[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);

	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 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 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,
	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 = container_of(kobj, struct request_queue, kobj);

	ssize_t res;

	if (!entry->store)
		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->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 (!q || !q->request_fn)
		return -ENXIO;

	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 (q && 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
	138
	139	static struct queue_sysfs_entry queue_requests_entry = {
	140	.attr = {.name = "nr_requests", .mode = S_IRUGO \| S_IWUSR },
	141	.show = queue_requests_show,
	142	.store = queue_requests_store,
	143	};
	144
	145	static struct queue_sysfs_entry queue_ra_entry = {
	146	.attr = {.name = "read_ahead_kb", .mode = S_IRUGO \| S_IWUSR },
	147	.show = queue_ra_show,
	148	.store = queue_ra_store,
	149	};
	150
	151	static struct queue_sysfs_entry queue_max_sectors_entry = {
	152	.attr = {.name = "max_sectors_kb", .mode = S_IRUGO \| S_IWUSR },
	153	.show = queue_max_sectors_show,
	154	.store = queue_max_sectors_store,
	155	};
	156
	157	static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
	158	.attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
	159	.show = queue_max_hw_sectors_show,
	160	};
	161
	162	static struct queue_sysfs_entry queue_iosched_entry = {
	163	.attr = {.name = "scheduler", .mode = S_IRUGO \| S_IWUSR },
	164	.show = elv_iosched_show,
	165	.store = elv_iosched_store,
	166	};
	167
e68b903c MP	168	static struct queue_sysfs_entry queue_hw_sector_size_entry = {
	169	.attr = {.name = "hw_sector_size", .mode = S_IRUGO },
	170	.show = queue_hw_sector_size_show,
	171	};
	172
8324aa91 JA	173	static struct attribute *default_attrs[] = {
	174	&queue_requests_entry.attr,
	175	&queue_ra_entry.attr,
	176	&queue_max_hw_sectors_entry.attr,
	177	&queue_max_sectors_entry.attr,
	178	&queue_iosched_entry.attr,
e68b903c	179	&queue_hw_sector_size_entry.attr,
8324aa91 JA	180	NULL,
	181	};
	182
	183	#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
	184
	185	static ssize_t
	186	queue_attr_show(struct kobject kobj, struct attribute attr, char *page)
	187	{
	188	struct queue_sysfs_entry *entry = to_queue(attr);
	189	struct request_queue *q =
	190	container_of(kobj, struct request_queue, kobj);
	191	ssize_t res;
	192
	193	if (!entry->show)
	194	return -EIO;
	195	mutex_lock(&q->sysfs_lock);
	196	if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
	197	mutex_unlock(&q->sysfs_lock);
	198	return -ENOENT;
	199	}
	200	res = entry->show(q, page);
	201	mutex_unlock(&q->sysfs_lock);
	202	return res;
	203	}
	204
	205	static ssize_t
	206	queue_attr_store(struct kobject kobj, struct attribute attr,
	207	const char *page, size_t length)
	208	{
	209	struct queue_sysfs_entry *entry = to_queue(attr);
	210	struct request_queue *q = container_of(kobj, struct request_queue, kobj);
	211
	212	ssize_t res;
	213
	214	if (!entry->store)
	215	return -EIO;
	216	mutex_lock(&q->sysfs_lock);
	217	if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
	218	mutex_unlock(&q->sysfs_lock);
	219	return -ENOENT;
	220	}
	221	res = entry->store(q, page, length);
	222	mutex_unlock(&q->sysfs_lock);
	223	return res;
	224	}
	225
	226	/**
	227	* blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
	228	* @kobj: the kobj belonging of the request queue to be released
	229	*
	230	* Description:
	231	* blk_cleanup_queue is the pair to blk_init_queue() or
	232	* blk_queue_make_request(). It should be called when a request queue is
	233	* being released; typically when a block device is being de-registered.
	234	* Currently, its primary task it to free all the &struct request
	235	* structures that were allocated to the queue and the queue itself.
	236	*
	237	* Caveat:
	238	* Hopefully the low level driver will have finished any
	239	* outstanding requests first...
	240	**/
	241	static void blk_release_queue(struct kobject *kobj)
	242	{
	243	struct request_queue *q =
244	container_of(kobj, struct request_queue, kobj);
245	struct request_list *rl = &q->rq;
246
247	blk_sync_queue(q);
248
249	if (rl->rq_pool)
250	mempool_destroy(rl->rq_pool);
251
252	if (q->queue_tags)
253	__blk_queue_free_tags(q);
254
255	blk_trace_shutdown(q);
256
257	bdi_destroy(&q->backing_dev_info);
258	kmem_cache_free(blk_requestq_cachep, q);
259	}
260
261	static struct sysfs_ops queue_sysfs_ops = {
262	.show = queue_attr_show,
263	.store = queue_attr_store,
264	};
265
266	struct kobj_type blk_queue_ktype = {
267	.sysfs_ops = &queue_sysfs_ops,
268	.default_attrs = default_attrs,
269	.release = blk_release_queue,
270	};
271
272	int blk_register_queue(struct gendisk *disk)
273	{
274	int ret;
275
276	struct request_queue *q = disk->queue;
277
278	if (!q \|\| !q->request_fn)
279	return -ENXIO;
280
281	ret = kobject_add(&q->kobj, kobject_get(&disk->dev.kobj),
282	"%s", "queue");
283	if (ret < 0)
284	return ret;
285
286	kobject_uevent(&q->kobj, KOBJ_ADD);
287
288	ret = elv_register_queue(q);
289	if (ret) {
290	kobject_uevent(&q->kobj, KOBJ_REMOVE);
291	kobject_del(&q->kobj);
292	return ret;
293	}
294
295	return 0;
296	}
297
298	void blk_unregister_queue(struct gendisk *disk)
299	{
300	struct request_queue *q = disk->queue;
301
302	if (q && q->request_fn) {
303	elv_unregister_queue(q);
304
305	kobject_uevent(&q->kobj, KOBJ_REMOVE);
306	kobject_del(&q->kobj);
307	kobject_put(&disk->dev.kobj);
308	}
309	}