1 /* Global fscache object list maintainer and viewer
3 * Copyright (C) 2009 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
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.
12 #define FSCACHE_DEBUG_LEVEL COOKIE
13 #include <linux/module.h>
14 #include <linux/seq_file.h>
15 #include <linux/slab.h>
16 #include <linux/key.h>
17 #include <keys/user-type.h>
20 static struct rb_root fscache_object_list;
21 static DEFINE_RWLOCK(fscache_object_list_lock);
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 */
40 u8 buf[512]; /* key and aux data buffer */
44 * Add an object to the object list
45 * - we use the address of the fscache_object structure as the key into the
48 void fscache_objlist_add(struct fscache_object *obj)
50 struct fscache_object *xobj;
51 struct rb_node **p = &fscache_object_list.rb_node, *parent = NULL;
53 write_lock(&fscache_object_list_lock);
57 xobj = rb_entry(parent, struct fscache_object, objlist_link);
67 rb_link_node(&obj->objlist_link, parent, p);
68 rb_insert_color(&obj->objlist_link, &fscache_object_list);
70 write_unlock(&fscache_object_list_lock);
74 * fscache_object_destroy - Note that a cache object is about to be destroyed
75 * @object: The object to be destroyed
77 * Note the imminent destruction and deallocation of a cache object record.
79 void fscache_object_destroy(struct fscache_object *obj)
81 write_lock(&fscache_object_list_lock);
83 BUG_ON(RB_EMPTY_ROOT(&fscache_object_list));
84 rb_erase(&obj->objlist_link, &fscache_object_list);
86 write_unlock(&fscache_object_list_lock);
88 EXPORT_SYMBOL(fscache_object_destroy);
91 * find the object in the tree on or after the specified index
93 static struct fscache_object *fscache_objlist_lookup(loff_t *_pos)
95 struct fscache_object *pobj, *obj = NULL, *minobj = NULL;
99 if (*_pos >= (unsigned long) ERR_PTR(-ENOENT))
103 /* banners (can't represent line 0 by pos 0 as that would involve
104 * returning a NULL pointer) */
106 return (struct fscache_object *)(long)++(*_pos);
108 return (struct fscache_object *)pos;
110 pobj = (struct fscache_object *)pos;
111 p = fscache_object_list.rb_node;
113 obj = rb_entry(p, struct fscache_object, objlist_link);
115 if (!minobj || minobj > obj)
118 } else if (pobj > obj) {
128 *_pos = (unsigned long) ERR_PTR(-ENOENT);
129 else if (minobj != obj)
130 *_pos = (unsigned long) minobj;
135 * set up the iterator to start reading from the first line
137 static void *fscache_objlist_start(struct seq_file *m, loff_t *_pos)
138 __acquires(&fscache_object_list_lock)
140 read_lock(&fscache_object_list_lock);
141 return fscache_objlist_lookup(_pos);
145 * move to the next line
147 static void *fscache_objlist_next(struct seq_file *m, void *v, loff_t *_pos)
150 return fscache_objlist_lookup(_pos);
154 * clean up after reading
156 static void fscache_objlist_stop(struct seq_file *m, void *v)
157 __releases(&fscache_object_list_lock)
159 read_unlock(&fscache_object_list_lock);
165 static int fscache_objlist_show(struct seq_file *m, void *v)
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;
173 u8 *buf = data->buf, *p;
175 if ((unsigned long) v == 1) {
176 seq_puts(m, "OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS"
178 " | NETFS_COOKIE_DEF TY FL NETFS_DATA");
179 if (config & (FSCACHE_OBJLIST_CONFIG_KEY |
180 FSCACHE_OBJLIST_CONFIG_AUX))
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))
188 if (config & FSCACHE_OBJLIST_CONFIG_AUX)
189 seq_puts(m, "AUX_DATA");
194 if ((unsigned long) v == 2) {
195 seq_puts(m, "======== ======== ==== ===== === === === == ====="
197 " | ================ == == ================");
198 if (config & (FSCACHE_OBJLIST_CONFIG_KEY |
199 FSCACHE_OBJLIST_CONFIG_AUX))
200 seq_puts(m, " ================");
205 /* filter out any unwanted objects */
206 #define FILTER(criterion, _yes, _no) \
208 unsigned long yes = FSCACHE_OBJLIST_CONFIG_##_yes; \
209 unsigned long no = FSCACHE_OBJLIST_CONFIG_##_no; \
211 if (!(config & yes)) \
214 if (!(config & no)) \
222 FILTER(obj->state != FSCACHE_OBJECT_ACTIVE ||
224 obj->n_obj_ops != 0 ||
226 !list_empty(&obj->dependents),
228 FILTER(test_bit(FSCACHE_OBJECT_PENDING_WRITE, &obj->flags),
230 FILTER(atomic_read(&obj->n_reads),
232 FILTER(obj->events & obj->event_mask,
234 FILTER(obj->work.flags & ~(1UL << SLOW_WORK_VERY_SLOW),
239 "%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %1lx %1lx | ",
241 obj->parent ? obj->parent->debug_id : -1,
242 fscache_object_states_short[obj->state],
248 atomic_read(&obj->n_reads),
249 obj->event_mask & FSCACHE_OBJECT_EVENTS_MASK,
257 spin_lock(&obj->lock);
259 switch (obj->cookie->def->type) {
267 sprintf(_type, "%02u",
268 obj->cookie->def->type);
273 seq_printf(m, "%-16s %s %2lx %16p",
274 obj->cookie->def->name,
277 obj->cookie->netfs_data);
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,
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);
293 spin_unlock(&obj->lock);
295 if (!no_cookie && (keylen > 0 || auxlen > 0)) {
297 for (p = buf; keylen > 0; keylen--)
298 seq_printf(m, "%02x", *p++);
300 if (config & FSCACHE_OBJLIST_CONFIG_KEY)
302 for (; auxlen > 0; auxlen--)
303 seq_printf(m, "%02x", *p++);
309 seq_printf(m, "<no_cookie>\n");
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,
323 * get the configuration for filtering the list
325 static void fscache_objlist_config(struct fscache_objlist_data *data)
328 struct user_key_payload *confkey;
329 unsigned long config;
334 key = request_key(&key_type_user, "fscache:objlist", NULL);
341 confkey = key->payload.data;
344 for (len = confkey->datalen - 1; len >= 0; 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;
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;
377 data->config = config;
382 data->config = ULONG_MAX;
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
389 static int fscache_objlist_open(struct inode *inode, struct file *file)
391 struct fscache_objlist_data *data;
395 ret = seq_open(file, &fscache_objlist_ops);
399 m = file->private_data;
401 /* buffer for key extraction */
402 data = kmalloc(sizeof(struct fscache_objlist_data), GFP_KERNEL);
404 seq_release(inode, file);
408 /* get the configuration key */
409 fscache_objlist_config(data);
418 static int fscache_objlist_release(struct inode *inode, struct file *file)
420 struct seq_file *m = file->private_data;
424 return seq_release(inode, file);
427 const struct file_operations fscache_objlist_fops = {
428 .owner = THIS_MODULE,
429 .open = fscache_objlist_open,
432 .release = fscache_objlist_release,