2 * Functions related to sysfs handling
4 #include <linux/kernel.h>
5 #include <linux/module.h>
7 #include <linux/blkdev.h>
8 #include <linux/blktrace_api.h>
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);
19 queue_var_show(unsigned int var, char *page)
21 return sprintf(page, "%d\n", var);
25 queue_var_store(unsigned long *var, const char *page, size_t count)
27 char *p = (char *) page;
29 *var = simple_strtoul(p, &p, 10);
33 static ssize_t queue_requests_show(struct request_queue *q, char *page)
35 return queue_var_show(q->nr_requests, (page));
39 queue_requests_store(struct request_queue *q, const char *page, size_t count)
41 struct request_list *rl = &q->rq;
43 int ret = queue_var_store(&nr, page, count);
44 if (nr < BLKDEV_MIN_RQ)
47 spin_lock_irq(q->queue_lock);
49 blk_queue_congestion_threshold(q);
51 if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
52 blk_set_queue_congested(q, BLK_RW_SYNC);
53 else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
54 blk_clear_queue_congested(q, BLK_RW_SYNC);
56 if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
57 blk_set_queue_congested(q, BLK_RW_ASYNC);
58 else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
59 blk_clear_queue_congested(q, BLK_RW_ASYNC);
61 if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
62 blk_set_queue_full(q, BLK_RW_SYNC);
63 } else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) {
64 blk_clear_queue_full(q, BLK_RW_SYNC);
65 wake_up(&rl->wait[BLK_RW_SYNC]);
68 if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
69 blk_set_queue_full(q, BLK_RW_ASYNC);
70 } else if (rl->count[BLK_RW_ASYNC]+1 <= q->nr_requests) {
71 blk_clear_queue_full(q, BLK_RW_ASYNC);
72 wake_up(&rl->wait[BLK_RW_ASYNC]);
74 spin_unlock_irq(q->queue_lock);
78 static ssize_t queue_ra_show(struct request_queue *q, char *page)
80 int ra_kb = q->backing_dev_info.ra_pages << (PAGE_CACHE_SHIFT - 10);
82 return queue_var_show(ra_kb, (page));
86 queue_ra_store(struct request_queue *q, const char *page, size_t count)
89 ssize_t ret = queue_var_store(&ra_kb, page, count);
91 q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
96 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
98 int max_sectors_kb = q->max_sectors >> 1;
100 return queue_var_show(max_sectors_kb, (page));
103 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
105 return queue_var_show(queue_logical_block_size(q), page);
109 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
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);
116 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
119 spin_lock_irq(q->queue_lock);
120 q->max_sectors = max_sectors_kb << 1;
121 spin_unlock_irq(q->queue_lock);
126 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
128 int max_hw_sectors_kb = q->max_hw_sectors >> 1;
130 return queue_var_show(max_hw_sectors_kb, (page));
133 static ssize_t queue_nonrot_show(struct request_queue *q, char *page)
135 return queue_var_show(!blk_queue_nonrot(q), page);
138 static ssize_t queue_nonrot_store(struct request_queue *q, const char *page,
142 ssize_t ret = queue_var_store(&nm, page, count);
144 spin_lock_irq(q->queue_lock);
146 queue_flag_clear(QUEUE_FLAG_NONROT, q);
148 queue_flag_set(QUEUE_FLAG_NONROT, q);
149 spin_unlock_irq(q->queue_lock);
154 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
156 return queue_var_show(blk_queue_nomerges(q), page);
159 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
163 ssize_t ret = queue_var_store(&nm, page, count);
165 spin_lock_irq(q->queue_lock);
167 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
169 queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
170 spin_unlock_irq(q->queue_lock);
175 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
177 unsigned int set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
179 return queue_var_show(set != 0, page);
183 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
185 ssize_t ret = -EINVAL;
186 #if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
189 ret = queue_var_store(&val, page, count);
190 spin_lock_irq(q->queue_lock);
192 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
194 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
195 spin_unlock_irq(q->queue_lock);
200 static ssize_t queue_iostats_show(struct request_queue *q, char *page)
202 return queue_var_show(blk_queue_io_stat(q), page);
205 static ssize_t queue_iostats_store(struct request_queue *q, const char *page,
209 ssize_t ret = queue_var_store(&stats, page, count);
211 spin_lock_irq(q->queue_lock);
213 queue_flag_set(QUEUE_FLAG_IO_STAT, q);
215 queue_flag_clear(QUEUE_FLAG_IO_STAT, q);
216 spin_unlock_irq(q->queue_lock);
221 static struct queue_sysfs_entry queue_requests_entry = {
222 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
223 .show = queue_requests_show,
