[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 "blk.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)
{
	char *p = (char *) page;

	*var = simple_strtoul(p, &p, 10);
	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)
{
	struct request_list *rl = &q->rq;
	unsigned long nr;
	int ret;

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

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

	spin_lock_irq(q->queue_lock);
	q->nr_requests = nr;
	blk_queue_congestion_threshold(q);

	if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
		blk_set_queue_congested(q, BLK_RW_SYNC);
	else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
		blk_clear_queue_congested(q, BLK_RW_SYNC);

	if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
		blk_set_queue_congested(q, BLK_RW_ASYNC);
	else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
		blk_clear_queue_congested(q, BLK_RW_ASYNC);

	if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
		blk_set_queue_full(q, BLK_RW_SYNC);
	} else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) {
		blk_clear_queue_full(q, BLK_RW_SYNC);
		wake_up(&rl->wait[BLK_RW_SYNC]);
	}

	if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
		blk_set_queue_full(q, BLK_RW_ASYNC);
	} else if (rl->count[BLK_RW_ASYNC]+1 <= q->nr_requests) {
		blk_clear_queue_full(q, BLK_RW_ASYNC);
		wake_up(&rl->wait[BLK_RW_ASYNC]);
	}
	spin_unlock_irq(q->queue_lock);
	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);

	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_segment_size_show(struct request_queue *q, char *page)
{
	if (test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags))
		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 queue_var_show(q->limits.max_discard_sectors << 9, page);
}

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_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 (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));
}

static ssize_t queue_nonrot_show(struct request_queue *q, char *page)
{
	return queue_var_show(!blk_queue_nonrot(q), page);
}

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

	spin_lock_irq(q->queue_lock);
	if (nm)
		queue_flag_clear(QUEUE_FLAG_NONROT, q);
	else
		queue_flag_set(QUEUE_FLAG_NONROT, q);
	spin_unlock_irq(q->queue_lock);

	return ret;
}

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);

	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);

	return queue_var_show(set, page);
}

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

	ret = queue_var_store(&val, page, count);
	spin_lock_irq(q->queue_lock);
	if (val)
		queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
	else
		queue_flag_clear(QUEUE_FLAG_SAME_COMP,  q);
	spin_unlock_irq(q->queue_lock);
#endif
	return ret;
}

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

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

	spin_lock_irq(q->queue_lock);
	if (stats)
		queue_flag_set(QUEUE_FLAG_IO_STAT, q);
	else
		queue_flag_clear(QUEUE_FLAG_IO_STAT, q);
	spin_unlock_irq(q->queue_lock);

	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_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_nonrot_entry = {
	.attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
	.show = queue_nonrot_show,
	.store = queue_nonrot_store,
};

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_iostats_show,
	.store = queue_iostats_store,
};

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_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_nonrot_entry.attr,
	&queue_nomerges_entry.attr,
	&queue_rq_affinity_entry.attr,
	&queue_iostats_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 (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
		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 (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
		mutex_unlock(&q->sysfs_lock);
		return -ENOENT;
	}
	res = entry->store(q, page, length);
	mutex_unlock(&q->sysfs_lock);
	return res;
}

/**
 * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
 * @kobj:    the kobj belonging of the request queue to be released
 *
 * Description:
 *     blk_cleanup_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);
	struct request_list *rl = &q->rq;

	blk_sync_queue(q);

	if (rl->rq_pool)
		mempool_destroy(rl->rq_pool);

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

	blk_trace_shutdown(q);

	bdi_destroy(&q->backing_dev_info);
	kmem_cache_free(blk_requestq_cachep, q);
}

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;

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

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

	kobject_uevent(&q->kobj, KOBJ_ADD);

	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(disk_to_dev(disk));
		return ret;
	}

	return 0;
}

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

	if (WARN_ON(!q))
		return;

