Merge tag 'fscache-next-20210829' of...

Merge tag 'fscache-next-20210829' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull fscache updates from David Howells:
 "Preparatory work for the fscache rewrite that's being worked on and
  fix some bugs. These include:

   - Always select netfs stats when enabling fscache stats since they're
     displayed through the same procfile.

   - Add a cookie debug ID that can be used in tracepoints instead of a
     pointer and cache it in the netfs_cache_resources struct rather
     than in the netfs_read_request struct to make it more available.

   - Use file_inode() in cachefiles rather than dereferencing
     file->f_inode directly.

   - Provide a procfile to display fscache cookies.

   - Remove the fscache and cachefiles histogram procfiles.

   - Remove the fscache object list procfile.

   - Avoid using %p in fscache and cachefiles as the value is hashed and
     not comparable to the register dump in an oops trace.

   - Fix the cookie hash function to actually achieve useful dispersion.

   - Fix fscache_cookie_put() so that it doesn't dereference the cookie
     pointer in the tracepoint after the refcount has been decremented
     (we're only allowed to do that if we decremented it to zero).

   - Use refcount_t rather than atomic_t for the fscache_cookie
     refcount"

* tag 'fscache-next-20210829' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  fscache: Use refcount_t for the cookie refcount instead of atomic_t
  fscache: Fix fscache_cookie_put() to not deref after dec
  fscache: Fix cookie key hashing
  cachefiles: Change %p in format strings to something else
  fscache: Change %p in format strings to something else
  fscache: Remove the object list procfile
  fscache, cachefiles: Remove the histogram stuff
  fscache: Procfile to display cookies
  fscache: Add a cookie debug ID and use that in traces
  cachefiles: Use file_inode() rather than accessing ->f_inode
  netfs: Move cookie debug ID to struct netfs_cache_resources
  fscache: Select netfs stats if fscache stats are enabled

fs/cachefiles/Kconfig

@@ -19,22 +19,3 @@ config CACHEFILES_DEBUG
 	  caching on files module.  If this is set, the debugging output may be
 	  enabled by setting bits in /sys/modules/cachefiles/parameter/debug or
 	  by including a debugging specifier in /etc/cachefilesd.conf.
-
-config CACHEFILES_HISTOGRAM
-	bool "Gather latency information on CacheFiles"
-	depends on CACHEFILES && PROC_FS
-	help
-
-	  This option causes latency information to be gathered on CacheFiles
-	  operation and exported through file:
-
-		/proc/fs/cachefiles/histogram
-
-	  The generation of this histogram adds a certain amount of overhead to
-	  execution as there are a number of points at which data is gathered,
-	  and on a multi-CPU system these may be on cachelines that keep
-	  bouncing between CPUs.  On the other hand, the histogram may be
-	  useful for debugging purposes.  Saying 'N' here is recommended.
-
-	  See Documentation/filesystems/caching/cachefiles.rst for more
-	  information.

fs/cachefiles/Makefile

@@ -15,6 +15,4 @@ cachefiles-y := \
 	security.o \
 	xattr.o
 
-cachefiles-$(CONFIG_CACHEFILES_HISTOGRAM) += proc.o
-
 obj-$(CONFIG_CACHEFILES) := cachefiles.o

fs/cachefiles/bind.c

@@ -108,8 +108,6 @@ static int cachefiles_daemon_add_cache(struct cachefiles_cache *cache)
 	atomic_set(&fsdef->usage, 1);
 	fsdef->type = FSCACHE_COOKIE_TYPE_INDEX;
 
-	_debug("- fsdef %p", fsdef);
-
 	/* look up the directory at the root of the cache */
 	ret = kern_path(cache->rootdirname, LOOKUP_DIRECTORY, &path);
 	if (ret < 0)

fs/cachefiles/interface.c

@@ -33,7 +33,7 @@ static struct fscache_object *cachefiles_alloc_object(
 
 	cache = container_of(_cache, struct cachefiles_cache, cache);
 
