[mirror_ubuntu-artful-kernel.git] / block / blk-sysfs.c

/*
 * Functions related to sysfs handling
 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/blktrace_api.h>
#include <linux/blk-mq.h>

#include "blk.h"
#include "blk-cgroup.h"
#include "blk-mq.h"

struct queue_sysfs_entry {
	struct attribute attr;
	ssize_t (*show)(struct request_queue *, char *);
	ssize_t (*store)(struct request_queue *, const char *, size_t);
};

static ssize_t
queue_var_show(unsigned long var, char *page)
{
	return sprintf(page, "%lu\n", var);
}

static ssize_t
queue_var_store(unsigned long *var, const char *page, size_t count)
{
	int err;
	unsigned long v;

	err = kstrtoul(page, 10, &v);
	if (err || v > UINT_MAX)
		return -EINVAL;

	*var = v;

	return count;
}

static ssize_t queue_requests_show(struct request_queue *q, char *page)
{
	return queue_var_show(q->nr_requests, (page));
}

static ssize_t
queue_requests_store(struct request_queue *q, const char *page, size_t count)
{
	unsigned long nr;
	int ret, err;

	if (!q->request_fn && !q->mq_ops)
		return -EINVAL;

	ret = queue_var_store(&nr, page, count);
	if (ret < 0)
		return ret;

	if (nr < BLKDEV_MIN_RQ)
		nr = BLKDEV_MIN_RQ;

	if (q->request_fn)
		err = blk_update_nr_requests(q, nr);
	else
		err = blk_mq_update_nr_requests(q, nr);

	if (err)
		return err;

	return ret;
}

static ssize_t queue_ra_show(struct request_queue *q, char *page)
{
	unsigned long ra_kb = q->backing_dev_info.ra_pages <<
					(PAGE_CACHE_SHIFT - 10);

	return queue_var_show(ra_kb, (page));
}

static ssize_t
queue_ra_store(struct request_queue *q, const char *page, size_t count)
{
	unsigned long ra_kb;
	ssize_t ret = queue_var_store(&ra_kb, page, count);

	if (ret < 0)
		return ret;

	q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);

	return ret;
}

static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
{
	int max_sectors_kb = queue_max_sectors(q) >> 1;

	return queue_var_show(max_sectors_kb, (page));
}

static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
{
	return queue_var_show(queue_max_segments(q), (page));
}

static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
{
	return queue_var_show(q->limits.max_integrity_segments, (page));
}

static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
{
	if (blk_queue_cluster(q))
		return queue_var_show(queue_max_segment_size(q), (page));

	return queue_var_show(PAGE_CACHE_SIZE, (page));
}

static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
{
	return queue_var_show(queue_logical_block_size(q), page);
}

static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
{
	return queue_var_show(queue_physical_block_size(q), page);
}

static ssize_t queue_io_min_show(struct request_queue *q, char *page)
{
	return queue_var_show(queue_io_min(q), page);
}

static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
{
	return queue_var_show(queue_io_opt(q), page);
}

static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
{
	return queue_var_show(q->limits.discard_granularity, page);
}

static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
{
	return sprintf(page, "%llu\n",
		       (unsigned long long)q->limits.max_discard_sectors << 9);
}

static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
{
	return queue_var_show(queue_discard_zeroes_data(q), page);
}

static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
{
	return sprintf(page, "%llu\n",
		(unsigned long long)q->limits.max_write_same_sectors << 9);
}


static ssize_t
queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
{
	unsigned long max_sectors_kb,
		max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
			page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
	ssize_t ret = queue_var_store(&max_sectors_kb, page, count);

	if (ret < 0)
		return ret;

	if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
		return -EINVAL;

	spin_lock_irq(q->queue_lock);
	q->limits.max_sectors = max_sectors_kb << 1;
	spin_unlock_irq(q->queue_lock);

	return ret;
}

static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
{
	int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;

	return queue_var_show(max_hw_sectors_kb, (page));
}

#define QUEUE_SYSFS_BIT_FNS(name, flag, neg)				\
static ssize_t								\
queue_show_##name(struct request_queue *q, char *page)			\
{									\
	int bit;							\
	bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);		\
	return queue_var_show(neg ? !bit : bit, page);			\
}									\
static ssize_t								\
queue_store_##name(struct request_queue *q, const char *page, size_t count) \
{									\
	unsigned long val;						\
	ssize_t ret;							\
	ret = queue_var_store(&val, page, count);			\
	if (ret < 0)							\
		 return ret;						\
	if (neg)							\
		val = !val;						\
									\
	spin_lock_irq(q->queue_lock);					\
	if (val)							\
		queue_flag_set(QUEUE_FLAG_##flag, q);			\
	else								\
		queue_flag_clear(QUEUE_FLAG_##flag, q);			\
	spin_unlock_irq(q->queue_lock);					\
	return ret;							\
}

QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
#undef QUEUE_SYSFS_BIT_FNS

static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
{
	return queue_var_show((blk_queue_nomerges(q) << 1) |
			       blk_queue_noxmerges(q), page);
}

static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
				    size_t count)
{
	unsigned long nm;
	ssize_t ret = queue_var_store(&nm, page, count);

	if (ret < 0)
		return ret;

	spin_lock_irq(q->queue_lock);
	queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
	queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
	if (nm == 2)
		queue_flag_set(QUEUE_FLAG_NOMERGES, q);
	else if (nm)
		queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
	spin_unlock_irq(q->queue_lock);

	return ret;
}

static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
{
	bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
	bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);

	return queue_var_show(set << force, page);
}

static ssize_t
queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
{
	ssize_t ret = -EINVAL;
#ifdef CONFIG_SMP
	unsigned long val;

	ret = queue_var_store(&val, page, count);
	if (ret < 0)
		return ret;

	spin_lock_irq(q->queue_lock);
	if (val == 2) {
		queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
		queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
	} else if (val == 1) {
		queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
		queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
	} else if (val == 0) {
		queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
		queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
	}
	spin_unlock_irq(q->queue_lock);
#endif
	return ret;
}

static struct queue_sysfs_entry queue_requests_entry = {
	.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
	.show = queue_requests_show,
	.store = queue_requests_store,
};

static struct queue_sysfs_entry queue_ra_entry = {
	.attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
	.show = queue_ra_show,
	.store = queue_ra_store,
};

static struct queue_sysfs_entry queue_max_sectors_entry = {
	.attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
	.show = queue_max_sectors_show,
	.store = queue_max_sectors_store,
};

static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
	.attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
	.show = queue_max_hw_sectors_show,
};

static struct queue_sysfs_entry queue_max_segments_entry = {
	.attr = {.name = "max_segments", .mode = S_IRUGO },
	.show = queue_max_segments_show,
};

static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
	.attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
	.show = queue_max_integrity_segments_show,
};

static struct queue_sysfs_entry queue_max_segment_size_entry = {
	.attr = {.name = "max_segment_size", .mode = S_IRUGO },
	.show = queue_max_segment_size_show,
};

static struct queue_sysfs_entry queue_iosched_entry = {
	.attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
	.show = elv_iosched_show,
	.store = elv_iosched_store,
};

static struct queue_sysfs_entry queue_hw_sector_size_entry = {
	.attr = {.name = "hw_sector_size", .mode = S_IRUGO },
	.show = queue_logical_block_size_show,
};

static struct queue_sysfs_entry queue_logical_block_size_entry = {
	.attr = {.name = "logical_block_size", .mode = S_IRUGO },
	.show = queue_logical_block_size_show,
};

static struct queue_sysfs_entry queue_physical_block_size_entry = {
	.attr = {.name = "physical_block_size", .mode = S_IRUGO },
	.show = queue_physical_block_size_show,
};

static struct queue_sysfs_entry queue_io_min_entry = {
	.attr = {.name = "minimum_io_size", .mode = S_IRUGO },
	.show = queue_io_min_show,
};

static struct queue_sysfs_entry queue_io_opt_entry = {
	.attr = {.name = "optimal_io_size", .mode = S_IRUGO },
	.show = queue_io_opt_show,
};

static struct queue_sysfs_entry queue_discard_granularity_entry = {
	.attr = {.name = "discard_granularity", .mode = S_IRUGO },
	.show = queue_discard_granularity_show,
};

static struct queue_sysfs_entry queue_discard_max_entry = {
	.attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
	.show = queue_discard_max_show,
};

static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
	.attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
	.show = queue_discard_zeroes_data_show,
};

static struct queue_sysfs_entry queue_write_same_max_entry = {
	.attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
	.show = queue_write_same_max_show,
};

static struct queue_sysfs_entry queue_nonrot_entry = {
	.attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
	.show = queue_show_nonrot,
	.store = queue_store_nonrot,
};

static struct queue_sysfs_entry queue_nomerges_entry = {
	.attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
	.show = queue_nomerges_show,
	.store = queue_nomerges_store,
};

static struct queue_sysfs_entry queue_rq_affinity_entry = {
	.attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
	.show = queue_rq_affinity_show,
	.store = queue_rq_affinity_store,
};

static struct queue_sysfs_entry queue_iostats_entry = {
	.attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
	.show = queue_show_iostats,
	.store = queue_store_iostats,
};

static struct queue_sysfs_entry queue_random_entry = {
	.attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
	.show = queue_show_random,
	.store = queue_store_random,
};

static struct attribute *default_attrs[] = {
	&queue_requests_entry.attr,
	&queue_ra_entry.attr,
	&queue_max_hw_sectors_entry.attr,
	&queue_max_sectors_entry.attr,
	&queue_max_segments_entry.attr,
	&queue_max_integrity_segments_entry.attr,
	&queue_max_segment_size_entry.attr,
	&queue_iosched_entry.attr,
	&queue_hw_sector_size_entry.attr,
	&queue_logical_block_size_entry.attr,
	&queue_physical_block_size_entry.attr,
	&queue_io_min_entry.attr,
	&queue_io_opt_entry.attr,
	&queue_discard_granularity_entry.attr,
	&queue_discard_max_entry.attr,
	&queue_discard_zeroes_data_entry.attr,
	&queue_write_same_max_entry.attr,
	&queue_nonrot_entry.attr,
	&queue_nomerges_entry.attr,
	&queue_rq_affinity_entry.attr,
	&queue_iostats_entry.attr,
	&queue_random_entry.attr,
	NULL,
};

