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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 00000000000..e590242fa41
--- /dev/null
+++ b/fs/fscache/object-list.c
@@ -0,0 +1,432 @@
+/* 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/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 slow work */
+#define FSCACHE_OBJLIST_CONFIG_NOWORK 0x00002000 /* show objects without slow 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, *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 *) ++(*_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(obj->work.flags & ~(1UL << SLOW_WORK_VERY_SLOW),
+ WORK, NOWORK);
+ }
+
+ seq_printf(m,
+ "%8x %8x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %1lx %1lx | ",
+ 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,
+ obj->work.flags);
+
+ 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,
+};