1 files changed, 202 insertions, 45 deletions

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 662937472e9b..79ad6b2c9608 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -44,6 +44,17 @@ struct nfsd_fcache_bucket {
 
 static DEFINE_PER_CPU(unsigned long, nfsd_file_cache_hits);
 
+struct nfsd_fcache_disposal {
+	struct list_head list;
+	struct work_struct work;
+	struct net *net;
+	spinlock_t lock;
+	struct list_head freeme;
+	struct rcu_head rcu;
+};
+
+struct workqueue_struct *nfsd_filecache_wq __read_mostly;
+
 static struct kmem_cache		*nfsd_file_slab;
 static struct kmem_cache		*nfsd_file_mark_slab;
 static struct nfsd_fcache_bucket	*nfsd_file_hashtbl;
@@ -52,32 +63,21 @@ static long				nfsd_file_lru_flags;
 static struct fsnotify_group		*nfsd_file_fsnotify_group;
 static atomic_long_t			nfsd_filecache_count;
 static struct delayed_work		nfsd_filecache_laundrette;
+static DEFINE_SPINLOCK(laundrette_lock);
+static LIST_HEAD(laundrettes);
 
-enum nfsd_file_laundrette_ctl {
-	NFSD_FILE_LAUNDRETTE_NOFLUSH = 0,
-	NFSD_FILE_LAUNDRETTE_MAY_FLUSH
-};
+static void nfsd_file_gc(void);
 
 static void
-nfsd_file_schedule_laundrette(enum nfsd_file_laundrette_ctl ctl)
+nfsd_file_schedule_laundrette(void)
 {
 	long count = atomic_long_read(&nfsd_filecache_count);
 
 	if (count == 0 || test_bit(NFSD_FILE_SHUTDOWN, &nfsd_file_lru_flags))
 		return;
 
-	/* Be more aggressive about scanning if over the threshold */
-	if (count > NFSD_FILE_LRU_THRESHOLD)
-		mod_delayed_work(system_wq, &nfsd_filecache_laundrette, 0);
-	else
-		schedule_delayed_work(&nfsd_filecache_laundrette, NFSD_LAUNDRETTE_DELAY);
-
-	if (ctl == NFSD_FILE_LAUNDRETTE_NOFLUSH)
-		return;
-
-	/* ...and don't delay flushing if we're out of control */
-	if (count >= NFSD_FILE_LRU_LIMIT)
-		flush_delayed_work(&nfsd_filecache_laundrette);
+	queue_delayed_work(system_wq, &nfsd_filecache_laundrette,
+			NFSD_LAUNDRETTE_DELAY);
 }
 
 static void
@@ -260,8 +260,6 @@ nfsd_file_do_unhash(struct nfsd_file *nf)
 		nfsd_reset_boot_verifier(net_generic(nf->nf_net, nfsd_net_id));
 	--nfsd_file_hashtbl[nf->nf_hashval].nfb_count;
 	hlist_del_rcu(&nf->nf_node);
-	if (!list_empty(&nf->nf_lru))
-		list_lru_del(&nfsd_file_lru, &nf->nf_lru);
 	atomic_long_dec(&nfsd_filecache_count);
 }
 
@@ -270,6 +268,8 @@ nfsd_file_unhash(struct nfsd_file *nf)
 {
 	if (test_and_clear_bit(NFSD_FILE_HASHED, &nf->nf_flags)) {
 		nfsd_file_do_unhash(nf);
+		if (!list_empty(&nf->nf_lru))
+			list_lru_del(&nfsd_file_lru, &nf->nf_lru);
 		return true;
 	}
 	return false;
@@ -316,7 +316,9 @@ nfsd_file_put(struct nfsd_file *nf)
 
 	set_bit(NFSD_FILE_REFERENCED, &nf->nf_flags);
 	if (nfsd_file_put_noref(nf) == 1 && is_hashed && unused)
-		nfsd_file_schedule_laundrette(NFSD_FILE_LAUNDRETTE_MAY_FLUSH);
+		nfsd_file_schedule_laundrette();
+	if (atomic_long_read(&nfsd_filecache_count) >= NFSD_FILE_LRU_LIMIT)
+		nfsd_file_gc();
 }
 
 struct nfsd_file *
@@ -357,6 +359,58 @@ nfsd_file_dispose_list_sync(struct list_head *dispose)
 		flush_delayed_fput();
 }
 