#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)

static ssize_t
queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
{
	struct queue_sysfs_entry *entry = to_queue(attr);
	struct request_queue *q =
		container_of(kobj, struct request_queue, kobj);
	ssize_t res;

	if (!entry->show)
		return -EIO;
	mutex_lock(&q->sysfs_lock);
	if (blk_queue_dying(q)) {
		mutex_unlock(&q->sysfs_lock);
		return -ENOENT;
	}
	res = entry->show(q, page);
	mutex_unlock(&q->sysfs_lock);
	return res;
}

static ssize_t
queue_attr_store(struct kobject *kobj, struct attribute *attr,
		    const char *page, size_t length)
{
	struct queue_sysfs_entry *entry = to_queue(attr);
	struct request_queue *q;
	ssize_t res;

	if (!entry->store)
		return -EIO;

	q = container_of(kobj, struct request_queue, kobj);
	mutex_lock(&q->sysfs_lock);
	if (blk_queue_dying(q)) {
		mutex_unlock(&q->sysfs_lock);
		return -ENOENT;
	}
	res = entry->store(q, page, length);
	mutex_unlock(&q->sysfs_lock);
	return res;
}

static void blk_free_queue_rcu(struct rcu_head *rcu_head)
{
	struct request_queue *q = container_of(rcu_head, struct request_queue,
					       rcu_head);
	kmem_cache_free(blk_requestq_cachep, q);
}

/**
 * blk_release_queue: - release a &struct request_queue when it is no longer needed
 * @kobj:    the kobj belonging to the request queue to be released
 *
 * Description:
 *     blk_release_queue is the pair to blk_init_queue() or
 *     blk_queue_make_request().  It should be called when a request queue is
 *     being released; typically when a block device is being de-registered.
 *     Currently, its primary task it to free all the &struct request
 *     structures that were allocated to the queue and the queue itself.
 *
 * Caveat:
 *     Hopefully the low level driver will have finished any
 *     outstanding requests first...
 **/
static void blk_release_queue(struct kobject *kobj)
{
	struct request_queue *q =
		container_of(kobj, struct request_queue, kobj);

	blk_sync_queue(q);

	blkcg_exit_queue(q);

	if (q->elevator) {
		spin_lock_irq(q->queue_lock);
		ioc_clear_queue(q);
		spin_unlock_irq(q->queue_lock);
		elevator_exit(q->elevator);
	}

	blk_exit_rl(&q->root_rl);

	if (q->queue_tags)
		__blk_queue_free_tags(q);

	if (q->mq_ops)
		blk_mq_free_queue(q);
	else
		blk_free_flush_queue(q->fq);

	blk_trace_shutdown(q);

	bdi_destroy(&q->backing_dev_info);

	ida_simple_remove(&blk_queue_ida, q->id);
	call_rcu(&q->rcu_head, blk_free_queue_rcu);
}

static const struct sysfs_ops queue_sysfs_ops = {
	.show	= queue_attr_show,
	.store	= queue_attr_store,
};

struct kobj_type blk_queue_ktype = {
	.sysfs_ops	= &queue_sysfs_ops,
	.default_attrs	= default_attrs,
	.release	= blk_release_queue,
};

int blk_register_queue(struct gendisk *disk)
{
	int ret;
	struct device *dev = disk_to_dev(disk);
	struct request_queue *q = disk->queue;

	if (WARN_ON(!q))
		return -ENXIO;

	/*
	 * SCSI probing may synchronously create and destroy a lot of
	 * request_queues for non-existent devices.  Shutting down a fully
	 * functional queue takes measureable wallclock time as RCU grace
	 * periods are involved.  To avoid excessive latency in these
	 * cases, a request_queue starts out in a degraded mode which is
	 * faster to shut down and is made fully functional here as
	 * request_queues for non-existent devices never get registered.
	 */
	if (!blk_queue_init_done(q)) {
		queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
		blk_queue_bypass_end(q);
		if (q->mq_ops)
			blk_mq_finish_init(q);
	}

	ret = blk_trace_init_sysfs(dev);
	if (ret)
		return ret;

	ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
	if (ret < 0) {
		blk_trace_remove_sysfs(dev);
		return ret;
	}

	kobject_uevent(&q->kobj, KOBJ_ADD);

	if (q->mq_ops)
		blk_mq_register_disk(disk);

	if (!q->request_fn)
		return 0;

	ret = elv_register_queue(q);
	if (ret) {
		kobject_uevent(&q->kobj, KOBJ_REMOVE);
		kobject_del(&q->kobj);
		blk_trace_remove_sysfs(dev);
		kobject_put(&dev->kobj);
		return ret;
	}

	return 0;
}

void blk_unregister_queue(struct gendisk *disk)
{
	struct request_queue *q = disk->queue;

	if (WARN_ON(!q))
		return;

	if (q->mq_ops)
		blk_mq_unregister_disk(disk);

	if (q->request_fn)
		elv_unregister_queue(q);

