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- /* Global fscache object list maintainer and viewer
- *
- * Copyright (C) 2009 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
- */
- #define FSCACHE_DEBUG_LEVEL COOKIE
- #include <linux/module.h>
- #include <linux/seq_file.h>
- #include <linux/slab.h>
- #include <linux/key.h>
- #include <keys/user-type.h>
- #include "internal.h"
- static struct rb_root fscache_object_list;
- static DEFINE_RWLOCK(fscache_object_list_lock);
- struct fscache_objlist_data {
- unsigned long config; /* display configuration */
- #define FSCACHE_OBJLIST_CONFIG_KEY 0x00000001 /* show object keys */
- #define FSCACHE_OBJLIST_CONFIG_AUX 0x00000002 /* show object auxdata */
- #define FSCACHE_OBJLIST_CONFIG_COOKIE 0x00000004 /* show objects with cookies */
- #define FSCACHE_OBJLIST_CONFIG_NOCOOKIE 0x00000008 /* show objects without cookies */
- #define FSCACHE_OBJLIST_CONFIG_BUSY 0x00000010 /* show busy objects */
- #define FSCACHE_OBJLIST_CONFIG_IDLE 0x00000020 /* show idle objects */
- #define FSCACHE_OBJLIST_CONFIG_PENDWR 0x00000040 /* show objects with pending writes */
- #define FSCACHE_OBJLIST_CONFIG_NOPENDWR 0x00000080 /* show objects without pending writes */
- #define FSCACHE_OBJLIST_CONFIG_READS 0x00000100 /* show objects with active reads */
- #define FSCACHE_OBJLIST_CONFIG_NOREADS 0x00000200 /* show objects without active reads */
- #define FSCACHE_OBJLIST_CONFIG_EVENTS 0x00000400 /* show objects with events */
- #define FSCACHE_OBJLIST_CONFIG_NOEVENTS 0x00000800 /* show objects without no events */
- #define FSCACHE_OBJLIST_CONFIG_WORK 0x00001000 /* show objects with work */
- #define FSCACHE_OBJLIST_CONFIG_NOWORK 0x00002000 /* show objects without work */
- u8 buf[512]; /* key and aux data buffer */
- };
- /*
- * Add an object to the object list
- * - we use the address of the fscache_object structure as the key into the
- * tree
- */
- void fscache_objlist_add(struct fscache_object *obj)
- {
- struct fscache_object *xobj;
- struct rb_node **p = &fscache_object_list.rb_node, *parent = NULL;
- write_lock(&fscache_object_list_lock);
- while (*p) {
- parent = *p;
- xobj = rb_entry(parent, struct fscache_object, objlist_link);
- if (obj < xobj)
- p = &(*p)->rb_left;
- else if (obj > xobj)
- p = &(*p)->rb_right;
- else
- BUG();
- }
- rb_link_node(&obj->objlist_link, parent, p);
- rb_insert_color(&obj->objlist_link, &fscache_object_list);
- write_unlock(&fscache_object_list_lock);
- }
- /**
- * fscache_object_destroy - Note that a cache object is about to be destroyed
- * @object: The object to be destroyed
- *
- * Note the imminent destruction and deallocation of a cache object record.
- */
- void fscache_object_destroy(struct fscache_object *obj)
- {
- write_lock(&fscache_object_list_lock);
- BUG_ON(RB_EMPTY_ROOT(&fscache_object_list));
- rb_erase(&obj->objlist_link, &fscache_object_list);
- write_unlock(&fscache_object_list_lock);
- }
- EXPORT_SYMBOL(fscache_object_destroy);
- /*
- * find the object in the tree on or after the specified index
- */
- static struct fscache_object *fscache_objlist_lookup(loff_t *_pos)
- {
- struct fscache_object *pobj, *obj = NULL, *minobj = NULL;
- struct rb_node *p;
- unsigned long pos;
- if (*_pos >= (unsigned long) ERR_PTR(-ENOENT))
- return NULL;
- pos = *_pos;
- /* banners (can't represent line 0 by pos 0 as that would involve
- * returning a NULL pointer) */
- if (pos == 0)
- return (struct fscache_object *)(long)++(*_pos);
- if (pos < 3)
- return (struct fscache_object *)pos;
- pobj = (struct fscache_object *)pos;
- p = fscache_object_list.rb_node;
- while (p) {
- obj = rb_entry(p, struct fscache_object, objlist_link);
- if (pobj < obj) {
- if (!minobj || minobj > obj)
- minobj = obj;
- p = p->rb_left;
- } else if (pobj > obj) {
- p = p->rb_right;
- } else {
- minobj = obj;
- break;
- }
- obj = NULL;
- }
- if (!minobj)
- *_pos = (unsigned long) ERR_PTR(-ENOENT);
- else if (minobj != obj)
- *_pos = (unsigned long) minobj;
