Merge branch 'for-4.9/block' of git://git.kernel.dk/linux-block

Pull block layer updates from Jens Axboe:
 "This is the main pull request for block layer changes in 4.9.

  As mentioned at the last merge window, I've changed things up and now
  do just one branch for core block layer changes, and driver changes.
  This avoids dependencies between the two branches. Outside of this
  main pull request, there are two topical branches coming as well.

  This pull request contains:

   - A set of fixes, and a conversion to blk-mq, of nbd. From Josef.

   - Set of fixes and updates for lightnvm from Matias, Simon, and Arnd.
     Followup dependency fix from Geert.

   - General fixes from Bart, Baoyou, Guoqing, and Linus W.

   - CFQ async write starvation fix from Glauber.

   - Add supprot for delayed kick of the requeue list, from Mike.

   - Pull out the scalable bitmap code from blk-mq-tag.c and make it
     generally available under the name of sbitmap. Only blk-mq-tag uses
     it for now, but the blk-mq scheduling bits will use it as well.
     From Omar.

   - bdev thaw error progagation from Pierre.

   - Improve the blk polling statistics, and allow the user to clear
     them. From Stephen.

   - Set of minor cleanups from Christoph in block/blk-mq.

   - Set of cleanups and optimizations from me for block/blk-mq.

   - Various nvme/nvmet/nvmeof fixes from the various folks"

* 'for-4.9/block' of git://git.kernel.dk/linux-block: (54 commits)
  fs/block_dev.c: return the right error in thaw_bdev()
  nvme: Pass pointers, not dma addresses, to nvme_get/set_features()
  nvme/scsi: Remove power management support
  nvmet: Make dsm number of ranges zero based
  nvmet: Use direct IO for writes
  admin-cmd: Added smart-log command support.
  nvme-fabrics: Add host_traddr options field to host infrastructure
  nvme-fabrics: revise host transport option descriptions
  nvme-fabrics: rework nvmf_get_address() for variable options
  nbd: use BLK_MQ_F_BLOCKING
  blkcg: Annotate blkg_hint correctly
  cfq: fix starvation of asynchronous writes
  blk-mq: add flag for drivers wanting blocking ->queue_rq()
  blk-mq: remove non-blocking pass in blk_mq_map_request
  blk-mq: get rid of manual run of queue with __blk_mq_run_hw_queue()
  block: export bio_free_pages to other modules
  lightnvm: propagate device_add() error code
  lightnvm: expose device geometry through sysfs
  lightnvm: control life of nvm_dev in driver
  blk-mq: register device instead of disk
  ...

9 files changed, 417 insertions, 34 deletions

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 23ddf4b..97cb48f 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -1,6 +1,4 @@
 /*
- * 2.5 block I/O model
- *
  * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
  *
  * This program is free software; you can redistribute it and/or modify
@@ -461,6 +459,7 @@ static inline void bio_flush_dcache_pages(struct bio *bi)
 
 extern void bio_copy_data(struct bio *dst, struct bio *src);
 extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
+extern void bio_free_pages(struct bio *bio);
 
 extern struct bio *bio_copy_user_iov(struct request_queue *,
 				     struct rq_map_data *,
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 10648e3..cbdbf34 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -45,7 +45,7 @@ struct blkcg {
 	spinlock_t			lock;
 
 	struct radix_tree_root		blkg_tree;
-	struct blkcg_gq			*blkg_hint;
+	struct blkcg_gq	__rcu		*blkg_hint;
 	struct hlist_head		blkg_list;
 
 	struct blkcg_policy_data	*cpd[BLKCG_MAX_POLS];
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index e43bbff..5daa0ef 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -2,6 +2,7 @@
 #define BLK_MQ_H
 
 #include <linux/blkdev.h>
+#include <linux/sbitmap.h>
 
 struct blk_mq_tags;
 struct blk_flush_queue;
@@ -12,21 +13,14 @@ struct blk_mq_cpu_notifier {
 	int (*notify)(void *data, unsigned long action, unsigned int cpu);
 };
 
-struct blk_mq_ctxmap {
-	unsigned int size;
-	unsigned int bits_per_word;
-	struct blk_align_bitmap *map;
-};
-
 struct blk_mq_hw_ctx {
 	struct {
 		spinlock_t		lock;
 		struct list_head	dispatch;
+		unsigned long		state;		/* BLK_MQ_S_* flags */
 	} ____cacheline_aligned_in_smp;
 