	kobject_uevent(&q->kobj, KOBJ_REMOVE);
	kobject_del(&q->kobj);
	blk_trace_remove_sysfs(disk_to_dev(disk));
	kobject_put(&disk_to_dev(disk)->kobj);
}
Commit	Line	Data
8324aa91 JA	1	/*
	2	* Functions related to sysfs handling
	3	*/
	4	#include <linux/kernel.h>
5a0e3ad6	5	#include <linux/slab.h>
8324aa91 JA	6	#include <linux/module.h>
	7	#include <linux/bio.h>
	8	#include <linux/blkdev.h>
	9	#include <linux/blktrace_api.h>
320ae51f	10	#include <linux/blk-mq.h>
8324aa91 JA	11
8324aa91 JA	12	#include "blk.h"
5efd6113	13	#include "blk-cgroup.h"
3edcc0ce	14	#include "blk-mq.h"
8324aa91 JA	15
	16	struct queue_sysfs_entry {
	17	struct attribute attr;
	18	ssize_t (show)(struct request_queue , char *);
	19	ssize_t (store)(struct request_queue , const char *, size_t);
	20	};
	21
	22	static ssize_t
9cb308ce	23	queue_var_show(unsigned long var, char *page)
8324aa91	24	{
9cb308ce	25	return sprintf(page, "%lu\n", var);
8324aa91 JA	26	}
	27
	28	static ssize_t
	29	queue_var_store(unsigned long var, const char page, size_t count)
	30	{
b1f3b64d DR	31	int err;
	32	unsigned long v;
	33
ed751e68	34	err = kstrtoul(page, 10, &v);
b1f3b64d DR	35	if (err \|\| v > UINT_MAX)
	36	return -EINVAL;
	37
	38	*var = v;
8324aa91	39
8324aa91 JA	40	return count;
	41	}
	42
	43	static ssize_t queue_requests_show(struct request_queue q, char page)
	44	{
	45	return queue_var_show(q->nr_requests, (page));
	46	}
	47
	48	static ssize_t
	49	queue_requests_store(struct request_queue q, const char page, size_t count)
	50	{
8324aa91	51	unsigned long nr;
e3a2b3f9	52	int ret, err;
b8a9ae77	53
e3a2b3f9	54	if (!q->request_fn && !q->mq_ops)
b8a9ae77 JA	55	return -EINVAL;
	56
	57	ret = queue_var_store(&nr, page, count);
b1f3b64d DR	58	if (ret < 0)
	59	return ret;
	60
8324aa91 JA	61	if (nr < BLKDEV_MIN_RQ)
	62	nr = BLKDEV_MIN_RQ;
	63
e3a2b3f9 JA	64	if (q->request_fn)
	65	err = blk_update_nr_requests(q, nr);
	66	else
	67	err = blk_mq_update_nr_requests(q, nr);
	68
	69	if (err)
	70	return err;
	71
8324aa91 JA	72	return ret;
	73	}
	74
	75	static ssize_t queue_ra_show(struct request_queue q, char page)
	76	{
9cb308ce XF	77	unsigned long ra_kb = q->backing_dev_info.ra_pages <<
9cb308ce XF	78	(PAGE_CACHE_SHIFT - 10);
8324aa91 JA	79
	80	return queue_var_show(ra_kb, (page));
	81	}
	82
	83	static ssize_t
	84	queue_ra_store(struct request_queue q, const char page, size_t count)
	85	{
	86	unsigned long ra_kb;
	87	ssize_t ret = queue_var_store(&ra_kb, page, count);
	88
b1f3b64d DR	89	if (ret < 0)
	90	return ret;
	91
8324aa91	92	q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
8324aa91 JA	93
	94	return ret;
	95	}
	96
	97	static ssize_t queue_max_sectors_show(struct request_queue q, char page)
	98	{
ae03bf63	99	int max_sectors_kb = queue_max_sectors(q) >> 1;
8324aa91 JA	100
	101	return queue_var_show(max_sectors_kb, (page));
	102	}
	103
c77a5710 MP	104	static ssize_t queue_max_segments_show(struct request_queue q, char page)
	105	{
	106	return queue_var_show(queue_max_segments(q), (page));
	107	}
	108
13f05c8d MP	109	static ssize_t queue_max_integrity_segments_show(struct request_queue q, char page)
	110	{
	111	return queue_var_show(q->limits.max_integrity_segments, (page));
	112	}
	113
c77a5710 MP	114	static ssize_t queue_max_segment_size_show(struct request_queue q, char page)
c77a5710 MP	115	{
e692cb66	116	if (blk_queue_cluster(q))
c77a5710 MP	117	return queue_var_show(queue_max_segment_size(q), (page));
	118
	119	return queue_var_show(PAGE_CACHE_SIZE, (page));
	120	}
	121
e1defc4f	122	static ssize_t queue_logical_block_size_show(struct request_queue q, char page)
e68b903c	123	{
e1defc4f	124	return queue_var_show(queue_logical_block_size(q), page);
e68b903c MP	125	}
e68b903c MP	126
c72758f3 MP	127	static ssize_t queue_physical_block_size_show(struct request_queue q, char page)
	128	{
	129	return queue_var_show(queue_physical_block_size(q), page);
	130	}
	131
	132	static ssize_t queue_io_min_show(struct request_queue q, char page)
	133	{
	134	return queue_var_show(queue_io_min(q), page);
	135	}
	136
	137	static ssize_t queue_io_opt_show(struct request_queue q, char page)
	138	{
	139	return queue_var_show(queue_io_opt(q), page);
