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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 */ | |
8b8edefa TH |
37 | #define FSCACHE_OBJLIST_CONFIG_WORK 0x00001000 /* show objects with work */ |
38 | #define FSCACHE_OBJLIST_CONFIG_NOWORK 0x00002000 /* show objects without work */ | |
4fbf4291 DH |
39 | }; |
40 | ||
41 | /* | |
42 | * Add an object to the object list | |
43 | * - we use the address of the fscache_object structure as the key into the | |
44 | * tree | |
45 | */ | |
46 | void fscache_objlist_add(struct fscache_object *obj) | |
47 | { | |
48 | struct fscache_object *xobj; | |
49 | struct rb_node **p = &fscache_object_list.rb_node, *parent = NULL; | |
50 | ||
7026f192 DH |
51 | ASSERT(RB_EMPTY_NODE(&obj->objlist_link)); |
52 | ||
4fbf4291 DH |
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 | ||
1362729b DH |
73 | /* |
74 | * Remove an object from the object list. | |
4fbf4291 | 75 | */ |
1362729b | 76 | void fscache_objlist_remove(struct fscache_object *obj) |
4fbf4291 | 77 | { |
7026f192 DH |
78 | if (RB_EMPTY_NODE(&obj->objlist_link)) |
79 | return; | |
80 | ||
4fbf4291 DH |
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 | } | |
4fbf4291 DH |
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) | |
cc68e3be | 105 | return (struct fscache_object *)(long)++(*_pos); |
4fbf4291 DH |
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; | |
1362729b | 168 | struct fscache_cookie *cookie; |
4fbf4291 | 169 | unsigned long config = data->config; |
4fbf4291 | 170 | char _type[3], *type; |
402cb8dd | 171 | u8 *p; |
4fbf4291 DH |
172 | |
173 | if ((unsigned long) v == 1) { | |
174 | seq_puts(m, "OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS" | |
caaef690 | 175 | " EM EV FL S" |
4fbf4291 DH |
176 | " | NETFS_COOKIE_DEF TY FL NETFS_DATA"); |
177 | if (config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
178 | FSCACHE_OBJLIST_CONFIG_AUX)) | |
179 | seq_puts(m, " "); | |
180 | if (config & FSCACHE_OBJLIST_CONFIG_KEY) | |
181 | seq_puts(m, "OBJECT_KEY"); | |
182 | if ((config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
183 | FSCACHE_OBJLIST_CONFIG_AUX)) == | |
184 | (FSCACHE_OBJLIST_CONFIG_KEY | FSCACHE_OBJLIST_CONFIG_AUX)) | |
185 | seq_puts(m, ", "); | |
186 | if (config & FSCACHE_OBJLIST_CONFIG_AUX) | |
187 | seq_puts(m, "AUX_DATA"); | |
188 | seq_puts(m, "\n"); | |
189 | return 0; | |
190 | } | |
191 | ||
192 | if ((unsigned long) v == 2) { | |
193 | seq_puts(m, "======== ======== ==== ===== === === === == =====" | |
caaef690 | 194 | " == == == =" |
4fbf4291 DH |
195 | " | ================ == == ================"); |
196 | if (config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
197 | FSCACHE_OBJLIST_CONFIG_AUX)) | |
198 | seq_puts(m, " ================"); | |
199 | seq_puts(m, "\n"); | |
200 | return 0; | |
201 | } | |
202 | ||
203 | /* filter out any unwanted objects */ | |
204 | #define FILTER(criterion, _yes, _no) \ | |
205 | do { \ | |
206 | unsigned long yes = FSCACHE_OBJLIST_CONFIG_##_yes; \ | |
207 | unsigned long no = FSCACHE_OBJLIST_CONFIG_##_no; \ | |
208 | if (criterion) { \ | |
209 | if (!(config & yes)) \ | |
210 | return 0; \ | |
211 | } else { \ | |
212 | if (!(config & no)) \ | |
213 | return 0; \ | |
214 | } \ | |
215 | } while(0) | |
216 | ||
1362729b | 217 | cookie = obj->cookie; |
4fbf4291 | 218 | if (~config) { |
1362729b | 219 | FILTER(cookie->def, |
4fbf4291 | 220 | COOKIE, NOCOOKIE); |
caaef690 | 221 | FILTER(fscache_object_is_active(obj) || |
