From 0e4697d0ac3ebf3bdf147e8616ecf5447c54c8be Mon Sep 17 00:00:00 2001
From: Dmitry Monakhov <dmonakhov@openvz.org>
Date: Wed, 26 May 2010 23:21:58 +0200
Subject: [PATCH] --- yaml --- r: 199359 b: refs/heads/master c:
 f32764bd2bbb6ea003c158b1d276b4dc9f900348 h: refs/heads/master i:   199357:
 20898b9be6b5f6a779cb86f98f31867ba6754f15   199355:
 429ba90863e79a6b2741a94a5bc253d9d095e55c   199351:
 4fda7c50ecb39a95055c5c69c22b9b07d8dd5409   199343:
 958306682d7b8acee95fe2e348e745c46e9af8d7   199327:
 fbfa550ea4cb2bab7ff33f827ef67ec66a8cdfc2   199295:
 6e32dc8b51cd2e41263ad28e70608694e8ec1997 v: v3

---
 [refs]                      |  2 +-
 trunk/fs/quota/dquot.c      | 46 +++++++++++--------------------------
 trunk/include/linux/quota.h | 16 ++++---------
 3 files changed, 18 insertions(+), 46 deletions(-)

diff --git a/[refs] b/[refs]
index 4da86c0182eb..f7e4bbbc5073 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1513b02c8b537af275ea74fdfb380c618b9e6778
+refs/heads/master: f32764bd2bbb6ea003c158b1d276b4dc9f900348
diff --git a/trunk/fs/quota/dquot.c b/trunk/fs/quota/dquot.c
index 1ff91314b8a0..531dee651ef7 100644
--- a/trunk/fs/quota/dquot.c
+++ b/trunk/fs/quota/dquot.c
@@ -228,10 +228,6 @@ static struct hlist_head *dquot_hash;
 
 struct dqstats dqstats;
 EXPORT_SYMBOL(dqstats);
-#ifdef CONFIG_SMP
-struct dqstats *dqstats_pcpu;
-EXPORT_SYMBOL(dqstats_pcpu);
-#endif
 
 static qsize_t inode_get_rsv_space(struct inode *inode);
 static void __dquot_initialize(struct inode *inode, int type);
@@ -676,27 +672,10 @@ static void prune_dqcache(int count)
 	}
 }
 
-static int dqstats_read(unsigned int type)
-{
-	int count = 0;
-#ifdef CONFIG_SMP
-	int cpu;
-	for_each_possible_cpu(cpu)
-		count += per_cpu_ptr(dqstats_pcpu, cpu)->stat[type];
-	/* Statistics reading is racy, but absolute accuracy isn't required */
-	if (count < 0)
-		count = 0;
-#else
-	count = dqstats.stat[type];
-#endif
-	return count;
-}
-
 /*
  * This is called from kswapd when we think we need some
  * more memory
  */
-
 static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
 {
 	if (nr) {
@@ -704,7 +683,9 @@ static int shrink_dqcache_memory(int nr, gfp_t gfp_mask)
 		prune_dqcache(nr);
 		spin_unlock(&dq_list_lock);
 	}
-	return (dqstats_read(DQST_FREE_DQUOTS)/100) * sysctl_vfs_cache_pressure;
+	return ((unsigned)
+		percpu_counter_read_positive(&dqstats.counter[DQST_FREE_DQUOTS])
+		/100) * sysctl_vfs_cache_pressure;
 }
 
 static struct shrinker dqcache_shrinker = {
@@ -2497,11 +2478,11 @@ EXPORT_SYMBOL(dquot_quotactl_ops);
 static int do_proc_dqstats(struct ctl_table *table, int write,
 		     void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-#ifdef CONFIG_SMP
-	/* Update global table */
 	unsigned int type = (int *)table->data - dqstats.stat;
-	dqstats.stat[type] = dqstats_read(type);
-#endif
+
+	/* Update global table */
+	dqstats.stat[type] =
+			percpu_counter_sum_positive(&dqstats.counter[type]);
 	return proc_dointvec(table, write, buffer, lenp, ppos);
 }
 
@@ -2594,7 +2575,7 @@ static ctl_table sys_table[] = {
 
 static int __init dquot_init(void)
 {
-	int i;
+	int i, ret;
 	unsigned long nr_hash, order;
 
 	printk(KERN_NOTICE "VFS: Disk quotas %s\n", __DQUOT_VERSION__);
@@ -2612,12 +2593,11 @@ static int __init dquot_init(void)
 	if (!dquot_hash)
 		panic("Cannot create dquot hash table");
 
-#ifdef CONFIG_SMP
-	dqstats_pcpu = alloc_percpu(struct dqstats);
-	if (!dqstats_pcpu)
-		panic("Cannot create dquot stats table");
-#endif
-	memset(&dqstats, 0, sizeof(struct dqstats));
+	for (i = 0; i < _DQST_DQSTAT_LAST; i++) {
+		ret = percpu_counter_init(&dqstats.counter[i], 0);
+		if (ret)
+			panic("Cannot create dquot stat counters");
+	}
 
 	/* Find power-of-two hlist_heads which can fit into allocation */
 	nr_hash = (1UL << order) * PAGE_SIZE / sizeof(struct hlist_head);
diff --git a/trunk/include/linux/quota.h b/trunk/include/linux/quota.h
index 2789d07c37be..94c1f03b50eb 100644
--- a/trunk/include/linux/quota.h
+++ b/trunk/include/linux/quota.h
@@ -174,8 +174,7 @@ enum {
 #include <linux/rwsem.h>
 #include <linux/spinlock.h>
 #include <linux/wait.h>
-#include <linux/percpu.h>
-#include <linux/smp.h>
+#include <linux/percpu_counter.h>
 
 #include <linux/dqblk_xfs.h>
 #include <linux/dqblk_v1.h>
@@ -254,6 +253,7 @@ enum {
 
 struct dqstats {
 	int stat[_DQST_DQSTAT_LAST];
+	struct percpu_counter counter[_DQST_DQSTAT_LAST];
 };
 
 extern struct dqstats *dqstats_pcpu;
@@ -261,20 +261,12 @@ extern struct dqstats dqstats;
 
 static inline void dqstats_inc(unsigned int type)
 {
-#ifdef CONFIG_SMP
-	per_cpu_ptr(dqstats_pcpu, smp_processor_id())->stat[type]++;
-#else
-	dqstats.stat[type]++;
-#endif
+	percpu_counter_inc(&dqstats.counter[type]);
 }
 
 static inline void dqstats_dec(unsigned int type)
 {
-#ifdef CONFIG_SMP
-	per_cpu_ptr(dqstats_pcpu, smp_processor_id())->stat[type]--;
-#else
-	dqstats.stat[type]--;
-#endif
+	percpu_counter_dec(&dqstats.counter[type]);
 }
 
 #define DQ_MOD_B	0	/* dquot modified since read */