e68b903c MP	140	}
e68b903c MP	141
86b37281 MP	142	static ssize_t queue_discard_granularity_show(struct request_queue q, char page)
	143	{
	144	return queue_var_show(q->limits.discard_granularity, page);
	145	}
	146
	147	static ssize_t queue_discard_max_show(struct request_queue q, char page)
	148	{
a934a00a MP	149	return sprintf(page, "%llu\n",
a934a00a MP	150	(unsigned long long)q->limits.max_discard_sectors << 9);
86b37281 MP	151	}
86b37281 MP	152
98262f27 MP	153	static ssize_t queue_discard_zeroes_data_show(struct request_queue q, char page)
	154	{
	155	return queue_var_show(queue_discard_zeroes_data(q), page);
	156	}
	157
4363ac7c MP	158	static ssize_t queue_write_same_max_show(struct request_queue q, char page)
	159	{
	160	return sprintf(page, "%llu\n",
	161	(unsigned long long)q->limits.max_write_same_sectors << 9);
	162	}
	163
	164
8324aa91 JA	165	static ssize_t
	166	queue_max_sectors_store(struct request_queue q, const char page, size_t count)
	167	{
	168	unsigned long max_sectors_kb,
ae03bf63	169	max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
8324aa91 JA	170	page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
	171	ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
	172
b1f3b64d DR	173	if (ret < 0)
	174	return ret;
	175
8324aa91 JA	176	if (max_sectors_kb > max_hw_sectors_kb \|\| max_sectors_kb < page_kb)
8324aa91 JA	177	return -EINVAL;
7c239517	178
8324aa91	179	spin_lock_irq(q->queue_lock);
c295fc05	180	q->limits.max_sectors = max_sectors_kb << 1;
8324aa91 JA	181	spin_unlock_irq(q->queue_lock);
	182
	183	return ret;
	184	}
	185
	186	static ssize_t queue_max_hw_sectors_show(struct request_queue q, char page)
	187	{
ae03bf63	188	int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
8324aa91 JA	189
	190	return queue_var_show(max_hw_sectors_kb, (page));
	191	}
	192
956bcb7c JA	193	#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
	194	static ssize_t \
	195	queue_show_##name(struct request_queue q, char page) \
	196	{ \
	197	int bit; \
	198	bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
	199	return queue_var_show(neg ? !bit : bit, page); \
	200	} \
	201	static ssize_t \
	202	queue_store_##name(struct request_queue q, const char page, size_t count) \
	203	{ \
	204	unsigned long val; \
	205	ssize_t ret; \
	206	ret = queue_var_store(&val, page, count); \
c678ef52 AB	207	if (ret < 0) \
c678ef52 AB	208	return ret; \
956bcb7c JA	209	if (neg) \
	210	val = !val; \
	211	\
	212	spin_lock_irq(q->queue_lock); \
	213	if (val) \
	214	queue_flag_set(QUEUE_FLAG_##flag, q); \
	215	else \
	216	queue_flag_clear(QUEUE_FLAG_##flag, q); \
	217	spin_unlock_irq(q->queue_lock); \
	218	return ret; \
1308835f BZ	219	}
1308835f BZ	220
956bcb7c JA	221	QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
	222	QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
	223	QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
	224	#undef QUEUE_SYSFS_BIT_FNS
1308835f	225
ac9fafa1 AB	226	static ssize_t queue_nomerges_show(struct request_queue q, char page)
ac9fafa1 AB	227	{
488991e2 AB	228	return queue_var_show((blk_queue_nomerges(q) << 1) \|
488991e2 AB	229	blk_queue_noxmerges(q), page);
ac9fafa1 AB	230	}
	231
	232	static ssize_t queue_nomerges_store(struct request_queue q, const char page,
	233	size_t count)
	234	{
	235	unsigned long nm;
	236	ssize_t ret = queue_var_store(&nm, page, count);
	237
b1f3b64d DR	238	if (ret < 0)
	239	return ret;
	240
bf0f9702	241	spin_lock_irq(q->queue_lock);
488991e2 AB	242	queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
	243	queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
	244	if (nm == 2)
bf0f9702	245	queue_flag_set(QUEUE_FLAG_NOMERGES, q);
488991e2 AB	246	else if (nm)
488991e2 AB	247	queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
bf0f9702	248	spin_unlock_irq(q->queue_lock);
1308835f	249
ac9fafa1 AB	250	return ret;
	251	}
	252
c7c22e4d JA	253	static ssize_t queue_rq_affinity_show(struct request_queue q, char page)
c7c22e4d JA	254	{
9cb308ce	255	bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
5757a6d7	256	bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
c7c22e4d	257
5757a6d7	258	return queue_var_show(set << force, page);