-	_enter("{%s},%p,", cache->cache.identifier, cookie);
+	_enter("{%s},%x,", cache->cache.identifier, cookie->debug_id);
 
 	lookup_data = kmalloc(sizeof(*lookup_data), cachefiles_gfp);
 	if (!lookup_data)
@@ -96,7 +96,7 @@ static struct fscache_object *cachefiles_alloc_object(
 	lookup_data->key = key;
 	object->lookup_data = lookup_data;
 
-	_leave(" = %p [%p]", &object->fscache, lookup_data);
+	_leave(" = %x [%p]", object->fscache.debug_id, lookup_data);
 	return &object->fscache;
 
 nomem_key:
@@ -379,7 +379,7 @@ static void cachefiles_sync_cache(struct fscache_cache *_cache)
 	const struct cred *saved_cred;
 	int ret;
 
-	_enter("%p", _cache);
+	_enter("%s", _cache->tag->name);
 
 	cache = container_of(_cache, struct cachefiles_cache, cache);
 

fs/cachefiles/internal.h

@@ -180,31 +180,6 @@ extern int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
 extern int cachefiles_check_in_use(struct cachefiles_cache *cache,
 				   struct dentry *dir, char *filename);
 
-/*
- * proc.c
- */
-#ifdef CONFIG_CACHEFILES_HISTOGRAM
-extern atomic_t cachefiles_lookup_histogram[HZ];
-extern atomic_t cachefiles_mkdir_histogram[HZ];
-extern atomic_t cachefiles_create_histogram[HZ];
-
-extern int __init cachefiles_proc_init(void);
-extern void cachefiles_proc_cleanup(void);
-static inline
-void cachefiles_hist(atomic_t histogram[], unsigned long start_jif)
-{
-	unsigned long jif = jiffies - start_jif;
-	if (jif >= HZ)
-		jif = HZ - 1;
-	atomic_inc(&histogram[jif]);
-}
-
-#else
-#define cachefiles_proc_init()		(0)
-#define cachefiles_proc_cleanup()	do {} while (0)
-#define cachefiles_hist(hist, start_jif) do {} while (0)
-#endif
-
 /*
  * rdwr.c
  */

fs/cachefiles/io.c

@@ -70,7 +70,7 @@ static int cachefiles_read(struct netfs_cache_resources *cres,
 
 	_enter("%pD,%li,%llx,%zx/%llx",
 	       file, file_inode(file)->i_ino, start_pos, len,
-	       i_size_read(file->f_inode));
+	       i_size_read(file_inode(file)));
 
 	/* If the caller asked us to seek for data before doing the read, then
 	 * we should do that now.  If we find a gap, we fill it with zeros.
@@ -194,7 +194,7 @@ static int cachefiles_write(struct netfs_cache_resources *cres,
 
 	_enter("%pD,%li,%llx,%zx/%llx",
 	       file, file_inode(file)->i_ino, start_pos, len,
-	       i_size_read(file->f_inode));
+	       i_size_read(file_inode(file)));
 
 	ki = kzalloc(sizeof(struct cachefiles_kiocb), GFP_KERNEL);
 	if (!ki)
@@ -410,7 +410,7 @@ int cachefiles_begin_read_operation(struct netfs_read_request *rreq,
 	rreq->cache_resources.cache_priv = op;
 	rreq->cache_resources.cache_priv2 = file;
 	rreq->cache_resources.ops = &cachefiles_netfs_cache_ops;
-	rreq->cookie_debug_id = object->fscache.debug_id;
+	rreq->cache_resources.debug_id = object->fscache.debug_id;
 	_leave("");
 	return 0;
 

fs/cachefiles/key.c

@@ -150,6 +150,6 @@ char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type)
 	key[len++] = 0;
 	key[len] = 0;
 
-	_leave(" = %p %d", key, len);
+	_leave(" = %s %d", key, len);
 	return key;
 }

fs/cachefiles/main.c

@@ -69,15 +69,9 @@ static int __init cachefiles_init(void)
 		goto error_object_jar;
 	}
 
-	ret = cachefiles_proc_init();
-	if (ret < 0)
-		goto error_proc;
-
 	pr_info("Loaded\n");
 	return 0;
 
-error_proc:
-	kmem_cache_destroy(cachefiles_object_jar);
 error_object_jar:
 	misc_deregister(&cachefiles_dev);
 error_dev:
@@ -94,7 +88,6 @@ static void __exit cachefiles_exit(void)
 {
 	pr_info("Unloading\n");
 