-	unsigned long		state;		/* BLK_MQ_S_* flags */
-	struct delayed_work	run_work;
-	struct delayed_work	delay_work;
+	struct work_struct	run_work;
 	cpumask_var_t		cpumask;
 	int			next_cpu;
 	int			next_cpu_batch;
@@ -38,10 +32,10 @@ struct blk_mq_hw_ctx {
 
 	void			*driver_data;
 
-	struct blk_mq_ctxmap	ctx_map;
+	struct sbitmap		ctx_map;
 
-	unsigned int		nr_ctx;
 	struct blk_mq_ctx	**ctxs;
+	unsigned int		nr_ctx;
 
 	atomic_t		wait_index;
 
@@ -49,7 +43,7 @@ struct blk_mq_hw_ctx {
 
 	unsigned long		queued;
 	unsigned long		run;
-#define BLK_MQ_MAX_DISPATCH_ORDER	10
+#define BLK_MQ_MAX_DISPATCH_ORDER	7
 	unsigned long		dispatched[BLK_MQ_MAX_DISPATCH_ORDER];
 
 	unsigned int		numa_node;
@@ -57,9 +51,12 @@ struct blk_mq_hw_ctx {
 
 	atomic_t		nr_active;
 
+	struct delayed_work	delay_work;
+
 	struct blk_mq_cpu_notifier	cpu_notifier;
 	struct kobject		kobj;
 
+	unsigned long		poll_considered;
 	unsigned long		poll_invoked;
 	unsigned long		poll_success;
 };
@@ -158,6 +155,7 @@ enum {
 	BLK_MQ_F_TAG_SHARED	= 1 << 1,
 	BLK_MQ_F_SG_MERGE	= 1 << 2,
 	BLK_MQ_F_DEFER_ISSUE	= 1 << 4,
+	BLK_MQ_F_BLOCKING	= 1 << 5,
 	BLK_MQ_F_ALLOC_POLICY_START_BIT = 8,
 	BLK_MQ_F_ALLOC_POLICY_BITS = 1,
 
@@ -178,8 +176,8 @@ enum {
 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
 						  struct request_queue *q);
-int blk_mq_register_disk(struct gendisk *);
-void blk_mq_unregister_disk(struct gendisk *);
+int blk_mq_register_dev(struct device *, struct request_queue *);
+void blk_mq_unregister_dev(struct device *, struct request_queue *);
 
 int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
 void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
@@ -221,7 +219,6 @@ static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
 }
 
 struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index);
-struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int, int);
 
 int blk_mq_request_started(struct request *rq);
 void blk_mq_start_request(struct request *rq);
@@ -232,6 +229,7 @@ void blk_mq_requeue_request(struct request *rq);
 void blk_mq_add_to_requeue_list(struct request *rq, bool at_head);
 void blk_mq_cancel_requeue_work(struct request_queue *q);
 void blk_mq_kick_requeue_list(struct request_queue *q);
+void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
 void blk_mq_abort_requeue_list(struct request_queue *q);
 void blk_mq_complete_request(struct request *rq, int error);
 
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 436f43f..cd395ec 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -16,7 +16,6 @@ struct block_device;
 struct io_context;
 struct cgroup_subsys_state;
 typedef void (bio_end_io_t) (struct bio *);
-typedef void (bio_destructor_t) (struct bio *);
 
 #ifdef CONFIG_BLOCK
 /*
@@ -89,14 +88,22 @@ struct bio {
 	struct bio_vec		bi_inline_vecs[0];
 };
 
-#define BIO_OP_SHIFT	(8 * sizeof(unsigned int) - REQ_OP_BITS)
+#define BIO_OP_SHIFT	(8 * FIELD_SIZEOF(struct bio, bi_opf) - REQ_OP_BITS)
+#define bio_flags(bio)	((bio)->bi_opf & ((1 << BIO_OP_SHIFT) - 1))
 #define bio_op(bio)	((bio)->bi_opf >> BIO_OP_SHIFT)
 
