xfs_dqtrx_hook_enable(void)
+{
+	xfs_hooks_switch_on(&xfs_dqtrx_hooks_switch);
+}
+
+/* Schedule a transactional dquot update on behalf of an inode. */
+void
+xfs_trans_mod_ino_dquot(
+	struct xfs_trans		*tp,
+	struct xfs_inode		*ip,
+	struct xfs_dquot		*dqp,
+	unsigned int			field,
+	int64_t				delta)
+{
+	xfs_trans_mod_dquot(tp, dqp, field, delta);
+
+	if (xfs_hooks_switched_on(&xfs_dqtrx_hooks_switch)) {
+		struct xfs_mod_ino_dqtrx_params	p = {
+			.tx_id		= (uintptr_t)tp,
+			.ino		= ip->i_ino,
+			.q_type		= xfs_dquot_type(dqp),
+			.q_id		= dqp->q_id,
+			.delta		= delta
+		};
+		struct xfs_quotainfo	*qi = tp->t_mountp->m_quotainfo;
+
+		xfs_hooks_call(&qi->qi_mod_ino_dqtrx_hooks, field, &p);
+	}
+}
+
+/* Call the specified functions during a dquot counter update. */
+int
+xfs_dqtrx_hook_add(
+	struct xfs_quotainfo	*qi,
+	struct xfs_dqtrx_hook	*hook)
+{
+	int			error;
+
+	/*
+	 * Transactional dquot updates first call the mod hook when changes
+	 * are attached to the transaction and then call the apply hook when
+	 * those changes are committed (or canceled).
+	 *
+	 * The apply hook must be installed before the mod hook so that we
+	 * never fail to catch the end of a quota update sequence.
+	 */
+	error = xfs_hooks_add(&qi->qi_apply_dqtrx_hooks, &hook->apply_hook);
+	if (error)
+		goto out;
+
+	error = xfs_hooks_add(&qi->qi_mod_ino_dqtrx_hooks, &hook->mod_hook);
+	if (error)
+		goto out_apply;
+
+	return 0;
+
+out_apply:
+	xfs_hooks_del(&qi->qi_apply_dqtrx_hooks, &hook->apply_hook);
+out:
+	return error;
+}
+
+/* Stop calling the specified function during a dquot counter update. */
+void
+xfs_dqtrx_hook_del(
+	struct xfs_quotainfo	*qi,
+	struct xfs_dqtrx_hook	*hook)
+{
+	/*
+	 * The mod hook must be removed before apply hook to avoid giving the
+	 * hook consumer with an incomplete update.  No hooks should be running
+	 * after these functions return.
+	 */
+	xfs_hooks_del(&qi->qi_mod_ino_dqtrx_hooks, &hook->mod_hook);
+	xfs_hooks_del(&qi->qi_apply_dqtrx_hooks, &hook->apply_hook);
+}
+
+/* Configure dquot update hook functions. */
+void
+xfs_dqtrx_hook_setup(
+	struct xfs_dqtrx_hook	*hook,
+	notifier_fn_t		mod_fn,
+	notifier_fn_t		apply_fn)
+{
+	xfs_hook_setup(&hook->mod_hook, mod_fn);
+	xfs_hook_setup(&hook->apply_hook, apply_fn);
+}
+#endif /* CONFIG_XFS_LIVE_HOOKS */
+
 /*
  * Wrap around mod_dquot to account for both user and group quotas.
  */
@@ -137,11 +248,11 @@ xfs_trans_mod_dquot_byino(
 		return;
 
 	if (XFS_IS_UQUOTA_ON(mp) && ip->i_udquot)
-		(void) xfs_trans_mod_dquot(tp, ip->i_udquot, field, delta);
+		xfs_trans_mod_ino_dquot(tp, ip, ip->i_udquot, field, delta);
 	if (XFS_IS_GQUOTA_ON(mp) && ip->i_gdquot)
-		(void) xfs_trans_mod_dquot(tp, ip->i_gdquot, field, delta);
+		xfs_trans_mod_ino_dquot(tp, ip, ip->i_gdquot, field, delta);
 	if (XFS_IS_PQUOTA_ON(mp) && ip->i_pdquot)
-		(void) xfs_trans_mod_dquot(tp, ip->i_pdquot, field, delta);
+		xfs_trans_mod_ino_dquot(tp, ip, ip->i_pdquot, field, delta);
 }
 
