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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 | 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 | ||
7026f192 DH |
53 | ASSERT(RB_EMPTY_NODE(&obj->objlist_link)); |
54 | ||
4fbf4291 DH |
55 | write_lock(&fscache_object_list_lock); |
56 | ||
57 | while (*p) { | |
58 | parent = *p; | |
59 | xobj = rb_entry(parent, struct fscache_object, objlist_link); | |
60 | ||
61 | if (obj < xobj) | |
62 | p = &(*p)->rb_left; | |
63 | else if (obj > xobj) | |
64 | p = &(*p)->rb_right; | |
65 | else | |
66 | BUG(); | |
67 | } | |
68 | ||
69 | rb_link_node(&obj->objlist_link, parent, p); | |
70 | rb_insert_color(&obj->objlist_link, &fscache_object_list); | |
71 | ||
72 | write_unlock(&fscache_object_list_lock); | |
73 | } | |
74 | ||
1362729b DH |
75 | /* |
76 | * Remove an object from the object list. | |
4fbf4291 | 77 | */ |
1362729b | 78 | void fscache_objlist_remove(struct fscache_object *obj) |
4fbf4291 | 79 | { |
7026f192 DH |
80 | if (RB_EMPTY_NODE(&obj->objlist_link)) |
81 | return; | |
82 | ||
4fbf4291 DH |
83 | write_lock(&fscache_object_list_lock); |
84 | ||
85 | BUG_ON(RB_EMPTY_ROOT(&fscache_object_list)); | |
86 | rb_erase(&obj->objlist_link, &fscache_object_list); | |
87 | ||
88 | write_unlock(&fscache_object_list_lock); | |
89 | } | |
4fbf4291 DH |
90 | |
91 | /* | |
92 | * find the object in the tree on or after the specified index | |
93 | */ | |
94 | static struct fscache_object *fscache_objlist_lookup(loff_t *_pos) | |
95 | { | |
ea58ceb5 | 96 | struct fscache_object *pobj, *obj = NULL, *minobj = NULL; |
4fbf4291 DH |
97 | struct rb_node *p; |
98 | unsigned long pos; | |
99 | ||
100 | if (*_pos >= (unsigned long) ERR_PTR(-ENOENT)) | |
101 | return NULL; | |
102 | pos = *_pos; | |
103 | ||
104 | /* banners (can't represent line 0 by pos 0 as that would involve | |
105 | * returning a NULL pointer) */ | |
106 | if (pos == 0) | |
cc68e3be | 107 | return (struct fscache_object *)(long)++(*_pos); |
4fbf4291 DH |
108 | if (pos < 3) |
109 | return (struct fscache_object *)pos; | |
110 | ||
111 | pobj = (struct fscache_object *)pos; | |
112 | p = fscache_object_list.rb_node; | |
113 | while (p) { | |
114 | obj = rb_entry(p, struct fscache_object, objlist_link); | |
115 | if (pobj < obj) { | |
116 | if (!minobj || minobj > obj) | |
117 | minobj = obj; | |
118 | p = p->rb_left; | |
119 | } else if (pobj > obj) { | |
120 | p = p->rb_right; | |
121 | } else { | |
122 | minobj = obj; | |
123 | break; | |
124 | } | |
125 | obj = NULL; | |
126 | } | |
127 | ||
128 | if (!minobj) | |
129 | *_pos = (unsigned long) ERR_PTR(-ENOENT); | |
130 | else if (minobj != obj) | |
131 | *_pos = (unsigned long) minobj; | |
132 | return minobj; | |
133 | } | |
134 | ||
135 | /* | |
136 | * set up the iterator to start reading from the first line | |
137 | */ | |
138 | static void *fscache_objlist_start(struct seq_file *m, loff_t *_pos) | |
139 | __acquires(&fscache_object_list_lock) | |
140 | { | |
141 | read_lock(&fscache_object_list_lock); | |
142 | return fscache_objlist_lookup(_pos); | |
143 | } | |
144 | ||
145 | /* | |
146 | * move to the next line | |
147 | */ | |
148 | static void *fscache_objlist_next(struct seq_file *m, void *v, loff_t *_pos) | |
149 | { | |
150 | (*_pos)++; | |
151 | return fscache_objlist_lookup(_pos); | |
152 | } | |
153 | ||
154 | /* | |
155 | * clean up after reading | |
156 | */ | |
157 | static void fscache_objlist_stop(struct seq_file *m, void *v) | |
158 | __releases(&fscache_object_list_lock) | |
159 | { | |
160 | read_unlock(&fscache_object_list_lock); | |
161 | } | |
162 | ||
163 | /* | |
164 | * display an object | |
165 | */ | |
166 | static int fscache_objlist_show(struct seq_file *m, void *v) | |
167 | { | |
168 | struct fscache_objlist_data *data = m->private; | |
