path: root/5000_BFQ-4-block-Switch-from-BFQ-v6r2-for-3.11.0-to-BFQ-v6r2-fo.patch

From 2e1646d06515b7dd1344db547dfcf9a4640dee8e Mon Sep 17 00:00:00 2001
From: Arianna Avanzini <avanzini.arianna@gmail.com>
Date: Wed, 11 Sep 2013 22:26:47 +0200
Subject: [PATCH] block: Switch from BFQ-v6r2 for 3.11.0 to BFQ-v6r2 for
 3.12.0-rc1

---
 block/bfq-cgroup.c | 115 +++++++++++++++++++++++++++++++----------------------
 block/bfq.h        |   2 +
 2 files changed, 70 insertions(+), 47 deletions(-)

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index bb9b851..afae4ca 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -16,9 +16,9 @@
 
 static DEFINE_MUTEX(bfqio_mutex);
 
-static bool bfqio_is_removed(struct cgroup *cgroup)
+static bool bfqio_is_removed(struct bfqio_cgroup *bgrp)
 {
-	return test_bit(CGRP_DEAD, &cgroup->flags);
+	return bgrp ? !bgrp->online : false;
 }
 
 static struct bfqio_cgroup bfqio_root_cgroup = {
@@ -38,10 +38,9 @@ static inline void bfq_init_entity(struct bfq_entity *entity,
 	entity->sched_data = &bfqg->sched_data;
 }
 
-static struct bfqio_cgroup *cgroup_to_bfqio(struct cgroup *cgroup)
+static struct bfqio_cgroup *css_to_bfqio(struct cgroup_subsys_state *css)
 {
-	return container_of(cgroup_subsys_state(cgroup, bfqio_subsys_id),
-			    struct bfqio_cgroup, css);
+	return css ? container_of(css, struct bfqio_cgroup, css) : NULL;
 }
 
 /*
@@ -103,20 +102,20 @@ static inline void bfq_group_set_parent(struct bfq_group *bfqg,
 /**
  * bfq_group_chain_alloc - allocate a chain of groups.
  * @bfqd: queue descriptor.
- * @cgroup: the leaf cgroup this chain starts from.
+ * @css: the leaf cgroup_subsys_state this chain starts from.
  *
  * Allocate a chain of groups starting from the one belonging to
  * @cgroup up to the root cgroup.  Stop if a cgroup on the chain
  * to the root has already an allocated group on @bfqd.
  */
 static struct bfq_group *bfq_group_chain_alloc(struct bfq_data *bfqd,
-					       struct cgroup *cgroup)
+					       struct cgroup_subsys_state *css)
 {
 	struct bfqio_cgroup *bgrp;
 	struct bfq_group *bfqg, *prev = NULL, *leaf = NULL;
 
-	for (; cgroup != NULL; cgroup = cgroup->parent) {
-		bgrp = cgroup_to_bfqio(cgroup);
+	for (; css != NULL; css = css->parent) {
+		bgrp = css_to_bfqio(css);
 
 		bfqg = bfqio_lookup_group(bgrp, bfqd);
 		if (bfqg != NULL) {
@@ -165,7 +164,7 @@ cleanup:
 /**
  * bfq_group_chain_link - link an allocatd group chain to a cgroup hierarchy.
  * @bfqd: the queue descriptor.
- * @cgroup: the leaf cgroup to start from.
+ * @css: the leaf cgroup_subsys_state to start from.
  * @leaf: the leaf group (to be associated to @cgroup).
  *
  * Try to link a chain of groups to a cgroup hierarchy, connecting the
@@ -177,7 +176,8 @@ cleanup:
  * per device) while the bfqio_cgroup lock protects the list of groups
  * belonging to the same cgroup.
  */
-static void bfq_group_chain_link(struct bfq_data *bfqd, struct cgroup *cgroup,
+static void bfq_group_chain_link(struct bfq_data *bfqd,
+				 struct cgroup_subsys_state *css,
 				 struct bfq_group *leaf)
 {
 	struct bfqio_cgroup *bgrp;
@@ -186,8 +186,8 @@ static void bfq_group_chain_link(struct bfq_data *bfqd, struct cgroup *cgroup,
 
 	assert_spin_locked(bfqd->queue->queue_lock);
 
