1 files changed, 32 insertions, 18 deletions

diff --git a/fs/inode.c b/fs/inode.c
index ae2727ab0c3a..da85e56378f3 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -102,26 +102,29 @@ static DECLARE_RWSEM(iprune_sem);
  */
 struct inodes_stat_t inodes_stat;
 
-static struct percpu_counter nr_inodes __cacheline_aligned_in_smp;
-static struct percpu_counter nr_inodes_unused __cacheline_aligned_in_smp;
+static DEFINE_PER_CPU(unsigned int, nr_inodes);
 
 static struct kmem_cache *inode_cachep __read_mostly;
 
-static inline int get_nr_inodes(void)
+static int get_nr_inodes(void)
 {
-        return percpu_counter_sum_positive(&nr_inodes);
+        int i;
+        int sum = 0;
+        for_each_possible_cpu(i)
+                sum += per_cpu(nr_inodes, i);
+        return sum < 0 ? 0 : sum;
 }
 
 static inline int get_nr_inodes_unused(void)
 {
-        return percpu_counter_sum_positive(&nr_inodes_unused);
+        return inodes_stat.nr_unused;
 }
 
 int get_nr_dirty_inodes(void)
 {
+        /* not actually dirty inodes, but a wild approximation */
         int nr_dirty = get_nr_inodes() - get_nr_inodes_unused();
         return nr_dirty > 0 ? nr_dirty : 0;
-
 }
 
 /*
@@ -132,7 +135,6 @@ int proc_nr_inodes(ctl_table *table, int write,
                    void __user *buffer, size_t *lenp, loff_t *ppos)
 {
         inodes_stat.nr_inodes = get_nr_inodes();
-        inodes_stat.nr_unused = get_nr_inodes_unused();
         return proc_dointvec(table, write, buffer, lenp, ppos);
 }
 #endif
@@ -224,7 +226,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
         inode->i_fsnotify_mask = 0;
 #endif
 
-        percpu_counter_inc(&nr_inodes);
+        this_cpu_inc(nr_inodes);
 
         return 0;
 out:
@@ -255,6 +257,12 @@ static struct inode *alloc_inode(struct super_block *sb)
         return inode;
 }
 
+void free_inode_nonrcu(struct inode *inode)
+{
+        kmem_cache_free(inode_cachep, inode);
+}
+EXPORT_SYMBOL(free_inode_nonrcu);
+
 void __destroy_inode(struct inode *inode)
 {
         BUG_ON(inode_has_buffers(inode));
@@ -266,10 +274,17 @@ void __destroy_inode(struct inode *inode)
         if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED)
                 posix_acl_release(inode->i_default_acl);
 #endif
-        percpu_counter_dec(&nr_inodes);
+        this_cpu_dec(nr_inodes);
 }
 EXPORT_SYMBOL(__destroy_inode);
 
+static void i_callback(struct rcu_head *head)
+{
+        struct inode *inode = container_of(head, struct inode, i_rcu);
+        INIT_LIST_HEAD(&inode->i_dentry);
+        kmem_cache_free(inode_cachep, inode);
+}
+
 static void destroy_inode(struct inode *inode)
 {
         BUG_ON(!list_empty(&inode->i_lru));
@@ -277,7 +292,7 @@ static void destroy_inode(struct inode *inode)
         if (inode->i_sb->s_op->destroy_inode)
                 inode->i_sb->s_op->destroy_inode(inode);
         else
-                kmem_cache_free(inode_cachep, (inode));
+                call_rcu(&inode->i_rcu, i_callback);
 }
 
 /*
@@ -335,7 +350,7 @@ static void inode_lru_list_add(struct inode *inode)
 {
         if (list_empty(&inode->i_lru)) {
                 list_add(&inode->i_lru, &inode_lru);
-                percpu_counter_inc(&nr_inodes_unused);
+                inodes_stat.nr_unused++;
         }
 }
 
@@ -343,7 +358,7 @@ static void inode_lru_list_del(struct inode *inode)
 {
         if (!list_empty(&inode->i_lru)) {
                 list_del_init(&inode->i_lru);
-                percpu_counter_dec(&nr_inodes_unused);
+                inodes_stat.nr_unused--;
         }
 }
 
@@ -430,6 +445,7 @@ void end_writeback(struct inode *inode)
         BUG_ON(!(inode->i_state & I_FREEING));
         BUG_ON(inode->i_state & I_CLEAR);
         inode_sync_wait(inode);
+        /* don't need i_lock here, no concurrent mods to i_state */
         inode->i_state = I_FREEING | I_CLEAR;
 }
 EXPORT_SYMBOL(end_writeback);
@@ -513,7 +529,7 @@ void evict_inodes(struct super_block *sb)
                 list_move(&inode->i_lru, &dispose);
                 list_del_init(&inode->i_wb_list);
                 if (!(inode->i_state & (I_DIRTY | I_SYNC)))
-                        percpu_counter_dec(&nr_inodes_unused);
+                        inodes_stat.nr_unused--;
         }
         spin_unlock(&inode_lock);
 
@@ -554,7 +570,7 @@ int invalidate_inodes(struct super_block *sb)
                 list_move(&inode->i_lru, &dispose);
                 list_del_init(&inode->i_wb_list);
                 if (!(inode->i_state & (I_DIRTY | I_SYNC)))
-                        percpu_counter_dec(&nr_inodes_unused);
+                        inodes_stat.nr_unused--;
         }
         spin_unlock(&inode_lock);
 
@@ -616,7 +632,7 @@ static void prune_icache(int nr_to_scan)
                 if (atomic_read(&inode->i_count) ||
                     (inode->i_state & ~I_REFERENCED)) {
                         list_del_init(&inode->i_lru);
-                        percpu_counter_dec(&nr_inodes_unused);
+                        inodes_stat.nr_unused--;
                         continue;
                 }
 
@@ -650,7 +666,7 @@ static void prune_icache(int nr_to_scan)
                  */
                 list_move(&inode->i_lru, &freeable);
                 list_del_init(&inode->i_wb_list);
-                percpu_counter_dec(&nr_inodes_unused);
+                inodes_stat.nr_unused--;
         }
         if (current_is_kswapd())
                 __count_vm_events(KSWAPD_INODESTEAL, reap);
@@ -1648,8 +1664,6 @@ void __init inode_init(void)
                                          SLAB_MEM_SPREAD),
                                          init_once);
         register_shrinker(&icache_shrinker);
-        percpu_counter_init(&nr_inodes, 0);
-        percpu_counter_init(&nr_inodes_unused, 0);
 
         /* Hash may have been set up in inode_init_early */
         if (!hashdist)