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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 | ||
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 DH |
77 | { |
78 | write_lock(&fscache_object_list_lock); | |
79 | ||
80 | BUG_ON(RB_EMPTY_ROOT(&fscache_object_list)); | |
81 | rb_erase(&obj->objlist_link, &fscache_object_list); | |
82 | ||
83 | write_unlock(&fscache_object_list_lock); | |
84 | } | |
4fbf4291 DH |
85 | |
86 | /* | |
87 | * find the object in the tree on or after the specified index | |
88 | */ | |
89 | static struct fscache_object *fscache_objlist_lookup(loff_t *_pos) | |
90 | { | |
ea58ceb5 | 91 | struct fscache_object *pobj, *obj = NULL, *minobj = NULL; |
4fbf4291 DH |
92 | struct rb_node *p; |
93 | unsigned long pos; | |
94 | ||
95 | if (*_pos >= (unsigned long) ERR_PTR(-ENOENT)) | |
96 | return NULL; | |
97 | pos = *_pos; | |
98 | ||
99 | /* banners (can't represent line 0 by pos 0 as that would involve | |
100 | * returning a NULL pointer) */ | |
101 | if (pos == 0) | |
cc68e3be | 102 | return (struct fscache_object *)(long)++(*_pos); |
4fbf4291 DH |
103 | if (pos < 3) |
104 | return (struct fscache_object *)pos; | |
105 | ||
106 | pobj = (struct fscache_object *)pos; | |
107 | p = fscache_object_list.rb_node; | |
108 | while (p) { | |
109 | obj = rb_entry(p, struct fscache_object, objlist_link); | |
110 | if (pobj < obj) { | |
111 | if (!minobj || minobj > obj) | |
112 | minobj = obj; | |
113 | p = p->rb_left; | |
114 | } else if (pobj > obj) { | |
115 | p = p->rb_right; | |
116 | } else { | |
117 | minobj = obj; | |
118 | break; | |
119 | } | |
120 | obj = NULL; | |
121 | } | |
122 | ||
123 | if (!minobj) | |
124 | *_pos = (unsigned long) ERR_PTR(-ENOENT); | |
125 | else if (minobj != obj) | |
126 | *_pos = (unsigned long) minobj; | |
127 | return minobj; | |
128 | } | |
129 | ||
130 | /* | |
131 | * set up the iterator to start reading from the first line | |
132 | */ | |
133 | static void *fscache_objlist_start(struct seq_file *m, loff_t *_pos) | |
134 | __acquires(&fscache_object_list_lock) | |
135 | { | |
136 | read_lock(&fscache_object_list_lock); | |
137 | return fscache_objlist_lookup(_pos); | |
138 | } | |
139 | ||
140 | /* | |
141 | * move to the next line | |
142 | */ | |
143 | static void *fscache_objlist_next(struct seq_file *m, void *v, loff_t *_pos) | |
144 | { | |
145 | (*_pos)++; | |
146 | return fscache_objlist_lookup(_pos); | |
147 | } | |
148 | ||
149 | /* | |
150 | * clean up after reading | |
151 | */ | |
152 | static void fscache_objlist_stop(struct seq_file *m, void *v) | |
153 | __releases(&fscache_object_list_lock) | |
154 | { | |
155 | read_unlock(&fscache_object_list_lock); | |
156 | } | |
157 | ||
158 | /* | |
159 | * display an object | |
160 | */ | |
161 | static int fscache_objlist_show(struct seq_file *m, void *v) | |
162 | { | |
163 | struct fscache_objlist_data *data = m->private; | |
164 | struct fscache_object *obj = v; | |
1362729b | 165 | struct fscache_cookie *cookie; |
4fbf4291 | 166 | unsigned long config = data->config; |
4fbf4291 | 167 | char _type[3], *type; |
4fbf4291 DH |
168 | u8 *buf = data->buf, *p; |
169 | ||
170 | if ((unsigned long) v == 1) { | |
171 | seq_puts(m, "OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS" | |
caaef690 | 172 | " EM EV FL S" |
4fbf4291 DH |
173 | " | NETFS_COOKIE_DEF TY FL NETFS_DATA"); |
174 | if (config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
175 | FSCACHE_OBJLIST_CONFIG_AUX)) | |
176 | seq_puts(m, " "); | |
177 | if (config & FSCACHE_OBJLIST_CONFIG_KEY) | |
178 | seq_puts(m, "OBJECT_KEY"); | |
179 | if ((config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
180 | FSCACHE_OBJLIST_CONFIG_AUX)) == | |
181 | (FSCACHE_OBJLIST_CONFIG_KEY | FSCACHE_OBJLIST_CONFIG_AUX)) | |
182 | seq_puts(m, ", "); | |
183 | if (config & FSCACHE_OBJLIST_CONFIG_AUX) | |
184 | seq_puts(m, "AUX_DATA"); | |
185 | seq_puts(m, "\n"); | |
186 | return 0; | |
187 | } | |
188 | ||
189 | if ((unsigned long) v == 2) { | |
190 | seq_puts(m, "======== ======== ==== ===== === === === == =====" | |
