---

yaml
---
r: 309224
b: refs/heads/master
c: 852c788
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f6e8d01bee036460e03bd4f6a79d014f98ba712e
+refs/heads/master: 852c788f8365062c8a383c5a93f7f7289977cb50

trunk/block/blk-core.c

@@ -696,7 +696,7 @@ static inline void blk_free_request(struct request_queue *q, struct request *rq)
 }
 
 static struct request *
-blk_alloc_request(struct request_queue *q, struct io_cq *icq,
+blk_alloc_request(struct request_queue *q, struct bio *bio, struct io_cq *icq,
 		  unsigned int flags, gfp_t gfp_mask)
 {
 	struct request *rq = mempool_alloc(q->rq.rq_pool, gfp_mask);
@@ -710,7 +710,7 @@ blk_alloc_request(struct request_queue *q, struct io_cq *icq,
 
 	if (flags & REQ_ELVPRIV) {
 		rq->elv.icq = icq;
-		if (unlikely(elv_set_request(q, rq, gfp_mask))) {
+		if (unlikely(elv_set_request(q, rq, bio, gfp_mask))) {
 			mempool_free(rq, q->rq.rq_pool);
 			return NULL;
 		}
@@ -809,6 +809,22 @@ static bool blk_rq_should_init_elevator(struct bio *bio)
 	return true;
 }
 
+/**
+ * rq_ioc - determine io_context for request allocation
+ * @bio: request being allocated is for this bio (can be %NULL)
+ *
+ * Determine io_context to use for request allocation for @bio.  May return
+ * %NULL if %current->io_context doesn't exist.
+ */
+static struct io_context *rq_ioc(struct bio *bio)
+{
+#ifdef CONFIG_BLK_CGROUP
+	if (bio && bio->bi_ioc)
+		return bio->bi_ioc;
+#endif
+	return current->io_context;
+}
+
 /**
  * get_request - get a free request
  * @q: request_queue to allocate request from
@@ -836,7 +852,7 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
 	int may_queue;
 retry:
 	et = q->elevator->type;
-	ioc = current->io_context;
+	ioc = rq_ioc(bio);
 
 	if (unlikely(blk_queue_dead(q)))
 		return NULL;
@@ -919,14 +935,16 @@ static struct request *get_request(struct request_queue *q, int rw_flags,
 
 	/* create icq if missing */
 	if ((rw_flags & REQ_ELVPRIV) && unlikely(et->icq_cache && !icq)) {
-		ioc = create_io_context(gfp_mask, q->node);
-		if (ioc)
-			icq = ioc_create_icq(ioc, q, gfp_mask);
+		create_io_context(gfp_mask, q->node);
+		ioc = rq_ioc(bio);
+		if (!ioc)
+			goto fail_alloc;
+		icq = ioc_create_icq(ioc, q, gfp_mask);
 		if (!icq)
 			goto fail_alloc;
 	}
 
-	rq = blk_alloc_request(q, icq, rw_flags, gfp_mask);
+	rq = blk_alloc_request(q, bio, icq, rw_flags, gfp_mask);
 	if (unlikely(!rq))
 		goto fail_alloc;
 

trunk/block/cfq-iosched.c

@@ -3299,7 +3299,8 @@ split_cfqq(struct cfq_io_cq *cic, struct cfq_queue *cfqq)
  * Allocate cfq data structures associated with this request.
  */
 static int
-cfq_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
+cfq_set_request(struct request_queue *q, struct request *rq, struct bio *bio,
+		gfp_t gfp_mask)
 {
 	struct cfq_data *cfqd = q->elevator->elevator_data;
 	struct cfq_io_cq *cic = icq_to_cic(rq->elv.icq);

trunk/block/elevator.c

@@ -663,12 +663,13 @@ struct request *elv_former_request(struct request_queue *q, struct request *rq)
 	return NULL;
 }
 
-int elv_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
+int elv_set_request(struct request_queue *q, struct request *rq,
+		    struct bio *bio, gfp_t gfp_mask)
 {
 	struct elevator_queue *e = q->elevator;
 
 	if (e->type->ops.elevator_set_req_fn)
-		return e->type->ops.elevator_set_req_fn(q, rq, gfp_mask);
+		return e->type->ops.elevator_set_req_fn(q, rq, bio, gfp_mask);
 	return 0;
 }
 

trunk/fs/bio.c

@@ -19,12 +19,14 @@
 #include <linux/swap.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
+#include <linux/iocontext.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mempool.h>
 #include <linux/workqueue.h>
+#include <linux/cgroup.h>
 #include <scsi/sg.h>		/* for struct sg_iovec */
 
 #include <trace/events/block.h>
@@ -418,6 +420,7 @@ void bio_put(struct bio *bio)
 	 * last put frees it
 	 */
 	if (atomic_dec_and_test(&bio->bi_cnt)) {
+		bio_disassociate_task(bio);
 		bio->bi_next = NULL;
 		bio->bi_destructor(bio);
 	}
@@ -1641,6 +1644,64 @@ struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad)
 }
 EXPORT_SYMBOL(bioset_create);
 