	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
	1	/*
	2	* Functions related to sysfs handling
	3	*/
	4	#include <linux/kernel.h>
	5	#include <linux/slab.h>
	6	#include <linux/module.h>
	7	#include <linux/bio.h>
	8	#include <linux/blkdev.h>
	9	#include <linux/blktrace_api.h>
	10
	11	#include "blk.h"
	12
	13	struct queue_sysfs_entry {
	14	struct attribute attr;
	15	ssize_t (show)(struct request_queue , char *);
	16	ssize_t (store)(struct request_queue , const char *, size_t);
	17	};
	18
	19	static ssize_t
	20	queue_var_show(unsigned long var, char *page)
	21	{
	22	return sprintf(page, "%lu\n", var);
	23	}
	24
	25	static ssize_t
	26	queue_var_store(unsigned long var, const char page, size_t count)
	27	{
	28	char p = (char ) page;
	29
	30	*var = simple_strtoul(p, &p, 10);
	31	return count;
	32	}
	33
	34	static ssize_t queue_requests_show(struct request_queue q, char page)
	35	{
	36	return queue_var_show(q->nr_requests, (page));
	37	}
	38
	39	static ssize_t
	40	queue_requests_store(struct request_queue q, const char page, size_t count)
	41	{
	42	struct request_list *rl = &q->rq;
	43	unsigned long nr;
	44	int ret;
	45
	46	if (!q->request_fn)
	47	return -EINVAL;
	48
	49	ret = queue_var_store(&nr, page, count);
	50	if (nr < BLKDEV_MIN_RQ)
	51	nr = BLKDEV_MIN_RQ;
	52
	53	spin_lock_irq(q->queue_lock);
	54	q->nr_requests = nr;
	55	blk_queue_congestion_threshold(q);
	56
	57	if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
	58	blk_set_queue_congested(q, BLK_RW_SYNC);
	59	else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
	60	blk_clear_queue_congested(q, BLK_RW_SYNC);
	61
	62	if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
	63	blk_set_queue_congested(q, BLK_RW_ASYNC);
	64	else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
	65	blk_clear_queue_congested(q, BLK_RW_ASYNC);
	66
	67	if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
	68	blk_set_queue_full(q, BLK_RW_SYNC);
	69	} else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) {
	70	blk_clear_queue_full(q, BLK_RW_SYNC);
	71	wake_up(&rl->wait[BLK_RW_SYNC]);
	72	}
	73
	74	if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
	75	blk_set_queue_full(q, BLK_RW_ASYNC);
	76	} else if (rl->count[BLK_RW_ASYNC]+1 <= q->nr_requests) {
	77	blk_clear_queue_full(q, BLK_RW_ASYNC);
	78	wake_up(&rl->wait[BLK_RW_ASYNC]);
	79	}
	80	spin_unlock_irq(q->queue_lock);
	81	return ret;
	82	}
	83
	84	static ssize_t queue_ra_show(struct request_queue q, char page)
	85	{
	86	unsigned long ra_kb = q->backing_dev_info.ra_pages <<
	87	(PAGE_CACHE_SHIFT - 10);
	88
	89	return queue_var_show(ra_kb, (page));
	90	}
	91
	92	static ssize_t
	93	queue_ra_store(struct request_queue q, const char page, size_t count)
	94	{
	95	unsigned long ra_kb;
	96	ssize_t ret = queue_var_store(&ra_kb, page, count);
	97
	98	q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
	99
	100	return ret;
	101	}
	102
	103	static ssize_t queue_max_sectors_show(struct request_queue q, char page)
	104	{
	105	int max_sectors_kb = queue_max_sectors(q) >> 1;
	106
	107	return queue_var_show(max_sectors_kb, (page));
	108	}
	109
	110	static ssize_t queue_max_segments_show(struct request_queue q, char page)
	111	{
	112	return queue_var_show(queue_max_segments(q), (page));
	113	}
	114
	115	static ssize_t queue_max_segment_size_show(struct request_queue q, char page)
	116	{
	117	if (test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags))
	118	return queue_var_show(queue_max_segment_size(q), (page));
	119
	120	return queue_var_show(PAGE_CACHE_SIZE, (page));
	121	}
	122
	123	static ssize_t queue_logical_block_size_show(struct request_queue q, char page)
	124	{
	125	return queue_var_show(queue_logical_block_size(q), page);
	126	}
	127
	128	static ssize_t queue_physical_block_size_show(struct request_queue q, char page)
	129	{
	130	return queue_var_show(queue_physical_block_size(q), page);
	131	}
	132
	133	static ssize_t queue_io_min_show(struct request_queue q, char page)
	134	{
	135	return queue_var_show(queue_io_min(q), page);
	136	}
	137
