Merge branch 'v2.6.37-rc2' into for-2.6.38/core

25 files changed, 2424 insertions, 770 deletions

diff --git a/block/Kconfig b/block/Kconfig
index 9be0b56eaee..6c9213ef15a 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -77,6 +77,18 @@ config BLK_DEV_INTEGRITY
 	T10/SCSI Data Integrity Field or the T13/ATA External Path
 	Protection.  If in doubt, say N.
 
+config BLK_DEV_THROTTLING
+	bool "Block layer bio throttling support"
+	depends on BLK_CGROUP=y && EXPERIMENTAL
+	default n
+	---help---
+	Block layer bio throttling support. It can be used to limit
+	the IO rate to a device. IO rate policies are per cgroup and
+	one needs to mount and use blkio cgroup controller for creating
+	cgroups and specifying per device IO rate policies.
+
+	See Documentation/cgroups/blkio-controller.txt for more information.
+
 endif # BLOCK
 
 config BLOCK_COMPAT
diff --git a/block/Makefile b/block/Makefile
index 0bb499a739c..0fec4b3fab5 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -3,12 +3,13 @@
 #
 
 obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \
-			blk-barrier.o blk-settings.o blk-ioc.o blk-map.o \
+			blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
 			blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
 			blk-iopoll.o blk-lib.o ioctl.o genhd.o scsi_ioctl.o
 
