1 files changed, 170 insertions, 172 deletions

diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 98236d0df3c..8bec0e3192d 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -52,6 +52,11 @@
 #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"
@@ -67,16 +72,44 @@
 #include "inode.h"
 #include "util.h"
 
-struct gfs2_quota_change_host {
-	u64 qc_change;
-	u32 qc_flags; /* GFS2_QCF_... */
-	struct kqid qc_id;
-};
+#define GFS2_QD_HASH_SHIFT      12
+#define GFS2_QD_HASH_SIZE       (1 << GFS2_QD_HASH_SHIFT)
+#define GFS2_QD_HASH_MASK       (GFS2_QD_HASH_SIZE - 1)
 
-/* Lock order: qd_lock -> qd->lockref.lock -> lru lock */
+/* 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);
+	kmem_cache_free(gfs2_quotad_cachep, qd);
+}
+
 static void gfs2_qd_dispose(struct list_head *list)
 {
 	struct gfs2_quota_data *qd;
@@ -93,6 +126,10 @@ static void gfs2_qd_dispose(struct list_head *list)
 		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);
+
 		gfs2_assert_warn(sdp, !qd->qd_change);
 		gfs2_assert_warn(sdp, !qd->qd_slot_count);
 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
@@ -101,7 +138,7 @@ static void gfs2_qd_dispose(struct list_head *list)
 		atomic_dec(&sdp->sd_quota_count);
 
 		/* Delete it from the common reclaim list */
-		kmem_cache_free(gfs2_quotad_cachep, qd);
+		call_rcu(&qd->qd_rcu, gfs2_qd_dealloc);
 	}
 }
 
@@ -171,83 +208,95 @@ static u64 qd2offset(struct gfs2_quota_data *qd)
 	return offset;
 }
 
-static int qd_alloc(struct gfs2_sbd *sdp, struct kqid qid,
-		    struct gfs2_quota_data **qdp)
+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 -ENOMEM;
+		return NULL;
 
+	qd->qd_sbd = sdp;
 	qd->qd_lockref.count = 1;
 	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;
 
-	*qdp = qd;
-
-	return 0;
+	return qd;
 
 fail:
 	kmem_cache_free(gfs2_quotad_cachep, qd);
-	return error;
+	return NULL;
 }
 
-static int qd_get(struct gfs2_sbd *sdp, struct kqid qid,
-		  struct gfs2_quota_data **qdp)
+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 = NULL, *new_qd = NULL;
-	int error, found;
-
-	*qdp = NULL;
+	struct gfs2_quota_data *qd;
+	struct hlist_bl_node *h;
 
-	for (;;) {
-		found = 0;
-		spin_lock(&qd_lock);
-		list_for_each_entry(qd, &sdp->sd_quota_list, qd_list) {
-			if (qid_eq(qd->qd_id, qid) &&
-			    lockref_get_not_dead(&qd->qd_lockref)) {
-				list_lru_del(&gfs2_qd_lru, &qd->qd_lru);
-				found = 1;
-				break;
-			}
+	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;
 		}
+	}
 
-		if (!found)
-			qd = NULL;
+	return NULL;
+}
 
-		if (!qd && new_qd) {
-			qd = new_qd;
-			list_add(&qd->qd_list, &sdp->sd_quota_list);
-			atomic_inc(&sdp->sd_quota_count);
-			new_qd = NULL;
-		}
 
-		spin_unlock(&qd_lock);
+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);
 
-		if (qd) {
-			if (new_qd) {
-				gfs2_glock_put(new_qd->qd_gl);
-				kmem_cache_free(gfs2_quotad_cachep, new_qd);
-			}
-			*qdp = qd;
-			return 0;
-		}
+	rcu_read_lock();
+	*qdp = qd = gfs2_qd_search_bucket(hash, sdp, qid);
+	rcu_read_unlock();
 
-		error = qd_alloc(sdp, qid, &new_qd);
-		if (error)
-			return error;
+	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) {
+		*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_gl->gl_sbd;
@@ -268,88 +317,48 @@ static void qd_put(struct gfs2_quota_data *qd)
 
 static int slot_get(struct gfs2_quota_data *qd)
 {
-	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
-	unsigned int c, o = 0, b;
-	unsigned char byte = 0;
+	struct gfs2_sbd *sdp = qd->qd_sbd;
+	unsigned int bit;
+	int error = 0;
 
-	spin_lock(&qd_lock);
+	spin_lock(&sdp->sd_bitmap_lock);
+	if (qd->qd_slot_count != 0)
+		goto out;
 
-	if (qd->qd_slot_count++) {
-		spin_unlock(&qd_lock);
-		return 0;
+	error = -ENOSPC;
+	bit = find_first_zero_bit(sdp->sd_quota_bitmap, sdp->sd_quota_slots);
+	if (bit < sdp->sd_quota_slots) {
+		set_bit(bit, sdp->sd_quota_bitmap);
+		qd->qd_slot = bit;
+out:
+		qd->qd_slot_count++;
 	}
+	spin_unlock(&sdp->sd_bitmap_lock);
 
