[linux-block.git] / block / blk-sysfs.c

/*
 * Functions related to sysfs handling
 */
#include <linux/kernel.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 int var, char *page)
{
	return sprintf(page, "%d\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 = 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[READ] >= queue_congestion_on_threshold(q))
		blk_set_queue_congested(q, READ);
	else if (rl->count[READ] < queue_congestion_off_threshold(q))
		blk_clear_queue_congested(q, READ);

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

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

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

static ssize_t queue_ra_show(struct request_queue *q, char *page)
{
	int 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 = q->max_sectors >> 1;

	return queue_var_show(max_sectors_kb, (page));
}

static ssize_t queue_hw_sector_size_show(struct request_queue *q, char *page)
{
	return queue_var_show(q->hardsect_size, 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 = q->max_hw_sectors >> 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->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 = q->max_hw_sectors >> 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), 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);
	if (nm)
		queue_flag_set(QUEUE_FLAG_NOMERGES, q);
	else
		queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
	spin_unlock_irq(q->queue_lock);

	return ret;
}

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

	return queue_var_show(set != 0, 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 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_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_hw_sector_size_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 attribute *default_attrs[] = {
	&queue_requests_entry.attr,
	&queue_ra_entry.attr,
	&queue_max_hw_sectors_entry.attr,
	&queue_max_sectors_entry.attr,
	&queue_iosched_entry.attr,
	&queue_hw_sector_size_entry.attr,
	&queue_nonrot_entry.attr,
	&queue_nomerges_entry.attr,
	&queue_rq_affinity_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 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 request_queue *q = disk->queue;

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

	if (!q->request_fn)
		return 0;

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

	kobject_uevent(&q->kobj, KOBJ_ADD);

	ret = elv_register_queue(q);
	if (ret) {
		kobject_uevent(&q->kobj, KOBJ_REMOVE);
		kobject_del(&q->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->request_fn) {
		elv_unregister_queue(q);