 obj-$(CONFIG_BLK_DEV_BSG)	+= bsg.o
 obj-$(CONFIG_BLK_CGROUP)	+= blk-cgroup.o
+obj-$(CONFIG_BLK_DEV_THROTTLING)	+= blk-throttle.o
 obj-$(CONFIG_IOSCHED_NOOP)	+= noop-iosched.o
 obj-$(CONFIG_IOSCHED_DEADLINE)	+= deadline-iosched.o
 obj-$(CONFIG_IOSCHED_CFQ)	+= cfq-iosched.o
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
deleted file mode 100644
index f0faefca032..00000000000
--- a/block/blk-barrier.c
+++ /dev/null
@@ -1,350 +0,0 @@
-/*
- * Functions related to barrier IO handling
- */
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/bio.h>
-#include <linux/blkdev.h>
-#include <linux/gfp.h>
-
-#include "blk.h"
-
-/**
- * blk_queue_ordered - does this queue support ordered writes
- * @q:        the request queue
- * @ordered:  one of QUEUE_ORDERED_*
- *
- * Description:
- *   For journalled file systems, doing ordered writes on a commit
- *   block instead of explicitly doing wait_on_buffer (which is bad
- *   for performance) can be a big win. Block drivers supporting this
- *   feature should call this function and indicate so.
- *
- **/
-int blk_queue_ordered(struct request_queue *q, unsigned ordered)
-{
-	if (ordered != QUEUE_ORDERED_NONE &&
-	    ordered != QUEUE_ORDERED_DRAIN &&
-	    ordered != QUEUE_ORDERED_DRAIN_FLUSH &&
-	    ordered != QUEUE_ORDERED_DRAIN_FUA &&
-	    ordered != QUEUE_ORDERED_TAG &&
-	    ordered != QUEUE_ORDERED_TAG_FLUSH &&
-	    ordered != QUEUE_ORDERED_TAG_FUA) {
-		printk(KERN_ERR "blk_queue_ordered: bad value %d\n", ordered);
-		return -EINVAL;
-	}
-
-	q->ordered = ordered;
-	q->next_ordered = ordered;
-
-	return 0;
-}
-EXPORT_SYMBOL(blk_queue_ordered);
-
-/*
- * Cache flushing for ordered writes handling
- */
-unsigned blk_ordered_cur_seq(struct request_queue *q)
-{
-	if (!q->ordseq)
-		return 0;
-	return 1 << ffz(q->ordseq);
-}
-
-unsigned blk_ordered_req_seq(struct request *rq)
-{
-	struct request_queue *q = rq->q;
-
-	BUG_ON(q->ordseq == 0);
-
-	if (rq == &q->pre_flush_rq)
-		return QUEUE_ORDSEQ_PREFLUSH;
-	if (rq == &q->bar_rq)
-		return QUEUE_ORDSEQ_BAR;
-	if (rq == &q->post_flush_rq)
-		return QUEUE_ORDSEQ_POSTFLUSH;
-
-	/*
-	 * !fs requests don't need to follow barrier ordering.  Always
-	 * put them at the front.  This fixes the following deadlock.
-	 *
-	 * http://thread.gmane.org/gmane.linux.kernel/537473
-	 */
-	if (rq->cmd_type != REQ_TYPE_FS)
-		return QUEUE_ORDSEQ_DRAIN;
-
-	if ((rq->cmd_flags & REQ_ORDERED_COLOR) ==
-	    (q->orig_bar_rq->cmd_flags & REQ_ORDERED_COLOR))
-		return QUEUE_ORDSEQ_DRAIN;
-	else
-		return QUEUE_ORDSEQ_DONE;
-}
-
-bool blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error)
-{
-	struct request *rq;
-
-	if (error && !q->orderr)
-		q->orderr = error;
-
-	BUG_ON(q->ordseq & seq);
-	q->ordseq |= seq;
-
-	if (blk_ordered_cur_seq(q) != QUEUE_ORDSEQ_DONE)
-		return false;
-
-	/*
-	 * Okay, sequence complete.
-	 */
-	q->ordseq = 0;
-	rq = q->orig_bar_rq;
-	__blk_end_request_all(rq, q->orderr);
-	return true;
-}
-
-static void pre_flush_end_io(struct request *rq, int error)
-{
-	elv_completed_request(rq->q, rq);
-	blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_PREFLUSH, error);
-}
-
-static void bar_end_io(struct request *rq, int error)
-{
-	elv_completed_request(rq->q, rq);
-	blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_BAR, error);
-}
-
-static void post_flush_end_io(struct request *rq, int error)
-{
-	elv_completed_request(rq->q, rq);
-	blk_ordered_complete_seq(rq->q, QUEUE_ORDSEQ_POSTFLUSH, error);
-}
-
-static void queue_flush(struct request_queue *q, unsigned which)
-{
-	struct request *rq;
-	rq_end_io_fn *end_io;
-
-	if (which == QUEUE_ORDERED_DO_PREFLUSH) {
-		rq = &q->pre_flush_rq;
-		end_io = pre_flush_end_io;
-	} else {
-		rq = &q->post_flush_rq;
-		end_io = post_flush_end_io;
-	}
-
-	blk_rq_init(q, rq);
-	rq->cmd_type = REQ_TYPE_FS;
-	rq->cmd_flags = REQ_HARDBARRIER | REQ_FLUSH;
-	rq->rq_disk = q->orig_bar_rq->rq_disk;
-	rq->end_io = end_io;
-
-	elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
-}
-
-static inline bool start_ordered(struct request_queue *q, struct request **rqp)
-{
-	struct request *rq = *rqp;
-	unsigned skip = 0;
-
-	q->orderr = 0;
-	q->ordered = q->next_ordered;
-	q->ordseq |= QUEUE_ORDSEQ_STARTED;
-
-	/*
-	 * For an empty barrier, there's no actual BAR request, which
-	 * in turn makes POSTFLUSH unnecessary.  Mask them off.
-	 */
-	if (!blk_rq_sectors(rq)) {
-		q->ordered &= ~(QUEUE_ORDERED_DO_BAR |
-				QUEUE_ORDERED_DO_POSTFLUSH);
-		/*
-		 * Empty barrier on a write-through device w/ ordered
-		 * tag has no command to issue and without any command
-		 * to issue, ordering by tag can't be used.  Drain
-		 * instead.
-		 */
-		if ((q->ordered & QUEUE_ORDERED_BY_TAG) &&
-		    !(q->ordered & QUEUE_ORDERED_DO_PREFLUSH)) {
-			q->ordered &= ~QUEUE_ORDERED_BY_TAG;
-			q->ordered |= QUEUE_ORDERED_BY_DRAIN;
-		}
-	}
-
-	/* stash away the original request */
-	blk_dequeue_request(rq);
-	q->orig_bar_rq = rq;
-	rq = NULL;
-
-	/*
-	 * Queue ordered sequence.  As we stack them at the head, we
