Merge commit 'v2.6.32' into reiserfs/kill-bkl

Merge-reason: The tree was based 2.6.31. It's better to be up to date
with 2.6.32. Although no conflicting changes were made in between,
it gives benchmarking results closer to the lastest kernel behaviour.

1 files changed, 93 insertions, 11 deletions

diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 392a41b1b79..e513ac599c8 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -14,9 +14,10 @@
 
 #define FSCACHE_DEBUG_LEVEL COOKIE
 #include <linux/module.h>
+#include <linux/seq_file.h>
 #include "internal.h"
 
-const char *fscache_object_states[] = {
+const char *fscache_object_states[FSCACHE_OBJECT__NSTATES] = {
 	[FSCACHE_OBJECT_INIT]		= "OBJECT_INIT",
 	[FSCACHE_OBJECT_LOOKING_UP]	= "OBJECT_LOOKING_UP",
 	[FSCACHE_OBJECT_CREATING]	= "OBJECT_CREATING",
@@ -33,9 +34,28 @@ const char *fscache_object_states[] = {
 };
 EXPORT_SYMBOL(fscache_object_states);
 
+const char fscache_object_states_short[FSCACHE_OBJECT__NSTATES][5] = {
+	[FSCACHE_OBJECT_INIT]		= "INIT",
+	[FSCACHE_OBJECT_LOOKING_UP]	= "LOOK",
+	[FSCACHE_OBJECT_CREATING]	= "CRTN",
+	[FSCACHE_OBJECT_AVAILABLE]	= "AVBL",
+	[FSCACHE_OBJECT_ACTIVE]		= "ACTV",
+	[FSCACHE_OBJECT_UPDATING]	= "UPDT",
+	[FSCACHE_OBJECT_DYING]		= "DYNG",
+	[FSCACHE_OBJECT_LC_DYING]	= "LCDY",
+	[FSCACHE_OBJECT_ABORT_INIT]	= "ABTI",
+	[FSCACHE_OBJECT_RELEASING]	= "RELS",
+	[FSCACHE_OBJECT_RECYCLING]	= "RCYC",
+	[FSCACHE_OBJECT_WITHDRAWING]	= "WTHD",
+	[FSCACHE_OBJECT_DEAD]		= "DEAD",
+};
+
 static void fscache_object_slow_work_put_ref(struct slow_work *);
 static int  fscache_object_slow_work_get_ref(struct slow_work *);
 static void fscache_object_slow_work_execute(struct slow_work *);
+#ifdef CONFIG_SLOW_WORK_PROC
+static void fscache_object_slow_work_desc(struct slow_work *, struct seq_file *);
+#endif
 static void fscache_initialise_object(struct fscache_object *);
 static void fscache_lookup_object(struct fscache_object *);
 static void fscache_object_available(struct fscache_object *);
@@ -45,9 +65,13 @@ static void fscache_enqueue_dependents(struct fscache_object *);
 static void fscache_dequeue_object(struct fscache_object *);
 
 const struct slow_work_ops fscache_object_slow_work_ops = {
+	.owner		= THIS_MODULE,
 	.get_ref	= fscache_object_slow_work_get_ref,
 	.put_ref	= fscache_object_slow_work_put_ref,
 	.execute	= fscache_object_slow_work_execute,
+#ifdef CONFIG_SLOW_WORK_PROC
+	.desc		= fscache_object_slow_work_desc,
+#endif
 };
 EXPORT_SYMBOL(fscache_object_slow_work_ops);
 
@@ -81,6 +105,7 @@ static inline void fscache_done_parent_op(struct fscache_object *object)
 static void fscache_object_state_machine(struct fscache_object *object)
 {
 	enum fscache_object_state new_state;
+	struct fscache_cookie *cookie;
 
 	ASSERT(object != NULL);
 
@@ -120,20 +145,31 @@ static void fscache_object_state_machine(struct fscache_object *object)
 	case FSCACHE_OBJECT_UPDATING:
 		clear_bit(FSCACHE_OBJECT_EV_UPDATE, &object->events);
 		fscache_stat(&fscache_n_updates_run);
+		fscache_stat(&fscache_n_cop_update_object);
 		object->cache->ops->update_object(object);
+		fscache_stat_d(&fscache_n_cop_update_object);
 		goto active_transit;
 
