From: Steven Whitehouse <swhiteho@redhat.com>
To: linux-kernel@vger.kernel.org, cluster-devel@redhat.com
Cc: Steven Whitehouse <swhiteho@redhat.com>,
Abhijith Das <adas@redhat.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH 17/24] GFS2: Use RCU/hlist_bl based hash for quotas
Date: Mon, 20 Jan 2014 12:23:40 +0000 [thread overview]
Message-ID: <1390220627-1571-18-git-send-email-swhiteho@redhat.com> (raw)
In-Reply-To: <1390220627-1571-1-git-send-email-swhiteho@redhat.com>
Prior to this patch, GFS2 kept all the quotas for each
super block in a single linked list. This is rather slow
when there are large numbers of quotas.
This patch introduces a hlist_bl based hash table, similar
to the one used for glocks. The initial look up of the quota
is now lockless in the case where it is already cached,
although we still have to take the per quota spinlock in
order to bump the ref count. Either way though, this is a
big improvement on what was there before.
The qd_lock and the per super block list is preserved, for
the time being. However it is intended that since this is no
longer used for its original role, it should be possible to
shrink the number of items on that list in due course and
remove the requirement to take qd_lock in qd_get.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Abhijith Das <adas@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index a99f60c..59d99ec 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -428,10 +428,13 @@ enum {
};
struct gfs2_quota_data {
+ struct hlist_bl_node qd_hlist;
struct list_head qd_list;
struct kqid qd_id;
+ struct gfs2_sbd *qd_sbd;
struct lockref qd_lockref;
struct list_head qd_lru;
+ unsigned qd_hash;
unsigned long qd_flags; /* QDF_... */
@@ -450,6 +453,7 @@ struct gfs2_quota_data {
u64 qd_sync_gen;
unsigned long qd_last_warn;
+ struct rcu_head qd_rcu;
};
struct gfs2_trans {
diff --git a/fs/gfs2/main.c b/fs/gfs2/main.c
index 0650db2..c272e73 100644
--- a/fs/gfs2/main.c
+++ b/fs/gfs2/main.c
@@ -76,6 +76,7 @@ static int __init init_gfs2_fs(void)
gfs2_str2qstr(&gfs2_qdot, ".");
gfs2_str2qstr(&gfs2_qdotdot, "..");
+ gfs2_quota_hash_init();
error = gfs2_sys_init();
if (error)
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index 1b6b367..a1df01d 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -52,6 +52,10 @@
#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 "gfs2.h"
#include "incore.h"
@@ -67,10 +71,43 @@
#include "inode.h"
#include "util.h"
-/* Lock order: qd_lock -> qd->lockref.lock -> lru lock */
+#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 -> bucket lock -> qd->lockref.lock -> lru 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;
@@ -87,6 +124,10 @@ 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);
@@ -95,7 +136,7 @@ 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);
}
}
@@ -165,83 +206,95 @@ 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;
@@ -1215,6 +1268,7 @@ 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;
u64 dblock;
u32 extlen = 0;
int error;
@@ -1272,8 +1326,9 @@ int gfs2_quota_init(struct gfs2_sbd *sdp)
if (!qc_change)
continue;
- error = qd_alloc(sdp, 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;
}
@@ -1289,6 +1344,10 @@ int gfs2_quota_init(struct gfs2_sbd *sdp)
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++;
}
@@ -1335,11 +1394,16 @@ void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
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);
+ spin_lock_bucket(qd->qd_hash);
+ hlist_bl_del_rcu(&qd->qd_hlist);
+ spin_unlock_bucket(qd->qd_hash);
