Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1798 insertions, 0 deletions

diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
new file mode 100644
index 0000000000..f689847bab
--- /dev/null
+++ b/fs/gfs2/quota.c
@@ -0,0 +1,1798 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
+ * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
+ */
+
+/*
+ * Quota change tags are associated with each transaction that allocates or
+ * deallocates space.  Those changes are accumulated locally to each node (in a
+ * per-node file) and then are periodically synced to the quota file.  This
+ * avoids the bottleneck of constantly touching the quota file, but introduces
+ * fuzziness in the current usage value of IDs that are being used on different
+ * nodes in the cluster simultaneously.  So, it is possible for a user on
+ * multiple nodes to overrun their quota, but that overrun is controlable.
+ * Since quota tags are part of transactions, there is no need for a quota check
+ * program to be run on node crashes or anything like that.
+ *
+ * There are couple of knobs that let the administrator manage the quota
+ * fuzziness.  "quota_quantum" sets the maximum time a quota change can be
+ * sitting on one node before being synced to the quota file.  (The default is
+ * 60 seconds.)  Another knob, "quota_scale" controls how quickly the frequency
+ * of quota file syncs increases as the user moves closer to their limit.  The
+ * more frequent the syncs, the more accurate the quota enforcement, but that
+ * means that there is more contention between the nodes for the quota file.
+ * The default value is one.  This sets the maximum theoretical quota overrun
+ * (with infinite node with infinite bandwidth) to twice the user's limit.  (In
+ * practice, the maximum overrun you see should be much less.)  A "quota_scale"
+ * number greater than one makes quota syncs more frequent and reduces the
+ * maximum overrun.  Numbers less than one (but greater than zero) make quota
+ * syncs less frequent.
+ *
+ * GFS quotas also use per-ID Lock Value Blocks (LVBs) to cache the contents of
+ * the quota file, so it is not being constantly read.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/buffer_head.h>
+#include <linux/sort.h>
+#include <linux/fs.h>
+#include <linux/bio.h>
+#include <linux/gfs2_ondisk.h>
+#include <linux/kthread.h>
+#include <linux/freezer.h>
+#include <linux/quota.h>
+#include <linux/dqblk_xfs.h>
+#include <linux/lockref.h>
+#include <linux/list_lru.h>
+#include <linux/rcupdate.h>
+#include <linux/rculist_bl.h>
+#include <linux/bit_spinlock.h>
+#include <linux/jhash.h>
+#include <linux/vmalloc.h>
+
+#include "gfs2.h"
+#include "incore.h"
+#include "bmap.h"
+#include "glock.h"
+#include "glops.h"
+#include "log.h"
+#include "meta_io.h"
+#include "quota.h"
+#include "rgrp.h"
+#include "super.h"
+#include "trans.h"
+#include "inode.h"
+#include "util.h"
+
+#define GFS2_QD_HASH_SHIFT      12
+#define GFS2_QD_HASH_SIZE       BIT(GFS2_QD_HASH_SHIFT)
+#define GFS2_QD_HASH_MASK       (GFS2_QD_HASH_SIZE - 1)
+
+#define QC_CHANGE 0
+#define QC_SYNC 1
+
+/* Lock order: qd_lock -> bucket lock -> qd->lockref.lock -> lru lock */
+/*                     -> sd_bitmap_lock                              */
+static DEFINE_SPINLOCK(qd_lock);
+struct list_lru gfs2_qd_lru;
+
+static struct hlist_bl_head qd_hash_table[GFS2_QD_HASH_SIZE];
+
+static unsigned int gfs2_qd_hash(const struct gfs2_sbd *sdp,
+				 const struct kqid qid)
+{
+	unsigned int h;
+
+	h = jhash(&sdp, sizeof(struct gfs2_sbd *), 0);
+	h = jhash(&qid, sizeof(struct kqid), h);
+
+	return h & GFS2_QD_HASH_MASK;
+}
+
+static inline void spin_lock_bucket(unsigned int hash)
+{
+        hlist_bl_lock(&qd_hash_table[hash]);
+}
+
+static inline void spin_unlock_bucket(unsigned int hash)
+{
+        hlist_bl_unlock(&qd_hash_table[hash]);
+}
+
+static void gfs2_qd_dealloc(struct rcu_head *rcu)
+{
+	struct gfs2_quota_data *qd = container_of(rcu, struct gfs2_quota_data, qd_rcu);
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+
+	kmem_cache_free(gfs2_quotad_cachep, qd);
+	if (atomic_dec_and_test(&sdp->sd_quota_count))
+		wake_up(&sdp->sd_kill_wait);
+}
+
+static void gfs2_qd_dispose(struct gfs2_quota_data *qd)
+{
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+
+	spin_lock(&qd_lock);
+	list_del(&qd->qd_list);
+	spin_unlock(&qd_lock);
+
+	spin_lock_bucket(qd->qd_hash);
+	hlist_bl_del_rcu(&qd->qd_hlist);
+	spin_unlock_bucket(qd->qd_hash);
+
+	if (!gfs2_withdrawn(sdp)) {
+		gfs2_assert_warn(sdp, !qd->qd_change);
+		gfs2_assert_warn(sdp, !qd->qd_slot_ref);
+		gfs2_assert_warn(sdp, !qd->qd_bh_count);
+	}
+
+	gfs2_glock_put(qd->qd_gl);
+	call_rcu(&qd->qd_rcu, gfs2_qd_dealloc);
+}
+
+static void gfs2_qd_list_dispose(struct list_head *list)
+{
+	struct gfs2_quota_data *qd;
+
+	while (!list_empty(list)) {
+		qd = list_first_entry(list, struct gfs2_quota_data, qd_lru);
+		list_del(&qd->qd_lru);
+
+		gfs2_qd_dispose(qd);
+	}
+}
+
+
+static enum lru_status gfs2_qd_isolate(struct list_head *item,
+		struct list_lru_one *lru, spinlock_t *lru_lock, void *arg)
+{
+	struct list_head *dispose = arg;
+	struct gfs2_quota_data *qd =
+		list_entry(item, struct gfs2_quota_data, qd_lru);
+	enum lru_status status;
+
+	if (!spin_trylock(&qd->qd_lockref.lock))
+		return LRU_SKIP;
+
+	status = LRU_SKIP;
+	if (qd->qd_lockref.count == 0) {
+		lockref_mark_dead(&qd->qd_lockref);
+		list_lru_isolate_move(lru, &qd->qd_lru, dispose);
+		status = LRU_REMOVED;
+	}
+
+	spin_unlock(&qd->qd_lockref.lock);
+	return status;
+}
+
+static unsigned long gfs2_qd_shrink_scan(struct shrinker *shrink,
+					 struct shrink_control *sc)
+{
+	LIST_HEAD(dispose);
+	unsigned long freed;
+
+	if (!(sc->gfp_mask & __GFP_FS))
+		return SHRINK_STOP;
+
+	freed = list_lru_shrink_walk(&gfs2_qd_lru, sc,
+				     gfs2_qd_isolate, &dispose);
+
+	gfs2_qd_list_dispose(&dispose);
+
+	return freed;
+}
+
+static unsigned long gfs2_qd_shrink_count(struct shrinker *shrink,
+					  struct shrink_control *sc)
+{
+	return vfs_pressure_ratio(list_lru_shrink_count(&gfs2_qd_lru, sc));
+}
+
+struct shrinker gfs2_qd_shrinker = {
+	.count_objects = gfs2_qd_shrink_count,