+static void
+nfsd_file_list_remove_disposal(struct list_head *dst,
+		struct nfsd_fcache_disposal *l)
+{
+	spin_lock(&l->lock);
+	list_splice_init(&l->freeme, dst);
+	spin_unlock(&l->lock);
+}
+
+static void
+nfsd_file_list_add_disposal(struct list_head *files, struct net *net)
+{
+	struct nfsd_fcache_disposal *l;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(l, &laundrettes, list) {
+		if (l->net == net) {
+			spin_lock(&l->lock);
+			list_splice_tail_init(files, &l->freeme);
+			spin_unlock(&l->lock);
+			queue_work(nfsd_filecache_wq, &l->work);
+			break;
+		}
+	}
+	rcu_read_unlock();
+}
+
+static void
+nfsd_file_list_add_pernet(struct list_head *dst, struct list_head *src,
+		struct net *net)
+{
+	struct nfsd_file *nf, *tmp;
+
+	list_for_each_entry_safe(nf, tmp, src, nf_lru) {
+		if (nf->nf_net == net)
+			list_move_tail(&nf->nf_lru, dst);
+	}
+}
+
+static void
+nfsd_file_dispose_list_delayed(struct list_head *dispose)
+{
+	LIST_HEAD(list);
+	struct nfsd_file *nf;
+
+	while(!list_empty(dispose)) {
+		nf = list_first_entry(dispose, struct nfsd_file, nf_lru);
+		nfsd_file_list_add_pernet(&list, dispose, nf->nf_net);
+		nfsd_file_list_add_disposal(&list, nf->nf_net);
+	}
+}
+
 /*
  * Note this can deadlock with nfsd_file_cache_purge.
  */
@@ -403,18 +457,40 @@ out_skip:
 	return LRU_SKIP;
 }
 
-static void
-nfsd_file_lru_dispose(struct list_head *head)
+static unsigned long
+nfsd_file_lru_walk_list(struct shrink_control *sc)
 {
-	while(!list_empty(head)) {
-		struct nfsd_file *nf = list_first_entry(head,
-				struct nfsd_file, nf_lru);
-		list_del_init(&nf->nf_lru);
+	LIST_HEAD(head);
+	struct nfsd_file *nf;
+	unsigned long ret;
+
+	if (sc)
+		ret = list_lru_shrink_walk(&nfsd_file_lru, sc,
+				nfsd_file_lru_cb, &head);
+	else
+		ret = list_lru_walk(&nfsd_file_lru,
+				nfsd_file_lru_cb,
+				&head, LONG_MAX);
+	list_for_each_entry(nf, &head, nf_lru) {
 		spin_lock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
 		nfsd_file_do_unhash(nf);
 		spin_unlock(&nfsd_file_hashtbl[nf->nf_hashval].nfb_lock);
-		nfsd_file_put_noref(nf);
 	}
+	nfsd_file_dispose_list_delayed(&head);
+	return ret;
+}
+
+static void
+nfsd_file_gc(void)
+{
+	nfsd_file_lru_walk_list(NULL);
+}
+
+static void
+nfsd_file_gc_worker(struct work_struct *work)
+{
+	nfsd_file_gc();
+	nfsd_file_schedule_laundrette();
 }
 
 static unsigned long
@@ -426,12 +502,7 @@ nfsd_file_lru_count(struct shrinker *s, struct shrink_control *sc)
 static unsigned long
 nfsd_file_lru_scan(struct shrinker *s, struct shrink_control *sc)
 {
-	LIST_HEAD(head);
-	unsigned long ret;
-
-	ret = list_lru_shrink_walk(&nfsd_file_lru, sc, nfsd_file_lru_cb, &head);
-	nfsd_file_lru_dispose(&head);
-	return ret;
+	return nfsd_file_lru_walk_list(sc);
 }
 
 static struct shrinker	nfsd_file_shrinker = {
@@ -493,7 +564,7 @@ nfsd_file_close_inode(struct inode *inode)
 
 	__nfsd_file_close_inode(inode, hashval, &dispose);
 	trace_nfsd_file_close_inode(inode, hashval, !list_empty(&dispose));
-	nfsd_file_dispose_list(&dispose);
+	nfsd_file_dispose_list_delayed(&dispose);
 }
 
 /**
@@ -509,16 +580,11 @@ static void
 nfsd_file_delayed_close(struct work_struct *work)
 {
 	LIST_HEAD(head);
+	struct nfsd_fcache_disposal *l = container_of(work,
+			struct nfsd_fcache_disposal, work);
 
-	list_lru_walk(&nfsd_file_lru, nfsd_file_lru_cb, &head, LONG_MAX);
-
-	if (test_and_clear_bit(NFSD_FILE_LRU_RESCAN, &nfsd_file_lru_flags))
-		nfsd_file_schedule_laundrette(NFSD_FILE_LAUNDRETTE_NOFLUSH);
-
-	if (!list_empty(&head)) {
-		nfsd_file_lru_dispose(&head);
-		flush_delayed_fput();
-	}
+	nfsd_file_list_remove_disposal(&head, l);
+	nfsd_file_dispose_list(&head);
 }
 
 static int
@@ -579,6 +645,10 @@ nfsd_file_cache_init(void)
 	if (nfsd_file_hashtbl)
 		return 0;
 
