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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> | |
5a0e3ad6 | 15 | #include <linux/slab.h> |
4fbf4291 DH |
16 | #include <linux/key.h> |
17 | #include <keys/user-type.h> | |
18 | #include "internal.h" | |
19 | ||
20 | static struct rb_root fscache_object_list; | |
21 | static DEFINE_RWLOCK(fscache_object_list_lock); | |
22 | ||
23 | struct fscache_objlist_data { | |
24 | unsigned long config; /* display configuration */ | |
25 | #define FSCACHE_OBJLIST_CONFIG_KEY 0x00000001 /* show object keys */ | |
26 | #define FSCACHE_OBJLIST_CONFIG_AUX 0x00000002 /* show object auxdata */ | |
27 | #define FSCACHE_OBJLIST_CONFIG_COOKIE 0x00000004 /* show objects with cookies */ | |
28 | #define FSCACHE_OBJLIST_CONFIG_NOCOOKIE 0x00000008 /* show objects without cookies */ | |
29 | #define FSCACHE_OBJLIST_CONFIG_BUSY 0x00000010 /* show busy objects */ | |
30 | #define FSCACHE_OBJLIST_CONFIG_IDLE 0x00000020 /* show idle objects */ | |
31 | #define FSCACHE_OBJLIST_CONFIG_PENDWR 0x00000040 /* show objects with pending writes */ | |
32 | #define FSCACHE_OBJLIST_CONFIG_NOPENDWR 0x00000080 /* show objects without pending writes */ | |
33 | #define FSCACHE_OBJLIST_CONFIG_READS 0x00000100 /* show objects with active reads */ | |
34 | #define FSCACHE_OBJLIST_CONFIG_NOREADS 0x00000200 /* show objects without active reads */ | |
35 | #define FSCACHE_OBJLIST_CONFIG_EVENTS 0x00000400 /* show objects with events */ | |
36 | #define FSCACHE_OBJLIST_CONFIG_NOEVENTS 0x00000800 /* show objects without no events */ | |
37 | #define FSCACHE_OBJLIST_CONFIG_WORK 0x00001000 /* show objects with slow work */ | |
38 | #define FSCACHE_OBJLIST_CONFIG_NOWORK 0x00002000 /* show objects without slow work */ | |
39 | ||
40 | u8 buf[512]; /* key and aux data buffer */ | |
41 | }; | |
42 | ||
43 | /* | |
44 | * Add an object to the object list | |
45 | * - we use the address of the fscache_object structure as the key into the | |
46 | * tree | |
47 | */ | |
48 | void fscache_objlist_add(struct fscache_object *obj) | |
49 | { | |
50 | struct fscache_object *xobj; | |
51 | struct rb_node **p = &fscache_object_list.rb_node, *parent = NULL; | |
52 | ||
53 | write_lock(&fscache_object_list_lock); | |
54 | ||
55 | while (*p) { | |
56 | parent = *p; | |
57 | xobj = rb_entry(parent, struct fscache_object, objlist_link); | |
58 | ||
59 | if (obj < xobj) | |
60 | p = &(*p)->rb_left; | |
61 | else if (obj > xobj) | |
62 | p = &(*p)->rb_right; | |
63 | else | |
64 | BUG(); | |
65 | } | |
66 | ||
67 | rb_link_node(&obj->objlist_link, parent, p); | |
68 | rb_insert_color(&obj->objlist_link, &fscache_object_list); | |
69 | ||
70 | write_unlock(&fscache_object_list_lock); | |
71 | } | |
72 | ||
73 | /** | |
74 | * fscache_object_destroy - Note that a cache object is about to be destroyed | |
75 | * @object: The object to be destroyed | |
76 | * | |
77 | * Note the imminent destruction and deallocation of a cache object record. | |
78 | */ | |
79 | void fscache_object_destroy(struct fscache_object *obj) | |
80 | { | |
81 | write_lock(&fscache_object_list_lock); | |
82 | ||
83 | BUG_ON(RB_EMPTY_ROOT(&fscache_object_list)); | |
84 | rb_erase(&obj->objlist_link, &fscache_object_list); | |
85 | ||
86 | write_unlock(&fscache_object_list_lock); | |
87 | } | |
88 | EXPORT_SYMBOL(fscache_object_destroy); | |
89 | ||
90 | /* | |
91 | * find the object in the tree on or after the specified index | |
92 | */ | |
93 | static struct fscache_object *fscache_objlist_lookup(loff_t *_pos) | |
94 | { | |
ea58ceb5 | 95 | struct fscache_object *pobj, *obj = NULL, *minobj = NULL; |
4fbf4291 DH |
96 | struct rb_node *p; |
97 | unsigned long pos; | |
98 | ||
99 | if (*_pos >= (unsigned long) ERR_PTR(-ENOENT)) | |
100 | return NULL; | |