+	.scan_objects = gfs2_qd_shrink_scan,
+	.seeks = DEFAULT_SEEKS,
+	.flags = SHRINKER_NUMA_AWARE,
+};
+
+
+static u64 qd2index(struct gfs2_quota_data *qd)
+{
+	struct kqid qid = qd->qd_id;
+	return (2 * (u64)from_kqid(&init_user_ns, qid)) +
+		((qid.type == USRQUOTA) ? 0 : 1);
+}
+
+static u64 qd2offset(struct gfs2_quota_data *qd)
+{
+	return qd2index(qd) * sizeof(struct gfs2_quota);
+}
+
+static struct gfs2_quota_data *qd_alloc(unsigned hash, struct gfs2_sbd *sdp, struct kqid qid)
+{
+	struct gfs2_quota_data *qd;
+	int error;
+
+	qd = kmem_cache_zalloc(gfs2_quotad_cachep, GFP_NOFS);
+	if (!qd)
+		return NULL;
+
+	qd->qd_sbd = sdp;
+	qd->qd_lockref.count = 0;
+	spin_lock_init(&qd->qd_lockref.lock);
+	qd->qd_id = qid;
+	qd->qd_slot = -1;
+	INIT_LIST_HEAD(&qd->qd_lru);
+	qd->qd_hash = hash;
+
+	error = gfs2_glock_get(sdp, qd2index(qd),
+			      &gfs2_quota_glops, CREATE, &qd->qd_gl);
+	if (error)
+		goto fail;
+
+	return qd;
+
+fail:
+	kmem_cache_free(gfs2_quotad_cachep, qd);
+	return NULL;
+}
+
+static struct gfs2_quota_data *gfs2_qd_search_bucket(unsigned int hash,
+						     const struct gfs2_sbd *sdp,
+						     struct kqid qid)
+{
+	struct gfs2_quota_data *qd;
+	struct hlist_bl_node *h;
+
+	hlist_bl_for_each_entry_rcu(qd, h, &qd_hash_table[hash], qd_hlist) {
+		if (!qid_eq(qd->qd_id, qid))
+			continue;
+		if (qd->qd_sbd != sdp)
+			continue;
+		if (lockref_get_not_dead(&qd->qd_lockref)) {
+			list_lru_del(&gfs2_qd_lru, &qd->qd_lru);
+			return qd;
+		}
+	}
+
+	return NULL;
+}
+
+
+static int qd_get(struct gfs2_sbd *sdp, struct kqid qid,
+		  struct gfs2_quota_data **qdp)
+{
+	struct gfs2_quota_data *qd, *new_qd;
+	unsigned int hash = gfs2_qd_hash(sdp, qid);
+
+	rcu_read_lock();
+	*qdp = qd = gfs2_qd_search_bucket(hash, sdp, qid);
+	rcu_read_unlock();
+
+	if (qd)
+		return 0;
+
+	new_qd = qd_alloc(hash, sdp, qid);
+	if (!new_qd)
+		return -ENOMEM;
+
+	spin_lock(&qd_lock);
+	spin_lock_bucket(hash);
+	*qdp = qd = gfs2_qd_search_bucket(hash, sdp, qid);
+	if (qd == NULL) {
+		new_qd->qd_lockref.count++;
+		*qdp = new_qd;
+		list_add(&new_qd->qd_list, &sdp->sd_quota_list);
+		hlist_bl_add_head_rcu(&new_qd->qd_hlist, &qd_hash_table[hash]);
+		atomic_inc(&sdp->sd_quota_count);
+	}
+	spin_unlock_bucket(hash);
+	spin_unlock(&qd_lock);
+
+	if (qd) {
+		gfs2_glock_put(new_qd->qd_gl);
+		kmem_cache_free(gfs2_quotad_cachep, new_qd);
+	}
+
+	return 0;
+}
+
+
+static void qd_hold(struct gfs2_quota_data *qd)
+{
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+	gfs2_assert(sdp, !__lockref_is_dead(&qd->qd_lockref));
+	lockref_get(&qd->qd_lockref);
+}
+
+static void qd_put(struct gfs2_quota_data *qd)
+{
+	struct gfs2_sbd *sdp;
+
+	if (lockref_put_or_lock(&qd->qd_lockref))
+		return;
+
+	BUG_ON(__lockref_is_dead(&qd->qd_lockref));
+	sdp = qd->qd_sbd;
+	if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))) {
+		lockref_mark_dead(&qd->qd_lockref);
+		spin_unlock(&qd->qd_lockref.lock);
+
+		gfs2_qd_dispose(qd);
+		return;
+	}
+
+	qd->qd_lockref.count = 0;
+	list_lru_add(&gfs2_qd_lru, &qd->qd_lru);
+	spin_unlock(&qd->qd_lockref.lock);
+}
+
+static int slot_get(struct gfs2_quota_data *qd)
+{
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+	unsigned int bit;
+	int error = 0;
+
+	spin_lock(&sdp->sd_bitmap_lock);
+	if (qd->qd_slot_ref == 0) {
+		bit = find_first_zero_bit(sdp->sd_quota_bitmap,
+					  sdp->sd_quota_slots);
+		if (bit >= sdp->sd_quota_slots) {
+			error = -ENOSPC;
+			goto out;
+		}
+		set_bit(bit, sdp->sd_quota_bitmap);
+		qd->qd_slot = bit;
+	}
+	qd->qd_slot_ref++;
+out:
+	spin_unlock(&sdp->sd_bitmap_lock);
+	return error;
+}
+
+static void slot_hold(struct gfs2_quota_data *qd)
+{
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+
+	spin_lock(&sdp->sd_bitmap_lock);
+	gfs2_assert(sdp, qd->qd_slot_ref);
+	qd->qd_slot_ref++;
+	spin_unlock(&sdp->sd_bitmap_lock);
+}
+
+static void slot_put(struct gfs2_quota_data *qd)
+{
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+
+	spin_lock(&sdp->sd_bitmap_lock);
+	gfs2_assert(sdp, qd->qd_slot_ref);
+	if (!--qd->qd_slot_ref) {
+		BUG_ON(!test_and_clear_bit(qd->qd_slot, sdp->sd_quota_bitmap));
+		qd->qd_slot = -1;
+	}
+	spin_unlock(&sdp->sd_bitmap_lock);
+}
+
+static int bh_get(struct gfs2_quota_data *qd)
+{
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+	struct inode *inode = sdp->sd_qc_inode;
+	struct gfs2_inode *ip = GFS2_I(inode);
+	unsigned int block, offset;
+	struct buffer_head *bh;
+	struct iomap iomap = { };
+	int error;
+
+	mutex_lock(&sdp->sd_quota_mutex);
+
+	if (qd->qd_bh_count++) {
+		mutex_unlock(&sdp->sd_quota_mutex);
+		return 0;
+	}
+
+	block = qd->qd_slot / sdp->sd_qc_per_block;
+	offset = qd->qd_slot % sdp->sd_qc_per_block;
+
+	error = gfs2_iomap_get(inode,
+			       (loff_t)block << inode->i_blkbits,
+			       i_blocksize(inode), &iomap);
+	if (error)
+		goto fail;
+	error = -ENOENT;
+	if (iomap.type != IOMAP_MAPPED)
+		goto fail;
+
+	error = gfs2_meta_read(ip->i_gl, iomap.addr >> inode->i_blkbits,
+			       DIO_WAIT, 0, &bh);
+	if (error)
+		goto fail;
+	error = -EIO;
+	if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC))
+		goto fail_brelse;
+
+	qd->qd_bh = bh;
+	qd->qd_bh_qc = (struct gfs2_quota_change *)
+		(bh->b_data + sizeof(struct gfs2_meta_header) +
+		 offset * sizeof(struct gfs2_quota_change));
+
+	mutex_unlock(&sdp->sd_quota_mutex);
+
+	return 0;
+
+fail_brelse:
+	brelse(bh);
+fail:
+	qd->qd_bh_count--;
+	mutex_unlock(&sdp->sd_quota_mutex);
+	return error;
+}
+
+static void bh_put(struct gfs2_quota_data *qd)
+{
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+
+	mutex_lock(&sdp->sd_quota_mutex);
+	gfs2_assert(sdp, qd->qd_bh_count);
+	if (!--qd->qd_bh_count) {
+		brelse(qd->qd_bh);
+		qd->qd_bh = NULL;
+		qd->qd_bh_qc = NULL;
+	}
+	mutex_unlock(&sdp->sd_quota_mutex);
+}
+
+static int qd_check_sync(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd,
+			 u64 *sync_gen)
+{
+	if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
+	    !test_bit(QDF_CHANGE, &qd->qd_flags) ||
+	    (sync_gen && (qd->qd_sync_gen >= *sync_gen)))
+		return 0;
+
+	/*
+	 * If qd_change is 0 it means a pending quota change was negated.