224 .store = queue_requests_store,
227 static struct queue_sysfs_entry queue_ra_entry = {
228 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
229 .show = queue_ra_show,
230 .store = queue_ra_store,
233 static struct queue_sysfs_entry queue_max_sectors_entry = {
234 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
235 .show = queue_max_sectors_show,
236 .store = queue_max_sectors_store,
239 static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
240 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
241 .show = queue_max_hw_sectors_show,
244 static struct queue_sysfs_entry queue_iosched_entry = {
245 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
246 .show = elv_iosched_show,
247 .store = elv_iosched_store,
250 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
251 .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
252 .show = queue_logical_block_size_show,
255 static struct queue_sysfs_entry queue_logical_block_size_entry = {
256 .attr = {.name = "logical_block_size", .mode = S_IRUGO },
257 .show = queue_logical_block_size_show,
260 static struct queue_sysfs_entry queue_nonrot_entry = {
261 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
262 .show = queue_nonrot_show,
263 .store = queue_nonrot_store,
266 static struct queue_sysfs_entry queue_nomerges_entry = {
267 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
268 .show = queue_nomerges_show,
269 .store = queue_nomerges_store,
272 static struct queue_sysfs_entry queue_rq_affinity_entry = {
273 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
274 .show = queue_rq_affinity_show,
275 .store = queue_rq_affinity_store,
278 static struct queue_sysfs_entry queue_iostats_entry = {
279 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
280 .show = queue_iostats_show,
281 .store = queue_iostats_store,
284 static struct attribute *default_attrs[] = {
285 &queue_requests_entry.attr,
286 &queue_ra_entry.attr,
287 &queue_max_hw_sectors_entry.attr,
288 &queue_max_sectors_entry.attr,
289 &queue_iosched_entry.attr,
290 &queue_hw_sector_size_entry.attr,
291 &queue_logical_block_size_entry.attr,
292 &queue_nonrot_entry.attr,
293 &queue_nomerges_entry.attr,
294 &queue_rq_affinity_entry.attr,
295 &queue_iostats_entry.attr,
299 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
302 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
304 struct queue_sysfs_entry *entry = to_queue(attr);
305 struct request_queue *q =
306 container_of(kobj, struct request_queue, kobj);
311 mutex_lock(&q->sysfs_lock);
312 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
313 mutex_unlock(&q->sysfs_lock);
316 res = entry->show(q, page);
317 mutex_unlock(&q->sysfs_lock);
322 queue_attr_store(struct kobject *kobj, struct attribute *attr,
323 const char *page, size_t length)
325 struct queue_sysfs_entry *entry = to_queue(attr);
326 struct request_queue *q;
332 q = container_of(kobj, struct request_queue, kobj);
333 mutex_lock(&q->sysfs_lock);
334 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
335 mutex_unlock(&q->sysfs_lock);
338 res = entry->store(q, page, length);
339 mutex_unlock(&q->sysfs_lock);
344 * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
345 * @kobj: the kobj belonging of the request queue to be released
348 * blk_cleanup_queue is the pair to blk_init_queue() or
349 * blk_queue_make_request(). It should be called when a request queue is
350 * being released; typically when a block device is being de-registered.
351 * Currently, its primary task it to free all the &struct request
352 * structures that were allocated to the queue and the queue itself.
355 * Hopefully the low level driver will have finished any
356 * outstanding requests first...
358 static void blk_release_queue(struct kobject *kobj)
360 struct request_queue *q =
361 container_of(kobj, struct request_queue, kobj);
362 struct request_list *rl = &q->rq;
367 mempool_destroy(rl->rq_pool);
370 __blk_queue_free_tags(q);
372 blk_trace_shutdown(q);
374 bdi_destroy(&q->backing_dev_info);
375 kmem_cache_free(blk_requestq_cachep, q);
378 static struct sysfs_ops queue_sysfs_ops = {
379 .show = queue_attr_show,
380 .store = queue_attr_store,
383 struct kobj_type blk_queue_ktype = {
384 .sysfs_ops = &queue_sysfs_ops,
385 .default_attrs = default_attrs,
386 .release = blk_release_queue,
389 int blk_register_queue(struct gendisk *disk)
393 struct request_queue *q = disk->queue;
401 ret = kobject_add(&q->kobj, kobject_get(&disk_to_dev(disk)->kobj),
406 kobject_uevent(&q->kobj, KOBJ_ADD);
408 ret = elv_register_queue(q);
410 kobject_uevent(&q->kobj, KOBJ_REMOVE);
411 kobject_del(&q->kobj);
418 void blk_unregister_queue(struct gendisk *disk)
420 struct request_queue *q = disk->queue;
426 elv_unregister_queue(q);
428 kobject_uevent(&q->kobj, KOBJ_REMOVE);
429 kobject_del(&q->kobj);
430 kobject_put(&disk_to_dev(disk)->kobj);