-#define bio_set_op_attrs(bio, op, op_flags) do {		\
-	WARN_ON(op >= (1 << REQ_OP_BITS));			\
-	(bio)->bi_opf &= ((1 << BIO_OP_SHIFT) - 1);		\
-	(bio)->bi_opf |= ((unsigned int) (op) << BIO_OP_SHIFT);	\
-	(bio)->bi_opf |= op_flags;				\
+#define bio_set_op_attrs(bio, op, op_flags) do {			\
+	if (__builtin_constant_p(op))					\
+		BUILD_BUG_ON((op) + 0U >= (1U << REQ_OP_BITS));		\
+	else								\
+		WARN_ON_ONCE((op) + 0U >= (1U << REQ_OP_BITS));		\
+	if (__builtin_constant_p(op_flags))				\
+		BUILD_BUG_ON((op_flags) + 0U >= (1U << BIO_OP_SHIFT));	\
+	else								\
+		WARN_ON_ONCE((op_flags) + 0U >= (1U << BIO_OP_SHIFT));	\
+	(bio)->bi_opf = bio_flags(bio);					\
+	(bio)->bi_opf |= (((op) + 0U) << BIO_OP_SHIFT);			\
+	(bio)->bi_opf |= (op_flags);					\
 } while (0)
 
 #define BIO_RESET_BYTES		offsetof(struct bio, bi_max_vecs)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e79055c..c47c358 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -449,7 +449,7 @@ struct request_queue {
 
 	struct list_head	requeue_list;
 	spinlock_t		requeue_lock;
-	struct work_struct	requeue_work;
+	struct delayed_work	requeue_work;
 
 	struct mutex		sysfs_lock;
 
@@ -1440,8 +1440,8 @@ static inline bool req_gap_front_merge(struct request *req, struct bio *bio)
 	return bio_will_gap(req->q, bio, req->bio);
 }
 
-struct work_struct;
 int kblockd_schedule_work(struct work_struct *work);
+int kblockd_schedule_work_on(int cpu, struct work_struct *work);
 int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay);
 int kblockd_schedule_delayed_work_on(int cpu, struct delayed_work *dwork, unsigned long delay);
 
diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h
index beb9ce1..8c12390 100644
--- a/include/linux/ioprio.h
+++ b/include/linux/ioprio.h
@@ -7,7 +7,6 @@
 /*
  * Gives us 8 prio classes with 13-bits of data for each class
  */
-#define IOPRIO_BITS		(16)
 #define IOPRIO_CLASS_SHIFT	(13)
 #define IOPRIO_PRIO_MASK	((1UL << IOPRIO_CLASS_SHIFT) - 1)
 
diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index ba78b83..d190786 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -352,7 +352,10 @@ struct nvm_dev {
 
 	/* Backend device */
 	struct request_queue *q;
+	struct device dev;
+	struct device *parent_dev;
 	char name[DISK_NAME_LEN];
+	void *private_data;
 
 	struct mutex mlock;
 	spinlock_t lock;
@@ -524,9 +527,9 @@ extern struct nvm_block *nvm_get_blk(struct nvm_dev *, struct nvm_lun *,
 								unsigned long);
 extern void nvm_put_blk(struct nvm_dev *, struct nvm_block *);
 
-extern int nvm_register(struct request_queue *, char *,
-						struct nvm_dev_ops *);
-extern void nvm_unregister(char *);
+extern struct nvm_dev *nvm_alloc_dev(int);
+extern int nvm_register(struct nvm_dev *);
+extern void nvm_unregister(struct nvm_dev *);
 
 void nvm_mark_blk(struct nvm_dev *dev, struct ppa_addr ppa, int type);
 
@@ -575,11 +578,14 @@ extern int nvm_dev_factory(struct nvm_dev *, int flags);
 #else /* CONFIG_NVM */
 struct nvm_dev_ops;
 
