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4fbf4291 DH |
1 | /* Global fscache object list maintainer and viewer |
2 | * | |
3 | * Copyright (C) 2009 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public Licence | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the Licence, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #define FSCACHE_DEBUG_LEVEL COOKIE | |
13 | #include <linux/module.h> | |
14 | #include <linux/seq_file.h> | |
15 | #include <linux/key.h> | |
16 | #include <keys/user-type.h> | |
17 | #include "internal.h" | |
18 | ||
19 | static struct rb_root fscache_object_list; | |
20 | static DEFINE_RWLOCK(fscache_object_list_lock); | |
21 | ||
22 | struct fscache_objlist_data { | |
23 | unsigned long config; /* display configuration */ | |
24 | #define FSCACHE_OBJLIST_CONFIG_KEY 0x00000001 /* show object keys */ | |
25 | #define FSCACHE_OBJLIST_CONFIG_AUX 0x00000002 /* show object auxdata */ | |
26 | #define FSCACHE_OBJLIST_CONFIG_COOKIE 0x00000004 /* show objects with cookies */ | |
27 | #define FSCACHE_OBJLIST_CONFIG_NOCOOKIE 0x00000008 /* show objects without cookies */ | |
28 | #define FSCACHE_OBJLIST_CONFIG_BUSY 0x00000010 /* show busy objects */ | |
29 | #define FSCACHE_OBJLIST_CONFIG_IDLE 0x00000020 /* show idle objects */ | |
30 | #define FSCACHE_OBJLIST_CONFIG_PENDWR 0x00000040 /* show objects with pending writes */ | |
31 | #define FSCACHE_OBJLIST_CONFIG_NOPENDWR 0x00000080 /* show objects without pending writes */ | |
32 | #define FSCACHE_OBJLIST_CONFIG_READS 0x00000100 /* show objects with active reads */ | |
33 | #define FSCACHE_OBJLIST_CONFIG_NOREADS 0x00000200 /* show objects without active reads */ | |
34 | #define FSCACHE_OBJLIST_CONFIG_EVENTS 0x00000400 /* show objects with events */ | |
35 | #define FSCACHE_OBJLIST_CONFIG_NOEVENTS 0x00000800 /* show objects without no events */ | |
36 | #define FSCACHE_OBJLIST_CONFIG_WORK 0x00001000 /* show objects with slow work */ | |
37 | #define FSCACHE_OBJLIST_CONFIG_NOWORK 0x00002000 /* show objects without slow work */ | |
38 | ||
39 | u8 buf[512]; /* key and aux data buffer */ | |
40 | }; | |
41 | ||
42 | /* | |
43 | * Add an object to the object list | |
44 | * - we use the address of the fscache_object structure as the key into the | |
45 | * tree | |
46 | */ | |
47 | void fscache_objlist_add(struct fscache_object *obj) | |
48 | { | |
49 | struct fscache_object *xobj; | |
50 | struct rb_node **p = &fscache_object_list.rb_node, *parent = NULL; | |
51 | ||
52 | write_lock(&fscache_object_list_lock); | |
53 | ||
54 | while (*p) { | |
55 | parent = *p; | |
56 | xobj = rb_entry(parent, struct fscache_object, objlist_link); | |
57 | ||
58 | if (obj < xobj) | |
59 | p = &(*p)->rb_left; | |
60 | else if (obj > xobj) | |
61 | p = &(*p)->rb_right; | |
62 | else | |
63 | BUG(); | |
64 | } | |
65 | ||
66 | rb_link_node(&obj->objlist_link, parent, p); | |
67 | rb_insert_color(&obj->objlist_link, &fscache_object_list); | |
68 | ||
69 | write_unlock(&fscache_object_list_lock); | |
70 | } | |
71 | ||
72 | /** | |
73 | * fscache_object_destroy - Note that a cache object is about to be destroyed | |
74 | * @object: The object to be destroyed | |
75 | * | |
76 | * Note the imminent destruction and deallocation of a cache object record. | |
77 | */ | |
78 | void fscache_object_destroy(struct fscache_object *obj) | |
79 | { | |
80 | write_lock(&fscache_object_list_lock); | |
81 | ||
82 | BUG_ON(RB_EMPTY_ROOT(&fscache_object_list)); | |
83 | rb_erase(&obj->objlist_link, &fscache_object_list); | |
84 | ||
85 | write_unlock(&fscache_object_list_lock); | |
86 | } | |
87 | EXPORT_SYMBOL(fscache_object_destroy); | |
88 | ||
89 | /* | |
90 | * find the object in the tree on or after the specified index | |
91 | */ | |
92 | static struct fscache_object *fscache_objlist_lookup(loff_t *_pos) | |
93 | { | |