169 | struct fscache_object *obj = v; | |
1362729b | 170 | struct fscache_cookie *cookie; |
4fbf4291 | 171 | unsigned long config = data->config; |
4fbf4291 | 172 | char _type[3], *type; |
4fbf4291 DH |
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" | |
caaef690 | 177 | " EM EV FL S" |
4fbf4291 DH |
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, "======== ======== ==== ===== === === === == =====" | |
caaef690 | 196 | " == == == =" |
4fbf4291 DH |
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 | ||
1362729b | 219 | cookie = obj->cookie; |
4fbf4291 | 220 | if (~config) { |
1362729b | 221 | FILTER(cookie->def, |
4fbf4291 | 222 | COOKIE, NOCOOKIE); |
caaef690 | 223 | FILTER(fscache_object_is_active(obj) || |
4fbf4291 DH |
224 | obj->n_ops != 0 || |
225 | obj->n_obj_ops != 0 || | |
226 | obj->flags || | |
227 | !list_empty(&obj->dependents), | |
228 | BUSY, IDLE); | |
229 | FILTER(test_bit(FSCACHE_OBJECT_PENDING_WRITE, &obj->flags), | |
230 | PENDWR, NOPENDWR); | |
231 | FILTER(atomic_read(&obj->n_reads), | |
232 | READS, NOREADS); | |
233 | FILTER(obj->events & obj->event_mask, | |
234 | EVENTS, NOEVENTS); | |
8b8edefa | 235 | FILTER(work_busy(&obj->work), WORK, NOWORK); |
4fbf4291 DH |
236 | } |
237 | ||
238 | seq_printf(m, | |
caaef690 | 239 | "%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %2lx %1x | ", |
4fbf4291 DH |
240 | obj->debug_id, |
241 | obj->parent ? obj->parent->debug_id : -1, | |
caaef690 | 242 | obj->state->short_name, |
4fbf4291 DH |
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), | |
c2d35bfe | 249 | obj->event_mask, |
4fbf4291 DH |
250 | obj->events, |
251 | obj->flags, | |
8b8edefa | 252 | work_busy(&obj->work)); |
4fbf4291 | 253 | |
1362729b DH |
254 | if (fscache_use_cookie(obj)) { |
255 | uint16_t keylen = 0, auxlen = 0; | |
4fbf4291 | 256 | |
1362729b DH |
257 | switch (cookie->def->type) { |
258 | case 0: | |
259 | type = "IX"; | |
260 | break; | |
261 | case 1: | |
262 | type = "DT"; | |
263 | break; | |
264 | default: | |
265 | sprintf(_type, "%02u", cookie->def->type); | |
266 | type = _type; | |
267 | break; | |
4fbf4291 | 268 | } |
4fbf4291 | 269 | |
1362729b DH |
270 | seq_printf(m, "%-16s %s %2lx %16p", |
271 | cookie->def->name, | |
272 | type, | |
273 | cookie->flags, | |
274 | cookie->netfs_data); | |
275 | ||
276 | if (cookie->def->get_key && | |
277 | config & FSCACHE_OBJLIST_CONFIG_KEY) | |
278 | keylen = cookie->def->get_key(cookie->netfs_data, | |
279 | buf, 400); | |
280 | ||
281 | if (cookie->def->get_aux && | |
282 | config & FSCACHE_OBJLIST_CONFIG_AUX) | |
283 | auxlen = cookie->def->get_aux(cookie->netfs_data, | |
284 | buf + keylen, 512 - keylen); | |
285 | fscache_unuse_cookie(obj); | |
286 | ||
287 | if (keylen > 0 || auxlen > 0) { | |
3185a88c | 288 | seq_puts(m, " "); |
4fbf4291 DH |
289 | for (p = buf; keylen > 0; keylen--) |
290 | seq_printf(m, "%02x", *p++); | |
291 | if (auxlen > 0) { | |
292 | if (config & FSCACHE_OBJLIST_CONFIG_KEY) | |
3185a88c | 293 | seq_puts(m, ", "); |
4fbf4291 DH |
294 | for (; auxlen > 0; auxlen--) |
295 | seq_printf(m, "%02x", *p++); | |
296 | } | |
297 | } | |
4fbf4291 | 298 | |
3185a88c | 299 | seq_puts(m, "\n"); |
1362729b | 300 | } else { |
3185a88c | 301 | seq_puts(m, "<no_netfs>\n"); |
1362729b | 302 | } |
4fbf4291 DH |
303 | return 0; |
304 | } | |
305 | ||
306 | static const struct seq_operations fscache_objlist_ops = { | |
307 | .start = fscache_objlist_start, | |
308 | .stop = fscache_objlist_stop, | |
309 | .next = fscache_objlist_next, | |
310 | .show = fscache_objlist_show, | |
311 | }; | |
312 | ||
313 | /* | |
314 | * get the configuration for filtering the list | |
315 | */ | |
316 | static void fscache_objlist_config(struct fscache_objlist_data *data) | |
317 | { | |
318 | #ifdef CONFIG_KEYS | |
146aa8b1 | 319 | const struct user_key_payload *confkey; |