101 | pos = *_pos; | |
102 | ||
103 | /* banners (can't represent line 0 by pos 0 as that would involve | |
104 | * returning a NULL pointer) */ | |
105 | if (pos == 0) | |
cc68e3be | 106 | return (struct fscache_object *)(long)++(*_pos); |
4fbf4291 DH |
107 | if (pos < 3) |
108 | return (struct fscache_object *)pos; | |
109 | ||
110 | pobj = (struct fscache_object *)pos; | |
111 | p = fscache_object_list.rb_node; | |
112 | while (p) { | |
113 | obj = rb_entry(p, struct fscache_object, objlist_link); | |
114 | if (pobj < obj) { | |
115 | if (!minobj || minobj > obj) | |
116 | minobj = obj; | |
117 | p = p->rb_left; | |
118 | } else if (pobj > obj) { | |
119 | p = p->rb_right; | |
120 | } else { | |
121 | minobj = obj; | |
122 | break; | |
123 | } | |
124 | obj = NULL; | |
125 | } | |
126 | ||
127 | if (!minobj) | |
128 | *_pos = (unsigned long) ERR_PTR(-ENOENT); | |
129 | else if (minobj != obj) | |
130 | *_pos = (unsigned long) minobj; | |
131 | return minobj; | |
132 | } | |
133 | ||
134 | /* | |
135 | * set up the iterator to start reading from the first line | |
136 | */ | |
137 | static void *fscache_objlist_start(struct seq_file *m, loff_t *_pos) | |
138 | __acquires(&fscache_object_list_lock) | |
139 | { | |
140 | read_lock(&fscache_object_list_lock); | |
141 | return fscache_objlist_lookup(_pos); | |
142 | } | |
143 | ||
144 | /* | |
145 | * move to the next line | |
146 | */ | |
147 | static void *fscache_objlist_next(struct seq_file *m, void *v, loff_t *_pos) | |
148 | { | |
149 | (*_pos)++; | |
150 | return fscache_objlist_lookup(_pos); | |
151 | } | |
152 | ||
153 | /* | |
154 | * clean up after reading | |
155 | */ | |
156 | static void fscache_objlist_stop(struct seq_file *m, void *v) | |
157 | __releases(&fscache_object_list_lock) | |
158 | { | |
159 | read_unlock(&fscache_object_list_lock); | |
160 | } | |
161 | ||
162 | /* | |
163 | * display an object | |
164 | */ | |
165 | static int fscache_objlist_show(struct seq_file *m, void *v) | |
166 | { | |
167 | struct fscache_objlist_data *data = m->private; | |
168 | struct fscache_object *obj = v; | |
169 | unsigned long config = data->config; | |
170 | uint16_t keylen, auxlen; | |
171 | char _type[3], *type; | |
172 | bool no_cookie; | |
173 | u8 *buf = data->buf, *p; | |
174 | ||
175 | if ((unsigned long) v == 1) { | |
176 | seq_puts(m, "OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS" | |
177 | " EM EV F S" | |
178 | " | NETFS_COOKIE_DEF TY FL NETFS_DATA"); | |
179 | if (config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
180 | FSCACHE_OBJLIST_CONFIG_AUX)) | |
181 | seq_puts(m, " "); | |
182 | if (config & FSCACHE_OBJLIST_CONFIG_KEY) | |
183 | seq_puts(m, "OBJECT_KEY"); | |
184 | if ((config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
185 | FSCACHE_OBJLIST_CONFIG_AUX)) == | |
186 | (FSCACHE_OBJLIST_CONFIG_KEY | FSCACHE_OBJLIST_CONFIG_AUX)) | |
187 | seq_puts(m, ", "); | |
188 | if (config & FSCACHE_OBJLIST_CONFIG_AUX) | |
189 | seq_puts(m, "AUX_DATA"); | |
190 | seq_puts(m, "\n"); | |
191 | return 0; | |
192 | } | |
193 | ||
194 | if ((unsigned long) v == 2) { | |
195 | seq_puts(m, "======== ======== ==== ===== === === === == =====" | |
196 | " == == = =" | |
197 | " | ================ == == ================"); | |
198 | if (config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
199 | FSCACHE_OBJLIST_CONFIG_AUX)) | |
200 | seq_puts(m, " ================"); | |
201 | seq_puts(m, "\n"); | |
202 | return 0; | |
203 | } | |
204 | ||
205 | /* filter out any unwanted objects */ | |
206 | #define FILTER(criterion, _yes, _no) \ | |
207 | do { \ | |
208 | unsigned long yes = FSCACHE_OBJLIST_CONFIG_##_yes; \ | |
209 | unsigned long no = FSCACHE_OBJLIST_CONFIG_##_no; \ | |
210 | if (criterion) { \ | |
211 | if (!(config & yes)) \ | |