caaef690 | 191 | " == == == =" |
4fbf4291 DH |
192 | " | ================ == == ================"); |
193 | if (config & (FSCACHE_OBJLIST_CONFIG_KEY | | |
194 | FSCACHE_OBJLIST_CONFIG_AUX)) | |
195 | seq_puts(m, " ================"); | |
196 | seq_puts(m, "\n"); | |
197 | return 0; | |
198 | } | |
199 | ||
200 | /* filter out any unwanted objects */ | |
201 | #define FILTER(criterion, _yes, _no) \ | |
202 | do { \ | |
203 | unsigned long yes = FSCACHE_OBJLIST_CONFIG_##_yes; \ | |
204 | unsigned long no = FSCACHE_OBJLIST_CONFIG_##_no; \ | |
205 | if (criterion) { \ | |
206 | if (!(config & yes)) \ | |
207 | return 0; \ | |
208 | } else { \ | |
209 | if (!(config & no)) \ | |
210 | return 0; \ | |
211 | } \ | |
212 | } while(0) | |
213 | ||
1362729b | 214 | cookie = obj->cookie; |
4fbf4291 | 215 | if (~config) { |
1362729b | 216 | FILTER(cookie->def, |
4fbf4291 | 217 | COOKIE, NOCOOKIE); |
caaef690 | 218 | FILTER(fscache_object_is_active(obj) || |
4fbf4291 DH |
219 | obj->n_ops != 0 || |
220 | obj->n_obj_ops != 0 || | |
221 | obj->flags || | |
222 | !list_empty(&obj->dependents), | |
223 | BUSY, IDLE); | |
224 | FILTER(test_bit(FSCACHE_OBJECT_PENDING_WRITE, &obj->flags), | |
225 | PENDWR, NOPENDWR); | |
226 | FILTER(atomic_read(&obj->n_reads), | |
227 | READS, NOREADS); | |
228 | FILTER(obj->events & obj->event_mask, | |
229 | EVENTS, NOEVENTS); | |
8b8edefa | 230 | FILTER(work_busy(&obj->work), WORK, NOWORK); |
4fbf4291 DH |
231 | } |
232 | ||
233 | seq_printf(m, | |
caaef690 | 234 | "%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %2lx %1x | ", |
4fbf4291 DH |
235 | obj->debug_id, |
236 | obj->parent ? obj->parent->debug_id : -1, | |
caaef690 | 237 | obj->state->short_name, |
4fbf4291 DH |
238 | obj->n_children, |
239 | obj->n_ops, | |
240 | obj->n_obj_ops, | |
241 | obj->n_in_progress, | |
242 | obj->n_exclusive, | |
243 | atomic_read(&obj->n_reads), | |
c2d35bfe | 244 | obj->event_mask, |
4fbf4291 DH |
245 | obj->events, |
246 | obj->flags, | |
8b8edefa | 247 | work_busy(&obj->work)); |
4fbf4291 | 248 | |
1362729b DH |
249 | if (fscache_use_cookie(obj)) { |
250 | uint16_t keylen = 0, auxlen = 0; | |
4fbf4291 | 251 | |
1362729b DH |
252 | switch (cookie->def->type) { |
253 | case 0: | |
254 | type = "IX"; | |
255 | break; | |
256 | case 1: | |
257 | type = "DT"; | |
258 | break; | |
259 | default: | |
260 | sprintf(_type, "%02u", cookie->def->type); | |
261 | type = _type; | |
262 | break; | |
4fbf4291 | 263 | } |
4fbf4291 | 264 | |
1362729b DH |
265 | seq_printf(m, "%-16s %s %2lx %16p", |
266 | cookie->def->name, | |
267 | type, | |
268 | cookie->flags, | |
269 | cookie->netfs_data); | |
270 | ||
271 | if (cookie->def->get_key && | |
272 | config & FSCACHE_OBJLIST_CONFIG_KEY) | |
273 | keylen = cookie->def->get_key(cookie->netfs_data, | |
274 | buf, 400); | |
275 | ||
276 | if (cookie->def->get_aux && | |
277 | config & FSCACHE_OBJLIST_CONFIG_AUX) | |
278 | auxlen = cookie->def->get_aux(cookie->netfs_data, | |
279 | buf + keylen, 512 - keylen); | |
280 | fscache_unuse_cookie(obj); | |
281 | ||
282 | if (keylen > 0 || auxlen > 0) { | |
4fbf4291 DH |
283 | seq_printf(m, " "); |
284 | for (p = buf; keylen > 0; keylen--) | |
285 | seq_printf(m, "%02x", *p++); | |
286 | if (auxlen > 0) { | |
287 | if (config & FSCACHE_OBJLIST_CONFIG_KEY) | |
288 | seq_printf(m, ", "); | |
289 | for (; auxlen > 0; auxlen--) | |
290 | seq_printf(m, "%02x", *p++); | |
291 | } | |
292 | } | |
4fbf4291 | 293 | |
4fbf4291 | 294 | seq_printf(m, "\n"); |
1362729b DH |
295 | } else { |
296 | seq_printf(m, "<no_netfs>\n"); | |
297 | } | |
4fbf4291 DH |
298 | return 0; |
299 | } | |
300 | ||
301 | static const struct seq_operations fscache_objlist_ops = { | |
302 | .start = fscache_objlist_start, | |
303 | .stop = fscache_objlist_stop, | |
304 | .next = fscache_objlist_next, | |
305 | .show = fscache_objlist_show, | |
306 | }; | |
307 | ||
308 | /* | |
309 | * get the configuration for filtering the list | |
310 | */ | |
311 | static void fscache_objlist_config(struct fscache_objlist_data *data) | |
312 | { | |
313 | #ifdef CONFIG_KEYS | |