-	 * need to queue in reverse order.  Note that we rely on that
-	 * no fs request uses ELEVATOR_INSERT_FRONT and thus no fs
-	 * request gets inbetween ordered sequence.
-	 */
-	if (q->ordered & QUEUE_ORDERED_DO_POSTFLUSH) {
-		queue_flush(q, QUEUE_ORDERED_DO_POSTFLUSH);
-		rq = &q->post_flush_rq;
-	} else
-		skip |= QUEUE_ORDSEQ_POSTFLUSH;
-
-	if (q->ordered & QUEUE_ORDERED_DO_BAR) {
-		rq = &q->bar_rq;
-
-		/* initialize proxy request and queue it */
-		blk_rq_init(q, rq);
-		if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)
-			rq->cmd_flags |= REQ_WRITE;
-		if (q->ordered & QUEUE_ORDERED_DO_FUA)
-			rq->cmd_flags |= REQ_FUA;
-		init_request_from_bio(rq, q->orig_bar_rq->bio);
-		rq->end_io = bar_end_io;
-
-		elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
-	} else
-		skip |= QUEUE_ORDSEQ_BAR;
-
-	if (q->ordered & QUEUE_ORDERED_DO_PREFLUSH) {
-		queue_flush(q, QUEUE_ORDERED_DO_PREFLUSH);
-		rq = &q->pre_flush_rq;
-	} else
-		skip |= QUEUE_ORDSEQ_PREFLUSH;
-
-	if ((q->ordered & QUEUE_ORDERED_BY_DRAIN) && queue_in_flight(q))
-		rq = NULL;
-	else
-		skip |= QUEUE_ORDSEQ_DRAIN;
-
-	*rqp = rq;
-
-	/*
-	 * Complete skipped sequences.  If whole sequence is complete,
-	 * return false to tell elevator that this request is gone.
-	 */
-	return !blk_ordered_complete_seq(q, skip, 0);
-}
-
-bool blk_do_ordered(struct request_queue *q, struct request **rqp)
-{
-	struct request *rq = *rqp;
-	const int is_barrier = rq->cmd_type == REQ_TYPE_FS &&
-				(rq->cmd_flags & REQ_HARDBARRIER);
-
-	if (!q->ordseq) {
-		if (!is_barrier)
-			return true;
-
-		if (q->next_ordered != QUEUE_ORDERED_NONE)
-			return start_ordered(q, rqp);
-		else {
-			/*
-			 * Queue ordering not supported.  Terminate
-			 * with prejudice.
-			 */
-			blk_dequeue_request(rq);
-			__blk_end_request_all(rq, -EOPNOTSUPP);
-			*rqp = NULL;
-			return false;
-		}
-	}
-
-	/*
-	 * Ordered sequence in progress
-	 */
-
-	/* Special requests are not subject to ordering rules. */
-	if (rq->cmd_type != REQ_TYPE_FS &&
-	    rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
-		return true;
-
-	if (q->ordered & QUEUE_ORDERED_BY_TAG) {
-		/* Ordered by tag.  Blocking the next barrier is enough. */
-		if (is_barrier && rq != &q->bar_rq)
-			*rqp = NULL;
-	} else {
-		/* Ordered by draining.  Wait for turn. */
-		WARN_ON(blk_ordered_req_seq(rq) < blk_ordered_cur_seq(q));
-		if (blk_ordered_req_seq(rq) > blk_ordered_cur_seq(q))
-			*rqp = NULL;
-	}
-
-	return true;
-}
-
-static void bio_end_empty_barrier(struct bio *bio, int err)
-{
-	if (err) {
-		if (err == -EOPNOTSUPP)
-			set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
-		clear_bit(BIO_UPTODATE, &bio->bi_flags);
-	}
-	if (bio->bi_private)
-		complete(bio->bi_private);
-	bio_put(bio);
-}
-
-/**
- * blkdev_issue_flush - queue a flush
- * @bdev:	blockdev to issue flush for
- * @gfp_mask:	memory allocation flags (for bio_alloc)
- * @error_sector:	error sector
- * @flags:	BLKDEV_IFL_* flags to control behaviour
- *
- * Description:
- *    Issue a flush for the block device in question. Caller can supply
- *    room for storing the error offset in case of a flush error, if they
- *    wish to. If WAIT flag is not passed then caller may check only what
- *    request was pushed in some internal queue for later handling.
- */
-int blkdev_issue_flush(struct block_device *bdev, gfp_t gfp_mask,
-		sector_t *error_sector, unsigned long flags)
-{
-	DECLARE_COMPLETION_ONSTACK(wait);
-	struct request_queue *q;
-	struct bio *bio;
-	int ret = 0;
-
-	if (bdev->bd_disk == NULL)
-		return -ENXIO;
-
-	q = bdev_get_queue(bdev);
-	if (!q)
-		return -ENXIO;
-
-	/*
-	 * some block devices may not have their queue correctly set up here
-	 * (e.g. loop device without a backing file) and so issuing a flush
-	 * here will panic. Ensure there is a request function before issuing
-	 * the barrier.
-	 */
-	if (!q->make_request_fn)
-		return -ENXIO;
-
-	bio = bio_alloc(gfp_mask, 0);
-	bio->bi_end_io = bio_end_empty_barrier;
-	bio->bi_bdev = bdev;
-	if (test_bit(BLKDEV_WAIT, &flags))
-		bio->bi_private = &wait;
-
-	bio_get(bio);
-	submit_bio(WRITE_BARRIER, bio);
-	if (test_bit(BLKDEV_WAIT, &flags)) {
-		wait_for_completion(&wait);
-		/*
-		 * The driver must store the error location in ->bi_sector, if
-		 * it supports it. For non-stacked drivers, this should be
-		 * copied from blk_rq_pos(rq).
-		 */
-		if (error_sector)
-			*error_sector = bio->bi_sector;
-	}
-
-	if (bio_flagged(bio, BIO_EOPNOTSUPP))
-		ret = -EOPNOTSUPP;
-	else if (!bio_flagged(bio, BIO_UPTODATE))
-		ret = -EIO;
-
-	bio_put(bio);
-	return ret;
-}
-EXPORT_SYMBOL(blkdev_issue_flush);
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 2fef1ef931a..b1febd0f6d2 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -37,6 +37,12 @@ static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *,
 static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *);
 static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *);
 