212 | return 0; \ | |
213 | } else { \ | |
214 | if (!(config & no)) \ | |
215 | return 0; \ | |
216 | } \ | |
217 | } while(0) | |
218 | ||
219 | if (~config) { | |
220 | FILTER(obj->cookie, | |
221 | COOKIE, NOCOOKIE); | |
222 | FILTER(obj->state != FSCACHE_OBJECT_ACTIVE || | |
223 | obj->n_ops != 0 || | |
224 | obj->n_obj_ops != 0 || | |
225 | obj->flags || | |
226 | !list_empty(&obj->dependents), | |
227 | BUSY, IDLE); | |
228 | FILTER(test_bit(FSCACHE_OBJECT_PENDING_WRITE, &obj->flags), | |
229 | PENDWR, NOPENDWR); | |
230 | FILTER(atomic_read(&obj->n_reads), | |
231 | READS, NOREADS); | |
232 | FILTER(obj->events & obj->event_mask, | |
233 | EVENTS, NOEVENTS); | |
234 | FILTER(obj->work.flags & ~(1UL << SLOW_WORK_VERY_SLOW), | |
235 | WORK, NOWORK); | |
236 | } | |
237 | ||
238 | seq_printf(m, | |
239 | "%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %1lx %1lx | ", | |
240 | obj->debug_id, | |
241 | obj->parent ? obj->parent->debug_id : -1, | |
242 | fscache_object_states_short[obj->state], | |
243 | obj->n_children, | |
244 | obj->n_ops, | |
245 | obj->n_obj_ops, | |
246 | obj->n_in_progress, | |
247 | obj->n_exclusive, | |
248 | atomic_read(&obj->n_reads), | |
249 | obj->event_mask & FSCACHE_OBJECT_EVENTS_MASK, | |
250 | obj->events, | |
251 | obj->flags, | |
252 | obj->work.flags); | |
253 | ||
254 | no_cookie = true; | |
255 | keylen = auxlen = 0; | |
256 | if (obj->cookie) { | |
257 | spin_lock(&obj->lock); | |
258 | if (obj->cookie) { | |
259 | switch (obj->cookie->def->type) { | |
260 | case 0: | |
261 | type = "IX"; | |
262 | break; | |
263 | case 1: | |
264 | type = "DT"; | |
265 | break; | |
266 | default: | |
267 | sprintf(_type, "%02u", | |
268 | obj->cookie->def->type); | |
269 | type = _type; | |
270 | break; | |
271 | } | |
272 | ||
273 | seq_printf(m, "%-16s %s %2lx %16p", | |
274 | obj->cookie->def->name, | |
275 | type, | |
276 | obj->cookie->flags, | |
277 | obj->cookie->netfs_data); | |
278 | ||
279 | if (obj->cookie->def->get_key && | |
280 | config & FSCACHE_OBJLIST_CONFIG_KEY) | |
281 | keylen = obj->cookie->def->get_key( | |
282 | obj->cookie->netfs_data, | |
283 | buf, 400); | |
284 | ||
285 | if (obj->cookie->def->get_aux && | |
286 | config & FSCACHE_OBJLIST_CONFIG_AUX) | |
287 | auxlen = obj->cookie->def->get_aux( | |
288 | obj->cookie->netfs_data, | |
289 | buf + keylen, 512 - keylen); | |
290 | ||
291 | no_cookie = false; | |
292 | } | |
293 | spin_unlock(&obj->lock); | |
294 | ||
295 | if (!no_cookie && (keylen > 0 || auxlen > 0)) { | |
296 | seq_printf(m, " "); | |
297 | for (p = buf; keylen > 0; keylen--) | |
298 | seq_printf(m, "%02x", *p++); | |
299 | if (auxlen > 0) { | |
300 | if (config & FSCACHE_OBJLIST_CONFIG_KEY) | |
301 | seq_printf(m, ", "); | |
302 | for (; auxlen > 0; auxlen--) | |
303 | seq_printf(m, "%02x", *p++); | |
304 | } | |
305 | } | |
306 | } | |
307 | ||
308 | if (no_cookie) | |
309 | seq_printf(m, "<no_cookie>\n"); | |
310 | else | |
311 | seq_printf(m, "\n"); | |
312 | return 0; | |
313 | } | |
314 | ||
315 | static const struct seq_operations fscache_objlist_ops = { | |
316 | .start = fscache_objlist_start, | |
317 | .stop = fscache_objlist_stop, | |
318 | .next = fscache_objlist_next, | |
319 | .show = fscache_objlist_show, | |
320 | }; | |
321 | ||
322 | /* | |
323 | * get the configuration for filtering the list | |
324 | */ | |
325 | static void fscache_objlist_config(struct fscache_objlist_data *data) | |
326 | { | |
327 | #ifdef CONFIG_KEYS | |
328 | struct user_key_payload *confkey; | |
329 | unsigned long config; | |
330 | struct key *key; | |
331 | const char *buf; | |
332 | int len; | |
333 | ||
334 | key = request_key(&key_type_user, "fscache:objlist", NULL); | |
335 | if (IS_ERR(key)) | |
336 | goto no_config; | |
337 | ||