	138	static ssize_t queue_io_opt_show(struct request_queue q, char page)
	139	{
	140	return queue_var_show(queue_io_opt(q), page);
	141	}
	142
	143	static ssize_t queue_discard_granularity_show(struct request_queue q, char page)
	144	{
	145	return queue_var_show(q->limits.discard_granularity, page);
	146	}
	147
	148	static ssize_t queue_discard_max_show(struct request_queue q, char page)
	149	{
	150	return queue_var_show(q->limits.max_discard_sectors << 9, page);
	151	}
	152
	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
	158	static ssize_t
	159	queue_max_sectors_store(struct request_queue q, const char page, size_t count)
	160	{
	161	unsigned long max_sectors_kb,
	162	max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
	163	page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
	164	ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
	165
	166	if (max_sectors_kb > max_hw_sectors_kb \|\| max_sectors_kb < page_kb)
	167	return -EINVAL;
	168
	169	spin_lock_irq(q->queue_lock);
	170	q->limits.max_sectors = max_sectors_kb << 1;
	171	spin_unlock_irq(q->queue_lock);
	172
	173	return ret;
	174	}
	175
	176	static ssize_t queue_max_hw_sectors_show(struct request_queue q, char page)
	177	{
	178	int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
	179
	180	return queue_var_show(max_hw_sectors_kb, (page));
	181	}
	182
	183	static ssize_t queue_nonrot_show(struct request_queue q, char page)
	184	{
	185	return queue_var_show(!blk_queue_nonrot(q), page);
	186	}
	187
	188	static ssize_t queue_nonrot_store(struct request_queue q, const char page,
	189	size_t count)
	190	{
	191	unsigned long nm;
	192	ssize_t ret = queue_var_store(&nm, page, count);
	193
	194	spin_lock_irq(q->queue_lock);
	195	if (nm)
	196	queue_flag_clear(QUEUE_FLAG_NONROT, q);
	197	else
	198	queue_flag_set(QUEUE_FLAG_NONROT, q);
	199	spin_unlock_irq(q->queue_lock);
	200
	201	return ret;
	202	}
	203
	204	static ssize_t queue_nomerges_show(struct request_queue q, char page)
	205	{
	206	return queue_var_show((blk_queue_nomerges(q) << 1) \|
	207	blk_queue_noxmerges(q), page);
	208	}
	209
	210	static ssize_t queue_nomerges_store(struct request_queue q, const char page,
	211	size_t count)
	212	{
	213	unsigned long nm;
	214	ssize_t ret = queue_var_store(&nm, page, count);
	215
	216	spin_lock_irq(q->queue_lock);
	217	queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
	218	queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
	219	if (nm == 2)
	220	queue_flag_set(QUEUE_FLAG_NOMERGES, q);
	221	else if (nm)
	222	queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
	223	spin_unlock_irq(q->queue_lock);
	224
	225	return ret;
	226	}
	227
	228	static ssize_t queue_rq_affinity_show(struct request_queue q, char page)
	229	{
	230	bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
	231
	232	return queue_var_show(set, page);
	233	}
	234
	235	static ssize_t
	236	queue_rq_affinity_store(struct request_queue q, const char page, size_t count)
	237	{
	238	ssize_t ret = -EINVAL;
	239	#if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
	240	unsigned long val;
	241
	242	ret = queue_var_store(&val, page, count);
	243	spin_lock_irq(q->queue_lock);
	244	if (val)
	245	queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
	246	else
	247	queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
	248	spin_unlock_irq(q->queue_lock);
	249	#endif
	250	return ret;
	251	}
	252
	253	static ssize_t queue_iostats_show(struct request_queue q, char page)
	254	{
	255	return queue_var_show(blk_queue_io_stat(q), page);
	256	}
	257
	258	static ssize_t queue_iostats_store(struct request_queue q, const char page,
	259	size_t count)
	260	{
	261	unsigned long stats;
	262	ssize_t ret = queue_var_store(&stats, page, count);
	263
	264	spin_lock_irq(q->queue_lock);
	265	if (stats)
	266	queue_flag_set(QUEUE_FLAG_IO_STAT, q);
	267	else
	268	queue_flag_clear(QUEUE_FLAG_IO_STAT, q);
	269	spin_unlock_irq(q->queue_lock);
	270
	271	return ret;
	272	}
	273
	274	static struct queue_sysfs_entry queue_requests_entry = {
	275	.attr = {.name = "nr_requests", .mode = S_IRUGO \| S_IWUSR },