c7c22e4d JA	259	}
	260
	261	static ssize_t
	262	queue_rq_affinity_store(struct request_queue q, const char page, size_t count)
	263	{
	264	ssize_t ret = -EINVAL;
0a06ff06	265	#ifdef CONFIG_SMP
c7c22e4d JA	266	unsigned long val;
	267
	268	ret = queue_var_store(&val, page, count);
b1f3b64d DR	269	if (ret < 0)
	270	return ret;
	271
c7c22e4d	272	spin_lock_irq(q->queue_lock);
e8037d49	273	if (val == 2) {
c7c22e4d	274	queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
e8037d49 ES	275	queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
	276	} else if (val == 1) {
	277	queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
	278	queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
	279	} else if (val == 0) {
5757a6d7 DW	280	queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
	281	queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
	282	}
c7c22e4d JA	283	spin_unlock_irq(q->queue_lock);
	284	#endif
	285	return ret;
	286	}
8324aa91 JA	287
	288	static struct queue_sysfs_entry queue_requests_entry = {
	289	.attr = {.name = "nr_requests", .mode = S_IRUGO \| S_IWUSR },
	290	.show = queue_requests_show,
	291	.store = queue_requests_store,
	292	};
	293
	294	static struct queue_sysfs_entry queue_ra_entry = {
	295	.attr = {.name = "read_ahead_kb", .mode = S_IRUGO \| S_IWUSR },
	296	.show = queue_ra_show,
	297	.store = queue_ra_store,
	298	};
	299
	300	static struct queue_sysfs_entry queue_max_sectors_entry = {
	301	.attr = {.name = "max_sectors_kb", .mode = S_IRUGO \| S_IWUSR },
	302	.show = queue_max_sectors_show,
	303	.store = queue_max_sectors_store,
	304	};
	305
	306	static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
	307	.attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
	308	.show = queue_max_hw_sectors_show,
	309	};
	310
c77a5710 MP	311	static struct queue_sysfs_entry queue_max_segments_entry = {
	312	.attr = {.name = "max_segments", .mode = S_IRUGO },
	313	.show = queue_max_segments_show,
	314	};
	315
13f05c8d MP	316	static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
	317	.attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
	318	.show = queue_max_integrity_segments_show,
	319	};
	320
c77a5710 MP	321	static struct queue_sysfs_entry queue_max_segment_size_entry = {
	322	.attr = {.name = "max_segment_size", .mode = S_IRUGO },
	323	.show = queue_max_segment_size_show,
	324	};
	325
8324aa91 JA	326	static struct queue_sysfs_entry queue_iosched_entry = {
	327	.attr = {.name = "scheduler", .mode = S_IRUGO \| S_IWUSR },
	328	.show = elv_iosched_show,
	329	.store = elv_iosched_store,
	330	};
	331
e68b903c MP	332	static struct queue_sysfs_entry queue_hw_sector_size_entry = {
e68b903c MP	333	.attr = {.name = "hw_sector_size", .mode = S_IRUGO },
e1defc4f MP	334	.show = queue_logical_block_size_show,
	335	};
	336
	337	static struct queue_sysfs_entry queue_logical_block_size_entry = {
	338	.attr = {.name = "logical_block_size", .mode = S_IRUGO },
	339	.show = queue_logical_block_size_show,
e68b903c MP	340	};
e68b903c MP	341
c72758f3 MP	342	static struct queue_sysfs_entry queue_physical_block_size_entry = {
	343	.attr = {.name = "physical_block_size", .mode = S_IRUGO },
	344	.show = queue_physical_block_size_show,
	345	};
	346
	347	static struct queue_sysfs_entry queue_io_min_entry = {
	348	.attr = {.name = "minimum_io_size", .mode = S_IRUGO },
	349	.show = queue_io_min_show,
	350	};
	351
	352	static struct queue_sysfs_entry queue_io_opt_entry = {
	353	.attr = {.name = "optimal_io_size", .mode = S_IRUGO },
	354	.show = queue_io_opt_show,
e68b903c MP	355	};
e68b903c MP	356
86b37281 MP	357	static struct queue_sysfs_entry queue_discard_granularity_entry = {
	358	.attr = {.name = "discard_granularity", .mode = S_IRUGO },
	359	.show = queue_discard_granularity_show,
	360	};
	361
	362	static struct queue_sysfs_entry queue_discard_max_entry = {
	363	.attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
	364	.show = queue_discard_max_show,
	365	};
	366
98262f27 MP	367	static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
	368	.attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
	369	.show = queue_discard_zeroes_data_show,