+	 * We should not sync it, but we still have a qd reference and slot
+	 * reference taken by gfs2_quota_change -> do_qc that need to be put.
+	 */
+	if (!qd->qd_change && test_and_clear_bit(QDF_CHANGE, &qd->qd_flags)) {
+		slot_put(qd);
+		qd_put(qd);
+		return 0;
+	}
+
+	if (!lockref_get_not_dead(&qd->qd_lockref))
+		return 0;
+
+	list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
+	set_bit(QDF_LOCKED, &qd->qd_flags);
+	qd->qd_change_sync = qd->qd_change;
+	slot_hold(qd);
+	return 1;
+}
+
+static int qd_bh_get_or_undo(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd)
+{
+	int error;
+
+	error = bh_get(qd);
+	if (!error)
+		return 0;
+
+	clear_bit(QDF_LOCKED, &qd->qd_flags);
+	slot_put(qd);
+	qd_put(qd);
+	return error;
+}
+
+static int qd_fish(struct gfs2_sbd *sdp, struct gfs2_quota_data **qdp)
+{
+	struct gfs2_quota_data *qd = NULL, *iter;
+	int error;
+
+	*qdp = NULL;
+
+	if (sb_rdonly(sdp->sd_vfs))
+		return 0;
+
+	spin_lock(&qd_lock);
+
+	list_for_each_entry(iter, &sdp->sd_quota_list, qd_list) {
+		if (qd_check_sync(sdp, iter, &sdp->sd_quota_sync_gen)) {
+			qd = iter;
+			break;
+		}
+	}
+
+	spin_unlock(&qd_lock);
+
+	if (qd) {
+		error = qd_bh_get_or_undo(sdp, qd);
+		if (error)
+			return error;
+		*qdp = qd;
+	}
+
+	return 0;
+}
+
+static void qdsb_put(struct gfs2_quota_data *qd)
+{
+	bh_put(qd);
+	slot_put(qd);
+	qd_put(qd);
+}
+
+static void qd_unlock(struct gfs2_quota_data *qd)
+{
+	gfs2_assert_warn(qd->qd_sbd, test_bit(QDF_LOCKED, &qd->qd_flags));
+	clear_bit(QDF_LOCKED, &qd->qd_flags);
+	qdsb_put(qd);
+}
+
+static int qdsb_get(struct gfs2_sbd *sdp, struct kqid qid,
+		    struct gfs2_quota_data **qdp)
+{
+	int error;
+
+	error = qd_get(sdp, qid, qdp);
+	if (error)
+		return error;
+
+	error = slot_get(*qdp);
+	if (error)
+		goto fail;
+
+	error = bh_get(*qdp);
+	if (error)
+		goto fail_slot;
+
+	return 0;
+
+fail_slot:
+	slot_put(*qdp);
+fail:
+	qd_put(*qdp);
+	return error;
+}
+
+/**
+ * gfs2_qa_get - make sure we have a quota allocations data structure,
+ *               if necessary
+ * @ip: the inode for this reservation
+ */
+int gfs2_qa_get(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct inode *inode = &ip->i_inode;
+
+	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
+		return 0;
+
+	spin_lock(&inode->i_lock);
+	if (ip->i_qadata == NULL) {
+		struct gfs2_qadata *tmp;
+
+		spin_unlock(&inode->i_lock);
+		tmp = kmem_cache_zalloc(gfs2_qadata_cachep, GFP_NOFS);
+		if (!tmp)
+			return -ENOMEM;
+
+		spin_lock(&inode->i_lock);
+		if (ip->i_qadata == NULL)
+			ip->i_qadata = tmp;
+		else
+			kmem_cache_free(gfs2_qadata_cachep, tmp);
+	}
+	ip->i_qadata->qa_ref++;
+	spin_unlock(&inode->i_lock);
+	return 0;
+}
+
+void gfs2_qa_put(struct gfs2_inode *ip)
+{
+	struct inode *inode = &ip->i_inode;
+
+	spin_lock(&inode->i_lock);
+	if (ip->i_qadata && --ip->i_qadata->qa_ref == 0) {
+		kmem_cache_free(gfs2_qadata_cachep, ip->i_qadata);
+		ip->i_qadata = NULL;
+	}
+	spin_unlock(&inode->i_lock);
+}
+
+int gfs2_quota_hold(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_quota_data **qd;
+	int error;
+
+	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
+		return 0;
+
+	error = gfs2_qa_get(ip);
+	if (error)
+		return error;
+
+	qd = ip->i_qadata->qa_qd;
+
+	if (gfs2_assert_warn(sdp, !ip->i_qadata->qa_qd_num) ||
+	    gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags))) {
+		error = -EIO;
+		gfs2_qa_put(ip);
+		goto out;
+	}
+
+	error = qdsb_get(sdp, make_kqid_uid(ip->i_inode.i_uid), qd);
+	if (error)
+		goto out_unhold;
+	ip->i_qadata->qa_qd_num++;
+	qd++;
+
+	error = qdsb_get(sdp, make_kqid_gid(ip->i_inode.i_gid), qd);
+	if (error)
+		goto out_unhold;
+	ip->i_qadata->qa_qd_num++;
+	qd++;
+
+	if (!uid_eq(uid, NO_UID_QUOTA_CHANGE) &&
+	    !uid_eq(uid, ip->i_inode.i_uid)) {
+		error = qdsb_get(sdp, make_kqid_uid(uid), qd);
+		if (error)
+			goto out_unhold;
+		ip->i_qadata->qa_qd_num++;
+		qd++;
+	}
+
+	if (!gid_eq(gid, NO_GID_QUOTA_CHANGE) &&
+	    !gid_eq(gid, ip->i_inode.i_gid)) {
+		error = qdsb_get(sdp, make_kqid_gid(gid), qd);
+		if (error)
+			goto out_unhold;
+		ip->i_qadata->qa_qd_num++;
+		qd++;
+	}
+
+out_unhold:
+	if (error)
+		gfs2_quota_unhold(ip);
+out:
+	return error;
+}
+
+void gfs2_quota_unhold(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	u32 x;
+
+	if (ip->i_qadata == NULL)
+		return;
+
+	gfs2_assert_warn(sdp, !test_bit(GIF_QD_LOCKED, &ip->i_flags));
+
+	for (x = 0; x < ip->i_qadata->qa_qd_num; x++) {
+		qdsb_put(ip->i_qadata->qa_qd[x]);
+		ip->i_qadata->qa_qd[x] = NULL;
+	}
+	ip->i_qadata->qa_qd_num = 0;
+	gfs2_qa_put(ip);
+}
+
+static int sort_qd(const void *a, const void *b)
+{
+	const struct gfs2_quota_data *qd_a = *(const struct gfs2_quota_data **)a;
+	const struct gfs2_quota_data *qd_b = *(const struct gfs2_quota_data **)b;
+
+	if (qid_lt(qd_a->qd_id, qd_b->qd_id))
+		return -1;
+	if (qid_lt(qd_b->qd_id, qd_a->qd_id))
+		return 1;
+	return 0;
+}
+
+static void do_qc(struct gfs2_quota_data *qd, s64 change, int qc_type)
+{
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
+	struct gfs2_quota_change *qc = qd->qd_bh_qc;
+	s64 x;
+
+	mutex_lock(&sdp->sd_quota_mutex);
+	gfs2_trans_add_meta(ip->i_gl, qd->qd_bh);
+
+	if (!test_bit(QDF_CHANGE, &qd->qd_flags)) {
+		qc->qc_change = 0;
+		qc->qc_flags = 0;
+		if (qd->qd_id.type == USRQUOTA)
+			qc->qc_flags = cpu_to_be32(GFS2_QCF_USER);
+		qc->qc_id = cpu_to_be32(from_kqid(&init_user_ns, qd->qd_id));
+	}
+
+	x = be64_to_cpu(qc->qc_change) + change;
+	qc->qc_change = cpu_to_be64(x);
+
+	spin_lock(&qd_lock);
+	qd->qd_change = x;
+	spin_unlock(&qd_lock);
+
+	if (qc_type == QC_CHANGE) {
+		if (!test_and_set_bit(QDF_CHANGE, &qd->qd_flags)) {
+			qd_hold(qd);
+			slot_hold(qd);
+		}
+	} else {
+		gfs2_assert_warn(sdp, test_bit(QDF_CHANGE, &qd->qd_flags));
+		clear_bit(QDF_CHANGE, &qd->qd_flags);
+		qc->qc_flags = 0;
+		qc->qc_id = 0;
+		slot_put(qd);
+		qd_put(qd);
+	}
+
+	if (change < 0) /* Reset quiet flag if we freed some blocks */
+		clear_bit(QDF_QMSG_QUIET, &qd->qd_flags);
+	mutex_unlock(&sdp->sd_quota_mutex);
+}
+
+static int gfs2_write_buf_to_page(struct gfs2_sbd *sdp, unsigned long index,