-static inline int nvm_register(struct request_queue *q, char *disk_name,
-							struct nvm_dev_ops *ops)
+static inline struct nvm_dev *nvm_alloc_dev(int node)
+{
+	return ERR_PTR(-EINVAL);
+}
+static inline int nvm_register(struct nvm_dev *dev)
 {
 	return -EINVAL;
 }
-static inline void nvm_unregister(char *disk_name) {}
+static inline void nvm_unregister(struct nvm_dev *dev) {}
 #endif /* CONFIG_NVM */
 #endif /* LIGHTNVM.H */
diff --git a/include/linux/sbitmap.h b/include/linux/sbitmap.h
new file mode 100644
index 0000000..f017fd6
--- /dev/null
+++ b/include/linux/sbitmap.h
@@ -0,0 +1,373 @@
+/*
+ * Fast and scalable bitmaps.
+ *
+ * Copyright (C) 2016 Facebook
+ * Copyright (C) 2013-2014 Jens Axboe
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef __LINUX_SCALE_BITMAP_H
+#define __LINUX_SCALE_BITMAP_H
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+/**
+ * struct sbitmap_word - Word in a &struct sbitmap.
+ */
+struct sbitmap_word {
+	/**
+	 * @word: The bitmap word itself.
+	 */
+	unsigned long word;
+
+	/**
+	 * @depth: Number of bits being used in @word.
+	 */
+	unsigned long depth;
+} ____cacheline_aligned_in_smp;
+
+/**
+ * struct sbitmap - Scalable bitmap.
+ *
+ * A &struct sbitmap is spread over multiple cachelines to avoid ping-pong. This
+ * trades off higher memory usage for better scalability.
+ */
+struct sbitmap {
+	/**
+	 * @depth: Number of bits used in the whole bitmap.
+	 */
+	unsigned int depth;
+
+	/**
+	 * @shift: log2(number of bits used per word)
+	 */
+	unsigned int shift;
+
+	/**
+	 * @map_nr: Number of words (cachelines) being used for the bitmap.
+	 */
+	unsigned int map_nr;
+
+	/**
+	 * @map: Allocated bitmap.
+	 */
+	struct sbitmap_word *map;
+};
+
+#define SBQ_WAIT_QUEUES 8
+#define SBQ_WAKE_BATCH 8
+
+/**
+ * struct sbq_wait_state - Wait queue in a &struct sbitmap_queue.
+ */
+struct sbq_wait_state {
+	/**
+	 * @wait_cnt: Number of frees remaining before we wake up.
+	 */
+	atomic_t wait_cnt;
+
+	/**
+	 * @wait: Wait queue.
+	 */
+	wait_queue_head_t wait;
+} ____cacheline_aligned_in_smp;
+
+/**
+ * struct sbitmap_queue - Scalable bitmap with the added ability to wait on free
+ * bits.
+ *
+ * A &struct sbitmap_queue uses multiple wait queues and rolling wakeups to
+ * avoid contention on the wait queue spinlock. This ensures that we don't hit a
+ * scalability wall when we run out of free bits and have to start putting tasks
+ * to sleep.
+ */
+struct sbitmap_queue {
+	/**
+	 * @sb: Scalable bitmap.
+	 */
+	struct sbitmap sb;
+
+	/*
+	 * @alloc_hint: Cache of last successfully allocated or freed bit.
+	 *
+	 * This is per-cpu, which allows multiple users to stick to different
+	 * cachelines until the map is exhausted.
+	 */
+	unsigned int __percpu *alloc_hint;
+
+	/**
+	 * @wake_batch: Number of bits which must be freed before we wake up any
+	 * waiters.
+	 */
+	unsigned int wake_batch;
+
+	/**
+	 * @wake_index: Next wait queue in @ws to wake up.
+	 */
+	atomic_t wake_index;
+
+	/**
+	 * @ws: Wait queues.
+	 */
+	struct sbq_wait_state *ws;
+
+	/**
+	 * @round_robin: Allocate bits in strict round-robin order.
+	 */
+	bool round_robin;
+};
+
+/**
+ * sbitmap_init_node() - Initialize a &struct sbitmap on a specific memory node.
+ * @sb: Bitmap to initialize.
+ * @depth: Number of bits to allocate.
+ * @shift: Use 2^@shift bits per word in the bitmap; if a negative number if
+ *         given, a good default is chosen.
+ * @flags: Allocation flags.
+ * @node: Memory node to allocate on.
+ *
+ * Return: Zero on success or negative errno on failure.
+ */
+int sbitmap_init_node(struct sbitmap *sb, unsigned int depth, int shift,