		kobject_uevent(&q->kobj, KOBJ_REMOVE);
		kobject_del(&q->kobj);
		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>
	5	#include <linux/module.h>
	6	#include <linux/bio.h>
	7	#include <linux/blkdev.h>
	8	#include <linux/blktrace_api.h>
	9
	10	#include "blk.h"
	11
	12	struct queue_sysfs_entry {
	13	struct attribute attr;
	14	ssize_t (show)(struct request_queue , char *);
	15	ssize_t (store)(struct request_queue , const char *, size_t);
	16	};
	17
	18	static ssize_t
	19	queue_var_show(unsigned int var, char *page)
	20	{
	21	return sprintf(page, "%d\n", var);
	22	}
	23
	24	static ssize_t
	25	queue_var_store(unsigned long var, const char page, size_t count)
	26	{
	27	char p = (char ) page;
	28
	29	*var = simple_strtoul(p, &p, 10);
	30	return count;
	31	}
	32
	33	static ssize_t queue_requests_show(struct request_queue q, char page)
	34	{
	35	return queue_var_show(q->nr_requests, (page));
	36	}
	37
	38	static ssize_t
	39	queue_requests_store(struct request_queue q, const char page, size_t count)
	40	{
	41	struct request_list *rl = &q->rq;
	42	unsigned long nr;
	43	int ret = queue_var_store(&nr, page, count);
	44	if (nr < BLKDEV_MIN_RQ)
	45	nr = BLKDEV_MIN_RQ;
	46
	47	spin_lock_irq(q->queue_lock);
	48	q->nr_requests = nr;
	49	blk_queue_congestion_threshold(q);
	50
	51	if (rl->count[READ] >= queue_congestion_on_threshold(q))
	52	blk_set_queue_congested(q, READ);
	53	else if (rl->count[READ] < queue_congestion_off_threshold(q))
	54	blk_clear_queue_congested(q, READ);
	55
	56	if (rl->count[WRITE] >= queue_congestion_on_threshold(q))
	57	blk_set_queue_congested(q, WRITE);
	58	else if (rl->count[WRITE] < queue_congestion_off_threshold(q))
	59	blk_clear_queue_congested(q, WRITE);
	60
	61	if (rl->count[READ] >= q->nr_requests) {
	62	blk_set_queue_full(q, READ);
	63	} else if (rl->count[READ]+1 <= q->nr_requests) {
	64	blk_clear_queue_full(q, READ);
65	wake_up(&rl->wait[READ]);
66	}
67
68	if (rl->count[WRITE] >= q->nr_requests) {
69	blk_set_queue_full(q, WRITE);
70	} else if (rl->count[WRITE]+1 <= q->nr_requests) {
71	blk_clear_queue_full(q, WRITE);
72	wake_up(&rl->wait[WRITE]);
73	}
74	spin_unlock_irq(q->queue_lock);
75	return ret;
76	}
77
78	static ssize_t queue_ra_show(struct request_queue q, char page)
79	{
80	int ra_kb = q->backing_dev_info.ra_pages << (PAGE_CACHE_SHIFT - 10);
81
82	return queue_var_show(ra_kb, (page));
83	}
84
85	static ssize_t
86	queue_ra_store(struct request_queue q, const char page, size_t count)
87	{
88	unsigned long ra_kb;
89	ssize_t ret = queue_var_store(&ra_kb, page, count);
90
8324aa91	91	q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
8324aa91 JA	92
	93	return ret;
	94	}
	95
	96	static ssize_t queue_max_sectors_show(struct request_queue q, char page)
	97	{
	98	int max_sectors_kb = q->max_sectors >> 1;
	99
	100	return queue_var_show(max_sectors_kb, (page));
	101	}
	102
e68b903c MP	103	static ssize_t queue_hw_sector_size_show(struct request_queue q, char page)
	104	{
	105	return queue_var_show(q->hardsect_size, page);
	106	}
	107
8324aa91 JA	108	static ssize_t
	109	queue_max_sectors_store(struct request_queue q, const char page, size_t count)
	110	{
	111	unsigned long max_sectors_kb,
	112	max_hw_sectors_kb = q->max_hw_sectors >> 1,
	113	page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
	114	ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
	115
	116	if (max_sectors_kb > max_hw_sectors_kb \|\| max_sectors_kb < page_kb)
	117	return -EINVAL;
7c239517	118
8324aa91 JA	119	spin_lock_irq(q->queue_lock);
	120	q->max_sectors = max_sectors_kb << 1;
	121	spin_unlock_irq(q->queue_lock);
	122
	123	return ret;
	124	}
	125
	126	static ssize_t queue_max_hw_sectors_show(struct request_queue q, char page)
	127	{
	128	int max_hw_sectors_kb = q->max_hw_sectors >> 1;
	129
	130	return queue_var_show(max_hw_sectors_kb, (page));
	131	}
	132
1308835f BZ	133	static ssize_t queue_nonrot_show(struct request_queue q, char page)
	134	{
	135	return queue_var_show(!blk_queue_nonrot(q), page);