+	nfsd_filecache_wq = alloc_workqueue("nfsd_filecache", 0, 0);
+	if (!nfsd_filecache_wq)
+		goto out;
+
 	nfsd_file_hashtbl = kcalloc(NFSD_FILE_HASH_SIZE,
 				sizeof(*nfsd_file_hashtbl), GFP_KERNEL);
 	if (!nfsd_file_hashtbl) {
@@ -632,7 +702,7 @@ nfsd_file_cache_init(void)
 		spin_lock_init(&nfsd_file_hashtbl[i].nfb_lock);
 	}
 
-	INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_delayed_close);
+	INIT_DELAYED_WORK(&nfsd_filecache_laundrette, nfsd_file_gc_worker);
 out:
 	return ret;
 out_notifier:
@@ -648,6 +718,8 @@ out_err:
 	nfsd_file_mark_slab = NULL;
 	kfree(nfsd_file_hashtbl);
 	nfsd_file_hashtbl = NULL;
+	destroy_workqueue(nfsd_filecache_wq);
+	nfsd_filecache_wq = NULL;
 	goto out;
 }
 
@@ -686,6 +758,88 @@ nfsd_file_cache_purge(struct net *net)
 	}
 }
 
+static struct nfsd_fcache_disposal *
+nfsd_alloc_fcache_disposal(struct net *net)
+{
+	struct nfsd_fcache_disposal *l;
+
+	l = kmalloc(sizeof(*l), GFP_KERNEL);
+	if (!l)
+		return NULL;
+	INIT_WORK(&l->work, nfsd_file_delayed_close);
+	l->net = net;
+	spin_lock_init(&l->lock);
+	INIT_LIST_HEAD(&l->freeme);
+	return l;
+}
+
+static void
+nfsd_free_fcache_disposal(struct nfsd_fcache_disposal *l)
+{
+	rcu_assign_pointer(l->net, NULL);
+	cancel_work_sync(&l->work);
+	nfsd_file_dispose_list(&l->freeme);
+	kfree_rcu(l, rcu);
+}
+
+static void
+nfsd_add_fcache_disposal(struct nfsd_fcache_disposal *l)
+{
+	spin_lock(&laundrette_lock);
+	list_add_tail_rcu(&l->list, &laundrettes);
+	spin_unlock(&laundrette_lock);
+}
+
+static void
+nfsd_del_fcache_disposal(struct nfsd_fcache_disposal *l)
+{
+	spin_lock(&laundrette_lock);
+	list_del_rcu(&l->list);
+	spin_unlock(&laundrette_lock);
+}
+
+static int
+nfsd_alloc_fcache_disposal_net(struct net *net)
+{
+	struct nfsd_fcache_disposal *l;
+
+	l = nfsd_alloc_fcache_disposal(net);
+	if (!l)
+		return -ENOMEM;
+	nfsd_add_fcache_disposal(l);
+	return 0;
+}
+
+static void
+nfsd_free_fcache_disposal_net(struct net *net)
+{
+	struct nfsd_fcache_disposal *l;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(l, &laundrettes, list) {
+		if (l->net != net)
+			continue;
+		nfsd_del_fcache_disposal(l);
+		rcu_read_unlock();
+		nfsd_free_fcache_disposal(l);
+		return;
+	}
+	rcu_read_unlock();
+}
+
+int
+nfsd_file_cache_start_net(struct net *net)
+{
+	return nfsd_alloc_fcache_disposal_net(net);
+}
+
+void
+nfsd_file_cache_shutdown_net(struct net *net)
+{
+	nfsd_file_cache_purge(net);
+	nfsd_free_fcache_disposal_net(net);
+}
+
 void
 nfsd_file_cache_shutdown(void)
 {
@@ -712,6 +866,8 @@ nfsd_file_cache_shutdown(void)
 	nfsd_file_mark_slab = NULL;
 	kfree(nfsd_file_hashtbl);
 	nfsd_file_hashtbl = NULL;
+	destroy_workqueue(nfsd_filecache_wq);
+	nfsd_filecache_wq = NULL;
 }
 
 static bool
@@ -881,7 +1037,8 @@ open_file:
 	nfsd_file_hashtbl[hashval].nfb_maxcount = max(nfsd_file_hashtbl[hashval].nfb_maxcount,
 			nfsd_file_hashtbl[hashval].nfb_count);
 	spin_unlock(&nfsd_file_hashtbl[hashval].nfb_lock);
-	atomic_long_inc(&nfsd_filecache_count);
+	if (atomic_long_inc_return(&nfsd_filecache_count) >= NFSD_FILE_LRU_THRESHOLD)
+		nfsd_file_gc();
 
 	nf->nf_mark = nfsd_file_mark_find_or_create(nf);
 	if (nf->nf_mark)