+/* for encoding cft->private value on file */
+#define BLKIOFILE_PRIVATE(x, val)	(((x) << 16) | (val))
+/* What policy owns the file, proportional or throttle */
+#define BLKIOFILE_POLICY(val)		(((val) >> 16) & 0xffff)
+#define BLKIOFILE_ATTR(val)		((val) & 0xffff)
+
 struct cgroup_subsys blkio_subsys = {
 	.name = "blkio",
 	.create = blkiocg_create,
@@ -59,6 +65,27 @@ static inline void blkio_policy_insert_node(struct blkio_cgroup *blkcg,
 	list_add(&pn->node, &blkcg->policy_list);
 }
 
+static inline bool cftype_blkg_same_policy(struct cftype *cft,
+			struct blkio_group *blkg)
+{
+	enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+
+	if (blkg->plid == plid)
+		return 1;
+
+	return 0;
+}
+
+/* Determines if policy node matches cgroup file being accessed */
+static inline bool pn_matches_cftype(struct cftype *cft,
+			struct blkio_policy_node *pn)
+{
+	enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+	int fileid = BLKIOFILE_ATTR(cft->private);
+
+	return (plid == pn->plid && fileid == pn->fileid);
+}
+
 /* Must be called with blkcg->lock held */
 static inline void blkio_policy_delete_node(struct blkio_policy_node *pn)
 {
@@ -67,12 +94,13 @@ static inline void blkio_policy_delete_node(struct blkio_policy_node *pn)
 
 /* Must be called with blkcg->lock held */
 static struct blkio_policy_node *
-blkio_policy_search_node(const struct blkio_cgroup *blkcg, dev_t dev)
+blkio_policy_search_node(const struct blkio_cgroup *blkcg, dev_t dev,
+		enum blkio_policy_id plid, int fileid)
 {
 	struct blkio_policy_node *pn;
 
 	list_for_each_entry(pn, &blkcg->policy_list, node) {
-		if (pn->dev == dev)
+		if (pn->dev == dev && pn->plid == plid && pn->fileid == fileid)
 			return pn;
 	}
 
@@ -86,6 +114,67 @@ struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup)
 }
 EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup);
 