4fbf4291 DH |
320 | unsigned long config; |
321 | struct key *key; | |
322 | const char *buf; | |
323 | int len; | |
324 | ||
325 | key = request_key(&key_type_user, "fscache:objlist", NULL); | |
326 | if (IS_ERR(key)) | |
327 | goto no_config; | |
328 | ||
329 | config = 0; | |
330 | rcu_read_lock(); | |
331 | ||
146aa8b1 | 332 | confkey = user_key_payload(key); |
4fbf4291 DH |
333 | buf = confkey->data; |
334 | ||
335 | for (len = confkey->datalen - 1; len >= 0; len--) { | |
336 | switch (buf[len]) { | |
337 | case 'K': config |= FSCACHE_OBJLIST_CONFIG_KEY; break; | |
338 | case 'A': config |= FSCACHE_OBJLIST_CONFIG_AUX; break; | |
339 | case 'C': config |= FSCACHE_OBJLIST_CONFIG_COOKIE; break; | |
340 | case 'c': config |= FSCACHE_OBJLIST_CONFIG_NOCOOKIE; break; | |
341 | case 'B': config |= FSCACHE_OBJLIST_CONFIG_BUSY; break; | |
342 | case 'b': config |= FSCACHE_OBJLIST_CONFIG_IDLE; break; | |
343 | case 'W': config |= FSCACHE_OBJLIST_CONFIG_PENDWR; break; | |
344 | case 'w': config |= FSCACHE_OBJLIST_CONFIG_NOPENDWR; break; | |
345 | case 'R': config |= FSCACHE_OBJLIST_CONFIG_READS; break; | |
346 | case 'r': config |= FSCACHE_OBJLIST_CONFIG_NOREADS; break; | |
347 | case 'S': config |= FSCACHE_OBJLIST_CONFIG_WORK; break; | |
348 | case 's': config |= FSCACHE_OBJLIST_CONFIG_NOWORK; break; | |
349 | } | |
350 | } | |
351 | ||
352 | rcu_read_unlock(); | |
353 | key_put(key); | |
354 | ||
355 | if (!(config & (FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE))) | |
356 | config |= FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE; | |
357 | if (!(config & (FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE))) | |
358 | config |= FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE; | |
359 | if (!(config & (FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR))) | |
360 | config |= FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR; | |
361 | if (!(config & (FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS))) | |
362 | config |= FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS; | |
363 | if (!(config & (FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS))) | |
364 | config |= FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS; | |
365 | if (!(config & (FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK))) | |
366 | config |= FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK; | |
367 | ||
368 | data->config = config; | |
369 | return; | |
370 | ||
371 | no_config: | |
372 | #endif | |
373 | data->config = ULONG_MAX; | |
374 | } | |
375 | ||
376 | /* | |
377 | * open "/proc/fs/fscache/objects" to provide a list of active objects | |
378 | * - can be configured by a user-defined key added to the caller's keyrings | |
379 | */ | |
380 | static int fscache_objlist_open(struct inode *inode, struct file *file) | |
381 | { | |
382 | struct fscache_objlist_data *data; | |
4fbf4291 | 383 | |
d5d96226 RJ |
384 | data = __seq_open_private(file, &fscache_objlist_ops, sizeof(*data)); |
385 | if (!data) | |
4fbf4291 | 386 | return -ENOMEM; |
4fbf4291 DH |
387 | |
388 | /* get the configuration key */ | |
389 | fscache_objlist_config(data); | |
390 | ||
4fbf4291 DH |
391 | return 0; |
392 | } | |
393 | ||
394 | /* | |
395 | * clean up on close | |
396 | */ | |
397 | static int fscache_objlist_release(struct inode *inode, struct file *file) | |
398 | { | |
399 | struct seq_file *m = file->private_data; | |
400 | ||
401 | kfree(m->private); | |
402 | m->private = NULL; | |
403 | return seq_release(inode, file); | |
404 | } | |
405 | ||
406 | const struct file_operations fscache_objlist_fops = { | |
407 | .owner = THIS_MODULE, | |
408 | .open = fscache_objlist_open, | |
409 | .read = seq_read, | |
410 | .llseek = seq_lseek, | |
411 | .release = fscache_objlist_release, | |
412 | }; |