- return minobj;
- }
- /*
- * set up the iterator to start reading from the first line
- */
- static void *fscache_objlist_start(struct seq_file *m, loff_t *_pos)
- __acquires(&fscache_object_list_lock)
- {
- read_lock(&fscache_object_list_lock);
- return fscache_objlist_lookup(_pos);
- }
- /*
- * move to the next line
- */
- static void *fscache_objlist_next(struct seq_file *m, void *v, loff_t *_pos)
- {
- (*_pos)++;
- return fscache_objlist_lookup(_pos);
- }
- /*
- * clean up after reading
- */
- static void fscache_objlist_stop(struct seq_file *m, void *v)
- __releases(&fscache_object_list_lock)
- {
- read_unlock(&fscache_object_list_lock);
- }
- /*
- * display an object
- */
- static int fscache_objlist_show(struct seq_file *m, void *v)
- {
- struct fscache_objlist_data *data = m->private;
- struct fscache_object *obj = v;
- unsigned long config = data->config;
- uint16_t keylen, auxlen;
- char _type[3], *type;
- bool no_cookie;
- u8 *buf = data->buf, *p;
- if ((unsigned long) v == 1) {
- seq_puts(m, "OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS"
- " EM EV F S"
- " | NETFS_COOKIE_DEF TY FL NETFS_DATA");
- if (config & (FSCACHE_OBJLIST_CONFIG_KEY |
- FSCACHE_OBJLIST_CONFIG_AUX))
- seq_puts(m, " ");
- if (config & FSCACHE_OBJLIST_CONFIG_KEY)
- seq_puts(m, "OBJECT_KEY");
- if ((config & (FSCACHE_OBJLIST_CONFIG_KEY |
- FSCACHE_OBJLIST_CONFIG_AUX)) ==
- (FSCACHE_OBJLIST_CONFIG_KEY | FSCACHE_OBJLIST_CONFIG_AUX))
- seq_puts(m, ", ");
- if (config & FSCACHE_OBJLIST_CONFIG_AUX)
- seq_puts(m, "AUX_DATA");
- seq_puts(m, "\n");
- return 0;
- }
- if ((unsigned long) v == 2) {
- seq_puts(m, "======== ======== ==== ===== === === === == ====="
- " == == = ="
- " | ================ == == ================");
- if (config & (FSCACHE_OBJLIST_CONFIG_KEY |
- FSCACHE_OBJLIST_CONFIG_AUX))
- seq_puts(m, " ================");
- seq_puts(m, "\n");
- return 0;
- }
- /* filter out any unwanted objects */
- #define FILTER(criterion, _yes, _no) \
- do { \
- unsigned long yes = FSCACHE_OBJLIST_CONFIG_##_yes; \
- unsigned long no = FSCACHE_OBJLIST_CONFIG_##_no; \
- if (criterion) { \
- if (!(config & yes)) \
- return 0; \
- } else { \
- if (!(config & no)) \
- return 0; \
- } \
- } while(0)
- if (~config) {
- FILTER(obj->cookie,
- COOKIE, NOCOOKIE);
- FILTER(obj->state != FSCACHE_OBJECT_ACTIVE ||
- obj->n_ops != 0 ||
- obj->n_obj_ops != 0 ||
- obj->flags ||
- !list_empty(&obj->dependents),
- BUSY, IDLE);
- FILTER(test_bit(FSCACHE_OBJECT_PENDING_WRITE, &obj->flags),
- PENDWR, NOPENDWR);
- FILTER(atomic_read(&obj->n_reads),
- READS, NOREADS);
- FILTER(obj->events & obj->event_mask,
- EVENTS, NOEVENTS);
- FILTER(work_busy(&obj->work), WORK, NOWORK);
- }
- seq_printf(m,
- "%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %1lx %1x | ",
- obj->debug_id,
- obj->parent ? obj->parent->debug_id : -1,
- fscache_object_states_short[obj->state],
- obj->n_children,
- obj->n_ops,
- obj->n_obj_ops,
- obj->n_in_progress,
- obj->n_exclusive,
- atomic_read(&obj->n_reads),
- obj->event_mask & FSCACHE_OBJECT_EVENTS_MASK,
- obj->events,
- obj->flags,
- work_busy(&obj->work));
- no_cookie = true;
- keylen = auxlen = 0;
- if (obj->cookie) {
- spin_lock(&obj->lock);
- if (obj->cookie) {
- switch (obj->cookie->def->type) {
- case 0:
- type = "IX";
- break;
- case 1:
- type = "DT";
- break;
- default:
- sprintf(_type, "%02u",
- obj->cookie->def->type);
- type = _type;
- break;
- }
- seq_printf(m, "%-16s %s %2lx %16p",
- obj->cookie->def->name,
- type,
- obj->cookie->flags,
- obj->cookie->netfs_data);
- if (obj->cookie->def->get_key &&
- config & FSCACHE_OBJLIST_CONFIG_KEY)
- keylen = obj->cookie->def->get_key(
- obj->cookie->netfs_data,
- buf, 400);
- if (obj->cookie->def->get_aux &&
- config & FSCACHE_OBJLIST_CONFIG_AUX)
- auxlen = obj->cookie->def->get_aux(
- obj->cookie->netfs_data,
- buf + keylen, 512 - keylen);
- no_cookie = false;
- }
- spin_unlock(&obj->lock);
- if (!no_cookie && (keylen > 0 || auxlen > 0)) {
- seq_printf(m, " ");