-	cachefiles_proc_cleanup();
 	kmem_cache_destroy(cachefiles_object_jar);
 	misc_deregister(&cachefiles_dev);
 }

fs/cachefiles/namei.c

@@ -39,18 +39,18 @@ void __cachefiles_printk_object(struct cachefiles_object *object,
 	pr_err("%sops=%u inp=%u exc=%u\n",
 	       prefix, object->fscache.n_ops, object->fscache.n_in_progress,
 	       object->fscache.n_exclusive);
-	pr_err("%sparent=%p\n",
-	       prefix, object->fscache.parent);
+	pr_err("%sparent=%x\n",
+	       prefix, object->fscache.parent ? object->fscache.parent->debug_id : 0);
 
 	spin_lock(&object->fscache.lock);
 	cookie = object->fscache.cookie;
 	if (cookie) {
-		pr_err("%scookie=%p [pr=%p nd=%p fl=%lx]\n",
+		pr_err("%scookie=%x [pr=%x nd=%p fl=%lx]\n",
 		       prefix,
-		       object->fscache.cookie,
-		       object->fscache.cookie->parent,
-		       object->fscache.cookie->netfs_data,
-		       object->fscache.cookie->flags);
+		       cookie->debug_id,
+		       cookie->parent ? cookie->parent->debug_id : 0,
+		       cookie->netfs_data,
+		       cookie->flags);
 		pr_err("%skey=[%u] '", prefix, cookie->key_len);
 		k = (cookie->key_len <= sizeof(cookie->inline_key)) ?
 			cookie->inline_key : cookie->key;
@@ -110,7 +110,7 @@ static void cachefiles_mark_object_buried(struct cachefiles_cache *cache,
 
 	/* found the dentry for  */
 found_dentry:
-	kdebug("preemptive burial: OBJ%x [%s] %p",
+	kdebug("preemptive burial: OBJ%x [%s] %pd",
 	       object->fscache.debug_id,
 	       object->fscache.state->name,
 	       dentry);
@@ -140,7 +140,7 @@ static int cachefiles_mark_object_active(struct cachefiles_cache *cache,
 	struct rb_node **_p, *_parent = NULL;
 	struct dentry *dentry;
 
-	_enter(",%p", object);
+	_enter(",%x", object->fscache.debug_id);
 
 try_again:
 	write_lock(&cache->active_lock);
@@ -298,8 +298,6 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
 
 	_enter(",'%pd','%pd'", dir, rep);
 
-	_debug("remove %p from %p", rep, dir);
-
 	/* non-directories can just be unlinked */
 	if (!d_is_dir(rep)) {
 		_debug("unlink stale object");
@@ -446,7 +444,7 @@ int cachefiles_delete_object(struct cachefiles_cache *cache,
 	struct dentry *dir;
 	int ret;
 
-	_enter(",OBJ%x{%p}", object->fscache.debug_id, object->dentry);
+	_enter(",OBJ%x{%pd}", object->fscache.debug_id, object->dentry);
 
 	ASSERT(object->dentry);
 	ASSERT(d_backing_inode(object->dentry));
@@ -496,11 +494,10 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
 	struct dentry *dir, *next = NULL;
 	struct inode *inode;
 	struct path path;
-	unsigned long start;
 	const char *name;
 	int ret, nlen;
 
-	_enter("OBJ%x{%p},OBJ%x,%s,",
+	_enter("OBJ%x{%pd},OBJ%x,%s,",
 	       parent->fscache.debug_id, parent->dentry,
 	       object->fscache.debug_id, key);
 