 STATIC struct xfs_dqtrx *
@@ -321,6 +432,29 @@ xfs_apply_quota_reservation_deltas(
 	}
 }
 
+#ifdef CONFIG_XFS_LIVE_HOOKS
+/* Call downstream hooks now that it's time to apply dquot deltas. */
+static inline void
+xfs_trans_apply_dquot_deltas_hook(
+	struct xfs_trans		*tp,
+	struct xfs_dquot		*dqp)
+{
+	if (xfs_hooks_switched_on(&xfs_dqtrx_hooks_switch)) {
+		struct xfs_apply_dqtrx_params	p = {
+			.tx_id		= (uintptr_t)tp,
+			.q_type		= xfs_dquot_type(dqp),
+			.q_id		= dqp->q_id,
+		};
+		struct xfs_quotainfo	*qi = tp->t_mountp->m_quotainfo;
+
+		xfs_hooks_call(&qi->qi_apply_dqtrx_hooks,
+				XFS_APPLY_DQTRX_COMMIT, &p);
+	}
+}
+#else
+# define xfs_trans_apply_dquot_deltas_hook(tp, dqp)	((void)0)
+#endif /* CONFIG_XFS_LIVE_HOOKS */
+
 /*
  * Called by xfs_trans_commit() and similar in spirit to
  * xfs_trans_apply_sb_deltas().
@@ -366,6 +500,8 @@ xfs_trans_apply_dquot_deltas(
 
 			ASSERT(XFS_DQ_IS_LOCKED(dqp));
 
+			xfs_trans_apply_dquot_deltas_hook(tp, dqp);
+
 			/*
 			 * adjust the actual number of blocks used
 			 */
@@ -465,6 +601,29 @@ xfs_trans_apply_dquot_deltas(
 	}
 }
 
+#ifdef CONFIG_XFS_LIVE_HOOKS
+/* Call downstream hooks now that it's time to cancel dquot deltas. */
+static inline void
+xfs_trans_unreserve_and_mod_dquots_hook(
+	struct xfs_trans		*tp,
+	struct xfs_dquot		*dqp)
+{
+	if (xfs_hooks_switched_on(&xfs_dqtrx_hooks_switch)) {
+		struct xfs_apply_dqtrx_params	p = {
+			.tx_id		= (uintptr_t)tp,
+			.q_type		= xfs_dquot_type(dqp),
+			.q_id		= dqp->q_id,
+		};
+		struct xfs_quotainfo	*qi = tp->t_mountp->m_quotainfo;
+
+		xfs_hooks_call(&qi->qi_apply_dqtrx_hooks,
+				XFS_APPLY_DQTRX_UNRESERVE, &p);
+	}
+}
+#else
+# define xfs_trans_unreserve_and_mod_dquots_hook(tp, dqp)	((void)0)
+#endif /* CONFIG_XFS_LIVE_HOOKS */
+
 /*
  * Release the reservations, and adjust the dquots accordingly.
  * This is called only when the transaction is being aborted. If by
@@ -495,6 +654,9 @@ xfs_trans_unreserve_and_mod_dquots(
 			 */
 			if ((dqp = qtrx->qt_dquot) == NULL)
 				break;
+
+			xfs_trans_unreserve_and_mod_dquots_hook(tp, dqp);
+
 			/*
 			 * Unreserve the original reservation. We don't care
 			 * about the number of blocks used field, or deltas.
@@ -706,6 +868,7 @@ xfs_trans_dqresv(
 error_corrupt:
 	xfs_dqunlock(dqp);
 	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
+	xfs_fs_mark_sick(mp, XFS_SICK_FS_QUOTACHECK);
 	return -EFSCORRUPTED;
 }