+static inline void
+blkio_update_group_weight(struct blkio_group *blkg, unsigned int weight)
+{
+	struct blkio_policy_type *blkiop;
+
+	list_for_each_entry(blkiop, &blkio_list, list) {
+		/* If this policy does not own the blkg, do not send updates */
+		if (blkiop->plid != blkg->plid)
+			continue;
+		if (blkiop->ops.blkio_update_group_weight_fn)
+			blkiop->ops.blkio_update_group_weight_fn(blkg->key,
+							blkg, weight);
+	}
+}
+
+static inline void blkio_update_group_bps(struct blkio_group *blkg, u64 bps,
+				int fileid)
+{
+	struct blkio_policy_type *blkiop;
+
+	list_for_each_entry(blkiop, &blkio_list, list) {
+
+		/* If this policy does not own the blkg, do not send updates */
+		if (blkiop->plid != blkg->plid)
+			continue;
+
+		if (fileid == BLKIO_THROTL_read_bps_device
+		    && blkiop->ops.blkio_update_group_read_bps_fn)
+			blkiop->ops.blkio_update_group_read_bps_fn(blkg->key,
+								blkg, bps);
+
+		if (fileid == BLKIO_THROTL_write_bps_device
+		    && blkiop->ops.blkio_update_group_write_bps_fn)
+			blkiop->ops.blkio_update_group_write_bps_fn(blkg->key,
+								blkg, bps);
+	}
+}
+
+static inline void blkio_update_group_iops(struct blkio_group *blkg,
+			unsigned int iops, int fileid)
+{
+	struct blkio_policy_type *blkiop;
+
+	list_for_each_entry(blkiop, &blkio_list, list) {
+
+		/* If this policy does not own the blkg, do not send updates */
+		if (blkiop->plid != blkg->plid)
+			continue;
+
+		if (fileid == BLKIO_THROTL_read_iops_device
+		    && blkiop->ops.blkio_update_group_read_iops_fn)
+			blkiop->ops.blkio_update_group_read_iops_fn(blkg->key,
+								blkg, iops);
+
+		if (fileid == BLKIO_THROTL_write_iops_device
+		    && blkiop->ops.blkio_update_group_write_iops_fn)
+			blkiop->ops.blkio_update_group_write_iops_fn(blkg->key,
+								blkg,iops);
+	}
+}
+
 /*
  * Add to the appropriate stat variable depending on the request type.
  * This should be called with the blkg->stats_lock held.
@@ -341,7 +430,8 @@ void blkiocg_update_io_merged_stats(struct blkio_group *blkg, bool direction,
 EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats);
 
 void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
-			struct blkio_group *blkg, void *key, dev_t dev)
+		struct blkio_group *blkg, void *key, dev_t dev,
+		enum blkio_policy_id plid)
 {
 	unsigned long flags;
 
@@ -350,6 +440,7 @@ void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
 	rcu_assign_pointer(blkg->key, key);
 	blkg->blkcg_id = css_id(&blkcg->css);
 	hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
+	blkg->plid = plid;
 	spin_unlock_irqrestore(&blkcg->lock, flags);
 	/* Need to take css reference ? */
 	cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path));
@@ -408,51 +499,6 @@ struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key)
 }
 EXPORT_SYMBOL_GPL(blkiocg_lookup_group);
 
-#define SHOW_FUNCTION(__VAR)						\
-static u64 blkiocg_##__VAR##_read(struct cgroup *cgroup,		\
-				       struct cftype *cftype)		\
-{									\
-	struct blkio_cgroup *blkcg;					\
-									\
-	blkcg = cgroup_to_blkio_cgroup(cgroup);				\
-	return (u64)blkcg->__VAR;					\
-}
-
-SHOW_FUNCTION(weight);
-#undef SHOW_FUNCTION
-
-static int
-blkiocg_weight_write(struct cgroup *cgroup, struct cftype *cftype, u64 val)
-{
-	struct blkio_cgroup *blkcg;
-	struct blkio_group *blkg;
-	struct hlist_node *n;
-	struct blkio_policy_type *blkiop;
-	struct blkio_policy_node *pn;
-
-	if (val < BLKIO_WEIGHT_MIN || val > BLKIO_WEIGHT_MAX)
-		return -EINVAL;
-
-	blkcg = cgroup_to_blkio_cgroup(cgroup);
-	spin_lock(&blkio_list_lock);
-	spin_lock_irq(&blkcg->lock);
-	blkcg->weight = (unsigned int)val;
-
-	hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
-		pn = blkio_policy_search_node(blkcg, blkg->dev);
-
-		if (pn)
-			continue;
-
-		list_for_each_entry(blkiop, &blkio_list, list)
-			blkiop->ops.blkio_update_group_weight_fn(blkg,
-					blkcg->weight);
-	}
-	spin_unlock_irq(&blkcg->lock);
-	spin_unlock(&blkio_list_lock);
-	return 0;
-}
-
 static int
 blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
 {
@@ -593,52 +639,6 @@ static uint64_t blkio_get_stat(struct blkio_group *blkg,
 	return disk_total;
 }
 