ea58ceb5 | 94 | struct fscache_object *pobj, *obj = NULL, *minobj = NULL; |
4fbf4291 DH |
95 | struct rb_node *p; |
96 | unsigned long pos; | |
97 | ||
98 | if (*_pos >= (unsigned long) ERR_PTR(-ENOENT)) | |
99 | return NULL; | |
100 | pos = *_pos; | |
101 | ||
102 | /* banners (can't represent line 0 by pos 0 as that would involve | |
103 | * returning a NULL pointer) */ | |
104 | if (pos == 0) | |
105 | return (struct fscache_object *) ++(*_pos); | |
106 | if (pos < 3) | |
107 | return (struct fscache_object *)pos; | |
108 | ||
109 | pobj = (struct fscache_object *)pos; | |
110 | p = fscache_object_list.rb_node; | |
111 | while (p) { | |
112 | obj = rb_entry(p, struct fscache_object, objlist_link); | |
113 | if (pobj < obj) { | |
114 | if (!minobj || minobj > obj) | |
115 | minobj = obj; | |
116 | p = p->rb_left; | |
117 | } else if (pobj > obj) { | |
118 | p = p->rb_right; | |
119 | } else { | |
120 | minobj = obj; | |
121 | break; | |
122 | } | |
123 | obj = NULL; | |
124 | } | |
125 | ||
126 | if (!minobj) | |
127 | *_pos = (unsigned long) ERR_PTR(-ENOENT); | |
128 | else if (minobj != obj) | |
129 | *_pos = (unsigned long) minobj; | |
130 | return minobj; | |
131 | } | |
132 | ||
133 | /* | |
134 | * set up the iterator to start reading from the first line | |
135 | */ | |
136 | static void *fscache_objlist_start(struct seq_file *m, loff_t *_pos) | |
137 | __acquires(&fscache_object_list_lock) | |
138 | { | |
139 | read_lock(&fscache_object_list_lock); | |
140 | return fscache_objlist_lookup(_pos); | |
141 | } | |
142 | ||
143 | /* | |
144 | * move to the next line | |
145 | */ | |
146 | static void *fscache_objlist_next(struct seq_file *m, void *v, loff_t *_pos) | |
147 | { | |
148 | (*_pos)++; | |
149 | return fscache_objlist_lookup(_pos); | |
150 | } | |
151 | ||
152 | /* | |
153 | * clean up after reading | |
154 | */ | |
155 | static void fscache_objlist_stop(struct seq_file *m, void *v) | |
156 | __releases(&fscache_object_list_lock) | |
157 | { | |
158 | read_unlock(&fscache_object_list_lock); | |
159 | } | |
160 | ||
161 | /* | |
162 | * display an object | |
163 | */ | |
164 | static int fscache_objlist_show(struct seq_file *m, void *v) | |
165 | { | |
166 | struct fscache_objlist_data *data = m->private; | |
167 | struct fscache_object *obj = v; | |
168 | unsigned long config = data->config; | |
169 | uint16_t keylen, auxlen; | |
170 | char _type[3], *type; | |
171 | bool no_cookie; | |
172 | u8 *buf = data->buf, *p; | |
173 | ||
174 | if ((unsigned long) v == 1) { | |
175 | seq_puts(m, "OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS" | |
176 | " EM EV F S" | |
177 | " | NETFS_COOKIE_DEF TY FL NETFS_DATA"); | |
178 | if (config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
179 | FSCACHE_OBJLIST_CONFIG_AUX)) | |
180 | seq_puts(m, " "); | |
181 | if (config & FSCACHE_OBJLIST_CONFIG_KEY) | |
182 | seq_puts(m, "OBJECT_KEY"); | |
183 | if ((config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
184 | FSCACHE_OBJLIST_CONFIG_AUX)) == | |
185 | (FSCACHE_OBJLIST_CONFIG_KEY | FSCACHE_OBJLIST_CONFIG_AUX)) | |
186 | seq_puts(m, ", "); | |
187 | if (config & FSCACHE_OBJLIST_CONFIG_AUX) | |
188 | seq_puts(m, "AUX_DATA"); | |
189 | seq_puts(m, "\n"); | |
190 | return 0; | |
191 | } | |
192 | ||
193 | if ((unsigned long) v == 2) { | |
194 | seq_puts(m, "======== ======== ==== ===== === === === == =====" | |
195 | " == == = =" | |
196 | " | ================ == == ================"); | |
197 | if (config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
198 | FSCACHE_OBJLIST_CONFIG_AUX)) | |
199 | seq_puts(m, " ================"); | |
200 | seq_puts(m, "\n"); | |
201 | return 0; | |
202 | } | |
203 | ||
204 | /* filter out any unwanted objects */ | |
205 | #define FILTER(criterion, _yes, _no) \ | |
206 | do { \ | |
207 | unsigned long yes = FSCACHE_OBJLIST_CONFIG_##_yes; \ | |