+#ifdef CONFIG_BLK_CGROUP
+/**
+ * bio_associate_current - associate a bio with %current
+ * @bio: target bio
+ *
+ * Associate @bio with %current if it hasn't been associated yet.  Block
+ * layer will treat @bio as if it were issued by %current no matter which
+ * task actually issues it.
+ *
+ * This function takes an extra reference of @task's io_context and blkcg
+ * which will be put when @bio is released.  The caller must own @bio,
+ * ensure %current->io_context exists, and is responsible for synchronizing
+ * calls to this function.
+ */
+int bio_associate_current(struct bio *bio)
+{
+	struct io_context *ioc;
+	struct cgroup_subsys_state *css;
+
+	if (bio->bi_ioc)
+		return -EBUSY;
+
+	ioc = current->io_context;
+	if (!ioc)
+		return -ENOENT;
+
+	/* acquire active ref on @ioc and associate */
+	get_io_context_active(ioc);
+	bio->bi_ioc = ioc;
+
+	/* associate blkcg if exists */
+	rcu_read_lock();
+	css = task_subsys_state(current, blkio_subsys_id);
+	if (css && css_tryget(css))
+		bio->bi_css = css;
+	rcu_read_unlock();
+
+	return 0;
+}
+
+/**
+ * bio_disassociate_task - undo bio_associate_current()
+ * @bio: target bio
+ */
+void bio_disassociate_task(struct bio *bio)
+{
+	if (bio->bi_ioc) {
+		put_io_context(bio->bi_ioc);
+		bio->bi_ioc = NULL;
+	}
+	if (bio->bi_css) {
+		css_put(bio->bi_css);
+		bio->bi_css = NULL;
+	}
+}
+
+#endif /* CONFIG_BLK_CGROUP */
+
 static void __init biovec_init_slabs(void)
 {
 	int i;

trunk/include/linux/bio.h

@@ -268,6 +268,14 @@ extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set
 extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
 extern unsigned int bvec_nr_vecs(unsigned short idx);
 
+#ifdef CONFIG_BLK_CGROUP
+int bio_associate_current(struct bio *bio);
+void bio_disassociate_task(struct bio *bio);
+#else	/* CONFIG_BLK_CGROUP */
+static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
+static inline void bio_disassociate_task(struct bio *bio) { }
+#endif	/* CONFIG_BLK_CGROUP */
+
 /*
  * bio_set is used to allow other portions of the IO system to
  * allocate their own private memory pools for bio and iovec structures.

trunk/include/linux/blk_types.h

@@ -14,6 +14,8 @@ struct bio;
 struct bio_integrity_payload;
 struct page;
 struct block_device;
+struct io_context;
+struct cgroup_subsys_state;
 typedef void (bio_end_io_t) (struct bio *, int);
 typedef void (bio_destructor_t) (struct bio *);
 
@@ -66,6 +68,14 @@ struct bio {
 	bio_end_io_t		*bi_end_io;
 
 	void			*bi_private;
+#ifdef CONFIG_BLK_CGROUP
+	/*
+	 * Optional ioc and css associated with this bio.  Put on bio
+	 * release.  Read comment on top of bio_associate_current().
+	 */
+	struct io_context	*bi_ioc;
+	struct cgroup_subsys_state *bi_css;
+#endif
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 	struct bio_integrity_payload *bi_integrity;  /* data integrity */
 #endif

trunk/include/linux/elevator.h

@@ -28,7 +28,8 @@ typedef int (elevator_may_queue_fn) (struct request_queue *, int);
 
 typedef void (elevator_init_icq_fn) (struct io_cq *);
 typedef void (elevator_exit_icq_fn) (struct io_cq *);
-typedef int (elevator_set_req_fn) (struct request_queue *, struct request *, gfp_t);
+typedef int (elevator_set_req_fn) (struct request_queue *, struct request *,
+				   struct bio *, gfp_t);
 typedef void (elevator_put_req_fn) (struct request *);
 typedef void (elevator_activate_req_fn) (struct request_queue *, struct request *);
 typedef void (elevator_deactivate_req_fn) (struct request_queue *, struct request *);
@@ -129,7 +130,8 @@ extern void elv_unregister_queue(struct request_queue *q);
 extern int elv_may_queue(struct request_queue *, int);
 extern void elv_abort_queue(struct request_queue *);
 extern void elv_completed_request(struct request_queue *, struct request *);
-extern int elv_set_request(struct request_queue *, struct request *, gfp_t);
+extern int elv_set_request(struct request_queue *q, struct request *rq,
+			   struct bio *bio, gfp_t gfp_mask);
 extern void elv_put_request(struct request_queue *, struct request *);
 extern void elv_drain_elevator(struct request_queue *);