	370	};
	371
4363ac7c MP	372	static struct queue_sysfs_entry queue_write_same_max_entry = {
	373	.attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
	374	.show = queue_write_same_max_show,
	375	};
	376
1308835f BZ	377	static struct queue_sysfs_entry queue_nonrot_entry = {
1308835f BZ	378	.attr = {.name = "rotational", .mode = S_IRUGO \| S_IWUSR },
956bcb7c JA	379	.show = queue_show_nonrot,
956bcb7c JA	380	.store = queue_store_nonrot,
1308835f BZ	381	};
1308835f BZ	382
ac9fafa1 AB	383	static struct queue_sysfs_entry queue_nomerges_entry = {
	384	.attr = {.name = "nomerges", .mode = S_IRUGO \| S_IWUSR },
	385	.show = queue_nomerges_show,
	386	.store = queue_nomerges_store,
	387	};
	388
c7c22e4d JA	389	static struct queue_sysfs_entry queue_rq_affinity_entry = {
	390	.attr = {.name = "rq_affinity", .mode = S_IRUGO \| S_IWUSR },
	391	.show = queue_rq_affinity_show,
	392	.store = queue_rq_affinity_store,
	393	};
	394
bc58ba94 JA	395	static struct queue_sysfs_entry queue_iostats_entry = {
bc58ba94 JA	396	.attr = {.name = "iostats", .mode = S_IRUGO \| S_IWUSR },
956bcb7c JA	397	.show = queue_show_iostats,
956bcb7c JA	398	.store = queue_store_iostats,
bc58ba94 JA	399	};
bc58ba94 JA	400
e2e1a148 JA	401	static struct queue_sysfs_entry queue_random_entry = {
e2e1a148 JA	402	.attr = {.name = "add_random", .mode = S_IRUGO \| S_IWUSR },
956bcb7c JA	403	.show = queue_show_random,
956bcb7c JA	404	.store = queue_store_random,
e2e1a148 JA	405	};
e2e1a148 JA	406
8324aa91 JA	407	static struct attribute *default_attrs[] = {
	408	&queue_requests_entry.attr,
	409	&queue_ra_entry.attr,
	410	&queue_max_hw_sectors_entry.attr,
	411	&queue_max_sectors_entry.attr,
c77a5710	412	&queue_max_segments_entry.attr,
13f05c8d	413	&queue_max_integrity_segments_entry.attr,
c77a5710	414	&queue_max_segment_size_entry.attr,
8324aa91	415	&queue_iosched_entry.attr,
e68b903c	416	&queue_hw_sector_size_entry.attr,
e1defc4f	417	&queue_logical_block_size_entry.attr,
c72758f3 MP	418	&queue_physical_block_size_entry.attr,
	419	&queue_io_min_entry.attr,
	420	&queue_io_opt_entry.attr,
86b37281 MP	421	&queue_discard_granularity_entry.attr,
86b37281 MP	422	&queue_discard_max_entry.attr,
98262f27	423	&queue_discard_zeroes_data_entry.attr,
4363ac7c	424	&queue_write_same_max_entry.attr,
1308835f	425	&queue_nonrot_entry.attr,
ac9fafa1	426	&queue_nomerges_entry.attr,
c7c22e4d	427	&queue_rq_affinity_entry.attr,
bc58ba94	428	&queue_iostats_entry.attr,
e2e1a148	429	&queue_random_entry.attr,
8324aa91 JA	430	NULL,
	431	};
	432
	433	#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
	434
	435	static ssize_t
	436	queue_attr_show(struct kobject kobj, struct attribute attr, char *page)
	437	{
	438	struct queue_sysfs_entry *entry = to_queue(attr);
	439	struct request_queue *q =
	440	container_of(kobj, struct request_queue, kobj);
	441	ssize_t res;
	442
	443	if (!entry->show)
	444	return -EIO;
	445	mutex_lock(&q->sysfs_lock);
3f3299d5	446	if (blk_queue_dying(q)) {
8324aa91 JA	447	mutex_unlock(&q->sysfs_lock);
	448	return -ENOENT;
	449	}
	450	res = entry->show(q, page);
	451	mutex_unlock(&q->sysfs_lock);
	452	return res;
	453	}
	454
	455	static ssize_t
	456	queue_attr_store(struct kobject kobj, struct attribute attr,
	457	const char *page, size_t length)
	458	{
	459	struct queue_sysfs_entry *entry = to_queue(attr);
6728cb0e	460	struct request_queue *q;
8324aa91 JA	461	ssize_t res;
	462
	463	if (!entry->store)
	464	return -EIO;
6728cb0e JA	465
6728cb0e JA	466	q = container_of(kobj, struct request_queue, kobj);
8324aa91	467	mutex_lock(&q->sysfs_lock);
3f3299d5	468	if (blk_queue_dying(q)) {
8324aa91 JA	469	mutex_unlock(&q->sysfs_lock);
	470	return -ENOENT;
	471	}
	472	res = entry->store(q, page, length);
	473	mutex_unlock(&q->sysfs_lock);
	474	return res;
	475	}
	476
548bc8e1 TH	477	static void blk_free_queue_rcu(struct rcu_head *rcu_head)
	478	{
	479	struct request_queue *q = container_of(rcu_head, struct request_queue,
	480	rcu_head);
	481	kmem_cache_free(blk_requestq_cachep, q);
	482	}
	483
8324aa91	484	/**
499337bb AM	485	* blk_release_queue: - release a &struct request_queue when it is no longer needed
