[linux.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);

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

	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;
	/*
	 * Take the queue lock to update the readahead and max_sectors
	 * values synchronously:
	 */
	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_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 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_nomerges_entry = {
	.attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
	.show = queue_nomerges_show,
	.store = queue_nomerges_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_nomerges_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->dev.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->dev.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
91	spin_lock_irq(q->queue_lock);
92	q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
93	spin_unlock_irq(q->queue_lock);
94
95	return ret;
96	}
97
98	static ssize_t queue_max_sectors_show(struct request_queue q, char page)
99	{
100	int max_sectors_kb = q->max_sectors >> 1;
101
102	return queue_var_show(max_sectors_kb, (page));
103	}
104
e68b903c MP	105	static ssize_t queue_hw_sector_size_show(struct request_queue q, char page)
	106	{
	107	return queue_var_show(q->hardsect_size, page);
	108	}
	109
8324aa91 JA	110	static ssize_t
	111	queue_max_sectors_store(struct request_queue q, const char page, size_t count)
	112	{
	113	unsigned long max_sectors_kb,
	114	max_hw_sectors_kb = q->max_hw_sectors >> 1,
	115	page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
	116	ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
	117
	118	if (max_sectors_kb > max_hw_sectors_kb \|\| max_sectors_kb < page_kb)
	119	return -EINVAL;
	120	/*
	121	* Take the queue lock to update the readahead and max_sectors
	122	* values synchronously:
	123	*/
	124	spin_lock_irq(q->queue_lock);
	125	q->max_sectors = max_sectors_kb << 1;
	126	spin_unlock_irq(q->queue_lock);
	127
	128	return ret;
	129	}
	130
	131	static ssize_t queue_max_hw_sectors_show(struct request_queue q, char page)
	132	{
	133	int max_hw_sectors_kb = q->max_hw_sectors >> 1;
	134
	135	return queue_var_show(max_hw_sectors_kb, (page));
	136	}
	137
ac9fafa1 AB	138	static ssize_t queue_nomerges_show(struct request_queue q, char page)
	139	{
	140	return queue_var_show(blk_queue_nomerges(q), page);
	141	}
	142
	143	static ssize_t queue_nomerges_store(struct request_queue q, const char page,
	144	size_t count)
	145	{
	146	unsigned long nm;
	147	ssize_t ret = queue_var_store(&nm, page, count);
	148
bf0f9702	149	spin_lock_irq(q->queue_lock);
ac9fafa1	150	if (nm)
bf0f9702	151	queue_flag_set(QUEUE_FLAG_NOMERGES, q);
ac9fafa1	152	else
bf0f9702	153	queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
ac9fafa1	154
bf0f9702	155	spin_unlock_irq(q->queue_lock);
ac9fafa1 AB	156	return ret;
	157	}
	158
8324aa91 JA	159
	160	static struct queue_sysfs_entry queue_requests_entry = {
	161	.attr = {.name = "nr_requests", .mode = S_IRUGO \| S_IWUSR },
	162	.show = queue_requests_show,
	163	.store = queue_requests_store,
	164	};
	165
	166	static struct queue_sysfs_entry queue_ra_entry = {
	167	.attr = {.name = "read_ahead_kb", .mode = S_IRUGO \| S_IWUSR },
	168	.show = queue_ra_show,
	169	.store = queue_ra_store,
	170	};
	171
	172	static struct queue_sysfs_entry queue_max_sectors_entry = {
	173	.attr = {.name = "max_sectors_kb", .mode = S_IRUGO \| S_IWUSR },
	174	.show = queue_max_sectors_show,
	175	.store = queue_max_sectors_store,
	176	};
	177
	178	static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
	179	.attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
	180	.show = queue_max_hw_sectors_show,
	181	};
	182
	183	static struct queue_sysfs_entry queue_iosched_entry = {
	184	.attr = {.name = "scheduler", .mode = S_IRUGO \| S_IWUSR },
	185	.show = elv_iosched_show,
	186	.store = elv_iosched_store,
	187	};
	188
e68b903c MP	189	static struct queue_sysfs_entry queue_hw_sector_size_entry = {
	190	.attr = {.name = "hw_sector_size", .mode = S_IRUGO },
	191	.show = queue_hw_sector_size_show,
	192	};
	193
ac9fafa1 AB	194	static struct queue_sysfs_entry queue_nomerges_entry = {