314 | struct user_key_payload *confkey; | |
315 | unsigned long config; | |
316 | struct key *key; | |
317 | const char *buf; | |
318 | int len; | |
319 | ||
320 | key = request_key(&key_type_user, "fscache:objlist", NULL); | |
321 | if (IS_ERR(key)) | |
322 | goto no_config; | |
323 | ||
324 | config = 0; | |
325 | rcu_read_lock(); | |
326 | ||
327 | confkey = key->payload.data; | |
328 | buf = confkey->data; | |
329 | ||
330 | for (len = confkey->datalen - 1; len >= 0; len--) { | |
331 | switch (buf[len]) { | |
332 | case 'K': config |= FSCACHE_OBJLIST_CONFIG_KEY; break; | |
333 | case 'A': config |= FSCACHE_OBJLIST_CONFIG_AUX; break; | |
334 | case 'C': config |= FSCACHE_OBJLIST_CONFIG_COOKIE; break; | |
335 | case 'c': config |= FSCACHE_OBJLIST_CONFIG_NOCOOKIE; break; | |
336 | case 'B': config |= FSCACHE_OBJLIST_CONFIG_BUSY; break; | |
337 | case 'b': config |= FSCACHE_OBJLIST_CONFIG_IDLE; break; | |
338 | case 'W': config |= FSCACHE_OBJLIST_CONFIG_PENDWR; break; | |
339 | case 'w': config |= FSCACHE_OBJLIST_CONFIG_NOPENDWR; break; | |
340 | case 'R': config |= FSCACHE_OBJLIST_CONFIG_READS; break; | |
341 | case 'r': config |= FSCACHE_OBJLIST_CONFIG_NOREADS; break; | |
342 | case 'S': config |= FSCACHE_OBJLIST_CONFIG_WORK; break; | |
343 | case 's': config |= FSCACHE_OBJLIST_CONFIG_NOWORK; break; | |
344 | } | |
345 | } | |
346 | ||
347 | rcu_read_unlock(); | |
348 | key_put(key); | |
349 | ||
350 | if (!(config & (FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE))) | |
351 | config |= FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE; | |
352 | if (!(config & (FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE))) | |
353 | config |= FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE; | |
354 | if (!(config & (FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR))) | |
355 | config |= FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR; | |
356 | if (!(config & (FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS))) | |
357 | config |= FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS; | |
358 | if (!(config & (FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS))) | |
359 | config |= FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS; | |
360 | if (!(config & (FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK))) | |
361 | config |= FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK; | |
362 | ||
363 | data->config = config; | |
364 | return; | |
365 | ||
366 | no_config: | |
367 | #endif | |
368 | data->config = ULONG_MAX; | |
369 | } | |
370 | ||
371 | /* | |
372 | * open "/proc/fs/fscache/objects" to provide a list of active objects | |
373 | * - can be configured by a user-defined key added to the caller's keyrings | |
374 | */ | |
375 | static int fscache_objlist_open(struct inode *inode, struct file *file) | |
376 | { | |
377 | struct fscache_objlist_data *data; | |
378 | struct seq_file *m; | |
379 | int ret; | |
380 | ||
381 | ret = seq_open(file, &fscache_objlist_ops); | |
382 | if (ret < 0) | |
383 | return ret; | |
384 | ||
385 | m = file->private_data; | |
386 | ||
387 | /* buffer for key extraction */ | |
388 | data = kmalloc(sizeof(struct fscache_objlist_data), GFP_KERNEL); | |
389 | if (!data) { | |
390 | seq_release(inode, file); | |
391 | return -ENOMEM; | |
392 | } | |
393 | ||
394 | /* get the configuration key */ | |
395 | fscache_objlist_config(data); | |
396 | ||
397 | m->private = data; | |
398 | return 0; | |
399 | } | |
400 | ||
401 | /* | |
402 | * clean up on close | |
403 | */ | |
404 | static int fscache_objlist_release(struct inode *inode, struct file *file) | |
405 | { | |
406 | struct seq_file *m = file->private_data; | |
407 | ||
408 | kfree(m->private); | |
409 | m->private = NULL; | |
410 | return seq_release(inode, file); | |
411 | } | |
412 | ||
413 | const struct file_operations fscache_objlist_fops = { | |
414 | .owner = THIS_MODULE, | |
415 | .open = fscache_objlist_open, | |
416 | .read = seq_read, | |
417 | .llseek = seq_lseek, | |
418 | .release = fscache_objlist_release, | |
419 | }; |