-	for (; cgroup != NULL && leaf != NULL; cgroup = cgroup->parent) {
-		bgrp = cgroup_to_bfqio(cgroup);
+	for (; css != NULL && leaf != NULL; css = css->parent) {
+		bgrp = css_to_bfqio(css);
 		next = leaf->bfqd;
 
 		bfqg = bfqio_lookup_group(bgrp, bfqd);
@@ -205,9 +205,9 @@ static void bfq_group_chain_link(struct bfq_data *bfqd, struct cgroup *cgroup,
 		leaf = next;
 	}
 
-	BUG_ON(cgroup == NULL && leaf != NULL);
-	if (cgroup != NULL && prev != NULL) {
-		bgrp = cgroup_to_bfqio(cgroup);
+	BUG_ON(css == NULL && leaf != NULL);
+	if (css != NULL && prev != NULL) {
+		bgrp = css_to_bfqio(css);
 		bfqg = bfqio_lookup_group(bgrp, bfqd);
 		bfq_group_set_parent(prev, bfqg);
 	}
@@ -233,18 +233,18 @@ static void bfq_group_chain_link(struct bfq_data *bfqd, struct cgroup *cgroup,
  * have been successful.
  */
 static struct bfq_group *bfq_find_alloc_group(struct bfq_data *bfqd,
-					      struct cgroup *cgroup)
+					      struct cgroup_subsys_state *css)
 {
-	struct bfqio_cgroup *bgrp = cgroup_to_bfqio(cgroup);
+	struct bfqio_cgroup *bgrp = css_to_bfqio(css);
 	struct bfq_group *bfqg;
 
 	bfqg = bfqio_lookup_group(bgrp, bfqd);
 	if (bfqg != NULL)
 		return bfqg;
 
-	bfqg = bfq_group_chain_alloc(bfqd, cgroup);
+	bfqg = bfq_group_chain_alloc(bfqd, css);
 	if (bfqg != NULL)
-		bfq_group_chain_link(bfqd, cgroup, bfqg);
+		bfq_group_chain_link(bfqd, css, bfqg);
 	else
 		bfqg = bfqd->root_group;
 
@@ -315,8 +315,8 @@ static void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq,
  * time here, at the price of slightly more complex code.
  */
 static struct bfq_group *__bfq_bic_change_cgroup(struct bfq_data *bfqd,
-						 struct bfq_io_cq *bic,
-						 struct cgroup *cgroup)
+						struct bfq_io_cq *bic,
+						struct cgroup_subsys_state *css)
 {
 	struct bfq_queue *async_bfqq = bic_to_bfqq(bic, 0);
 	struct bfq_queue *sync_bfqq = bic_to_bfqq(bic, 1);
@@ -324,9 +324,9 @@ static struct bfq_group *__bfq_bic_change_cgroup(struct bfq_data *bfqd,
 	struct bfq_group *bfqg;
 	struct bfqio_cgroup *bgrp;
 
-	bgrp = cgroup_to_bfqio(cgroup);
+	bgrp = css_to_bfqio(css);
 
-	bfqg = bfq_find_alloc_group(bfqd, cgroup);
+	bfqg = bfq_find_alloc_group(bfqd, css);
 	if (async_bfqq != NULL) {
 		entity = &async_bfqq->entity;
 
@@ -357,14 +357,14 @@ static struct bfq_group *__bfq_bic_change_cgroup(struct bfq_data *bfqd,
  * moved into its new parent group.
  */
 static void bfq_bic_change_cgroup(struct bfq_io_cq *bic,
-				  struct cgroup *cgroup)
+				  struct cgroup_subsys_state *css)
 {
 	struct bfq_data *bfqd;
 	unsigned long uninitialized_var(flags);
 
 	bfqd = bfq_get_bfqd_locked(&(bic->icq.q->elevator->elevator_data), &flags);
 	if (bfqd != NULL) {
-		__bfq_bic_change_cgroup(bfqd, bic, cgroup);
+		__bfq_bic_change_cgroup(bfqd, bic, css);
 		bfq_put_bfqd_unlock(bfqd, &flags);
 	}
 }
@@ -394,13 +394,13 @@ static struct bfq_group *bfq_bic_update_cgroup(struct bfq_io_cq *bic)
 {
 	struct bfq_data *bfqd = bic_to_bfqd(bic);
 	struct bfq_group *bfqg;
-	struct cgroup *cgroup;
+	struct cgroup_subsys_state *css;
 