-	for (c = 0; c < sdp->sd_quota_chunks; c++)
-		for (o = 0; o < PAGE_SIZE; o++) {
-			byte = sdp->sd_quota_bitmap[c][o];
-			if (byte != 0xFF)
-				goto found;
-		}
-
-	goto fail;
-
-found:
-	for (b = 0; b < 8; b++)
-		if (!(byte & (1 << b)))
-			break;
-	qd->qd_slot = c * (8 * PAGE_SIZE) + o * 8 + b;
-
-	if (qd->qd_slot >= sdp->sd_quota_slots)
-		goto fail;
-
-	sdp->sd_quota_bitmap[c][o] |= 1 << b;
-
-	spin_unlock(&qd_lock);
-
-	return 0;
-
-fail:
-	qd->qd_slot_count--;
-	spin_unlock(&qd_lock);
-	return -ENOSPC;
+	return error;
 }
 
 static void slot_hold(struct gfs2_quota_data *qd)
 {
-	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
+	struct gfs2_sbd *sdp = qd->qd_sbd;
 
-	spin_lock(&qd_lock);
+	spin_lock(&sdp->sd_bitmap_lock);
 	gfs2_assert(sdp, qd->qd_slot_count);
 	qd->qd_slot_count++;
-	spin_unlock(&qd_lock);
-}
-
-static void gfs2_icbit_munge(struct gfs2_sbd *sdp, unsigned char **bitmap,
-			     unsigned int bit, int new_value)
-{
-	unsigned int c, o, b = bit;
-	int old_value;
-
-	c = b / (8 * PAGE_SIZE);
-	b %= 8 * PAGE_SIZE;
-	o = b / 8;
-	b %= 8;
-
-	old_value = (bitmap[c][o] & (1 << b));
-	gfs2_assert_withdraw(sdp, !old_value != !new_value);
-
-	if (new_value)
-		bitmap[c][o] |= 1 << b;
-	else
-		bitmap[c][o] &= ~(1 << b);
+	spin_unlock(&sdp->sd_bitmap_lock);
 }
 
 static void slot_put(struct gfs2_quota_data *qd)
 {
-	struct gfs2_sbd *sdp = qd->qd_gl->gl_sbd;
+	struct gfs2_sbd *sdp = qd->qd_sbd;
 
-	spin_lock(&qd_lock);
+	spin_lock(&sdp->sd_bitmap_lock);
 	gfs2_assert(sdp, qd->qd_slot_count);
 	if (!--qd->qd_slot_count) {
-		gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, qd->qd_slot, 0);
+		BUG_ON(!test_and_clear_bit(qd->qd_slot, sdp->sd_quota_bitmap));
 		qd->qd_slot = -1;
 	}
-	spin_unlock(&qd_lock);
+	spin_unlock(&sdp->sd_bitmap_lock);
 }
 
 static int bh_get(struct gfs2_quota_data *qd)
@@ -427,8 +436,7 @@ static int qd_check_sync(struct gfs2_sbd *sdp, struct gfs2_quota_data *qd,
 	list_move_tail(&qd->qd_list, &sdp->sd_quota_list);
 	set_bit(QDF_LOCKED, &qd->qd_flags);
 	qd->qd_change_sync = qd->qd_change;
-	gfs2_assert_warn(sdp, qd->qd_slot_count);
-	qd->qd_slot_count++;
+	slot_hold(qd);
 	return 1;
 }
 
@@ -1214,17 +1222,6 @@ int gfs2_quota_refresh(struct gfs2_sbd *sdp, struct kqid qid)
 	return error;
 }
 
-static void gfs2_quota_change_in(struct gfs2_quota_change_host *qc, const void *buf)
-{
-	const struct gfs2_quota_change *str = buf;
-
-	qc->qc_change = be64_to_cpu(str->qc_change);
-	qc->qc_flags = be32_to_cpu(str->qc_flags);
-	qc->qc_id = make_kqid(&init_user_ns,
-			      (qc->qc_flags & GFS2_QCF_USER)?USRQUOTA:GRPQUOTA,
-			      be32_to_cpu(str->qc_id));
-}
-
 int gfs2_quota_init(struct gfs2_sbd *sdp)
 {
 	struct gfs2_inode *ip = GFS2_I(sdp->sd_qc_inode);
@@ -1232,6 +1229,8 @@ int gfs2_quota_init(struct gfs2_sbd *sdp)
 	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;
@@ -1240,23 +1239,20 @@ int gfs2_quota_init(struct gfs2_sbd *sdp)
 		return -EIO;
 
 	sdp->sd_quota_slots = blocks * sdp->sd_qc_per_block;
-	sdp->sd_quota_chunks = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * PAGE_SIZE);
-
+	bm_size = DIV_ROUND_UP(sdp->sd_quota_slots, 8 * sizeof(unsigned long));
+	bm_size *= sizeof(unsigned long);
 	error = -ENOMEM;
-
-	sdp->sd_quota_bitmap = kcalloc(sdp->sd_quota_chunks,
-				       sizeof(unsigned char *), GFP_NOFS);
+	sdp->sd_quota_bitmap = kmalloc(bm_size, GFP_NOFS|__GFP_NOWARN);
+	if (sdp->sd_quota_bitmap == NULL)
+		sdp->sd_quota_bitmap = __vmalloc(bm_size, GFP_NOFS, PAGE_KERNEL);
 	if (!sdp->sd_quota_bitmap)
 		return error;
 