@@ -535,9 +532,7 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
 
 	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
 
-	start = jiffies;
 	next = lookup_one_len(name, dir, nlen);
-	cachefiles_hist(cachefiles_lookup_histogram, start);
 	if (IS_ERR(next)) {
 		trace_cachefiles_lookup(object, next, NULL);
 		goto lookup_error;
@@ -545,7 +540,7 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
 
 	inode = d_backing_inode(next);
 	trace_cachefiles_lookup(object, next, inode);
-	_debug("next -> %p %s", next, inode ? "positive" : "negative");
+	_debug("next -> %pd %s", next, inode ? "positive" : "negative");
 
 	if (!key)
 		object->new = !inode;
@@ -568,9 +563,7 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
 			ret = security_path_mkdir(&path, next, 0);
 			if (ret < 0)
 				goto create_error;
-			start = jiffies;
 			ret = vfs_mkdir(&init_user_ns, d_inode(dir), next, 0);
-			cachefiles_hist(cachefiles_mkdir_histogram, start);
 			if (!key)
 				trace_cachefiles_mkdir(object, next, ret);
 			if (ret < 0)
@@ -583,8 +576,8 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
 			}
 			ASSERT(d_backing_inode(next));
 
-			_debug("mkdir -> %p{%p{ino=%lu}}",
-			       next, d_backing_inode(next), d_backing_inode(next)->i_ino);
+			_debug("mkdir -> %pd{ino=%lu}",
+			       next, d_backing_inode(next)->i_ino);
 
 		} else if (!d_can_lookup(next)) {
 			pr_err("inode %lu is not a directory\n",
@@ -604,18 +597,16 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
 			ret = security_path_mknod(&path, next, S_IFREG, 0);
 			if (ret < 0)
 				goto create_error;
-			start = jiffies;
 			ret = vfs_create(&init_user_ns, d_inode(dir), next,
 					 S_IFREG, true);
-			cachefiles_hist(cachefiles_create_histogram, start);
 			trace_cachefiles_create(object, next, ret);
 			if (ret < 0)
 				goto create_error;
 
 			ASSERT(d_backing_inode(next));
 
-			_debug("create -> %p{%p{ino=%lu}}",
-			       next, d_backing_inode(next), d_backing_inode(next)->i_ino);
+			_debug("create -> %pd{ino=%lu}",
+			       next, d_backing_inode(next)->i_ino);
 
 		} else if (!d_can_lookup(next) &&
 			   !d_is_reg(next)
@@ -765,7 +756,6 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
 					const char *dirname)
 {
 	struct dentry *subdir;
-	unsigned long start;
 	struct path path;
 	int ret;
 
@@ -775,16 +765,14 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
 	inode_lock(d_inode(dir));
 
 retry:
-	start = jiffies;
 	subdir = lookup_one_len(dirname, dir, strlen(dirname));
-	cachefiles_hist(cachefiles_lookup_histogram, start);
 	if (IS_ERR(subdir)) {
 		if (PTR_ERR(subdir) == -ENOMEM)
 			goto nomem_d_alloc;
 		goto lookup_error;
 	}
 
-	_debug("subdir -> %p %s",
+	_debug("subdir -> %pd %s",
 	       subdir, d_backing_inode(subdir) ? "positive" : "negative");
 
 	/* we need to create the subdir if it doesn't exist yet */
@@ -810,10 +798,8 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
 		}
 		ASSERT(d_backing_inode(subdir));
 
-		_debug("mkdir -> %p{%p{ino=%lu}}",
-		       subdir,
-		       d_backing_inode(subdir),
-		       d_backing_inode(subdir)->i_ino);
+		_debug("mkdir -> %pd{ino=%lu}",
+		       subdir, d_backing_inode(subdir)->i_ino);
 	}
 
 	inode_unlock(d_inode(dir));
@@ -876,7 +862,6 @@ static struct dentry *cachefiles_check_active(struct cachefiles_cache *cache,
 	struct cachefiles_object *object;
 	struct rb_node *_n;
 	struct dentry *victim;
-	unsigned long start;
 	int ret;
 
 	//_enter(",%pd/,%s",
@@ -885,13 +870,11 @@ static struct dentry *cachefiles_check_active(struct cachefiles_cache *cache,
 	/* look up the victim */
 	inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
 
-	start = jiffies;
 	victim = lookup_one_len(filename, dir, strlen(filename));
-	cachefiles_hist(cachefiles_lookup_histogram, start);
 	if (IS_ERR(victim))
 		goto lookup_error;
 
-	//_debug("victim -> %p %s",
+	//_debug("victim -> %pd %s",
 	//       victim, d_backing_inode(victim) ? "positive" : "negative");
 