	136	}
	137
	138	static ssize_t queue_nonrot_store(struct request_queue q, const char page,
	139	size_t count)
	140	{
	141	unsigned long nm;
	142	ssize_t ret = queue_var_store(&nm, page, count);
	143
	144	spin_lock_irq(q->queue_lock);
	145	if (nm)
	146	queue_flag_clear(QUEUE_FLAG_NONROT, q);
	147	else
	148	queue_flag_set(QUEUE_FLAG_NONROT, q);
	149	spin_unlock_irq(q->queue_lock);
	150
	151	return ret;
	152	}
	153
ac9fafa1 AB	154	static ssize_t queue_nomerges_show(struct request_queue q, char page)
	155	{
	156	return queue_var_show(blk_queue_nomerges(q), page);
	157	}
	158
	159	static ssize_t queue_nomerges_store(struct request_queue q, const char page,
	160	size_t count)
	161	{
	162	unsigned long nm;
	163	ssize_t ret = queue_var_store(&nm, page, count);
	164
bf0f9702	165	spin_lock_irq(q->queue_lock);
ac9fafa1	166	if (nm)
bf0f9702	167	queue_flag_set(QUEUE_FLAG_NOMERGES, q);
ac9fafa1	168	else
bf0f9702	169	queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
bf0f9702	170	spin_unlock_irq(q->queue_lock);
1308835f	171
ac9fafa1 AB	172	return ret;
	173	}
	174
c7c22e4d JA	175	static ssize_t queue_rq_affinity_show(struct request_queue q, char page)
	176	{
	177	unsigned int set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
	178
	179	return queue_var_show(set != 0, page);
	180	}
	181
	182	static ssize_t
	183	queue_rq_affinity_store(struct request_queue q, const char page, size_t count)
	184	{
	185	ssize_t ret = -EINVAL;
	186	#if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
	187	unsigned long val;
	188
	189	ret = queue_var_store(&val, page, count);
	190	spin_lock_irq(q->queue_lock);
	191	if (val)
	192	queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
	193	else
	194	queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
	195	spin_unlock_irq(q->queue_lock);
	196	#endif
	197	return ret;
	198	}
8324aa91 JA	199
	200	static struct queue_sysfs_entry queue_requests_entry = {
	201	.attr = {.name = "nr_requests", .mode = S_IRUGO \| S_IWUSR },
	202	.show = queue_requests_show,
	203	.store = queue_requests_store,
	204	};
	205
	206	static struct queue_sysfs_entry queue_ra_entry = {
	207	.attr = {.name = "read_ahead_kb", .mode = S_IRUGO \| S_IWUSR },
	208	.show = queue_ra_show,
	209	.store = queue_ra_store,
	210	};
	211
	212	static struct queue_sysfs_entry queue_max_sectors_entry = {
	213	.attr = {.name = "max_sectors_kb", .mode = S_IRUGO \| S_IWUSR },
	214	.show = queue_max_sectors_show,
	215	.store = queue_max_sectors_store,
	216	};
	217
	218	static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
	219	.attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
	220	.show = queue_max_hw_sectors_show,
	221	};
	222
	223	static struct queue_sysfs_entry queue_iosched_entry = {
	224	.attr = {.name = "scheduler", .mode = S_IRUGO \| S_IWUSR },
	225	.show = elv_iosched_show,
	226	.store = elv_iosched_store,
	227	};
	228
e68b903c MP	229	static struct queue_sysfs_entry queue_hw_sector_size_entry = {
	230	.attr = {.name = "hw_sector_size", .mode = S_IRUGO },
	231	.show = queue_hw_sector_size_show,
	232	};
	233
1308835f BZ	234	static struct queue_sysfs_entry queue_nonrot_entry = {
	235	.attr = {.name = "rotational", .mode = S_IRUGO \| S_IWUSR },
	236	.show = queue_nonrot_show,
	237	.store = queue_nonrot_store,
	238	};
	239
ac9fafa1 AB	240	static struct queue_sysfs_entry queue_nomerges_entry = {
	241	.attr = {.name = "nomerges", .mode = S_IRUGO \| S_IWUSR },
	242	.show = queue_nomerges_show,
	243	.store = queue_nomerges_store,
	244	};
	245
c7c22e4d JA	246	static struct queue_sysfs_entry queue_rq_affinity_entry = {
	247	.attr = {.name = "rq_affinity", .mode = S_IRUGO \| S_IWUSR },
	248	.show = queue_rq_affinity_show,
	249	.store = queue_rq_affinity_store,
	250	};
	251
8324aa91 JA	252	static struct attribute *default_attrs[] = {
	253	&queue_requests_entry.attr,
	254	&queue_ra_entry.attr,
	255	&queue_max_hw_sectors_entry.attr,
	256	&queue_max_sectors_entry.attr,