208 | unsigned long no = FSCACHE_OBJLIST_CONFIG_##_no; \ | |
209 | if (criterion) { \ | |
210 | if (!(config & yes)) \ | |
211 | return 0; \ | |
212 | } else { \ | |
213 | if (!(config & no)) \ | |
214 | return 0; \ | |
215 | } \ | |
216 | } while(0) | |
217 | ||
218 | if (~config) { | |
219 | FILTER(obj->cookie, | |
220 | COOKIE, NOCOOKIE); | |
221 | FILTER(obj->state != FSCACHE_OBJECT_ACTIVE || | |
222 | obj->n_ops != 0 || | |
223 | obj->n_obj_ops != 0 || | |
224 | obj->flags || | |
225 | !list_empty(&obj->dependents), | |
226 | BUSY, IDLE); | |
227 | FILTER(test_bit(FSCACHE_OBJECT_PENDING_WRITE, &obj->flags), | |
228 | PENDWR, NOPENDWR); | |
229 | FILTER(atomic_read(&obj->n_reads), | |
230 | READS, NOREADS); | |
231 | FILTER(obj->events & obj->event_mask, | |
232 | EVENTS, NOEVENTS); | |
233 | FILTER(obj->work.flags & ~(1UL << SLOW_WORK_VERY_SLOW), | |
234 | WORK, NOWORK); | |
235 | } | |
236 | ||
237 | seq_printf(m, | |
238 | "%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %1lx %1lx | ", | |
239 | obj->debug_id, | |
240 | obj->parent ? obj->parent->debug_id : -1, | |
241 | fscache_object_states_short[obj->state], | |
242 | obj->n_children, | |
243 | obj->n_ops, | |
244 | obj->n_obj_ops, | |
245 | obj->n_in_progress, | |
246 | obj->n_exclusive, | |
247 | atomic_read(&obj->n_reads), | |
248 | obj->event_mask & FSCACHE_OBJECT_EVENTS_MASK, | |
249 | obj->events, | |
250 | obj->flags, | |
251 | obj->work.flags); | |
252 | ||
253 | no_cookie = true; | |
254 | keylen = auxlen = 0; | |
255 | if (obj->cookie) { | |
256 | spin_lock(&obj->lock); | |
257 | if (obj->cookie) { | |
258 | switch (obj->cookie->def->type) { | |
259 | case 0: | |
260 | type = "IX"; | |
261 | break; | |
262 | case 1: | |
263 | type = "DT"; | |
264 | break; | |
265 | default: | |
266 | sprintf(_type, "%02u", | |
267 | obj->cookie->def->type); | |
268 | type = _type; | |
269 | break; | |
270 | } | |
271 | ||
272 | seq_printf(m, "%-16s %s %2lx %16p", | |
273 | obj->cookie->def->name, | |
274 | type, | |
275 | obj->cookie->flags, | |
276 | obj->cookie->netfs_data); | |
277 | ||
278 | if (obj->cookie->def->get_key && | |
279 | config & FSCACHE_OBJLIST_CONFIG_KEY) | |
280 | keylen = obj->cookie->def->get_key( | |
281 | obj->cookie->netfs_data, | |
282 | buf, 400); | |
283 | ||
284 | if (obj->cookie->def->get_aux && | |
285 | config & FSCACHE_OBJLIST_CONFIG_AUX) | |
286 | auxlen = obj->cookie->def->get_aux( | |
287 | obj->cookie->netfs_data, | |
288 | buf + keylen, 512 - keylen); | |
289 | ||
290 | no_cookie = false; | |
291 | } | |
292 | spin_unlock(&obj->lock); | |
293 | ||
294 | if (!no_cookie && (keylen > 0 || auxlen > 0)) { | |
295 | seq_printf(m, " "); | |
296 | for (p = buf; keylen > 0; keylen--) | |
297 | seq_printf(m, "%02x", *p++); | |
298 | if (auxlen > 0) { | |
299 | if (config & FSCACHE_OBJLIST_CONFIG_KEY) | |
300 | seq_printf(m, ", "); | |
301 | for (; auxlen > 0; auxlen--) | |
302 | seq_printf(m, "%02x", *p++); | |
303 | } | |
304 | } | |
305 | } | |
306 | ||
307 | if (no_cookie) | |
308 | seq_printf(m, "<no_cookie>\n"); | |
309 | else | |
310 | seq_printf(m, "\n"); | |
311 | return 0; | |
312 | } | |
313 | ||
314 | static const struct seq_operations fscache_objlist_ops = { | |
315 | .start = fscache_objlist_start, | |
316 | .stop = fscache_objlist_stop, | |
317 | .next = fscache_objlist_next, | |
318 | .show = fscache_objlist_show, | |
319 | }; | |
320 | ||
321 | /* | |
322 | * get the configuration for filtering the list | |
323 | */ | |
324 | static void fscache_objlist_config(struct fscache_objlist_data *data) | |
325 | { | |
326 | #ifdef CONFIG_KEYS | |
327 | struct user_key_payload *confkey; | |
328 | unsigned long config; | |
329 | struct key *key; | |
330 | const char *buf; | |
331 | int len; | |
332 | ||
333 | key = request_key(&key_type_user, "fscache:objlist", NULL); | |