- for (p = buf; keylen > 0; keylen--)
- seq_printf(m, "%02x", *p++);
- if (auxlen > 0) {
- if (config & FSCACHE_OBJLIST_CONFIG_KEY)
- seq_printf(m, ", ");
- for (; auxlen > 0; auxlen--)
- seq_printf(m, "%02x", *p++);
- }
- }
- }
- if (no_cookie)
- seq_printf(m, "<no_cookie>\n");
- else
- seq_printf(m, "\n");
- return 0;
- }
- static const struct seq_operations fscache_objlist_ops = {
- .start = fscache_objlist_start,
- .stop = fscache_objlist_stop,
- .next = fscache_objlist_next,
- .show = fscache_objlist_show,
- };
- /*
- * get the configuration for filtering the list
- */
- static void fscache_objlist_config(struct fscache_objlist_data *data)
- {
- #ifdef CONFIG_KEYS
- struct user_key_payload *confkey;
- unsigned long config;
- struct key *key;
- const char *buf;
- int len;
- key = request_key(&key_type_user, "fscache:objlist", NULL);
- if (IS_ERR(key))
- goto no_config;
- config = 0;
- rcu_read_lock();
- confkey = key->payload.data;
- buf = confkey->data;
- for (len = confkey->datalen - 1; len >= 0; len--) {
- switch (buf[len]) {
- case 'K': config |= FSCACHE_OBJLIST_CONFIG_KEY; break;
- case 'A': config |= FSCACHE_OBJLIST_CONFIG_AUX; break;
- case 'C': config |= FSCACHE_OBJLIST_CONFIG_COOKIE; break;
- case 'c': config |= FSCACHE_OBJLIST_CONFIG_NOCOOKIE; break;
- case 'B': config |= FSCACHE_OBJLIST_CONFIG_BUSY; break;
- case 'b': config |= FSCACHE_OBJLIST_CONFIG_IDLE; break;
- case 'W': config |= FSCACHE_OBJLIST_CONFIG_PENDWR; break;
- case 'w': config |= FSCACHE_OBJLIST_CONFIG_NOPENDWR; break;
- case 'R': config |= FSCACHE_OBJLIST_CONFIG_READS; break;
- case 'r': config |= FSCACHE_OBJLIST_CONFIG_NOREADS; break;
- case 'S': config |= FSCACHE_OBJLIST_CONFIG_WORK; break;
- case 's': config |= FSCACHE_OBJLIST_CONFIG_NOWORK; break;
- }
- }
- rcu_read_unlock();
- key_put(key);
- if (!(config & (FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE)))
- config |= FSCACHE_OBJLIST_CONFIG_COOKIE | FSCACHE_OBJLIST_CONFIG_NOCOOKIE;
- if (!(config & (FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE)))
- config |= FSCACHE_OBJLIST_CONFIG_BUSY | FSCACHE_OBJLIST_CONFIG_IDLE;
- if (!(config & (FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR)))
- config |= FSCACHE_OBJLIST_CONFIG_PENDWR | FSCACHE_OBJLIST_CONFIG_NOPENDWR;
- if (!(config & (FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS)))
- config |= FSCACHE_OBJLIST_CONFIG_READS | FSCACHE_OBJLIST_CONFIG_NOREADS;
- if (!(config & (FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS)))
- config |= FSCACHE_OBJLIST_CONFIG_EVENTS | FSCACHE_OBJLIST_CONFIG_NOEVENTS;
- if (!(config & (FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK)))
- config |= FSCACHE_OBJLIST_CONFIG_WORK | FSCACHE_OBJLIST_CONFIG_NOWORK;
- data->config = config;
- return;
- no_config:
- #endif
- data->config = ULONG_MAX;
- }
- /*
- * open "/proc/fs/fscache/objects" to provide a list of active objects
- * - can be configured by a user-defined key added to the caller's keyrings
- */
- static int fscache_objlist_open(struct inode *inode, struct file *file)
- {
- struct fscache_objlist_data *data;
- struct seq_file *m;
- int ret;
- ret = seq_open(file, &fscache_objlist_ops);
- if (ret < 0)
- return ret;
- m = file->private_data;
- /* buffer for key extraction */
- data = kmalloc(sizeof(struct fscache_objlist_data), GFP_KERNEL);
- if (!data) {
- seq_release(inode, file);
- return -ENOMEM;
- }
- /* get the configuration key */
- fscache_objlist_config(data);
- m->private = data;
- return 0;
- }
- /*
- * clean up on close
- */
- static int fscache_objlist_release(struct inode *inode, struct file *file)
- {
- struct seq_file *m = file->private_data;
- kfree(m->private);
- m->private = NULL;
- return seq_release(inode, file);
- }
- const struct file_operations fscache_objlist_fops = {
- .owner = THIS_MODULE,
- .open = fscache_objlist_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = fscache_objlist_release,
- };
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