 	/* if the object is no longer there then we probably retired the object
@@ -922,7 +905,7 @@ static struct dentry *cachefiles_check_active(struct cachefiles_cache *cache,
 
 	read_unlock(&cache->active_lock);
 
-	//_leave(" = %p", victim);
+	//_leave(" = %pd", victim);
 	return victim;
 
 object_in_use:
@@ -968,7 +951,7 @@ int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir,
 	if (IS_ERR(victim))
 		return PTR_ERR(victim);
 
-	_debug("victim -> %p %s",
+	_debug("victim -> %pd %s",
 	       victim, d_backing_inode(victim) ? "positive" : "negative");
 
 	/* okay... the victim is not being used so we can cull it

fs/cachefiles/proc.c

-// SPDX-License-Identifier: GPL-2.0-or-later
-/* CacheFiles statistics
- *
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- */
-
-#include <linux/module.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include "internal.h"
-
-atomic_t cachefiles_lookup_histogram[HZ];
-atomic_t cachefiles_mkdir_histogram[HZ];
-atomic_t cachefiles_create_histogram[HZ];
-
-/*
- * display the latency histogram
- */
-static int cachefiles_histogram_show(struct seq_file *m, void *v)
-{
-	unsigned long index;
-	unsigned x, y, z, t;
-
-	switch ((unsigned long) v) {
-	case 1:
-		seq_puts(m, "JIFS  SECS  LOOKUPS   MKDIRS    CREATES\n");
-		return 0;
-	case 2:
-		seq_puts(m, "===== ===== ========= ========= =========\n");
-		return 0;
-	default:
-		index = (unsigned long) v - 3;
-		x = atomic_read(&cachefiles_lookup_histogram[index]);
-		y = atomic_read(&cachefiles_mkdir_histogram[index]);
-		z = atomic_read(&cachefiles_create_histogram[index]);
-		if (x == 0 && y == 0 && z == 0)
-			return 0;
-
-		t = (index * 1000) / HZ;
-
-		seq_printf(m, "%4lu  0.%03u %9u %9u %9u\n", index, t, x, y, z);
-		return 0;
-	}
-}
-
-/*
- * set up the iterator to start reading from the first line
- */
-static void *cachefiles_histogram_start(struct seq_file *m, loff_t *_pos)
-{
-	if ((unsigned long long)*_pos >= HZ + 2)
-		return NULL;
-	if (*_pos == 0)
-		*_pos = 1;
-	return (void *)(unsigned long) *_pos;
-}
-
-/*
- * move to the next line
- */
-static void *cachefiles_histogram_next(struct seq_file *m, void *v, loff_t *pos)
-{
-	(*pos)++;
-	return (unsigned long long)*pos > HZ + 2 ?
-		NULL : (void *)(unsigned long) *pos;
-}
-
-/*
- * clean up after reading
- */
-static void cachefiles_histogram_stop(struct seq_file *m, void *v)
-{
-}
-
-static const struct seq_operations cachefiles_histogram_ops = {
-	.start		= cachefiles_histogram_start,
-	.stop		= cachefiles_histogram_stop,
-	.next		= cachefiles_histogram_next,
-	.show		= cachefiles_histogram_show,
-};
-
-/*
- * initialise the /proc/fs/cachefiles/ directory
- */
-int __init cachefiles_proc_init(void)
-{
-	_enter("");
-
-	if (!proc_mkdir("fs/cachefiles", NULL))
-		goto error_dir;
-
-	if (!proc_create_seq("fs/cachefiles/histogram", S_IFREG | 0444, NULL,
-			 &cachefiles_histogram_ops))
-		goto error_histogram;
-
-	_leave(" = 0");
-	return 0;
-
-error_histogram:
-	remove_proc_entry("fs/cachefiles", NULL);
-error_dir:
-	_leave(" = -ENOMEM");
-	return -ENOMEM;
-}
-
-/*
- * clean up the /proc/fs/cachefiles/ directory
- */
-void cachefiles_proc_cleanup(void)
-{
-	remove_proc_entry("fs/cachefiles/histogram", NULL);
-	remove_proc_entry("fs/cachefiles", NULL);
-}

fs/cachefiles/xattr.c

@@ -36,7 +36,7 @@ int cachefiles_check_object_type(struct cachefiles_object *object)
 	else
 		snprintf(type, 3, "%02x", object->fscache.cookie->def->type);
 