334 | if (IS_ERR(key)) | |
335 | goto no_config; | |
336 | ||
337 | config = 0; | |
338 | rcu_read_lock(); | |
339 | ||
340 | confkey = key->payload.data; | |
341 | buf = confkey->data; | |
342 | ||
343 | for (len = confkey->datalen - 1; len >= 0; len--) { | |
344 | switch (buf[len]) { | |
345 | case 'K': config |= FSCACHE_OBJLIST_CONFIG_KEY; break; | |
346 | case 'A': config |= FSCACHE_OBJLIST_CONFIG_AUX; break; | |
347 | case 'C': config |= FSCACHE_OBJLIST_CONFIG_COOKIE; break; | |
348 | case 'c': config |= FSCACHE_OBJLIST_CONFIG_NOCOOKIE; break; | |
349 | case 'B': config |= FSCACHE_OBJLIST_CONFIG_BUSY; break; | |
350 | case 'b': config |= FSCACHE_OBJLIST_CONFIG_IDLE; break; | |
351 | case 'W': config |= FSCACHE_OBJLIST_CONFIG_PENDWR; break; | |
352 | case 'w': config |= FSCACHE_OBJLIST_CONFIG_NOPENDWR; break; | |
353 | case 'R': config |= FSCACHE_OBJLIST_CONFIG_READS; break; | |
354 | case 'r': config |= FSCACHE_OBJLIST_CONFIG_NOREADS; break; | |
355 | case 'S': config |= FSCACHE_OBJLIST_CONFIG_WORK; break; | |
356 | case 's': config |= FSCACHE_OBJLIST_CONFIG_NOWORK; break; | |
357 | } | |
358 | } | |
359 | ||
360 | rcu_read_unlock(); | |
361 | key_put(key); | |
362 | ||
363 | if (!(config & (FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE))) | |
364 | config |= FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE; | |
365 | if (!(config & (FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE))) | |
366 | config |= FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE; | |
367 | if (!(config & (FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR))) | |
368 | config |= FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR; | |
369 | if (!(config & (FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS))) | |
370 | config |= FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS; | |
371 | if (!(config & (FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS))) | |
372 | config |= FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS; | |
373 | if (!(config & (FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK))) | |
374 | config |= FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK; | |
375 | ||
376 | data->config = config; | |
377 | return; | |
378 | ||
379 | no_config: | |
380 | #endif | |
381 | data->config = ULONG_MAX; | |
382 | } | |
383 | ||
384 | /* | |
385 | * open "/proc/fs/fscache/objects" to provide a list of active objects | |
386 | * - can be configured by a user-defined key added to the caller's keyrings | |
387 | */ | |
388 | static int fscache_objlist_open(struct inode *inode, struct file *file) | |
389 | { | |
390 | struct fscache_objlist_data *data; | |
391 | struct seq_file *m; | |
392 | int ret; | |
393 | ||
394 | ret = seq_open(file, &fscache_objlist_ops); | |
395 | if (ret < 0) | |
396 | return ret; | |
397 | ||
398 | m = file->private_data; | |
399 | ||
400 | /* buffer for key extraction */ | |
401 | data = kmalloc(sizeof(struct fscache_objlist_data), GFP_KERNEL); | |
402 | if (!data) { | |
403 | seq_release(inode, file); | |
404 | return -ENOMEM; | |
405 | } | |
406 | ||
407 | /* get the configuration key */ | |
408 | fscache_objlist_config(data); | |
409 | ||
410 | m->private = data; | |
411 | return 0; | |
412 | } | |
413 | ||
414 | /* | |
415 | * clean up on close | |
416 | */ | |
417 | static int fscache_objlist_release(struct inode *inode, struct file *file) | |
418 | { | |
419 | struct seq_file *m = file->private_data; | |
420 | ||
421 | kfree(m->private); | |
422 | m->private = NULL; | |
423 | return seq_release(inode, file); | |
424 | } | |
425 | ||
426 | const struct file_operations fscache_objlist_fops = { | |
427 | .owner = THIS_MODULE, | |
428 | .open = fscache_objlist_open, | |
429 | .read = seq_read, | |
430 | .llseek = seq_lseek, | |
431 | .release = fscache_objlist_release, | |
432 | }; |