4fbf4291 DH |
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); | |
8b8edefa | 233 | FILTER(work_busy(&obj->work), WORK, NOWORK); |
4fbf4291 DH |
234 | } |
235 | ||
236 | seq_printf(m, | |
caaef690 | 237 | "%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %2lx %1x | ", |
4fbf4291 DH |
238 | obj->debug_id, |
239 | obj->parent ? obj->parent->debug_id : -1, | |
caaef690 | 240 | obj->state->short_name, |
4fbf4291 DH |
241 | obj->n_children, |
242 | obj->n_ops, | |
243 | obj->n_obj_ops, | |
244 | obj->n_in_progress, | |
245 | obj->n_exclusive, | |
246 | atomic_read(&obj->n_reads), | |
c2d35bfe | 247 | obj->event_mask, |
4fbf4291 DH |
248 | obj->events, |
249 | obj->flags, | |
8b8edefa | 250 | work_busy(&obj->work)); |
4fbf4291 | 251 | |
1362729b DH |
252 | if (fscache_use_cookie(obj)) { |
253 | uint16_t keylen = 0, auxlen = 0; | |
4fbf4291 | 254 | |
402cb8dd | 255 | switch (cookie->type) { |
1362729b DH |
256 | case 0: |
257 | type = "IX"; | |
258 | break; | |
259 | case 1: | |
260 | type = "DT"; | |
261 | break; | |
262 | default: | |
ebfddb3d | 263 | snprintf(_type, sizeof(_type), "%02u", |
402cb8dd | 264 | cookie->type); |
1362729b DH |
265 | type = _type; |
266 | break; | |
4fbf4291 | 267 | } |
4fbf4291 | 268 | |
1362729b DH |
269 | seq_printf(m, "%-16s %s %2lx %16p", |
270 | cookie->def->name, | |
271 | type, | |
272 | cookie->flags, | |
273 | cookie->netfs_data); | |
274 | ||
402cb8dd DH |
275 | if (config & FSCACHE_OBJLIST_CONFIG_KEY) |
276 | keylen = cookie->key_len; | |
1362729b | 277 | |
402cb8dd DH |
278 | if (config & FSCACHE_OBJLIST_CONFIG_AUX) |
279 | auxlen = cookie->aux_len; | |
1362729b DH |
280 | |
281 | if (keylen > 0 || auxlen > 0) { | |
3185a88c | 282 | seq_puts(m, " "); |
402cb8dd DH |
283 | p = keylen <= sizeof(cookie->inline_key) ? |
284 | cookie->inline_key : cookie->key; | |
285 | for (; keylen > 0; keylen--) | |
4fbf4291 DH |
286 | seq_printf(m, "%02x", *p++); |
287 | if (auxlen > 0) { | |
288 | if (config & FSCACHE_OBJLIST_CONFIG_KEY) | |
3185a88c | 289 | seq_puts(m, ", "); |
402cb8dd DH |
290 | p = auxlen <= sizeof(cookie->inline_aux) ? |
291 | cookie->inline_aux : cookie->aux; | |
4fbf4291 DH |
292 | for (; auxlen > 0; auxlen--) |
293 | seq_printf(m, "%02x", *p++); | |
294 | } | |
295 | } | |
4fbf4291 | 296 | |
3185a88c | 297 | seq_puts(m, "\n"); |
402cb8dd | 298 | fscache_unuse_cookie(obj); |
1362729b | 299 | } else { |
3185a88c | 300 | seq_puts(m, "<no_netfs>\n"); |
1362729b | 301 | } |
4fbf4291 DH |
302 | return 0; |
303 | } | |
304 | ||
305 | static const struct seq_operations fscache_objlist_ops = { | |
306 | .start = fscache_objlist_start, | |
307 | .stop = fscache_objlist_stop, | |
308 | .next = fscache_objlist_next, | |
309 | .show = fscache_objlist_show, | |
310 | }; | |
311 | ||
312 | /* | |
313 | * get the configuration for filtering the list | |
314 | */ | |
315 | static void fscache_objlist_config(struct fscache_objlist_data *data) | |
316 | { | |
317 | #ifdef CONFIG_KEYS | |
146aa8b1 | 318 | const struct user_key_payload *confkey; |
4fbf4291 DH |
319 | unsigned long config; |
320 | struct key *key; | |
321 | const char *buf; | |
322 | int len; | |
323 | ||
324 | key = request_key(&key_type_user, "fscache:objlist", NULL); | |
325 | if (IS_ERR(key)) | |
326 | goto no_config; | |
327 | ||
328 | config = 0; | |
329 | rcu_read_lock(); | |
330 | ||
0837e49a | 331 | confkey = user_key_payload_rcu(key); |
d124b2c5 EB |
332 | if (!confkey) { |
333 | /* key was revoked */ | |
334 | rcu_read_unlock(); | |