+				  unsigned off, void *buf, unsigned bytes)
+{
+	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
+	struct inode *inode = &ip->i_inode;
+	struct address_space *mapping = inode->i_mapping;
+	struct page *page;
+	struct buffer_head *bh;
+	u64 blk;
+	unsigned bsize = sdp->sd_sb.sb_bsize, bnum = 0, boff = 0;
+	unsigned to_write = bytes, pg_off = off;
+
+	blk = index << (PAGE_SHIFT - sdp->sd_sb.sb_bsize_shift);
+	boff = off % bsize;
+
+	page = grab_cache_page(mapping, index);
+	if (!page)
+		return -ENOMEM;
+	if (!page_has_buffers(page))
+		create_empty_buffers(page, bsize, 0);
+
+	bh = page_buffers(page);
+	for(;;) {
+		/* Find the beginning block within the page */
+		if (pg_off >= ((bnum * bsize) + bsize)) {
+			bh = bh->b_this_page;
+			bnum++;
+			blk++;
+			continue;
+		}
+		if (!buffer_mapped(bh)) {
+			gfs2_block_map(inode, blk, bh, 1);
+			if (!buffer_mapped(bh))
+				goto unlock_out;
+			/* If it's a newly allocated disk block, zero it */
+			if (buffer_new(bh))
+				zero_user(page, bnum * bsize, bh->b_size);
+		}
+		if (PageUptodate(page))
+			set_buffer_uptodate(bh);
+		if (bh_read(bh, REQ_META | REQ_PRIO) < 0)
+			goto unlock_out;
+		gfs2_trans_add_data(ip->i_gl, bh);
+
+		/* If we need to write to the next block as well */
+		if (to_write > (bsize - boff)) {
+			pg_off += (bsize - boff);
+			to_write -= (bsize - boff);
+			boff = pg_off % bsize;
+			continue;
+		}
+		break;
+	}
+
+	/* Write to the page, now that we have setup the buffer(s) */
+	memcpy_to_page(page, off, buf, bytes);
+	flush_dcache_page(page);
+	unlock_page(page);
+	put_page(page);
+
+	return 0;
+
+unlock_out:
+	unlock_page(page);
+	put_page(page);
+	return -EIO;
+}
+
+static int gfs2_write_disk_quota(struct gfs2_sbd *sdp, struct gfs2_quota *qp,
+				 loff_t loc)
+{
+	unsigned long pg_beg;
+	unsigned pg_off, nbytes, overflow = 0;
+	int error;
+	void *ptr;
+
+	nbytes = sizeof(struct gfs2_quota);
+
+	pg_beg = loc >> PAGE_SHIFT;
+	pg_off = offset_in_page(loc);
+
+	/* If the quota straddles a page boundary, split the write in two */
+	if ((pg_off + nbytes) > PAGE_SIZE)
+		overflow = (pg_off + nbytes) - PAGE_SIZE;
+
+	ptr = qp;
+	error = gfs2_write_buf_to_page(sdp, pg_beg, pg_off, ptr,
+				       nbytes - overflow);
+	/* If there's an overflow, write the remaining bytes to the next page */
+	if (!error && overflow)
+		error = gfs2_write_buf_to_page(sdp, pg_beg + 1, 0,
+					       ptr + nbytes - overflow,
+					       overflow);
+	return error;
+}
+
+/**
+ * gfs2_adjust_quota - adjust record of current block usage
+ * @sdp: The superblock
+ * @loc: Offset of the entry in the quota file
+ * @change: The amount of usage change to record
+ * @qd: The quota data
+ * @fdq: The updated limits to record
+ *
+ * This function was mostly borrowed from gfs2_block_truncate_page which was
+ * in turn mostly borrowed from ext3
+ *
+ * Returns: 0 or -ve on error
+ */
+
+static int gfs2_adjust_quota(struct gfs2_sbd *sdp, loff_t loc,
+			     s64 change, struct gfs2_quota_data *qd,
+			     struct qc_dqblk *fdq)
+{
+	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
+	struct inode *inode = &ip->i_inode;
+	struct gfs2_quota q;
+	int err;
+	u64 size;
+
+	if (gfs2_is_stuffed(ip)) {
+		err = gfs2_unstuff_dinode(ip);
+		if (err)
+			return err;
+	}
+
+	memset(&q, 0, sizeof(struct gfs2_quota));
+	err = gfs2_internal_read(ip, (char *)&q, &loc, sizeof(q));
+	if (err < 0)
+		return err;
+
+	loc -= sizeof(q); /* gfs2_internal_read would've advanced the loc ptr */
+	be64_add_cpu(&q.qu_value, change);
+	if (((s64)be64_to_cpu(q.qu_value)) < 0)
+		q.qu_value = 0; /* Never go negative on quota usage */
+	qd->qd_qb.qb_value = q.qu_value;
+	if (fdq) {
+		if (fdq->d_fieldmask & QC_SPC_SOFT) {
+			q.qu_warn = cpu_to_be64(fdq->d_spc_softlimit >> sdp->sd_sb.sb_bsize_shift);
+			qd->qd_qb.qb_warn = q.qu_warn;
+		}
+		if (fdq->d_fieldmask & QC_SPC_HARD) {
+			q.qu_limit = cpu_to_be64(fdq->d_spc_hardlimit >> sdp->sd_sb.sb_bsize_shift);
+			qd->qd_qb.qb_limit = q.qu_limit;
+		}
+		if (fdq->d_fieldmask & QC_SPACE) {
+			q.qu_value = cpu_to_be64(fdq->d_space >> sdp->sd_sb.sb_bsize_shift);
+			qd->qd_qb.qb_value = q.qu_value;
+		}
+	}
+
+	err = gfs2_write_disk_quota(sdp, &q, loc);
+	if (!err) {
+		size = loc + sizeof(struct gfs2_quota);
+		if (size > inode->i_size)
+			i_size_write(inode, size);
+		inode->i_mtime = inode_set_ctime_current(inode);
+		mark_inode_dirty(inode);
+		set_bit(QDF_REFRESH, &qd->qd_flags);
+	}
+
+	return err;
+}
+
+static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
+{
+	struct gfs2_sbd *sdp = (*qda)->qd_sbd;
+	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
+	struct gfs2_alloc_parms ap = { .aflags = 0, };
+	unsigned int data_blocks, ind_blocks;
+	struct gfs2_holder *ghs, i_gh;
+	unsigned int qx, x;
+	struct gfs2_quota_data *qd;
+	unsigned reserved;
+	loff_t offset;
+	unsigned int nalloc = 0, blocks;
+	int error;
+
+	gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
+			      &data_blocks, &ind_blocks);
+
+	ghs = kmalloc_array(num_qd, sizeof(struct gfs2_holder), GFP_NOFS);
+	if (!ghs)
+		return -ENOMEM;
+
+	sort(qda, num_qd, sizeof(struct gfs2_quota_data *), sort_qd, NULL);
+	inode_lock(&ip->i_inode);
+	for (qx = 0; qx < num_qd; qx++) {
+		error = gfs2_glock_nq_init(qda[qx]->qd_gl, LM_ST_EXCLUSIVE,
+					   GL_NOCACHE, &ghs[qx]);
+		if (error)
+			goto out_dq;
+	}
+
+	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
+	if (error)
+		goto out_dq;
+
+	for (x = 0; x < num_qd; x++) {
+		offset = qd2offset(qda[x]);
+		if (gfs2_write_alloc_required(ip, offset,
+					      sizeof(struct gfs2_quota)))
+			nalloc++;
+	}
+
+	/* 
+	 * 1 blk for unstuffing inode if stuffed. We add this extra
+	 * block to the reservation unconditionally. If the inode
+	 * doesn't need unstuffing, the block will be released to the 
+	 * rgrp since it won't be allocated during the transaction
+	 */
+	/* +3 in the end for unstuffing block, inode size update block
+	 * and another block in case quota straddles page boundary and 
+	 * two blocks need to be updated instead of 1 */