	257	&queue_iosched_entry.attr,
e68b903c	258	&queue_hw_sector_size_entry.attr,
1308835f	259	&queue_nonrot_entry.attr,
ac9fafa1	260	&queue_nomerges_entry.attr,
c7c22e4d	261	&queue_rq_affinity_entry.attr,
8324aa91 JA	262	NULL,
	263	};
	264
	265	#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
	266
	267	static ssize_t
	268	queue_attr_show(struct kobject kobj, struct attribute attr, char *page)
	269	{
	270	struct queue_sysfs_entry *entry = to_queue(attr);
	271	struct request_queue *q =
	272	container_of(kobj, struct request_queue, kobj);
	273	ssize_t res;
	274
	275	if (!entry->show)
	276	return -EIO;
	277	mutex_lock(&q->sysfs_lock);
	278	if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
	279	mutex_unlock(&q->sysfs_lock);
	280	return -ENOENT;
	281	}
	282	res = entry->show(q, page);
	283	mutex_unlock(&q->sysfs_lock);
	284	return res;
	285	}
	286
	287	static ssize_t
	288	queue_attr_store(struct kobject kobj, struct attribute attr,
	289	const char *page, size_t length)
	290	{
	291	struct queue_sysfs_entry *entry = to_queue(attr);
6728cb0e	292	struct request_queue *q;
8324aa91 JA	293	ssize_t res;
	294
	295	if (!entry->store)
	296	return -EIO;
6728cb0e JA	297
6728cb0e JA	298	q = container_of(kobj, struct request_queue, kobj);
8324aa91 JA	299	mutex_lock(&q->sysfs_lock);
	300	if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
	301	mutex_unlock(&q->sysfs_lock);
	302	return -ENOENT;
	303	}
	304	res = entry->store(q, page, length);
	305	mutex_unlock(&q->sysfs_lock);
	306	return res;
	307	}
	308
	309	/**
	310	* blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
	311	* @kobj: the kobj belonging of the request queue to be released
	312	*
	313	* Description:
	314	* blk_cleanup_queue is the pair to blk_init_queue() or
	315	* blk_queue_make_request(). It should be called when a request queue is
	316	* being released; typically when a block device is being de-registered.
	317	* Currently, its primary task it to free all the &struct request
	318	* structures that were allocated to the queue and the queue itself.
	319	*
	320	* Caveat:
	321	* Hopefully the low level driver will have finished any
	322	* outstanding requests first...
	323	**/
	324	static void blk_release_queue(struct kobject *kobj)
	325	{
	326	struct request_queue *q =
	327	container_of(kobj, struct request_queue, kobj);
	328	struct request_list *rl = &q->rq;
	329
	330	blk_sync_queue(q);
	331
	332	if (rl->rq_pool)
	333	mempool_destroy(rl->rq_pool);
	334
	335	if (q->queue_tags)
	336	__blk_queue_free_tags(q);
	337
	338	blk_trace_shutdown(q);
	339
	340	bdi_destroy(&q->backing_dev_info);
	341	kmem_cache_free(blk_requestq_cachep, q);
	342	}
	343
	344	static struct sysfs_ops queue_sysfs_ops = {
	345	.show = queue_attr_show,
	346	.store = queue_attr_store,
	347	};
	348
	349	struct kobj_type blk_queue_ktype = {
	350	.sysfs_ops = &queue_sysfs_ops,
	351	.default_attrs = default_attrs,
	352	.release = blk_release_queue,
	353	};
	354
	355	int blk_register_queue(struct gendisk *disk)
	356	{
	357	int ret;
	358
	359	struct request_queue *q = disk->queue;
	360
fb199746	361	if (WARN_ON(!q))
8324aa91 JA	362	return -ENXIO;
8324aa91 JA	363
fb199746 AM	364	if (!q->request_fn)
	365	return 0;
	366
ed9e1982	367	ret = kobject_add(&q->kobj, kobject_get(&disk_to_dev(disk)->kobj),
8324aa91 JA	368	"%s", "queue");
	369	if (ret < 0)
	370	return ret;
	371
	372	kobject_uevent(&q->kobj, KOBJ_ADD);
	373
	374	ret = elv_register_queue(q);
	375	if (ret) {
	376	kobject_uevent(&q->kobj, KOBJ_REMOVE);
	377	kobject_del(&q->kobj);
	378	return ret;
	379	}
	380
	381	return 0;
	382	}
	383
	384	void blk_unregister_queue(struct gendisk *disk)
	385	{
	386	struct request_queue *q = disk->queue;
	387
fb199746 AM	388	if (WARN_ON(!q))
	389	return;
	390
	391	if (q->request_fn) {
8324aa91 JA	392	elv_unregister_queue(q);
	393
	394	kobject_uevent(&q->kobj, KOBJ_REMOVE);
	395	kobject_del(&q->kobj);
ed9e1982	396	kobject_put(&disk_to_dev(disk)->kobj);
8324aa91 JA	397	}
8324aa91 JA	398	}