	195	.attr = {.name = "nomerges", .mode = S_IRUGO \| S_IWUSR },
	196	.show = queue_nomerges_show,
	197	.store = queue_nomerges_store,
	198	};
	199
8324aa91 JA	200	static struct attribute *default_attrs[] = {
	201	&queue_requests_entry.attr,
	202	&queue_ra_entry.attr,
	203	&queue_max_hw_sectors_entry.attr,
	204	&queue_max_sectors_entry.attr,
	205	&queue_iosched_entry.attr,
e68b903c	206	&queue_hw_sector_size_entry.attr,
ac9fafa1	207	&queue_nomerges_entry.attr,
8324aa91 JA	208	NULL,
	209	};
	210
	211	#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
	212
	213	static ssize_t
	214	queue_attr_show(struct kobject kobj, struct attribute attr, char *page)
	215	{
	216	struct queue_sysfs_entry *entry = to_queue(attr);
	217	struct request_queue *q =
	218	container_of(kobj, struct request_queue, kobj);
	219	ssize_t res;
	220
	221	if (!entry->show)
	222	return -EIO;
	223	mutex_lock(&q->sysfs_lock);
	224	if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
	225	mutex_unlock(&q->sysfs_lock);
	226	return -ENOENT;
	227	}
	228	res = entry->show(q, page);
	229	mutex_unlock(&q->sysfs_lock);
	230	return res;
	231	}
	232
	233	static ssize_t
	234	queue_attr_store(struct kobject kobj, struct attribute attr,
	235	const char *page, size_t length)
	236	{
	237	struct queue_sysfs_entry *entry = to_queue(attr);
6728cb0e	238	struct request_queue *q;
8324aa91 JA	239	ssize_t res;
	240
	241	if (!entry->store)
	242	return -EIO;
6728cb0e JA	243
6728cb0e JA	244	q = container_of(kobj, struct request_queue, kobj);
8324aa91 JA	245	mutex_lock(&q->sysfs_lock);
	246	if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
	247	mutex_unlock(&q->sysfs_lock);
	248	return -ENOENT;
	249	}
	250	res = entry->store(q, page, length);
	251	mutex_unlock(&q->sysfs_lock);
	252	return res;
	253	}
	254
	255	/**
	256	* blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
	257	* @kobj: the kobj belonging of the request queue to be released
	258	*
	259	* Description:
	260	* blk_cleanup_queue is the pair to blk_init_queue() or
	261	* blk_queue_make_request(). It should be called when a request queue is
	262	* being released; typically when a block device is being de-registered.
	263	* Currently, its primary task it to free all the &struct request
	264	* structures that were allocated to the queue and the queue itself.
	265	*
	266	* Caveat:
	267	* Hopefully the low level driver will have finished any
	268	* outstanding requests first...
	269	**/
	270	static void blk_release_queue(struct kobject *kobj)
	271	{
	272	struct request_queue *q =
	273	container_of(kobj, struct request_queue, kobj);
	274	struct request_list *rl = &q->rq;
	275
	276	blk_sync_queue(q);
	277
	278	if (rl->rq_pool)
	279	mempool_destroy(rl->rq_pool);
	280
	281	if (q->queue_tags)
	282	__blk_queue_free_tags(q);
	283
	284	blk_trace_shutdown(q);
	285
	286	bdi_destroy(&q->backing_dev_info);
	287	kmem_cache_free(blk_requestq_cachep, q);
	288	}
	289
	290	static struct sysfs_ops queue_sysfs_ops = {
	291	.show = queue_attr_show,
	292	.store = queue_attr_store,
	293	};
	294
	295	struct kobj_type blk_queue_ktype = {
	296	.sysfs_ops = &queue_sysfs_ops,
	297	.default_attrs = default_attrs,
	298	.release = blk_release_queue,
	299	};
	300
	301	int blk_register_queue(struct gendisk *disk)
	302	{
	303	int ret;
	304
	305	struct request_queue *q = disk->queue;
	306
fb199746	307	if (WARN_ON(!q))
8324aa91 JA	308	return -ENXIO;
8324aa91 JA	309
fb199746 AM	310	if (!q->request_fn)
	311	return 0;
	312
8324aa91 JA	313	ret = kobject_add(&q->kobj, kobject_get(&disk->dev.kobj),
	314	"%s", "queue");
	315	if (ret < 0)
	316	return ret;
	317
	318	kobject_uevent(&q->kobj, KOBJ_ADD);
	319
	320	ret = elv_register_queue(q);
	321	if (ret) {
	322	kobject_uevent(&q->kobj, KOBJ_REMOVE);
	323	kobject_del(&q->kobj);
	324	return ret;
	325	}
	326
	327	return 0;
	328	}
	329
	330	void blk_unregister_queue(struct gendisk *disk)
	331	{
	332	struct request_queue *q = disk->queue;
	333
fb199746 AM	334	if (WARN_ON(!q))
	335	return;
	336
	337	if (q->request_fn) {
8324aa91 JA	338	elv_unregister_queue(q);
	339
	340	kobject_uevent(&q->kobj, KOBJ_REMOVE);
	341	kobject_del(&q->kobj);
	342	kobject_put(&disk->dev.kobj);
	343	}
	344	}