+	blocks = num_qd * data_blocks + RES_DINODE + num_qd + 3;
+
+	reserved = 1 + (nalloc * (data_blocks + ind_blocks));
+	ap.target = reserved;
+	error = gfs2_inplace_reserve(ip, &ap);
+	if (error)
+		goto out_alloc;
+
+	if (nalloc)
+		blocks += gfs2_rg_blocks(ip, reserved) + nalloc * ind_blocks + RES_STATFS;
+
+	error = gfs2_trans_begin(sdp, blocks, 0);
+	if (error)
+		goto out_ipres;
+
+	for (x = 0; x < num_qd; x++) {
+		qd = qda[x];
+		offset = qd2offset(qd);
+		error = gfs2_adjust_quota(sdp, offset, qd->qd_change_sync, qd,
+							NULL);
+		if (error)
+			goto out_end_trans;
+
+		do_qc(qd, -qd->qd_change_sync, QC_SYNC);
+		set_bit(QDF_REFRESH, &qd->qd_flags);
+	}
+
+out_end_trans:
+	gfs2_trans_end(sdp);
+out_ipres:
+	gfs2_inplace_release(ip);
+out_alloc:
+	gfs2_glock_dq_uninit(&i_gh);
+out_dq:
+	while (qx--)
+		gfs2_glock_dq_uninit(&ghs[qx]);
+	inode_unlock(&ip->i_inode);
+	kfree(ghs);
+	gfs2_log_flush(ip->i_gl->gl_name.ln_sbd, ip->i_gl,
+		       GFS2_LOG_HEAD_FLUSH_NORMAL | GFS2_LFC_DO_SYNC);
+	if (!error) {
+		for (x = 0; x < num_qd; x++)
+			qda[x]->qd_sync_gen = sdp->sd_quota_sync_gen;
+	}
+	return error;
+}
+
+static int update_qd(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd)
+{
+	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
+	struct gfs2_quota q;
+	struct gfs2_quota_lvb *qlvb;
+	loff_t pos;
+	int error;
+
+	memset(&q, 0, sizeof(struct gfs2_quota));
+	pos = qd2offset(qd);
+	error = gfs2_internal_read(ip, (char *)&q, &pos, sizeof(q));
+	if (error < 0)
+		return error;
+
+	qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
+	qlvb->qb_magic = cpu_to_be32(GFS2_MAGIC);
+	qlvb->__pad = 0;
+	qlvb->qb_limit = q.qu_limit;
+	qlvb->qb_warn = q.qu_warn;
+	qlvb->qb_value = q.qu_value;
+	qd->qd_qb = *qlvb;
+
+	return 0;
+}
+
+static int do_glock(struct gfs2_quota_data *qd, int force_refresh,
+		    struct gfs2_holder *q_gh)
+{
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
+	struct gfs2_holder i_gh;
+	int error;
+
+	gfs2_assert_warn(sdp, sdp == qd->qd_gl->gl_name.ln_sbd);
+restart:
+	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_SHARED, 0, q_gh);
+	if (error)
+		return error;
+
+	if (test_and_clear_bit(QDF_REFRESH, &qd->qd_flags))
+		force_refresh = FORCE;
+
+	qd->qd_qb = *(struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
+
+	if (force_refresh || qd->qd_qb.qb_magic != cpu_to_be32(GFS2_MAGIC)) {
+		gfs2_glock_dq_uninit(q_gh);
+		error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_EXCLUSIVE,
+					   GL_NOCACHE, q_gh);
+		if (error)
+			return error;
+
+		error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &i_gh);
+		if (error)
+			goto fail;
+
+		error = update_qd(sdp, qd);
+		if (error)
+			goto fail_gunlock;
+
+		gfs2_glock_dq_uninit(&i_gh);
+		gfs2_glock_dq_uninit(q_gh);
+		force_refresh = 0;
+		goto restart;
+	}
+
+	return 0;
+
+fail_gunlock:
+	gfs2_glock_dq_uninit(&i_gh);
+fail:
+	gfs2_glock_dq_uninit(q_gh);
+	return error;
+}
+
+int gfs2_quota_lock(struct gfs2_inode *ip, kuid_t uid, kgid_t gid)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_quota_data *qd;
+	u32 x;
+	int error;
+
+	if (sdp->sd_args.ar_quota != GFS2_QUOTA_ON &&
+	    sdp->sd_args.ar_quota != GFS2_QUOTA_QUIET)
+		return 0;
+
+	error = gfs2_quota_hold(ip, uid, gid);
+	if (error)
+		return error;
+
+	sort(ip->i_qadata->qa_qd, ip->i_qadata->qa_qd_num,
+	     sizeof(struct gfs2_quota_data *), sort_qd, NULL);
+
+	for (x = 0; x < ip->i_qadata->qa_qd_num; x++) {
+		qd = ip->i_qadata->qa_qd[x];
+		error = do_glock(qd, NO_FORCE, &ip->i_qadata->qa_qd_ghs[x]);
+		if (error)
+			break;
+	}
+
+	if (!error)
+		set_bit(GIF_QD_LOCKED, &ip->i_flags);
+	else {
+		while (x--)
+			gfs2_glock_dq_uninit(&ip->i_qadata->qa_qd_ghs[x]);
+		gfs2_quota_unhold(ip);
+	}
+
+	return error;
+}
+
+static bool need_sync(struct gfs2_quota_data *qd)
+{
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+	struct gfs2_tune *gt = &sdp->sd_tune;
+	s64 value;
+	unsigned int num, den;
+
+	if (!qd->qd_qb.qb_limit)
+		return false;
+
+	spin_lock(&qd_lock);
+	value = qd->qd_change;
+	spin_unlock(&qd_lock);
+
+	spin_lock(&gt->gt_spin);
+	num = gt->gt_quota_scale_num;
+	den = gt->gt_quota_scale_den;
+	spin_unlock(&gt->gt_spin);
+
+	if (value <= 0)
+		return false;
+	else if ((s64)be64_to_cpu(qd->qd_qb.qb_value) >=
+		 (s64)be64_to_cpu(qd->qd_qb.qb_limit))
+		return false;
+	else {
+		value *= gfs2_jindex_size(sdp) * num;
+		value = div_s64(value, den);
+		value += (s64)be64_to_cpu(qd->qd_qb.qb_value);
+		if (value < (s64)be64_to_cpu(qd->qd_qb.qb_limit))
+			return false;
+	}
+
+	return true;
+}
+
+void gfs2_quota_unlock(struct gfs2_inode *ip)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_quota_data *qda[2 * GFS2_MAXQUOTAS];
+	unsigned int count = 0;
+	u32 x;
+	int found;
+
+	if (!test_and_clear_bit(GIF_QD_LOCKED, &ip->i_flags))
+		return;
+
+	for (x = 0; x < ip->i_qadata->qa_qd_num; x++) {
+		struct gfs2_quota_data *qd;
+		bool sync;
+
+		qd = ip->i_qadata->qa_qd[x];
+		sync = need_sync(qd);
+
+		gfs2_glock_dq_uninit(&ip->i_qadata->qa_qd_ghs[x]);
+		if (!sync)
+			continue;
+
+		spin_lock(&qd_lock);
+		found = qd_check_sync(sdp, qd, NULL);
+		spin_unlock(&qd_lock);
+
+		if (!found)
+			continue;
+
+		if (!qd_bh_get_or_undo(sdp, qd))
+			qda[count++] = qd;
+	}
+
+	if (count) {
+		do_sync(count, qda);
+		for (x = 0; x < count; x++)
+			qd_unlock(qda[x]);
+	}
+
+	gfs2_quota_unhold(ip);
+}
+
+#define MAX_LINE 256
+
+static int print_message(struct gfs2_quota_data *qd, char *type)
+{
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+
+	if (sdp->sd_args.ar_quota != GFS2_QUOTA_QUIET)
+		fs_info(sdp, "quota %s for %s %u\n",
+			type,
+			(qd->qd_id.type == USRQUOTA) ? "user" : "group",
+			from_kqid(&init_user_ns, qd->qd_id));
+
+	return 0;
+}
+
+/**
+ * gfs2_quota_check - check if allocating new blocks will exceed quota
+ * @ip:  The inode for which this check is being performed
+ * @uid: The uid to check against
+ * @gid: The gid to check against
+ * @ap:  The allocation parameters. ap->target contains the requested
+ *       blocks. ap->min_target, if set, contains the minimum blks
+ *       requested.