+		      gfp_t flags, int node);
+
+/**
+ * sbitmap_free() - Free memory used by a &struct sbitmap.
+ * @sb: Bitmap to free.
+ */
+static inline void sbitmap_free(struct sbitmap *sb)
+{
+	kfree(sb->map);
+	sb->map = NULL;
+}
+
+/**
+ * sbitmap_resize() - Resize a &struct sbitmap.
+ * @sb: Bitmap to resize.
+ * @depth: New number of bits to resize to.
+ *
+ * Doesn't reallocate anything. It's up to the caller to ensure that the new
+ * depth doesn't exceed the depth that the sb was initialized with.
+ */
+void sbitmap_resize(struct sbitmap *sb, unsigned int depth);
+
+/**
+ * sbitmap_get() - Try to allocate a free bit from a &struct sbitmap.
+ * @sb: Bitmap to allocate from.
+ * @alloc_hint: Hint for where to start searching for a free bit.
+ * @round_robin: If true, be stricter about allocation order; always allocate
+ *               starting from the last allocated bit. This is less efficient
+ *               than the default behavior (false).
+ *
+ * Return: Non-negative allocated bit number if successful, -1 otherwise.
+ */
+int sbitmap_get(struct sbitmap *sb, unsigned int alloc_hint, bool round_robin);
+
+/**
+ * sbitmap_any_bit_set() - Check for a set bit in a &struct sbitmap.
+ * @sb: Bitmap to check.
+ *
+ * Return: true if any bit in the bitmap is set, false otherwise.
+ */
+bool sbitmap_any_bit_set(const struct sbitmap *sb);
+
+/**
+ * sbitmap_any_bit_clear() - Check for an unset bit in a &struct
+ * sbitmap.
+ * @sb: Bitmap to check.
+ *
+ * Return: true if any bit in the bitmap is clear, false otherwise.
+ */
+bool sbitmap_any_bit_clear(const struct sbitmap *sb);
+
+typedef bool (*sb_for_each_fn)(struct sbitmap *, unsigned int, void *);
+
+/**
+ * sbitmap_for_each_set() - Iterate over each set bit in a &struct sbitmap.
+ * @sb: Bitmap to iterate over.
+ * @fn: Callback. Should return true to continue or false to break early.
+ * @data: Pointer to pass to callback.
+ *
+ * This is inline even though it's non-trivial so that the function calls to the
+ * callback will hopefully get optimized away.
+ */
+static inline void sbitmap_for_each_set(struct sbitmap *sb, sb_for_each_fn fn,
+					void *data)
+{
+	unsigned int i;
+
+	for (i = 0; i < sb->map_nr; i++) {
+		struct sbitmap_word *word = &sb->map[i];
+		unsigned int off, nr;
+
+		if (!word->word)
+			continue;
+
+		nr = 0;
+		off = i << sb->shift;
+		while (1) {
+			nr = find_next_bit(&word->word, word->depth, nr);
+			if (nr >= word->depth)
+				break;
+
+			if (!fn(sb, off + nr, data))
+				return;
+
+			nr++;
+		}
+	}
+}
+
+#define SB_NR_TO_INDEX(sb, bitnr) ((bitnr) >> (sb)->shift)
+#define SB_NR_TO_BIT(sb, bitnr) ((bitnr) & ((1U << (sb)->shift) - 1U))
+
+static inline unsigned long *__sbitmap_word(struct sbitmap *sb,
+					    unsigned int bitnr)
+{
+	return &sb->map[SB_NR_TO_INDEX(sb, bitnr)].word;
+}
+
+/* Helpers equivalent to the operations in asm/bitops.h and linux/bitmap.h */
+
+static inline void sbitmap_set_bit(struct sbitmap *sb, unsigned int bitnr)
+{
+	set_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr));
+}
+
+static inline void sbitmap_clear_bit(struct sbitmap *sb, unsigned int bitnr)
+{
+	clear_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr));
+}
+
+static inline int sbitmap_test_bit(struct sbitmap *sb, unsigned int bitnr)
+{
+	return test_bit(SB_NR_TO_BIT(sb, bitnr), __sbitmap_word(sb, bitnr));
+}
+
+unsigned int sbitmap_weight(const struct sbitmap *sb);
+
+/**
+ * sbitmap_queue_init_node() - Initialize a &struct sbitmap_queue on a specific
+ * memory node.
+ * @sbq: Bitmap queue to initialize.