-	_enter("%p{%s}", object, type);
+	_enter("%x{%s}", object->fscache.debug_id, type);
 
 	/* attempt to install a type label directly */
 	ret = vfs_setxattr(&init_user_ns, dentry, cachefiles_xattr_cache, type,
@@ -134,7 +134,7 @@ int cachefiles_update_object_xattr(struct cachefiles_object *object,
 	if (!dentry)
 		return -ESTALE;
 
-	_enter("%p,#%d", object, auxdata->len);
+	_enter("%x,#%d", object->fscache.debug_id, auxdata->len);
 
 	/* attempt to install the cache metadata directly */
 	_debug("SET #%u", auxdata->len);

fs/fscache/Kconfig

@@ -14,6 +14,7 @@ config FSCACHE
 config FSCACHE_STATS
 	bool "Gather statistical information on local caching"
 	depends on FSCACHE && PROC_FS
+	select NETFS_STATS
 	help
 	  This option causes statistical information to be gathered on local
 	  caching and exported through file:
@@ -28,23 +29,6 @@ config FSCACHE_STATS
 
 	  See Documentation/filesystems/caching/fscache.rst for more information.
 
-config FSCACHE_HISTOGRAM
-	bool "Gather latency information on local caching"
-	depends on FSCACHE && PROC_FS
-	help
-	  This option causes latency information to be gathered on local
-	  caching and exported through file:
-
-		/proc/fs/fscache/histogram
-
-	  The generation of this histogram adds a certain amount of overhead to
-	  execution as there are a number of points at which data is gathered,
-	  and on a multi-CPU system these may be on cachelines that keep
-	  bouncing between CPUs.  On the other hand, the histogram may be
-	  useful for debugging purposes.  Saying 'N' here is recommended.
-
-	  See Documentation/filesystems/caching/fscache.rst for more information.
-
 config FSCACHE_DEBUG
 	bool "Debug FS-Cache"
 	depends on FSCACHE
@@ -54,10 +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

fs/fscache/Makefile

@@ -16,7 +16,5 @@ fscache-y := \
 
 fscache-$(CONFIG_PROC_FS) += proc.o
 fscache-$(CONFIG_FSCACHE_STATS) += stats.o
-fscache-$(CONFIG_FSCACHE_HISTOGRAM) += histogram.o
-fscache-$(CONFIG_FSCACHE_OBJECT_LIST) += object-list.o
 
 obj-$(CONFIG_FSCACHE) := fscache.o

fs/fscache/cache.c

@@ -116,7 +116,7 @@ struct fscache_cache *fscache_select_cache_for_object(
 			cache = NULL;
 
 		spin_unlock(&cookie->lock);
-		_leave(" = %p [parent]", cache);
+		_leave(" = %s [parent]", cache ? cache->tag->name : "NULL");
 		return cache;
 	}
 
@@ -152,14 +152,14 @@ struct fscache_cache *fscache_select_cache_for_object(
 	if (test_bit(FSCACHE_IOERROR, &tag->cache->flags))
 		return NULL;
 
-	_leave(" = %p [specific]", tag->cache);
+	_leave(" = %s [specific]", tag->name);
 	return tag->cache;
 
 no_preference:
 	/* netfs has no preference - just select first cache */
 	cache = list_entry(fscache_cache_list.next,
 			   struct fscache_cache, link);
-	_leave(" = %p [first]", cache);
+	_leave(" = %s [first]", cache->tag->name);
 	return cache;
 }
 
@@ -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 */
@@ -270,7 +269,7 @@ int fscache_add_cache(struct fscache_cache *cache,
 	hlist_add_head(&ifsdef->cookie_link,
 		       &fscache_fsdef_index.backing_objects);
 
-	atomic_inc(&fscache_fsdef_index.usage);
+	refcount_inc(&fscache_fsdef_index.ref);
 