+ *
+ * Returns: 0 on success.
+ *                  min_req = ap->min_target ? ap->min_target : ap->target;
+ *                  quota must allow at least min_req blks for success and
+ *                  ap->allowed is set to the number of blocks allowed
+ *
+ *          -EDQUOT otherwise, quota violation. ap->allowed is set to number
+ *                  of blocks available.
+ */
+int gfs2_quota_check(struct gfs2_inode *ip, kuid_t uid, kgid_t gid,
+		     struct gfs2_alloc_parms *ap)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+	struct gfs2_quota_data *qd;
+	s64 value, warn, limit;
+	u32 x;
+	int error = 0;
+
+	ap->allowed = UINT_MAX; /* Assume we are permitted a whole lot */
+	if (!test_bit(GIF_QD_LOCKED, &ip->i_flags))
+		return 0;
+
+	for (x = 0; x < ip->i_qadata->qa_qd_num; x++) {
+		qd = ip->i_qadata->qa_qd[x];
+
+		if (!(qid_eq(qd->qd_id, make_kqid_uid(uid)) ||
+		      qid_eq(qd->qd_id, make_kqid_gid(gid))))
+			continue;
+
+		warn = (s64)be64_to_cpu(qd->qd_qb.qb_warn);
+		limit = (s64)be64_to_cpu(qd->qd_qb.qb_limit);
+		value = (s64)be64_to_cpu(qd->qd_qb.qb_value);
+		spin_lock(&qd_lock);
+		value += qd->qd_change;
+		spin_unlock(&qd_lock);
+
+		if (limit > 0 && (limit - value) < ap->allowed)
+			ap->allowed = limit - value;
+		/* If we can't meet the target */
+		if (limit && limit < (value + (s64)ap->target)) {
+			/* If no min_target specified or we don't meet
+			 * min_target, return -EDQUOT */
+			if (!ap->min_target || ap->min_target > ap->allowed) {
+				if (!test_and_set_bit(QDF_QMSG_QUIET,
+						      &qd->qd_flags)) {
+					print_message(qd, "exceeded");
+					quota_send_warning(qd->qd_id,
+							   sdp->sd_vfs->s_dev,
+							   QUOTA_NL_BHARDWARN);
+				}
+				error = -EDQUOT;
+				break;
+			}
+		} else if (warn && warn < value &&
+			   time_after_eq(jiffies, qd->qd_last_warn +
+					 gfs2_tune_get(sdp, gt_quota_warn_period)
+					 * HZ)) {
+			quota_send_warning(qd->qd_id,
+					   sdp->sd_vfs->s_dev, QUOTA_NL_BSOFTWARN);
+			error = print_message(qd, "warning");
+			qd->qd_last_warn = jiffies;
+		}
+	}
+	return error;
+}
+
+void gfs2_quota_change(struct gfs2_inode *ip, s64 change,
+		       kuid_t uid, kgid_t gid)
+{
+	struct gfs2_quota_data *qd;
+	u32 x;
+	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
+
+	if ((sdp->sd_args.ar_quota != GFS2_QUOTA_ON &&
+	    sdp->sd_args.ar_quota != GFS2_QUOTA_QUIET) ||
+	    gfs2_assert_warn(sdp, change))
+		return;
+	if (ip->i_diskflags & GFS2_DIF_SYSTEM)
+		return;
+
+	if (gfs2_assert_withdraw(sdp, ip->i_qadata &&
+				 ip->i_qadata->qa_ref > 0))
+		return;
+	for (x = 0; x < ip->i_qadata->qa_qd_num; x++) {
+		qd = ip->i_qadata->qa_qd[x];
+
+		if (qid_eq(qd->qd_id, make_kqid_uid(uid)) ||
+		    qid_eq(qd->qd_id, make_kqid_gid(gid))) {
+			do_qc(qd, change, QC_CHANGE);
+		}
+	}
+}
+
+static bool qd_changed(struct gfs2_sbd *sdp)
+{
+	struct gfs2_quota_data *qd;
+	bool changed = false;
+
+	spin_lock(&qd_lock);
+	list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
+		if (test_bit(QDF_LOCKED, &qd->qd_flags) ||
+		    !test_bit(QDF_CHANGE, &qd->qd_flags))
+			continue;
+
+		changed = true;
+		break;
+	}
+	spin_unlock(&qd_lock);
+	return changed;
+}
+
+int gfs2_quota_sync(struct super_block *sb, int type)
+{
+	struct gfs2_sbd *sdp = sb->s_fs_info;
+	struct gfs2_quota_data **qda;
+	unsigned int max_qd = PAGE_SIZE / sizeof(struct gfs2_holder);
+	unsigned int num_qd;
+	unsigned int x;
+	int error = 0;
+
+	if (!qd_changed(sdp))
+		return 0;
+
+	qda = kcalloc(max_qd, sizeof(struct gfs2_quota_data *), GFP_KERNEL);
+	if (!qda)
+		return -ENOMEM;
+
+	mutex_lock(&sdp->sd_quota_sync_mutex);
+	sdp->sd_quota_sync_gen++;
+
+	do {
+		num_qd = 0;
+
+		for (;;) {
+			error = qd_fish(sdp, qda + num_qd);
+			if (error || !qda[num_qd])
+				break;
+			if (++num_qd == max_qd)
+				break;
+		}
+
+		if (num_qd) {
+			if (!error)
+				error = do_sync(num_qd, qda);
+
+			for (x = 0; x < num_qd; x++)
+				qd_unlock(qda[x]);
+		}
+	} while (!error && num_qd == max_qd);
+
+	mutex_unlock(&sdp->sd_quota_sync_mutex);
+	kfree(qda);
+
+	return error;
+}
+
+int gfs2_quota_refresh(struct gfs2_sbd *sdp, struct kqid qid)
+{
+	struct gfs2_quota_data *qd;
+	struct gfs2_holder q_gh;
+	int error;
+
+	error = qd_get(sdp, qid, &qd);
+	if (error)
+		return error;
+
+	error = do_glock(qd, FORCE, &q_gh);
+	if (!error)
+		gfs2_glock_dq_uninit(&q_gh);
+
+	qd_put(qd);
+	return error;
+}
+
+int gfs2_quota_init(struct gfs2_sbd *sdp)
+{
+	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
+	u64 size = i_size_read(sdp->sd_qc_inode);
+	unsigned int blocks = size >> sdp->sd_sb.sb_bsize_shift;
+	unsigned int x, slot = 0;
+	unsigned int found = 0;
+	unsigned int hash;
+	unsigned int bm_size;
+	u64 dblock;
+	u32 extlen = 0;
+	int error;
+
+	if (gfs2_check_internal_file_size(sdp->sd_qc_inode, 1, 64 << 20))
+		return -EIO;
+
+	sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
+	bm_size = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * sizeof(unsigned long));
+	bm_size *= sizeof(unsigned long);
+	error = -ENOMEM;
+	sdp->sd_quota_bitmap = kzalloc(bm_size, GFP_NOFS | __GFP_NOWARN);
+	if (sdp->sd_quota_bitmap == NULL)
+		sdp->sd_quota_bitmap = __vmalloc(bm_size, GFP_NOFS |
+						 __GFP_ZERO);
+	if (!sdp->sd_quota_bitmap)
+		return error;
+
+	for (x = 0; x < blocks; x++) {
+		struct buffer_head *bh;
+		const struct gfs2_quota_change *qc;
+		unsigned int y;
+
+		if (!extlen) {
+			extlen = 32;
+			error = gfs2_get_extent(&ip->i_inode, x, &dblock, &extlen);
+			if (error)
+				goto fail;
+		}
+		error = -EIO;
+		bh = gfs2_meta_ra(ip->i_gl, dblock, extlen);
+		if (!bh)
+			goto fail;
+		if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_QC)) {
+			brelse(bh);
+			goto fail;
+		}
+
+		qc = (const struct gfs2_quota_change *)(bh->b_data + sizeof(struct gfs2_meta_header));
+		for (y = 0; y < sdp->sd_qc_per_block && slot < sdp->sd_quota_slots;
+		     y++, slot++) {
+			struct gfs2_quota_data *qd;
+			s64 qc_change = be64_to_cpu(qc->qc_change);
+			u32 qc_flags = be32_to_cpu(qc->qc_flags);
+			enum quota_type qtype = (qc_flags & GFS2_QCF_USER) ?