338 | config = 0; | |
339 | rcu_read_lock(); | |
340 | ||
341 | confkey = key->payload.data; | |
342 | buf = confkey->data; | |
343 | ||
344 | for (len = confkey->datalen - 1; len >= 0; len--) { | |
345 | switch (buf[len]) { | |
346 | case 'K': config |= FSCACHE_OBJLIST_CONFIG_KEY; break; | |
347 | case 'A': config |= FSCACHE_OBJLIST_CONFIG_AUX; break; | |
348 | case 'C': config |= FSCACHE_OBJLIST_CONFIG_COOKIE; break; | |
349 | case 'c': config |= FSCACHE_OBJLIST_CONFIG_NOCOOKIE; break; | |
350 | case 'B': config |= FSCACHE_OBJLIST_CONFIG_BUSY; break; | |
351 | case 'b': config |= FSCACHE_OBJLIST_CONFIG_IDLE; break; | |
352 | case 'W': config |= FSCACHE_OBJLIST_CONFIG_PENDWR; break; | |
353 | case 'w': config |= FSCACHE_OBJLIST_CONFIG_NOPENDWR; break; | |
354 | case 'R': config |= FSCACHE_OBJLIST_CONFIG_READS; break; | |
355 | case 'r': config |= FSCACHE_OBJLIST_CONFIG_NOREADS; break; | |
356 | case 'S': config |= FSCACHE_OBJLIST_CONFIG_WORK; break; | |
357 | case 's': config |= FSCACHE_OBJLIST_CONFIG_NOWORK; break; | |
358 | } | |
359 | } | |
360 | ||
361 | rcu_read_unlock(); | |
362 | key_put(key); | |
363 | ||
364 | if (!(config & (FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE))) | |
365 | config |= FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE; | |
366 | if (!(config & (FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE))) | |
367 | config |= FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE; | |
368 | if (!(config & (FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR))) | |
369 | config |= FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR; | |
370 | if (!(config & (FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS))) | |
371 | config |= FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS; | |
372 | if (!(config & (FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS))) | |
373 | config |= FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS; | |
374 | if (!(config & (FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK))) | |
375 | config |= FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK; | |
376 | ||
377 | data->config = config; | |
378 | return; | |
379 | ||
380 | no_config: | |
381 | #endif | |
382 | data->config = ULONG_MAX; | |
383 | } | |
384 | ||
385 | /* | |
386 | * open "/proc/fs/fscache/objects" to provide a list of active objects | |
387 | * - can be configured by a user-defined key added to the caller's keyrings | |
388 | */ | |
389 | static int fscache_objlist_open(struct inode *inode, struct file *file) | |
390 | { | |
391 | struct fscache_objlist_data *data; | |
392 | struct seq_file *m; | |
393 | int ret; | |
394 | ||
395 | ret = seq_open(file, &fscache_objlist_ops); | |
396 | if (ret < 0) | |
397 | return ret; | |
398 | ||
399 | m = file->private_data; | |
400 | ||
401 | /* buffer for key extraction */ | |
402 | data = kmalloc(sizeof(struct fscache_objlist_data), GFP_KERNEL); | |
403 | if (!data) { | |
404 | seq_release(inode, file); | |
405 | return -ENOMEM; | |
406 | } | |
407 | ||
408 | /* get the configuration key */ | |
409 | fscache_objlist_config(data); | |
410 | ||
411 | m->private = data; | |
412 | return 0; | |
413 | } | |
414 | ||
415 | /* | |
416 | * clean up on close | |
417 | */ | |
418 | static int fscache_objlist_release(struct inode *inode, struct file *file) | |
419 | { | |
420 | struct seq_file *m = file->private_data; | |
421 | ||
422 | kfree(m->private); | |
423 | m->private = NULL; | |
424 | return seq_release(inode, file); | |
425 | } | |
426 | ||
427 | const struct file_operations fscache_objlist_fops = { | |
428 | .owner = THIS_MODULE, | |
429 | .open = fscache_objlist_open, | |
430 | .read = seq_read, | |
431 | .llseek = seq_lseek, | |
432 | .release = fscache_objlist_release, | |
433 | }; |