 	/* done */
 	spin_unlock(&fscache_fsdef_index.lock);
@@ -335,7 +334,7 @@ static void fscache_withdraw_all_objects(struct fscache_cache *cache,
 					    struct fscache_object, cache_link);
 			list_move_tail(&object->cache_link, dying_objects);
 
-			_debug("withdraw %p", object->cookie);
+			_debug("withdraw %x", object->cookie->debug_id);
 
 			/* This must be done under object_list_lock to prevent
 			 * a race with fscache_drop_object().

fs/fscache/fsdef.c

@@ -45,7 +45,8 @@ static struct fscache_cookie_def fscache_fsdef_index_def = {
 };
 
 struct fscache_cookie fscache_fsdef_index = {
-	.usage		= ATOMIC_INIT(1),
+	.debug_id	= 1,
+	.ref		= REFCOUNT_INIT(1),
 	.n_active	= ATOMIC_INIT(1),
 	.lock		= __SPIN_LOCK_UNLOCKED(fscache_fsdef_index.lock),
 	.backing_objects = HLIST_HEAD_INIT,

fs/fscache/histogram.c

-// SPDX-License-Identifier: GPL-2.0-or-later
-/* FS-Cache latency histogram
- *
- * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
- * Written by David Howells (dhowells@redhat.com)
- */
-
-#define FSCACHE_DEBUG_LEVEL THREAD
-#include <linux/module.h>
-#include <linux/proc_fs.h>
-#include <linux/seq_file.h>
-#include "internal.h"
-
-atomic_t fscache_obj_instantiate_histogram[HZ];
-atomic_t fscache_objs_histogram[HZ];
-atomic_t fscache_ops_histogram[HZ];
-atomic_t fscache_retrieval_delay_histogram[HZ];
-atomic_t fscache_retrieval_histogram[HZ];
-
-/*
- * display the time-taken histogram
- */
-static int fscache_histogram_show(struct seq_file *m, void *v)
-{
-	unsigned long index;
-	unsigned n[5], t;
-
-	switch ((unsigned long) v) {
-	case 1:
-		seq_puts(m, "JIFS  SECS  OBJ INST  OP RUNS   OBJ RUNS  RETRV DLY RETRIEVLS\n");
-		return 0;
-	case 2:
-		seq_puts(m, "===== ===== ========= ========= ========= ========= =========\n");
-		return 0;
-	default:
-		index = (unsigned long) v - 3;
-		n[0] = atomic_read(&fscache_obj_instantiate_histogram[index]);
-		n[1] = atomic_read(&fscache_ops_histogram[index]);
-		n[2] = atomic_read(&fscache_objs_histogram[index]);
-		n[3] = atomic_read(&fscache_retrieval_delay_histogram[index]);
-		n[4] = atomic_read(&fscache_retrieval_histogram[index]);
-		if (!(n[0] | n[1] | n[2] | n[3] | n[4]))
-			return 0;
-
-		t = (index * 1000) / HZ;
-
-		seq_printf(m, "%4lu  0.%03u %9u %9u %9u %9u %9u\n",
-			   index, t, n[0], n[1], n[2], n[3], n[4]);
-		return 0;
-	}
-}
-
-/*
- * set up the iterator to start reading from the first line
- */
-static void *fscache_histogram_start(struct seq_file *m, loff_t *_pos)
-{
-	if ((unsigned long long)*_pos >= HZ + 2)
-		return NULL;
-	if (*_pos == 0)
-		*_pos = 1;
-	return (void *)(unsigned long) *_pos;
-}
-
-/*
- * move to the next line
- */
-static void *fscache_histogram_next(struct seq_file *m, void *v, loff_t *pos)
-{
-	(*pos)++;
-	return (unsigned long long)*pos > HZ + 2 ?
-		NULL : (void *)(unsigned long) *pos;
-}
-
-/*
- * clean up after reading
- */
-static void fscache_histogram_stop(struct seq_file *m, void *v)
-{
-}
-
-const struct seq_operations fscache_histogram_ops = {
-	.start		= fscache_histogram_start,
-	.stop		= fscache_histogram_stop,
-	.next		= fscache_histogram_next,
-	.show		= fscache_histogram_show,
-};