-#define SHOW_FUNCTION_PER_GROUP(__VAR, type, show_total)		\
-static int blkiocg_##__VAR##_read(struct cgroup *cgroup,		\
-		struct cftype *cftype, struct cgroup_map_cb *cb)	\
-{									\
-	struct blkio_cgroup *blkcg;					\
-	struct blkio_group *blkg;					\
-	struct hlist_node *n;						\
-	uint64_t cgroup_total = 0;					\
-									\
-	if (!cgroup_lock_live_group(cgroup))				\
-		return -ENODEV;						\
-									\
-	blkcg = cgroup_to_blkio_cgroup(cgroup);				\
-	rcu_read_lock();						\
-	hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) {\
-		if (blkg->dev) {					\
-			spin_lock_irq(&blkg->stats_lock);		\
-			cgroup_total += blkio_get_stat(blkg, cb,	\
-						blkg->dev, type);	\
-			spin_unlock_irq(&blkg->stats_lock);		\
-		}							\
-	}								\
-	if (show_total)							\
-		cb->fill(cb, "Total", cgroup_total);			\
-	rcu_read_unlock();						\
-	cgroup_unlock();						\
-	return 0;							\
-}
-
-SHOW_FUNCTION_PER_GROUP(time, BLKIO_STAT_TIME, 0);
-SHOW_FUNCTION_PER_GROUP(sectors, BLKIO_STAT_SECTORS, 0);
-SHOW_FUNCTION_PER_GROUP(io_service_bytes, BLKIO_STAT_SERVICE_BYTES, 1);
-SHOW_FUNCTION_PER_GROUP(io_serviced, BLKIO_STAT_SERVICED, 1);
-SHOW_FUNCTION_PER_GROUP(io_service_time, BLKIO_STAT_SERVICE_TIME, 1);
-SHOW_FUNCTION_PER_GROUP(io_wait_time, BLKIO_STAT_WAIT_TIME, 1);
-SHOW_FUNCTION_PER_GROUP(io_merged, BLKIO_STAT_MERGED, 1);
-SHOW_FUNCTION_PER_GROUP(io_queued, BLKIO_STAT_QUEUED, 1);
-#ifdef CONFIG_DEBUG_BLK_CGROUP
-SHOW_FUNCTION_PER_GROUP(dequeue, BLKIO_STAT_DEQUEUE, 0);
-SHOW_FUNCTION_PER_GROUP(avg_queue_size, BLKIO_STAT_AVG_QUEUE_SIZE, 0);
-SHOW_FUNCTION_PER_GROUP(group_wait_time, BLKIO_STAT_GROUP_WAIT_TIME, 0);
-SHOW_FUNCTION_PER_GROUP(idle_time, BLKIO_STAT_IDLE_TIME, 0);
-SHOW_FUNCTION_PER_GROUP(empty_time, BLKIO_STAT_EMPTY_TIME, 0);
-#endif
-#undef SHOW_FUNCTION_PER_GROUP
-
 static int blkio_check_dev_num(dev_t dev)
 {
 	int part = 0;
@@ -652,13 +652,14 @@ static int blkio_check_dev_num(dev_t dev)
 }
 
 static int blkio_policy_parse_and_set(char *buf,
-				      struct blkio_policy_node *newpn)
+	struct blkio_policy_node *newpn, enum blkio_policy_id plid, int fileid)
 {
 	char *s[4], *p, *major_s = NULL, *minor_s = NULL;
 	int ret;
 	unsigned long major, minor, temp;
 	int i = 0;
 	dev_t dev;
+	u64 bps, iops;
 
 	memset(s, 0, sizeof(s));
 
@@ -705,12 +706,47 @@ static int blkio_policy_parse_and_set(char *buf,
 	if (s[1] == NULL)
 		return -EINVAL;
 
-	ret = strict_strtoul(s[1], 10, &temp);
-	if (ret || (temp < BLKIO_WEIGHT_MIN && temp > 0) ||
-	    temp > BLKIO_WEIGHT_MAX)
-		return -EINVAL;
+	switch (plid) {
+	case BLKIO_POLICY_PROP:
+		ret = strict_strtoul(s[1], 10, &temp);
+		if (ret || (temp < BLKIO_WEIGHT_MIN && temp > 0) ||
+			temp > BLKIO_WEIGHT_MAX)
+			return -EINVAL;
 
