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-rw-r--r--fs/fscache/object-list.c432
1 files changed, 432 insertions, 0 deletions
diff --git a/fs/fscache/object-list.c b/fs/fscache/object-list.c
new file mode 100644
index 000000000000..e590242fa41a
--- /dev/null
+++ b/fs/fscache/object-list.c
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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
19static struct rb_root fscache_object_list;
20static DEFINE_RWLOCK(fscache_object_list_lock);
21
22struct 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 */
47void 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 */
78void 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}
87EXPORT_SYMBOL(fscache_object_destroy);
88
89/*
90 * find the object in the tree on or after the specified index
91 */
92static struct fscache_object *fscache_objlist_lookup(loff_t *_pos)
93{
94 struct fscache_object *pobj, *obj, *minobj = NULL;
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 */
136static 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 */
146static 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 */
155static 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 */
164static 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
314static 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 */
324static 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
379no_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 */
388static 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 */
417static 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
426const 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};
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-24 19:02:11 -0500