[PATCH 07/12] fscache: Remove the object list procfile

From: David Howells
Date: Mon Jun 21 2021 - 17:46:40 EST


Remove the object list procfile from fscache as objects will become
entirely internal to the cache.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

fs/fscache/Kconfig | 7 -
fs/fscache/Makefile | 1
fs/fscache/cache.c | 1
fs/fscache/cookie.c | 2
fs/fscache/internal.h | 13 -
fs/fscache/object-list.c | 414 -----------------------------------------
fs/fscache/object.c | 2
include/linux/fscache-cache.h | 3
8 files changed, 443 deletions(-)
delete mode 100644 fs/fscache/object-list.c

diff --git a/fs/fscache/Kconfig b/fs/fscache/Kconfig
index 5e3a5b3f950d..b313a978ae0a 100644
--- a/fs/fscache/Kconfig
+++ b/fs/fscache/Kconfig
@@ -38,10 +38,3 @@ config FSCACHE_DEBUG
enabled by setting bits in /sys/modules/fscache/parameter/debug.

See Documentation/filesystems/caching/fscache.rst for more information.
-
-config FSCACHE_OBJECT_LIST
- bool "Maintain global object list for debugging purposes"
- depends on FSCACHE && PROC_FS
- help
- Maintain a global list of active fscache objects that can be
- retrieved through /proc/fs/fscache/objects for debugging purposes
diff --git a/fs/fscache/Makefile b/fs/fscache/Makefile
index 45d5235a449b..03a871d689bb 100644
--- a/fs/fscache/Makefile
+++ b/fs/fscache/Makefile
@@ -16,6 +16,5 @@ fscache-y := \

fscache-$(CONFIG_PROC_FS) += proc.o
fscache-$(CONFIG_FSCACHE_STATS) += stats.o
-fscache-$(CONFIG_FSCACHE_OBJECT_LIST) += object-list.o

obj-$(CONFIG_FSCACHE) := fscache.o
diff --git a/fs/fscache/cache.c b/fs/fscache/cache.c
index fcc136361415..8a6ffcac867f 100644
--- a/fs/fscache/cache.c
+++ b/fs/fscache/cache.c
@@ -261,7 +261,6 @@ int fscache_add_cache(struct fscache_cache *cache,
spin_lock(&cache->object_list_lock);
list_add_tail(&ifsdef->cache_link, &cache->object_list);
spin_unlock(&cache->object_list_lock);
- fscache_objlist_add(ifsdef);

/* add the cache's netfs definition index object to the top level index
* cookie as a known backing object */
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index c7047544972b..2f4d5271ad2e 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -620,8 +620,6 @@ static int fscache_attach_object(struct fscache_cookie *cookie,

/* Attach to the cookie. The object already has a ref on it. */
hlist_add_head(&object->cookie_link, &cookie->backing_objects);
-
- fscache_objlist_add(object);
ret = 0;

cant_attach_object:
diff --git a/fs/fscache/internal.h b/fs/fscache/internal.h
index 796678b2b32a..200082cafdda 100644
--- a/fs/fscache/internal.h
+++ b/fs/fscache/internal.h
@@ -84,19 +84,6 @@ static inline bool fscache_object_congested(void)
*/
extern void fscache_enqueue_object(struct fscache_object *);