 	BUG_ON(bfqd == NULL);
 
 	rcu_read_lock();
-	cgroup = task_cgroup(current, bfqio_subsys_id);
-	bfqg = __bfq_bic_change_cgroup(bfqd, bic, cgroup);
+	css = task_css(current, bfqio_subsys_id);
+	bfqg = __bfq_bic_change_cgroup(bfqd, bic, css);
 	rcu_read_unlock();
 
 	return bfqg;
@@ -622,17 +622,16 @@ static struct bfq_group *bfq_alloc_root_group(struct bfq_data *bfqd, int node)
 }
 
 #define SHOW_FUNCTION(__VAR)						\
-static u64 bfqio_cgroup_##__VAR##_read(struct cgroup *cgroup,		\
+static u64 bfqio_cgroup_##__VAR##_read(struct cgroup_subsys_state *css, \
 				       struct cftype *cftype)		\
 {									\
-	struct bfqio_cgroup *bgrp;					\
+	struct bfqio_cgroup *bgrp = css_to_bfqio(css);			\
 	u64 ret = -ENODEV;						\
 									\
 	mutex_lock(&bfqio_mutex);					\
-	if (bfqio_is_removed(cgroup))					\
+	if (bfqio_is_removed(bgrp))					\
 		goto out_unlock;					\
 									\
-	bgrp = cgroup_to_bfqio(cgroup);					\
 	spin_lock_irq(&bgrp->lock);					\
 	ret = bgrp->__VAR;						\
 	spin_unlock_irq(&bgrp->lock);					\
@@ -648,11 +647,11 @@ SHOW_FUNCTION(ioprio_class);
 #undef SHOW_FUNCTION
 
 #define STORE_FUNCTION(__VAR, __MIN, __MAX)				\
-static int bfqio_cgroup_##__VAR##_write(struct cgroup *cgroup,		\
+static int bfqio_cgroup_##__VAR##_write(struct cgroup_subsys_state *css,\
 					struct cftype *cftype,		\
 					u64 val)			\
 {									\
-	struct bfqio_cgroup *bgrp;					\
+	struct bfqio_cgroup *bgrp = css_to_bfqio(css);			\
 	struct bfq_group *bfqg;						\
 	int ret = -EINVAL;						\
 									\
@@ -661,12 +660,10 @@ static int bfqio_cgroup_##__VAR##_write(struct cgroup *cgroup,		\
 									\
 	ret = -ENODEV;							\
 	mutex_lock(&bfqio_mutex);					\
-	if (bfqio_is_removed(cgroup))					\
+	if (bfqio_is_removed(bgrp))					\
 		goto out_unlock;					\
 	ret = 0;							\
 									\
-	bgrp = cgroup_to_bfqio(cgroup);					\
-									\
 	spin_lock_irq(&bgrp->lock);					\
 	bgrp->__VAR = (unsigned short)val;				\
 	hlist_for_each_entry(bfqg, &bgrp->group_data, group_node) {	\
@@ -713,11 +710,11 @@ static struct cftype bfqio_files[] = {
 	{ },	/* terminate */
 };
 
-static struct cgroup_subsys_state *bfqio_create(struct cgroup *cgroup)
+static struct cgroup_subsys_state *bfqio_create(struct cgroup_subsys_state *parent_css)
 {
 	struct bfqio_cgroup *bgrp;
 
-	if (cgroup->parent != NULL) {
+	if (parent_css != NULL) {
 		bgrp = kzalloc(sizeof(*bgrp), GFP_KERNEL);
 		if (bgrp == NULL)
 			return ERR_PTR(-ENOMEM);
@@ -740,13 +737,14 @@ static struct cgroup_subsys_state *bfqio_create(struct cgroup *cgroup)
  * behavior is that a group containing a task that forked using CLONE_IO
  * will not be destroyed until the tasks sharing the ioc die.
  */
-static int bfqio_can_attach(struct cgroup *cgroup, struct cgroup_taskset *tset)
+static int bfqio_can_attach(struct cgroup_subsys_state *css,
+			    struct cgroup_taskset *tset)
 {
 	struct task_struct *task;
 	struct io_context *ioc;
 	int ret = 0;
 