-	newpn->weight =  temp;
+		newpn->plid = plid;
+		newpn->fileid = fileid;
+		newpn->val.weight = temp;
+		break;
+	case BLKIO_POLICY_THROTL:
+		switch(fileid) {
+		case BLKIO_THROTL_read_bps_device:
+		case BLKIO_THROTL_write_bps_device:
+			ret = strict_strtoull(s[1], 10, &bps);
+			if (ret)
+				return -EINVAL;
+
+			newpn->plid = plid;
+			newpn->fileid = fileid;
+			newpn->val.bps = bps;
+			break;
+		case BLKIO_THROTL_read_iops_device:
+		case BLKIO_THROTL_write_iops_device:
+			ret = strict_strtoull(s[1], 10, &iops);
+			if (ret)
+				return -EINVAL;
+
+			if (iops > THROTL_IOPS_MAX)
+				return -EINVAL;
+
+			newpn->plid = plid;
+			newpn->fileid = fileid;
+			newpn->val.iops = (unsigned int)iops;
+			break;
+		}
+		break;
+	default:
+		BUG();
+	}
 
 	return 0;
 }
@@ -720,26 +756,180 @@ unsigned int blkcg_get_weight(struct blkio_cgroup *blkcg,
 {
 	struct blkio_policy_node *pn;
 
-	pn = blkio_policy_search_node(blkcg, dev);
+	pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_PROP,
+				BLKIO_PROP_weight_device);
 	if (pn)
-		return pn->weight;
+		return pn->val.weight;
 	else
 		return blkcg->weight;
 }
 EXPORT_SYMBOL_GPL(blkcg_get_weight);
 
+uint64_t blkcg_get_read_bps(struct blkio_cgroup *blkcg, dev_t dev)
+{
+	struct blkio_policy_node *pn;
+
+	pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
+				BLKIO_THROTL_read_bps_device);
+	if (pn)
+		return pn->val.bps;
+	else
+		return -1;
+}
+
+uint64_t blkcg_get_write_bps(struct blkio_cgroup *blkcg, dev_t dev)
+{
+	struct blkio_policy_node *pn;
+	pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
+				BLKIO_THROTL_write_bps_device);
+	if (pn)
+		return pn->val.bps;
+	else
+		return -1;
+}
+
+unsigned int blkcg_get_read_iops(struct blkio_cgroup *blkcg, dev_t dev)
+{
+	struct blkio_policy_node *pn;
+
+	pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
+				BLKIO_THROTL_read_iops_device);
+	if (pn)
+		return pn->val.iops;
+	else
+		return -1;
+}
+
+unsigned int blkcg_get_write_iops(struct blkio_cgroup *blkcg, dev_t dev)
+{
+	struct blkio_policy_node *pn;
+	pn = blkio_policy_search_node(blkcg, dev, BLKIO_POLICY_THROTL,
+				BLKIO_THROTL_write_iops_device);
+	if (pn)
+		return pn->val.iops;
+	else
+		return -1;
+}
+
+/* Checks whether user asked for deleting a policy rule */
+static bool blkio_delete_rule_command(struct blkio_policy_node *pn)
+{
+	switch(pn->plid) {
+	case BLKIO_POLICY_PROP:
+		if (pn->val.weight == 0)
+			return 1;
+		break;
+	case BLKIO_POLICY_THROTL:
+		switch(pn->fileid) {
+		case BLKIO_THROTL_read_bps_device:
+		case BLKIO_THROTL_write_bps_device:
+			if (pn->val.bps == 0)
+				return 1;
+			break;
+		case BLKIO_THROTL_read_iops_device:
+		case BLKIO_THROTL_write_iops_device:
+			if (pn->val.iops == 0)
+				return 1;
+		}
+		break;
+	default:
+		BUG();
+	}
+
+	return 0;
+}
+
+static void blkio_update_policy_rule(struct blkio_policy_node *oldpn,
+					struct blkio_policy_node *newpn)
+{
+	switch(oldpn->plid) {
+	case BLKIO_POLICY_PROP:
+		oldpn->val.weight = newpn->val.weight;
+		break;
+	case BLKIO_POLICY_THROTL:
+		switch(newpn->fileid) {
+		case BLKIO_THROTL_read_bps_device:
+		case BLKIO_THROTL_write_bps_device:
+			oldpn->val.bps = newpn->val.bps;
+			break;
+		case BLKIO_THROTL_read_iops_device:
+		case BLKIO_THROTL_write_iops_device:
+			oldpn->val.iops = newpn->val.iops;
+		}
+		break;
+	default:
+		BUG();
+	}
+}
+
+/*
+ * Some rules/values in blkg have changed. Propogate those to respective
+ * policies.
+ */
+static void blkio_update_blkg_policy(struct blkio_cgroup *blkcg,
+		struct blkio_group *blkg, struct blkio_policy_node *pn)
+{
+	unsigned int weight, iops;
+	u64 bps;
+
+	switch(pn->plid) {
+	case BLKIO_POLICY_PROP:
+		weight = pn->val.weight ? pn->val.weight :
+				blkcg->weight;
+		blkio_update_group_weight(blkg, weight);
+		break;
+	case BLKIO_POLICY_THROTL:
+		switch(pn->fileid) {
+		case BLKIO_THROTL_read_bps_device:
+		case BLKIO_THROTL_write_bps_device:
+			bps = pn->val.bps ? pn->val.bps : (-1);
+			blkio_update_group_bps(blkg, bps, pn->fileid);
+			break;
+		case BLKIO_THROTL_read_iops_device:
+		case BLKIO_THROTL_write_iops_device:
+			iops = pn->val.iops ? pn->val.iops : (-1);
+			blkio_update_group_iops(blkg, iops, pn->fileid);
+			break;
+		}
+		break;
+	default:
+		BUG();
+	}
+}
+
+/*
+ * A policy node rule has been updated. Propogate this update to all the
+ * block groups which might be affected by this update.
+ */
+static void blkio_update_policy_node_blkg(struct blkio_cgroup *blkcg,
+				struct blkio_policy_node *pn)
+{
+	struct blkio_group *blkg;
+	struct hlist_node *n;
+
+	spin_lock(&blkio_list_lock);
+	spin_lock_irq(&blkcg->lock);
+
+	hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) {
+		if (pn->dev != blkg->dev || pn->plid != blkg->plid)
+			continue;
+		blkio_update_blkg_policy(blkcg, blkg, pn);
+	}
+
+	spin_unlock_irq(&blkcg->lock);
+	spin_unlock(&blkio_list_lock);
+}
 