 		/* handle an object dying during lookup or creation */
 	case FSCACHE_OBJECT_LC_DYING:
 		object->event_mask &= ~(1 << FSCACHE_OBJECT_EV_UPDATE);
+		fscache_stat(&fscache_n_cop_lookup_complete);
 		object->cache->ops->lookup_complete(object);
+		fscache_stat_d(&fscache_n_cop_lookup_complete);
 
 		spin_lock(&object->lock);
 		object->state = FSCACHE_OBJECT_DYING;
-		if (test_and_clear_bit(FSCACHE_COOKIE_CREATING,
-				       &object->cookie->flags))
-			wake_up_bit(&object->cookie->flags,
-				    FSCACHE_COOKIE_CREATING);
+		cookie = object->cookie;
+		if (cookie) {
+			if (test_and_clear_bit(FSCACHE_COOKIE_LOOKING_UP,
+					       &cookie->flags))
+				wake_up_bit(&cookie->flags,
+					    FSCACHE_COOKIE_LOOKING_UP);
+			if (test_and_clear_bit(FSCACHE_COOKIE_CREATING,
+					       &cookie->flags))
+				wake_up_bit(&cookie->flags,
+					    FSCACHE_COOKIE_CREATING);
+		}
 		spin_unlock(&object->lock);
 
 		fscache_done_parent_op(object);
@@ -165,6 +201,7 @@ static void fscache_object_state_machine(struct fscache_object *object)
 		}
 		spin_unlock(&object->lock);
 		fscache_enqueue_dependents(object);
+		fscache_start_operations(object);
 		goto terminal_transit;
 
 		/* handle an abort during initialisation */
@@ -316,14 +353,29 @@ static void fscache_object_slow_work_execute(struct slow_work *work)
 
 	_enter("{OBJ%x}", object->debug_id);
 
-	clear_bit(FSCACHE_OBJECT_EV_REQUEUE, &object->events);
-
 	start = jiffies;
 	fscache_object_state_machine(object);
 	fscache_hist(fscache_objs_histogram, start);
 	if (object->events & object->event_mask)
 		fscache_enqueue_object(object);
+	clear_bit(FSCACHE_OBJECT_EV_REQUEUE, &object->events);
+}
+
+/*
+ * describe an object for slow-work debugging
+ */
+#ifdef CONFIG_SLOW_WORK_PROC
+static void fscache_object_slow_work_desc(struct slow_work *work,
+					  struct seq_file *m)
+{
+	struct fscache_object *object =
+		container_of(work, struct fscache_object, work);
+
+	seq_printf(m, "FSC: OBJ%x: %s",
+		   object->debug_id,
+		   fscache_object_states_short[object->state]);
 }
+#endif
 
 /*
  * initialise an object
@@ -376,7 +428,9 @@ static void fscache_initialise_object(struct fscache_object *object)
 			 * binding on to us, so we need to make sure we don't
 			 * add ourself to the list multiple times */
 			if (list_empty(&object->dep_link)) {
+				fscache_stat(&fscache_n_cop_grab_object);
 				object->cache->ops->grab_object(object);
+				fscache_stat_d(&fscache_n_cop_grab_object);
 				list_add(&object->dep_link,
 					 &parent->dependents);
 
@@ -414,6 +468,7 @@ static void fscache_lookup_object(struct fscache_object *object)
 {
 	struct fscache_cookie *cookie = object->cookie;
 	struct fscache_object *parent;
+	int ret;
 
 	_enter("");
 
@@ -438,11 +493,20 @@ static void fscache_lookup_object(struct fscache_object *object)
 	       object->cache->tag->name);
 
 	fscache_stat(&fscache_n_object_lookups);
-	object->cache->ops->lookup_object(object);
+	fscache_stat(&fscache_n_cop_lookup_object);
+	ret = object->cache->ops->lookup_object(object);
+	fscache_stat_d(&fscache_n_cop_lookup_object);
 
 	if (test_bit(FSCACHE_OBJECT_EV_ERROR, &object->events))
 		set_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
 