+						USRQUOTA : GRPQUOTA;
+			struct kqid qc_id = make_kqid(&init_user_ns, qtype,
+						      be32_to_cpu(qc->qc_id));
+			qc++;
+			if (!qc_change)
+				continue;
+
+			hash = gfs2_qd_hash(sdp, qc_id);
+			qd = qd_alloc(hash, sdp, qc_id);
+			if (qd == NULL) {
+				brelse(bh);
+				goto fail;
+			}
+
+			set_bit(QDF_CHANGE, &qd->qd_flags);
+			qd->qd_change = qc_change;
+			qd->qd_slot = slot;
+			qd->qd_slot_ref = 1;
+
+			spin_lock(&qd_lock);
+			BUG_ON(test_and_set_bit(slot, sdp->sd_quota_bitmap));
+			list_add(&qd->qd_list, &sdp->sd_quota_list);
+			atomic_inc(&sdp->sd_quota_count);
+			spin_unlock(&qd_lock);
+
+			spin_lock_bucket(hash);
+			hlist_bl_add_head_rcu(&qd->qd_hlist, &qd_hash_table[hash]);
+			spin_unlock_bucket(hash);
+
+			found++;
+		}
+
+		brelse(bh);
+		dblock++;
+		extlen--;
+	}
+
+	if (found)
+		fs_info(sdp, "found %u quota changes\n", found);
+
+	return 0;
+
+fail:
+	gfs2_quota_cleanup(sdp);
+	return error;
+}
+
+void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
+{
+	struct gfs2_quota_data *qd;
+	LIST_HEAD(dispose);
+	int count;
+
+	BUG_ON(!test_bit(SDF_NORECOVERY, &sdp->sd_flags) &&
+		test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags));
+
+	spin_lock(&qd_lock);
+	list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
+		spin_lock(&qd->qd_lockref.lock);
+		if (qd->qd_lockref.count != 0) {
+			spin_unlock(&qd->qd_lockref.lock);
+			continue;
+		}
+		lockref_mark_dead(&qd->qd_lockref);
+		spin_unlock(&qd->qd_lockref.lock);
+
+		list_lru_del(&gfs2_qd_lru, &qd->qd_lru);
+		list_add(&qd->qd_lru, &dispose);
+	}
+	spin_unlock(&qd_lock);
+
+	gfs2_qd_list_dispose(&dispose);
+
+	wait_event_timeout(sdp->sd_kill_wait,
+		(count = atomic_read(&sdp->sd_quota_count)) == 0,
+		HZ * 60);
+
+	if (count != 0)
+		fs_err(sdp, "%d left-over quota data objects\n", count);
+
+	kvfree(sdp->sd_quota_bitmap);
+	sdp->sd_quota_bitmap = NULL;
+}
+
+static void quotad_error(struct gfs2_sbd *sdp, const char *msg, int error)
+{
+	if (error == 0 || error == -EROFS)
+		return;
+	if (!gfs2_withdrawn(sdp)) {
+		if (!cmpxchg(&sdp->sd_log_error, 0, error))
+			fs_err(sdp, "gfs2_quotad: %s error %d\n", msg, error);
+		wake_up(&sdp->sd_logd_waitq);
+	}
+}
+
+static void quotad_check_timeo(struct gfs2_sbd *sdp, const char *msg,
+			       int (*fxn)(struct super_block *sb, int type),
+			       unsigned long t, unsigned long *timeo,
+			       unsigned int *new_timeo)
+{
+	if (t >= *timeo) {
+		int error = fxn(sdp->sd_vfs, 0);
+		quotad_error(sdp, msg, error);
+		*timeo = gfs2_tune_get_i(&sdp->sd_tune, new_timeo) * HZ;
+	} else {
+		*timeo -= t;
+	}
+}
+
+void gfs2_wake_up_statfs(struct gfs2_sbd *sdp) {
+	if (!sdp->sd_statfs_force_sync) {
+		sdp->sd_statfs_force_sync = 1;
+		wake_up(&sdp->sd_quota_wait);
+	}
+}
+
+
+/**
+ * gfs2_quotad - Write cached quota changes into the quota file
+ * @data: Pointer to GFS2 superblock
+ *
+ */
+
+int gfs2_quotad(void *data)
+{
+	struct gfs2_sbd *sdp = data;
+	struct gfs2_tune *tune = &sdp->sd_tune;
+	unsigned long statfs_timeo = 0;
+	unsigned long quotad_timeo = 0;
+	unsigned long t = 0;
+
+	while (!kthread_should_stop()) {
+		if (gfs2_withdrawn(sdp))
+			break;
+
+		/* Update the master statfs file */
+		if (sdp->sd_statfs_force_sync) {
+			int error = gfs2_statfs_sync(sdp->sd_vfs, 0);
+			quotad_error(sdp, "statfs", error);
+			statfs_timeo = gfs2_tune_get(sdp, gt_statfs_quantum) * HZ;
+		}
+		else
+			quotad_check_timeo(sdp, "statfs", gfs2_statfs_sync, t,
+				   	   &statfs_timeo,
+					   &tune->gt_statfs_quantum);
+
+		/* Update quota file */
+		quotad_check_timeo(sdp, "sync", gfs2_quota_sync, t,
+				   &quotad_timeo, &tune->gt_quota_quantum);
+
+		try_to_freeze();
+
+		t = min(quotad_timeo, statfs_timeo);
+
+		t = wait_event_interruptible_timeout(sdp->sd_quota_wait,
+				sdp->sd_statfs_force_sync ||
+				gfs2_withdrawn(sdp) ||
+				kthread_should_stop(),
+				t);
+
+		if (sdp->sd_statfs_force_sync)
+			t = 0;
+	}
+
+	return 0;
+}
+
+static int gfs2_quota_get_state(struct super_block *sb, struct qc_state *state)
+{
+	struct gfs2_sbd *sdp = sb->s_fs_info;
+
+	memset(state, 0, sizeof(*state));
+
+	switch (sdp->sd_args.ar_quota) {
+	case GFS2_QUOTA_QUIET:
+		fallthrough;
+	case GFS2_QUOTA_ON:
+		state->s_state[USRQUOTA].flags |= QCI_LIMITS_ENFORCED;
+		state->s_state[GRPQUOTA].flags |= QCI_LIMITS_ENFORCED;
+		fallthrough;
+	case GFS2_QUOTA_ACCOUNT:
+		state->s_state[USRQUOTA].flags |= QCI_ACCT_ENABLED |
+						  QCI_SYSFILE;
+		state->s_state[GRPQUOTA].flags |= QCI_ACCT_ENABLED |
+						  QCI_SYSFILE;
+		break;
+	case GFS2_QUOTA_OFF:
+		break;
+	}
+	if (sdp->sd_quota_inode) {