499337bb AM	486	* @kobj: the kobj belonging to the request queue to be released
8324aa91 JA	487	*
8324aa91 JA	488	* Description:
499337bb	489	* blk_release_queue is the pair to blk_init_queue() or
8324aa91 JA	490	* blk_queue_make_request(). It should be called when a request queue is
	491	* being released; typically when a block device is being de-registered.
	492	* Currently, its primary task it to free all the &struct request
	493	* structures that were allocated to the queue and the queue itself.
	494	*
	495	* Caveat:
	496	* Hopefully the low level driver will have finished any
	497	* outstanding requests first...
	498	**/
	499	static void blk_release_queue(struct kobject *kobj)
	500	{
	501	struct request_queue *q =
	502	container_of(kobj, struct request_queue, kobj);
8324aa91 JA	503
	504	blk_sync_queue(q);
	505
e8989fae TH	506	blkcg_exit_queue(q);
e8989fae TH	507
7e5a8794 TH	508	if (q->elevator) {
	509	spin_lock_irq(q->queue_lock);
	510	ioc_clear_queue(q);
	511	spin_unlock_irq(q->queue_lock);
777eb1bf	512	elevator_exit(q->elevator);
7e5a8794	513	}
777eb1bf	514
a051661c	515	blk_exit_rl(&q->root_rl);
8324aa91 JA	516
	517	if (q->queue_tags)
	518	__blk_queue_free_tags(q);
	519
320ae51f JA	520	if (q->mq_ops)
320ae51f JA	521	blk_mq_free_queue(q);
f70ced09 ML	522	else
f70ced09 ML	523	blk_free_flush_queue(q->fq);
18741986	524
8324aa91 JA	525	blk_trace_shutdown(q);
	526
	527	bdi_destroy(&q->backing_dev_info);
a73f730d TH	528
a73f730d TH	529	ida_simple_remove(&blk_queue_ida, q->id);
548bc8e1	530	call_rcu(&q->rcu_head, blk_free_queue_rcu);
8324aa91 JA	531	}
8324aa91 JA	532
52cf25d0	533	static const struct sysfs_ops queue_sysfs_ops = {
8324aa91 JA	534	.show = queue_attr_show,
	535	.store = queue_attr_store,
	536	};
	537
	538	struct kobj_type blk_queue_ktype = {
	539	.sysfs_ops = &queue_sysfs_ops,
	540	.default_attrs = default_attrs,
	541	.release = blk_release_queue,
	542	};
	543
	544	int blk_register_queue(struct gendisk *disk)
	545	{
	546	int ret;
1d54ad6d	547	struct device *dev = disk_to_dev(disk);
8324aa91 JA	548	struct request_queue *q = disk->queue;
8324aa91 JA	549
fb199746	550	if (WARN_ON(!q))
8324aa91 JA	551	return -ENXIO;
8324aa91 JA	552
749fefe6	553	/*
17497acb TH	554	* SCSI probing may synchronously create and destroy a lot of
	555	* request_queues for non-existent devices. Shutting down a fully
	556	* functional queue takes measureable wallclock time as RCU grace
	557	* periods are involved. To avoid excessive latency in these
	558	* cases, a request_queue starts out in a degraded mode which is
	559	* faster to shut down and is made fully functional here as
	560	* request_queues for non-existent devices never get registered.
749fefe6	561	*/
df35c7c9 AS	562	if (!blk_queue_init_done(q)) {
	563	queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
	564	blk_queue_bypass_end(q);
17497acb TH	565	if (q->mq_ops)
17497acb TH	566	blk_mq_finish_init(q);
df35c7c9	567	}
749fefe6	568
1d54ad6d LZ	569	ret = blk_trace_init_sysfs(dev);
	570	if (ret)
	571	return ret;
	572
c9059598	573	ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
ed5302d3 LY	574	if (ret < 0) {
ed5302d3 LY	575	blk_trace_remove_sysfs(dev);
8324aa91	576	return ret;
ed5302d3	577	}
8324aa91 JA	578
	579	kobject_uevent(&q->kobj, KOBJ_ADD);
	580
320ae51f JA	581	if (q->mq_ops)
	582	blk_mq_register_disk(disk);
	583
cd43e26f MP	584	if (!q->request_fn)
	585	return 0;
	586
8324aa91 JA	587	ret = elv_register_queue(q);
	588	if (ret) {
	589	kobject_uevent(&q->kobj, KOBJ_REMOVE);
	590	kobject_del(&q->kobj);
80656b67	591	blk_trace_remove_sysfs(dev);
c87ffbb8	592	kobject_put(&dev->kobj);
8324aa91 JA	593	return ret;
	594	}
	595
	596	return 0;
	597	}
	598
	599	void blk_unregister_queue(struct gendisk *disk)
	600	{
	601	struct request_queue *q = disk->queue;
	602
fb199746 AM	603	if (WARN_ON(!q))
	604	return;
	605
320ae51f JA	606	if (q->mq_ops)
	607	blk_mq_unregister_disk(disk);
	608
48c0d4d4	609	if (q->request_fn)
8324aa91 JA	610	elv_unregister_queue(q);
8324aa91 JA	611
48c0d4d4 ZK	612	kobject_uevent(&q->kobj, KOBJ_REMOVE);
	613	kobject_del(&q->kobj);
	614	blk_trace_remove_sysfs(disk_to_dev(disk));
	615	kobject_put(&disk_to_dev(disk)->kobj);
8324aa91	616	}