-	cgroup_taskset_for_each(task, cgroup, tset) {
+	cgroup_taskset_for_each(task, css, tset) {
 		/* task_lock() is needed to avoid races with exit_io_context() */
 		task_lock(task);
 		ioc = task->io_context;
@@ -766,7 +764,8 @@ static int bfqio_can_attach(struct cgroup *cgroup, struct cgroup_taskset *tset)
 	return ret;
 }
 
-static void bfqio_attach(struct cgroup *cgroup, struct cgroup_taskset *tset)
+static void bfqio_attach(struct cgroup_subsys_state *css,
+			 struct cgroup_taskset *tset)
 {
 	struct task_struct *task;
 	struct io_context *ioc;
@@ -776,7 +775,7 @@ static void bfqio_attach(struct cgroup *cgroup, struct cgroup_taskset *tset)
 	 * IMPORTANT NOTE: The move of more than one process at a time to a
 	 * new group has not yet been tested.
 	 */
-	cgroup_taskset_for_each(task, cgroup, tset) {
+	cgroup_taskset_for_each(task, css, tset) {
 		ioc = get_task_io_context(task, GFP_ATOMIC, NUMA_NO_NODE);
 		if (ioc) {
 			/*
@@ -787,16 +786,16 @@ static void bfqio_attach(struct cgroup *cgroup, struct cgroup_taskset *tset)
 				if (!strncmp(icq->q->elevator->type->elevator_name,
 					     "bfq", ELV_NAME_MAX))
 					bfq_bic_change_cgroup(icq_to_bic(icq),
-							      cgroup);
+							      css);
 			rcu_read_unlock();
 			put_io_context(ioc);
 		}
 	}
 }
 
-static void bfqio_destroy(struct cgroup *cgroup)
+static void bfqio_destroy(struct cgroup_subsys_state *css)
 {
-	struct bfqio_cgroup *bgrp = cgroup_to_bfqio(cgroup);
+	struct bfqio_cgroup *bgrp = css_to_bfqio(css);
 	struct hlist_node *tmp;
 	struct bfq_group *bfqg;
 
@@ -815,9 +814,31 @@ static void bfqio_destroy(struct cgroup *cgroup)
 	kfree(bgrp);
 }
 
+static int bfqio_css_online(struct cgroup_subsys_state *css)
+{
+	struct bfqio_cgroup *bgrp = css_to_bfqio(css);
+
+	mutex_lock(&bfqio_mutex);
+	bgrp->online = true;
+	mutex_unlock(&bfqio_mutex);
+
+	return 0;
+}
+
+static void bfqio_css_offline(struct cgroup_subsys_state *css)
+{
+	struct bfqio_cgroup *bgrp = css_to_bfqio(css);
+
+	mutex_lock(&bfqio_mutex);
+	bgrp->online = false;
+	mutex_unlock(&bfqio_mutex);
+}
+
 struct cgroup_subsys bfqio_subsys = {
 	.name = "bfqio",
 	.css_alloc = bfqio_create,
+	.css_online = bfqio_css_online,
+	.css_offline = bfqio_css_offline,
 	.can_attach = bfqio_can_attach,
 	.attach = bfqio_attach,
 	.css_free = bfqio_destroy,
diff --git a/block/bfq.h b/block/bfq.h
index bb52975..885e62c 100644
--- a/block/bfq.h
+++ b/block/bfq.h
@@ -510,6 +510,7 @@ struct bfq_group {
 /**
  * struct bfqio_cgroup - bfq cgroup data structure.
  * @css: subsystem state for bfq in the containing cgroup.
+ * @online: flag marked when the subsystem is inserted.
  * @weight: cgroup weight.
  * @ioprio: cgroup ioprio.
  * @ioprio_class: cgroup ioprio_class.
@@ -521,6 +522,7 @@ struct bfq_group {
  */
 struct bfqio_cgroup {
 	struct cgroup_subsys_state css;
+	bool online;
 
 	unsigned short weight, ioprio, ioprio_class;
 
-- 
1.8.1.4