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