-static int blkiocg_weight_device_write(struct cgroup *cgrp, struct cftype *cft,
-				       const char *buffer)
+static int blkiocg_file_write(struct cgroup *cgrp, struct cftype *cft,
+ 				       const char *buffer)
 {
 	int ret = 0;
 	char *buf;
 	struct blkio_policy_node *newpn, *pn;
 	struct blkio_cgroup *blkcg;
-	struct blkio_group *blkg;
 	int keep_newpn = 0;
-	struct hlist_node *n;
-	struct blkio_policy_type *blkiop;
+	enum blkio_policy_id plid = BLKIOFILE_POLICY(cft->private);
+	int fileid = BLKIOFILE_ATTR(cft->private);
 
 	buf = kstrdup(buffer, GFP_KERNEL);
 	if (!buf)
@@ -751,7 +941,7 @@ static int blkiocg_weight_device_write(struct cgroup *cgrp, struct cftype *cft,
 		goto free_buf;
 	}
 
-	ret = blkio_policy_parse_and_set(buf, newpn);
+	ret = blkio_policy_parse_and_set(buf, newpn, plid, fileid);
 	if (ret)
 		goto free_newpn;
 
@@ -759,9 +949,9 @@ static int blkiocg_weight_device_write(struct cgroup *cgrp, struct cftype *cft,
 
 	spin_lock_irq(&blkcg->lock);
 
-	pn = blkio_policy_search_node(blkcg, newpn->dev);
+	pn = blkio_policy_search_node(blkcg, newpn->dev, plid, fileid);
 	if (!pn) {
-		if (newpn->weight != 0) {
+		if (!blkio_delete_rule_command(newpn)) {
 			blkio_policy_insert_node(blkcg, newpn);
 			keep_newpn = 1;
 		}
@@ -769,33 +959,17 @@ static int blkiocg_weight_device_write(struct cgroup *cgrp, struct cftype *cft,
 		goto update_io_group;
 	}
 
-	if (newpn->weight == 0) {
-		/* weight == 0 means deleteing a specific weight */
+	if (blkio_delete_rule_command(newpn)) {
 		blkio_policy_delete_node(pn);
 		spin_unlock_irq(&blkcg->lock);
 		goto update_io_group;
 	}
 	spin_unlock_irq(&blkcg->lock);
 
-	pn->weight = newpn->weight;
+	blkio_update_policy_rule(pn, newpn);
 
 update_io_group:
-	/* update weight for each cfqg */
-	spin_lock(&blkio_list_lock);
-	spin_lock_irq(&blkcg->lock);
-