335 | key_put(key); | |
336 | goto no_config; | |
337 | } | |
338 | ||
4fbf4291 DH |
339 | buf = confkey->data; |
340 | ||
341 | for (len = confkey->datalen - 1; len >= 0; len--) { | |
342 | switch (buf[len]) { | |
343 | case 'K': config |= FSCACHE_OBJLIST_CONFIG_KEY; break; | |
344 | case 'A': config |= FSCACHE_OBJLIST_CONFIG_AUX; break; | |
345 | case 'C': config |= FSCACHE_OBJLIST_CONFIG_COOKIE; break; | |
346 | case 'c': config |= FSCACHE_OBJLIST_CONFIG_NOCOOKIE; break; | |
347 | case 'B': config |= FSCACHE_OBJLIST_CONFIG_BUSY; break; | |
348 | case 'b': config |= FSCACHE_OBJLIST_CONFIG_IDLE; break; | |
349 | case 'W': config |= FSCACHE_OBJLIST_CONFIG_PENDWR; break; | |
350 | case 'w': config |= FSCACHE_OBJLIST_CONFIG_NOPENDWR; break; | |
351 | case 'R': config |= FSCACHE_OBJLIST_CONFIG_READS; break; | |
352 | case 'r': config |= FSCACHE_OBJLIST_CONFIG_NOREADS; break; | |
353 | case 'S': config |= FSCACHE_OBJLIST_CONFIG_WORK; break; | |
354 | case 's': config |= FSCACHE_OBJLIST_CONFIG_NOWORK; break; | |
355 | } | |
356 | } | |
357 | ||
358 | rcu_read_unlock(); | |
359 | key_put(key); | |
360 | ||
361 | if (!(config & (FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE))) | |
362 | config |= FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE; | |
363 | if (!(config & (FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE))) | |
364 | config |= FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE; | |
365 | if (!(config & (FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR))) | |
366 | config |= FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR; | |
367 | if (!(config & (FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS))) | |
368 | config |= FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS; | |
369 | if (!(config & (FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS))) | |
370 | config |= FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS; | |
371 | if (!(config & (FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK))) | |
372 | config |= FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK; | |
373 | ||
374 | data->config = config; | |
375 | return; | |
376 | ||
377 | no_config: | |
378 | #endif | |
379 | data->config = ULONG_MAX; | |
380 | } | |
381 | ||
382 | /* | |
383 | * open "/proc/fs/fscache/objects" to provide a list of active objects | |
384 | * - can be configured by a user-defined key added to the caller's keyrings | |
385 | */ | |
386 | static int fscache_objlist_open(struct inode *inode, struct file *file) | |
387 | { | |
388 | struct fscache_objlist_data *data; | |
4fbf4291 | 389 | |
d5d96226 RJ |
390 | data = __seq_open_private(file, &fscache_objlist_ops, sizeof(*data)); |
391 | if (!data) | |
4fbf4291 | 392 | return -ENOMEM; |
4fbf4291 DH |
393 | |
394 | /* get the configuration key */ | |
395 | fscache_objlist_config(data); | |
396 | ||
4fbf4291 DH |
397 | return 0; |
398 | } | |
399 | ||
400 | /* | |
401 | * clean up on close | |
402 | */ | |
403 | static int fscache_objlist_release(struct inode *inode, struct file *file) | |
404 | { | |
405 | struct seq_file *m = file->private_data; | |
406 | ||
407 | kfree(m->private); | |
408 | m->private = NULL; | |
409 | return seq_release(inode, file); | |
410 | } | |
411 | ||
412 | const struct file_operations fscache_objlist_fops = { | |
4fbf4291 DH |
413 | .open = fscache_objlist_open, |
414 | .read = seq_read, | |
415 | .llseek = seq_lseek, | |
416 | .release = fscache_objlist_release, | |
417 | }; |