-	for (x = 0; x < sdp->sd_quota_chunks; x++) {
-		sdp->sd_quota_bitmap[x] = kzalloc(PAGE_SIZE, GFP_NOFS);
-		if (!sdp->sd_quota_bitmap[x])
-			goto fail;
-	}
+	memset(sdp->sd_quota_bitmap, 0, bm_size);
 
 	for (x = 0; x < blocks; x++) {
 		struct buffer_head *bh;
+		const struct gfs2_quota_change *qc;
 		unsigned int y;
 
 		if (!extlen) {
@@ -1274,34 +1270,42 @@ int gfs2_quota_init(struct gfs2_sbd *sdp)
 			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_change_host qc;
 			struct gfs2_quota_data *qd;
-
-			gfs2_quota_change_in(&qc, bh->b_data +
-					  sizeof(struct gfs2_meta_header) +
-					  y * sizeof(struct gfs2_quota_change));
-			if (!qc.qc_change)
+			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;
 
-			error = qd_alloc(sdp, qc.qc_id, &qd);
-			if (error) {
+			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.qc_change;
+			qd->qd_change = qc_change;
 			qd->qd_slot = slot;
 			qd->qd_slot_count = 1;
 
 			spin_lock(&qd_lock);
-			gfs2_icbit_munge(sdp, sdp->sd_quota_bitmap, slot, 1);
+			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++;
 		}
 
@@ -1324,44 +1328,28 @@ void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
 {
 	struct list_head *head = &sdp->sd_quota_list;
 	struct gfs2_quota_data *qd;
-	unsigned int x;
 
 	spin_lock(&qd_lock);
 	while (!list_empty(head)) {
 		qd = list_entry(head->prev, struct gfs2_quota_data, qd_list);
 
-		/*
-		 * To be removed in due course... we should be able to
-		 * ensure that all refs to the qd have done by this point
-		 * so that this rather odd test is not required
-		 */
-		spin_lock(&qd->qd_lockref.lock);
-		if (qd->qd_lockref.count > 1 ||
-		    (qd->qd_lockref.count && !test_bit(QDF_CHANGE, &qd->qd_flags))) {
-			spin_unlock(&qd->qd_lockref.lock);
-			list_move(&qd->qd_list, head);
-			spin_unlock(&qd_lock);
-			schedule();
-			spin_lock(&qd_lock);
-			continue;
-		}
-		spin_unlock(&qd->qd_lockref.lock);
-
 		list_del(&qd->qd_list);
+
 		/* Also remove if this qd exists in the reclaim list */
 		list_lru_del(&gfs2_qd_lru, &qd->qd_lru);
 		atomic_dec(&sdp->sd_quota_count);
 		spin_unlock(&qd_lock);
 
-		if (!qd->qd_lockref.count) {
-			gfs2_assert_warn(sdp, !qd->qd_change);
-			gfs2_assert_warn(sdp, !qd->qd_slot_count);
-		} else
-			gfs2_assert_warn(sdp, qd->qd_slot_count == 1);
+		spin_lock_bucket(qd->qd_hash);
+		hlist_bl_del_rcu(&qd->qd_hlist);
+		spin_unlock_bucket(qd->qd_hash);
+
+		gfs2_assert_warn(sdp, !qd->qd_change);
+		gfs2_assert_warn(sdp, !qd->qd_slot_count);
 		gfs2_assert_warn(sdp, !qd->qd_bh_count);
 
 		gfs2_glock_put(qd->qd_gl);
-		kmem_cache_free(gfs2_quotad_cachep, qd);
+		call_rcu(&qd->qd_rcu, gfs2_qd_dealloc);
 
 		spin_lock(&qd_lock);
 	}
@@ -1370,9 +1358,11 @@ void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
 	gfs2_assert_warn(sdp, !atomic_read(&sdp->sd_quota_count));
 
 	if (sdp->sd_quota_bitmap) {
-		for (x = 0; x < sdp->sd_quota_chunks; x++)
-			kfree(sdp->sd_quota_bitmap[x]);
-		kfree(sdp->sd_quota_bitmap);
+		if (is_vmalloc_addr(sdp->sd_quota_bitmap))
+			vfree(sdp->sd_quota_bitmap);
+		else
+			kfree(sdp->sd_quota_bitmap);
+		sdp->sd_quota_bitmap = NULL;
 	}
 }
 
@@ -1656,3 +1646,11 @@ const struct quotactl_ops gfs2_quotactl_ops = {
 	.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]);
+}