-/*
- * object-list.c
- */
-#ifdef CONFIG_FSCACHE_OBJECT_LIST
-extern const struct proc_ops fscache_objlist_proc_ops;
-
-extern void fscache_objlist_add(struct fscache_object *);
-extern void fscache_objlist_remove(struct fscache_object *);
-#else
-#define fscache_objlist_add(object) do {} while(0)
-#define fscache_objlist_remove(object) do {} while(0)
-#endif
-
/*
* operation.c
*/
diff --git a/fs/fscache/object-list.c b/fs/fscache/object-list.c
deleted file mode 100644
index 1a0dc32c0a33..000000000000
--- a/fs/fscache/object-list.c
+++ /dev/null
@@ -1,414 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/* Global fscache object list maintainer and viewer
- *
- * Copyright (C) 2009 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@xxxxxxxxxx)
- */
-
-#define FSCACHE_DEBUG_LEVEL COOKIE
-#include <linux/module.h>
-#include <linux/proc_fs.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 */
-};
-
-/*
- * 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;
-
- ASSERT(RB_EMPTY_NODE(&obj->objlist_link));
-
- 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);
-}
-
-/*
- * Remove an object from the object list.
- */
-void fscache_objlist_remove(struct fscache_object *obj)
-{
- if (RB_EMPTY_NODE(&obj->objlist_link))
- return;
-
- 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);
-}
-
-/*
- * 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;
- struct fscache_cookie *cookie;
- unsigned long config = data->config;
- char _type[3], *type;
- u8 *p;
-
- if ((unsigned long) v == 1) {
- seq_puts(m, "OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS"
- " EM EV FL S"
- " | COOKIE 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)
-
- cookie = obj->cookie;
- if (~config) {
- FILTER(cookie->def,
- COOKIE, NOCOOKIE);
- FILTER(fscache_object_is_active(obj) ||
- 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,
- "%08x %08x %s %5u %3u %3u %3u %2u %5u %2lx %2lx %2lx %1x | ",
- obj->debug_id,
- obj->parent ? obj->parent->debug_id : UINT_MAX,
- obj->state->short_name,
- 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,
- obj->events,
- obj->flags,
- work_busy(&obj->work));
-
- if (obj->cookie) {
- uint16_t keylen = 0, auxlen = 0;
-
- switch (cookie->type) {
- case 0:
- type = "IX";
- break;
- case 1:
- type = "DT";
- break;
- default:
- snprintf(_type, sizeof(_type), "%02u",
- cookie->type);
- type = _type;
- break;
- }
-
- seq_printf(m, "%08x %-16s %s %3lx %16p",
- cookie->debug_id,
- cookie->def->name,
- type,
- cookie->flags,
- cookie->netfs_data);
-
- if (config & FSCACHE_OBJLIST_CONFIG_KEY)
- keylen = cookie->key_len;
-
- if (config & FSCACHE_OBJLIST_CONFIG_AUX)
- auxlen = cookie->aux_len;
-
- if (keylen > 0 || auxlen > 0) {
- seq_puts(m, " ");
- p = keylen <= sizeof(cookie->inline_key) ?
- cookie->inline_key : cookie->key;
- for (; keylen > 0; keylen--)
- seq_printf(m, "%02x", *p++);
- if (auxlen > 0) {
- if (config & FSCACHE_OBJLIST_CONFIG_KEY)
- seq_puts(m, ", ");
- p = auxlen <= sizeof(cookie->inline_aux) ?
- cookie->inline_aux : cookie->aux;
- for (; auxlen > 0; auxlen--)
- seq_printf(m, "%02x", *p++);
- }
- }
-
- seq_puts(m, "\n");
- } else {
- seq_puts(m, "<no_netfs>\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
- const 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 = user_key_payload_rcu(key);
- if (!confkey) {
- /* key was revoked */
- rcu_read_unlock();
- key_put(key);
- goto no_config;
- }
-
- 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;
-
- data = __seq_open_private(file, &fscache_objlist_ops, sizeof(*data));
- if (!data)
- return -ENOMEM;
-
- /* get the configuration key */
- fscache_objlist_config(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 proc_ops fscache_objlist_proc_ops = {
- .proc_open = fscache_objlist_open,
- .proc_read = seq_read,
- .proc_lseek = seq_lseek,
- .proc_release = fscache_objlist_release,
-};
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index 5dbaab2e1262..b3853274733f 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -794,8 +794,6 @@ static void fscache_put_object(struct fscache_object *object,
*/
void fscache_object_destroy(struct fscache_object *object)
{
- fscache_objlist_remove(object);
-
/* We can get rid of the cookie now */
fscache_cookie_put(object->cookie, fscache_cookie_put_object);
object->cookie = NULL;
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index fbff0b7e3ef1..8d39491c5f9f 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -384,9 +384,6 @@ struct fscache_object {
struct list_head dependents; /* FIFO of dependent objects */
struct list_head dep_link; /* link in parent's dependents list */
struct list_head pending_ops; /* unstarted operations on this object */
-#ifdef CONFIG_FSCACHE_OBJECT_LIST
- struct rb_node objlist_link; /* link in global object list */
-#endif
pgoff_t store_limit; /* current storage limit */
loff_t store_limit_l; /* current storage limit */
};