+
if (!qd->qd_lockref.count) {
gfs2_assert_warn(sdp, !qd->qd_change);
gfs2_assert_warn(sdp, !qd->qd_slot_count);
@@ -1348,7 +1412,7 @@ void gfs2_quota_cleanup(struct gfs2_sbd *sdp)
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);
}
@@ -1643,3 +1707,11 @@ 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]);
+}
diff --git a/fs/gfs2/quota.h b/fs/gfs2/quota.h
index 96e4f34..55d506e 100644
--- a/fs/gfs2/quota.h
+++ b/fs/gfs2/quota.h
@@ -57,5 +57,6 @@ static inline int gfs2_quota_lock_check(struct gfs2_inode *ip)
extern const struct quotactl_ops gfs2_quotactl_ops;
extern struct shrinker gfs2_qd_shrinker;
extern struct list_lru gfs2_qd_lru;
+extern void __init gfs2_quota_hash_init(void);
#endif /* __QUOTA_DOT_H__ */
--
1.8.3.1
next prev parent reply other threads:[~2014-01-20 12:25 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-20 12:23 GFS2: Pre-pull patch posting (merge window) Steven Whitehouse
2014-01-20 12:23 ` [PATCH 01/24] GFS2: If requested is too large, use the largest extent in the rgrp Steven Whitehouse
2014-01-20 12:23 ` [PATCH 02/24] GFS2: Drop inadequate rgrps from the reservation tree Steven Whitehouse
2014-01-20 12:23 ` [PATCH 03/24] GFS2: Implement a "rgrp has no extents longer than X" scheme Steven Whitehouse
2014-01-20 12:23 ` [PATCH 04/24] GFS2: Clean up releasepage Steven Whitehouse
2014-01-20 12:23 ` [PATCH 05/24] GFS2: Remove gfs2_quota_change_host structure Steven Whitehouse
2014-01-20 12:23 ` [PATCH 06/24] GFS2: Remove test which is always true Steven Whitehouse
2014-01-20 12:23 ` [PATCH 07/24] GFS2: Use range based functions for rgrp sync/invalidation Steven Whitehouse
2014-01-20 12:23 ` [PATCH 08/24] GFS2: Use only a single address space for rgrps Steven Whitehouse
2014-01-20 12:23 ` [PATCH 09/24] GFS2: Add directory addition info structure Steven Whitehouse
2014-01-20 12:23 ` [PATCH 10/24] GFS2: Consolidate transaction blocks calculation for dir add Steven Whitehouse
2014-01-20 12:23 ` [PATCH 11/24] GFS2: Remember directory insert point Steven Whitehouse
2014-01-20 12:23 ` [PATCH 12/24] GFS2: Increase i_writecount during gfs2_setattr_chown Steven Whitehouse
2014-01-20 12:23 ` [PATCH 13/24] GFS2: For exhash conversion, only one block is needed Steven Whitehouse
2014-01-20 12:23 ` [PATCH 14/24] GFS2: Add hints to directory leaf blocks Steven Whitehouse
2014-01-20 12:23 ` [PATCH 15/24] GFS2: Add initialization for address space in super block Steven Whitehouse
2014-01-20 12:23 ` [PATCH 16/24] GFS2: No need to invalidate pages for a dio read Steven Whitehouse
2014-01-20 12:23 ` Steven Whitehouse [this message]
2014-01-22 5:32 ` [PATCH 17/24] GFS2: Use RCU/hlist_bl based hash for quotas Paul E. McKenney
2014-01-22 6:06 ` Sasha Levin
2014-01-22 9:43 ` Steven Whitehouse
2014-01-22 9:58 ` Steven Whitehouse
2014-01-20 12:23 ` [PATCH 18/24] GFS2: Only run logd and quota when mounted read/write Steven Whitehouse
2014-01-20 12:23 ` [PATCH 19/24] GFS2: Clean up quota slot allocation Steven Whitehouse
2014-01-20 12:23 ` [PATCH 20/24] GFS2: Move quota bitmap operations under their own lock Steven Whitehouse
2014-01-20 12:23 ` [PATCH 21/24] GFS2: Fix kbuild test robot reported warning Steven Whitehouse
2014-01-20 12:23 ` [PATCH 22/24] GFS2: Don't use ENOBUFS when ENOMEM is the correct error code Steven Whitehouse
2014-01-20 12:23 ` [PATCH 23/24] GFS2: Small cleanup Steven Whitehouse
2014-01-20 12:23 ` [PATCH 24/24] GFS2: revert "GFS2: d_splice_alias() can't return error" Steven Whitehouse
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