	276	.show = queue_requests_show,
	277	.store = queue_requests_store,
	278	};
	279
	280	static struct queue_sysfs_entry queue_ra_entry = {
	281	.attr = {.name = "read_ahead_kb", .mode = S_IRUGO \| S_IWUSR },
	282	.show = queue_ra_show,
	283	.store = queue_ra_store,
	284	};
	285
	286	static struct queue_sysfs_entry queue_max_sectors_entry = {
	287	.attr = {.name = "max_sectors_kb", .mode = S_IRUGO \| S_IWUSR },
	288	.show = queue_max_sectors_show,
	289	.store = queue_max_sectors_store,
	290	};
	291
	292	static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
	293	.attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
	294	.show = queue_max_hw_sectors_show,
	295	};
	296
	297	static struct queue_sysfs_entry queue_max_segments_entry = {
	298	.attr = {.name = "max_segments", .mode = S_IRUGO },
	299	.show = queue_max_segments_show,
	300	};
	301
	302	static struct queue_sysfs_entry queue_max_segment_size_entry = {
	303	.attr = {.name = "max_segment_size", .mode = S_IRUGO },
	304	.show = queue_max_segment_size_show,
	305	};
	306
	307	static struct queue_sysfs_entry queue_iosched_entry = {
	308	.attr = {.name = "scheduler", .mode = S_IRUGO \| S_IWUSR },
	309	.show = elv_iosched_show,
	310	.store = elv_iosched_store,
	311	};
	312
	313	static struct queue_sysfs_entry queue_hw_sector_size_entry = {
	314	.attr = {.name = "hw_sector_size", .mode = S_IRUGO },
	315	.show = queue_logical_block_size_show,
	316	};
	317
	318	static struct queue_sysfs_entry queue_logical_block_size_entry = {
	319	.attr = {.name = "logical_block_size", .mode = S_IRUGO },
	320	.show = queue_logical_block_size_show,
	321	};
	322
	323	static struct queue_sysfs_entry queue_physical_block_size_entry = {
	324	.attr = {.name = "physical_block_size", .mode = S_IRUGO },
	325	.show = queue_physical_block_size_show,
	326	};
	327
	328	static struct queue_sysfs_entry queue_io_min_entry = {
	329	.attr = {.name = "minimum_io_size", .mode = S_IRUGO },
	330	.show = queue_io_min_show,
	331	};
	332
	333	static struct queue_sysfs_entry queue_io_opt_entry = {
	334	.attr = {.name = "optimal_io_size", .mode = S_IRUGO },
	335	.show = queue_io_opt_show,
	336	};
	337
	338	static struct queue_sysfs_entry queue_discard_granularity_entry = {
	339	.attr = {.name = "discard_granularity", .mode = S_IRUGO },
	340	.show = queue_discard_granularity_show,
	341	};
	342
	343	static struct queue_sysfs_entry queue_discard_max_entry = {
	344	.attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
	345	.show = queue_discard_max_show,
	346	};
	347
	348	static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
	349	.attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
	350	.show = queue_discard_zeroes_data_show,
	351	};
	352
	353	static struct queue_sysfs_entry queue_nonrot_entry = {
	354	.attr = {.name = "rotational", .mode = S_IRUGO \| S_IWUSR },
	355	.show = queue_nonrot_show,
	356	.store = queue_nonrot_store,
	357	};
	358
	359	static struct queue_sysfs_entry queue_nomerges_entry = {
	360	.attr = {.name = "nomerges", .mode = S_IRUGO \| S_IWUSR },
	361	.show = queue_nomerges_show,
	362	.store = queue_nomerges_store,
	363	};
	364
	365	static struct queue_sysfs_entry queue_rq_affinity_entry = {
	366	.attr = {.name = "rq_affinity", .mode = S_IRUGO \| S_IWUSR },
	367	.show = queue_rq_affinity_show,
	368	.store = queue_rq_affinity_store,
	369	};
	370
	371	static struct queue_sysfs_entry queue_iostats_entry = {
	372	.attr = {.name = "iostats", .mode = S_IRUGO \| S_IWUSR },
	373	.show = queue_iostats_show,
	374	.store = queue_iostats_store,
	375	};
	376
	377	static struct attribute *default_attrs[] = {
	378	&queue_requests_entry.attr,
	379	&queue_ra_entry.attr,
	380	&queue_max_hw_sectors_entry.attr,
	381	&queue_max_sectors_entry.attr,
	382	&queue_max_segments_entry.attr,
	383	&queue_max_segment_size_entry.attr,
	384	&queue_iosched_entry.attr,
	385	&queue_hw_sector_size_entry.attr,
	386	&queue_logical_block_size_entry.attr,
	387	&queue_physical_block_size_entry.attr,
	388	&queue_io_min_entry.attr,