+	if (ret == -ETIMEDOUT) {
+		/* probably stuck behind another object, so move this one to
+		 * the back of the queue */
+		fscache_stat(&fscache_n_object_lookups_timed_out);
+		set_bit(FSCACHE_OBJECT_EV_REQUEUE, &object->events);
+	}
+
 	_leave("");
 }
 
@@ -546,7 +610,8 @@ static void fscache_object_available(struct fscache_object *object)
 
 	spin_lock(&object->lock);
 
-	if (test_and_clear_bit(FSCACHE_COOKIE_CREATING, &object->cookie->flags))
+	if (object->cookie &&
+	    test_and_clear_bit(FSCACHE_COOKIE_CREATING, &object->cookie->flags))
 		wake_up_bit(&object->cookie->flags, FSCACHE_COOKIE_CREATING);
 
 	fscache_done_parent_op(object);
@@ -562,7 +627,9 @@ static void fscache_object_available(struct fscache_object *object)
 	}
 	spin_unlock(&object->lock);
 
+	fscache_stat(&fscache_n_cop_lookup_complete);
 	object->cache->ops->lookup_complete(object);
+	fscache_stat_d(&fscache_n_cop_lookup_complete);
 	fscache_enqueue_dependents(object);
 
 	fscache_hist(fscache_obj_instantiate_histogram, object->lookup_jif);
@@ -581,11 +648,16 @@ static void fscache_drop_object(struct fscache_object *object)
 
 	_enter("{OBJ%x,%d}", object->debug_id, object->n_children);
 
+	ASSERTCMP(object->cookie, ==, NULL);
+	ASSERT(hlist_unhashed(&object->cookie_link));
+
 	spin_lock(&cache->object_list_lock);
 	list_del_init(&object->cache_link);
 	spin_unlock(&cache->object_list_lock);
 
+	fscache_stat(&fscache_n_cop_drop_object);
 	cache->ops->drop_object(object);
+	fscache_stat_d(&fscache_n_cop_drop_object);
 
 	if (parent) {
 		_debug("release parent OBJ%x {%d}",
@@ -600,7 +672,9 @@ static void fscache_drop_object(struct fscache_object *object)
 	}
 
 	/* this just shifts the object release to the slow work processor */
+	fscache_stat(&fscache_n_cop_put_object);
 	object->cache->ops->put_object(object);
+	fscache_stat_d(&fscache_n_cop_put_object);
 
 	_leave("");
 }
@@ -690,8 +764,12 @@ static int fscache_object_slow_work_get_ref(struct slow_work *work)
 {
 	struct fscache_object *object =
 		container_of(work, struct fscache_object, work);
+	int ret;
 
-	return object->cache->ops->grab_object(object) ? 0 : -EAGAIN;
+	fscache_stat(&fscache_n_cop_grab_object);
+	ret = object->cache->ops->grab_object(object) ? 0 : -EAGAIN;
+	fscache_stat_d(&fscache_n_cop_grab_object);
+	return ret;
 }
 
 /*
@@ -702,7 +780,9 @@ static void fscache_object_slow_work_put_ref(struct slow_work *work)
 	struct fscache_object *object =
 		container_of(work, struct fscache_object, work);
 
-	return object->cache->ops->put_object(object);
+	fscache_stat(&fscache_n_cop_put_object);
+	object->cache->ops->put_object(object);
+	fscache_stat_d(&fscache_n_cop_put_object);
 }
 
 /*
@@ -739,7 +819,9 @@ static void fscache_enqueue_dependents(struct fscache_object *object)
 
 		/* sort onto appropriate lists */
 		fscache_enqueue_object(dep);
+		fscache_stat(&fscache_n_cop_put_object);
 		dep->cache->ops->put_object(dep);
+		fscache_stat_d(&fscache_n_cop_put_object);
 
 		if (!list_empty(&object->dependents))
 			cond_resched_lock(&object->lock);