+		state->s_state[USRQUOTA].ino =
+					GFS2_I(sdp->sd_quota_inode)->i_no_addr;
+		state->s_state[USRQUOTA].blocks = sdp->sd_quota_inode->i_blocks;
+	}
+	state->s_state[USRQUOTA].nextents = 1;	/* unsupported */
+	state->s_state[GRPQUOTA] = state->s_state[USRQUOTA];
+	state->s_incoredqs = list_lru_count(&gfs2_qd_lru);
+	return 0;
+}
+
+static int gfs2_get_dqblk(struct super_block *sb, struct kqid qid,
+			  struct qc_dqblk *fdq)
+{
+	struct gfs2_sbd *sdp = sb->s_fs_info;
+	struct gfs2_quota_lvb *qlvb;
+	struct gfs2_quota_data *qd;
+	struct gfs2_holder q_gh;
+	int error;
+
+	memset(fdq, 0, sizeof(*fdq));
+
+	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
+		return -ESRCH; /* Crazy XFS error code */
+
+	if ((qid.type != USRQUOTA) &&
+	    (qid.type != GRPQUOTA))
+		return -EINVAL;
+
+	error = qd_get(sdp, qid, &qd);
+	if (error)
+		return error;
+	error = do_glock(qd, FORCE, &q_gh);
+	if (error)
+		goto out;
+
+	qlvb = (struct gfs2_quota_lvb *)qd->qd_gl->gl_lksb.sb_lvbptr;
+	fdq->d_spc_hardlimit = be64_to_cpu(qlvb->qb_limit) << sdp->sd_sb.sb_bsize_shift;
+	fdq->d_spc_softlimit = be64_to_cpu(qlvb->qb_warn) << sdp->sd_sb.sb_bsize_shift;
+	fdq->d_space = be64_to_cpu(qlvb->qb_value) << sdp->sd_sb.sb_bsize_shift;
+
+	gfs2_glock_dq_uninit(&q_gh);
+out:
+	qd_put(qd);
+	return error;
+}
+
+/* GFS2 only supports a subset of the XFS fields */
+#define GFS2_FIELDMASK (QC_SPC_SOFT|QC_SPC_HARD|QC_SPACE)
+
+static int gfs2_set_dqblk(struct super_block *sb, struct kqid qid,
+			  struct qc_dqblk *fdq)
+{
+	struct gfs2_sbd *sdp = sb->s_fs_info;
+	struct gfs2_inode *ip = GFS2_I(sdp->sd_quota_inode);
+	struct gfs2_quota_data *qd;
+	struct gfs2_holder q_gh, i_gh;
+	unsigned int data_blocks, ind_blocks;
+	unsigned int blocks = 0;
+	int alloc_required;
+	loff_t offset;
+	int error;
+
+	if (sdp->sd_args.ar_quota == GFS2_QUOTA_OFF)
+		return -ESRCH; /* Crazy XFS error code */
+
+	if ((qid.type != USRQUOTA) &&
+	    (qid.type != GRPQUOTA))
+		return -EINVAL;
+
+	if (fdq->d_fieldmask & ~GFS2_FIELDMASK)
+		return -EINVAL;
+
+	error = qd_get(sdp, qid, &qd);
+	if (error)
+		return error;
+
+	error = gfs2_qa_get(ip);
+	if (error)
+		goto out_put;
+
+	inode_lock(&ip->i_inode);
+	error = gfs2_glock_nq_init(qd->qd_gl, LM_ST_EXCLUSIVE, 0, &q_gh);
+	if (error)
+		goto out_unlockput;
+	error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
+	if (error)
+		goto out_q;
+
+	/* Check for existing entry, if none then alloc new blocks */
+	error = update_qd(sdp, qd);
+	if (error)
+		goto out_i;
+
+	/* If nothing has changed, this is a no-op */
+	if ((fdq->d_fieldmask & QC_SPC_SOFT) &&
+	    ((fdq->d_spc_softlimit >> sdp->sd_sb.sb_bsize_shift) == be64_to_cpu(qd->qd_qb.qb_warn)))
+		fdq->d_fieldmask ^= QC_SPC_SOFT;
+
+	if ((fdq->d_fieldmask & QC_SPC_HARD) &&
+	    ((fdq->d_spc_hardlimit >> sdp->sd_sb.sb_bsize_shift) == be64_to_cpu(qd->qd_qb.qb_limit)))
+		fdq->d_fieldmask ^= QC_SPC_HARD;
+
+	if ((fdq->d_fieldmask & QC_SPACE) &&
+	    ((fdq->d_space >> sdp->sd_sb.sb_bsize_shift) == be64_to_cpu(qd->qd_qb.qb_value)))
+		fdq->d_fieldmask ^= QC_SPACE;
+
+	if (fdq->d_fieldmask == 0)
+		goto out_i;
+
+	offset = qd2offset(qd);
+	alloc_required = gfs2_write_alloc_required(ip, offset, sizeof(struct gfs2_quota));
+	if (gfs2_is_stuffed(ip))
+		alloc_required = 1;
+	if (alloc_required) {
+		struct gfs2_alloc_parms ap = { .aflags = 0, };
+		gfs2_write_calc_reserv(ip, sizeof(struct gfs2_quota),
+				       &data_blocks, &ind_blocks);
+		blocks = 1 + data_blocks + ind_blocks;
+		ap.target = blocks;
+		error = gfs2_inplace_reserve(ip, &ap);
+		if (error)
+			goto out_i;
+		blocks += gfs2_rg_blocks(ip, blocks);
+	}
+
+	/* Some quotas span block boundaries and can update two blocks,
+	   adding an extra block to the transaction to handle such quotas */
+	error = gfs2_trans_begin(sdp, blocks + RES_DINODE + 2, 0);
+	if (error)
+		goto out_release;
+
+	/* Apply changes */
+	error = gfs2_adjust_quota(sdp, offset, 0, qd, fdq);
+	if (!error)
+		clear_bit(QDF_QMSG_QUIET, &qd->qd_flags);
+
+	gfs2_trans_end(sdp);
+out_release:
+	if (alloc_required)
+		gfs2_inplace_release(ip);
+out_i:
+	gfs2_glock_dq_uninit(&i_gh);
+out_q:
+	gfs2_glock_dq_uninit(&q_gh);
+out_unlockput:
+	gfs2_qa_put(ip);
+	inode_unlock(&ip->i_inode);
+out_put:
+	qd_put(qd);
+	return error;
+}
+
+const struct quotactl_ops gfs2_quotactl_ops = {
+	.quota_sync     = gfs2_quota_sync,
+	.get_state	= gfs2_quota_get_state,
+	.get_dqblk	= gfs2_get_dqblk,
+	.set_dqblk	= gfs2_set_dqblk,
+};
+
+void __init gfs2_quota_hash_init(void)
+{
+	unsigned i;
+
+	for(i = 0; i < GFS2_QD_HASH_SIZE; i++)
+		INIT_HLIST_BL_HEAD(&qd_hash_table[i]);
+}