	389	&queue_io_opt_entry.attr,
	390	&queue_discard_granularity_entry.attr,
	391	&queue_discard_max_entry.attr,
	392	&queue_discard_zeroes_data_entry.attr,
	393	&queue_nonrot_entry.attr,
	394	&queue_nomerges_entry.attr,
	395	&queue_rq_affinity_entry.attr,
	396	&queue_iostats_entry.attr,
	397	NULL,
	398	};
	399
	400	#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
	401
	402	static ssize_t
	403	queue_attr_show(struct kobject kobj, struct attribute attr, char *page)
	404	{
	405	struct queue_sysfs_entry *entry = to_queue(attr);
	406	struct request_queue *q =
	407	container_of(kobj, struct request_queue, kobj);
	408	ssize_t res;
	409
	410	if (!entry->show)
	411	return -EIO;
	412	mutex_lock(&q->sysfs_lock);
	413	if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
	414	mutex_unlock(&q->sysfs_lock);
	415	return -ENOENT;
	416	}
	417	res = entry->show(q, page);
	418	mutex_unlock(&q->sysfs_lock);
	419	return res;
	420	}
	421
	422	static ssize_t
	423	queue_attr_store(struct kobject kobj, struct attribute attr,
	424	const char *page, size_t length)
	425	{
	426	struct queue_sysfs_entry *entry = to_queue(attr);
	427	struct request_queue *q;
	428	ssize_t res;
	429
	430	if (!entry->store)
	431	return -EIO;
	432
	433	q = container_of(kobj, struct request_queue, kobj);
	434	mutex_lock(&q->sysfs_lock);
	435	if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
	436	mutex_unlock(&q->sysfs_lock);
	437	return -ENOENT;
	438	}
	439	res = entry->store(q, page, length);
	440	mutex_unlock(&q->sysfs_lock);
	441	return res;
	442	}
	443
	444	/**
	445	* blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
	446	* @kobj: the kobj belonging of the request queue to be released
	447	*
	448	* Description:
	449	* blk_cleanup_queue is the pair to blk_init_queue() or
	450	* blk_queue_make_request(). It should be called when a request queue is
	451	* being released; typically when a block device is being de-registered.
	452	* Currently, its primary task it to free all the &struct request
	453	* structures that were allocated to the queue and the queue itself.
	454	*
	455	* Caveat:
	456	* Hopefully the low level driver will have finished any
	457	* outstanding requests first...
	458	**/
	459	static void blk_release_queue(struct kobject *kobj)
	460	{
	461	struct request_queue *q =
	462	container_of(kobj, struct request_queue, kobj);
	463	struct request_list *rl = &q->rq;
	464
	465	blk_sync_queue(q);
	466
	467	if (rl->rq_pool)
	468	mempool_destroy(rl->rq_pool);
	469
	470	if (q->queue_tags)
	471	__blk_queue_free_tags(q);
	472
	473	blk_trace_shutdown(q);
	474
	475	bdi_destroy(&q->backing_dev_info);
	476	kmem_cache_free(blk_requestq_cachep, q);
	477	}
	478
	479	static const struct sysfs_ops queue_sysfs_ops = {
	480	.show = queue_attr_show,
	481	.store = queue_attr_store,
	482	};
	483
	484	struct kobj_type blk_queue_ktype = {
	485	.sysfs_ops = &queue_sysfs_ops,
	486	.default_attrs = default_attrs,
	487	.release = blk_release_queue,
	488	};
	489
	490	int blk_register_queue(struct gendisk *disk)
	491	{
	492	int ret;
	493	struct device *dev = disk_to_dev(disk);
	494
	495	struct request_queue *q = disk->queue;
	496
	497	if (WARN_ON(!q))
	498	return -ENXIO;
	499
	500	ret = blk_trace_init_sysfs(dev);
	501	if (ret)
	502	return ret;
	503
	504	ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
	505	if (ret < 0)
	506	return ret;
	507
	508	kobject_uevent(&q->kobj, KOBJ_ADD);
	509
	510	if (!q->request_fn)
	511	return 0;
	512
	513	ret = elv_register_queue(q);
	514	if (ret) {
	515	kobject_uevent(&q->kobj, KOBJ_REMOVE);
	516	kobject_del(&q->kobj);
	517	blk_trace_remove_sysfs(disk_to_dev(disk));
	518	return ret;
	519	}
	520
	521	return 0;
	522	}
	523
	524	void blk_unregister_queue(struct gendisk *disk)
	525	{
	526	struct request_queue *q = disk->queue;
	527
	528	if (WARN_ON(!q))
	529	return;
	530
	531	if (q->request_fn)
	532	elv_unregister_queue(q);
	533
	534	kobject_uevent(&q->kobj, KOBJ_REMOVE);
	535	kobject_del(&q->kobj);
	536	blk_trace_remove_sysfs(disk_to_dev(disk));
	537	kobject_put(&disk_to_dev(disk)->kobj);
	538	}