+ * @depth: See sbitmap_init_node().
+ * @shift: See sbitmap_init_node().
+ * @round_robin: See sbitmap_get().
+ * @flags: Allocation flags.
+ * @node: Memory node to allocate on.
+ *
+ * Return: Zero on success or negative errno on failure.
+ */
+int sbitmap_queue_init_node(struct sbitmap_queue *sbq, unsigned int depth,
+			    int shift, bool round_robin, gfp_t flags, int node);
+
+/**
+ * sbitmap_queue_free() - Free memory used by a &struct sbitmap_queue.
+ *
+ * @sbq: Bitmap queue to free.
+ */
+static inline void sbitmap_queue_free(struct sbitmap_queue *sbq)
+{
+	kfree(sbq->ws);
+	free_percpu(sbq->alloc_hint);
+	sbitmap_free(&sbq->sb);
+}
+
+/**
+ * sbitmap_queue_resize() - Resize a &struct sbitmap_queue.
+ * @sbq: Bitmap queue to resize.
+ * @depth: New number of bits to resize to.
+ *
+ * Like sbitmap_resize(), this doesn't reallocate anything. It has to do
+ * some extra work on the &struct sbitmap_queue, so it's not safe to just
+ * resize the underlying &struct sbitmap.
+ */
+void sbitmap_queue_resize(struct sbitmap_queue *sbq, unsigned int depth);
+
+/**
+ * __sbitmap_queue_get() - Try to allocate a free bit from a &struct
+ * sbitmap_queue with preemption already disabled.
+ * @sbq: Bitmap queue to allocate from.
+ *
+ * Return: Non-negative allocated bit number if successful, -1 otherwise.
+ */
+int __sbitmap_queue_get(struct sbitmap_queue *sbq);
+
+/**
+ * sbitmap_queue_get() - Try to allocate a free bit from a &struct
+ * sbitmap_queue.
+ * @sbq: Bitmap queue to allocate from.
+ * @cpu: Output parameter; will contain the CPU we ran on (e.g., to be passed to
+ *       sbitmap_queue_clear()).
+ *
+ * Return: Non-negative allocated bit number if successful, -1 otherwise.
+ */
+static inline int sbitmap_queue_get(struct sbitmap_queue *sbq,
+				    unsigned int *cpu)
+{
+	int nr;
+
+	*cpu = get_cpu();
+	nr = __sbitmap_queue_get(sbq);
+	put_cpu();
+	return nr;
+}
+
+/**
+ * sbitmap_queue_clear() - Free an allocated bit and wake up waiters on a
+ * &struct sbitmap_queue.
+ * @sbq: Bitmap to free from.
+ * @nr: Bit number to free.
+ * @cpu: CPU the bit was allocated on.
+ */
+void sbitmap_queue_clear(struct sbitmap_queue *sbq, unsigned int nr,
+			 unsigned int cpu);
+
+static inline int sbq_index_inc(int index)
+{
+	return (index + 1) & (SBQ_WAIT_QUEUES - 1);
+}
+
+static inline void sbq_index_atomic_inc(atomic_t *index)
+{
+	int old = atomic_read(index);
+	int new = sbq_index_inc(old);
+	atomic_cmpxchg(index, old, new);
+}
+
+/**
+ * sbq_wait_ptr() - Get the next wait queue to use for a &struct
+ * sbitmap_queue.
+ * @sbq: Bitmap queue to wait on.
+ * @wait_index: A counter per "user" of @sbq.
+ */
+static inline struct sbq_wait_state *sbq_wait_ptr(struct sbitmap_queue *sbq,
+						  atomic_t *wait_index)
+{
+	struct sbq_wait_state *ws;
+
+	ws = &sbq->ws[atomic_read(wait_index)];
+	sbq_index_atomic_inc(wait_index);
+	return ws;
+}
+
+/**
+ * sbitmap_queue_wake_all() - Wake up everything waiting on a &struct
+ * sbitmap_queue.
+ * @sbq: Bitmap queue to wake up.
+ */
+void sbitmap_queue_wake_all(struct sbitmap_queue *sbq);
+
+#endif /* __LINUX_SCALE_BITMAP_H */
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 26cc1df..fc6e221 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -442,6 +442,7 @@ extern int schedule_on_each_cpu(work_func_t func);
 int execute_in_process_context(work_func_t fn, struct execute_work *);
 
 extern bool flush_work(struct work_struct *work);
+extern bool cancel_work(struct work_struct *work);
 extern bool cancel_work_sync(struct work_struct *work);
 
 extern bool flush_delayed_work(struct delayed_work *dwork);