fs/fscache/internal.h

@@ -45,6 +45,7 @@ extern struct fscache_cache *fscache_select_cache_for_object(
  * cookie.c
  */
 extern struct kmem_cache *fscache_cookie_jar;
+extern const struct seq_operations fscache_cookies_seq_ops;
 
 extern void fscache_free_cookie(struct fscache_cookie *);
 extern struct fscache_cookie *fscache_alloc_cookie(struct fscache_cookie *,
@@ -53,39 +54,24 @@ extern struct fscache_cookie *fscache_alloc_cookie(struct fscache_cookie *,
 						   const void *, size_t,
 						   void *, loff_t);
 extern struct fscache_cookie *fscache_hash_cookie(struct fscache_cookie *);
+extern struct fscache_cookie *fscache_cookie_get(struct fscache_cookie *,
+						 enum fscache_cookie_trace);
 extern void fscache_cookie_put(struct fscache_cookie *,
 			       enum fscache_cookie_trace);
 
+static inline void fscache_cookie_see(struct fscache_cookie *cookie,
+				      enum fscache_cookie_trace where)
+{
+	trace_fscache_cookie(cookie->debug_id, refcount_read(&cookie->ref),
+			     where);
+}
+
 /*
  * fsdef.c
  */
 extern struct fscache_cookie fscache_fsdef_index;
 extern struct fscache_cookie_def fscache_fsdef_netfs_def;
 
-/*
- * histogram.c
- */
-#ifdef CONFIG_FSCACHE_HISTOGRAM
-extern atomic_t fscache_obj_instantiate_histogram[HZ];
-extern atomic_t fscache_objs_histogram[HZ];
-extern atomic_t fscache_ops_histogram[HZ];
-extern atomic_t fscache_retrieval_delay_histogram[HZ];
-extern atomic_t fscache_retrieval_histogram[HZ];
-
-static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
-{
-	unsigned long jif = jiffies - start_jif;
-	if (jif >= HZ)
-		jif = HZ - 1;
-	atomic_inc(&histogram[jif]);
-}
-
-extern const struct seq_operations fscache_histogram_ops;
-
-#else
-#define fscache_hist(hist, start_jif) do {} while (0)
-#endif
-
 /*
  * main.c
  */
@@ -97,6 +83,8 @@ extern struct workqueue_struct *fscache_object_wq;
 extern struct workqueue_struct *fscache_op_wq;
 DECLARE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
 
+extern unsigned int fscache_hash(unsigned int salt, unsigned int *data, unsigned int n);
+
 static inline bool fscache_object_congested(void)
 {
 	return workqueue_congested(WORK_CPU_UNBOUND, fscache_object_wq);
@@ -107,19 +95,6 @@ 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
  */
@@ -320,14 +295,6 @@ static inline void fscache_raise_event(struct fscache_object *object,
 		fscache_enqueue_object(object);
 }
 
-static inline void fscache_cookie_get(struct fscache_cookie *cookie,
-				      enum fscache_cookie_trace where)
-{
-	int usage = atomic_inc_return(&cookie->usage);
-
-	trace_fscache_cookie(cookie, where, usage);
-}
-
 /*
  * get an extra reference to a netfs retrieval context
  */

fs/fscache/main.c

@@ -93,6 +93,45 @@ static struct ctl_table fscache_sysctls_root[] = {
 };
 #endif
 
+/*
+ * Mixing scores (in bits) for (7,20):
+ * Input delta: 1-bit      2-bit
+ * 1 round:     330.3     9201.6
+ * 2 rounds:   1246.4    25475.4
+ * 3 rounds:   1907.1    31295.1
+ * 4 rounds:   2042.3    31718.6
+ * Perfect:    2048      31744
+ *            (32*64)   (32*31/2 * 64)
+ */
+#define HASH_MIX(x, y, a)	\
+	(	x ^= (a),	\
+	y ^= x,	x = rol32(x, 7),\
+	x += y,	y = rol32(y,20),\
+	y *= 9			)
+
+static inline unsigned int fold_hash(unsigned long x, unsigned long y)
+{
+	/* Use arch-optimized multiply if one exists */
+	return __hash_32(y ^ __hash_32(x));
+}
+
+/*
+ * Generate a hash.  This is derived from full_name_hash(), but we want to be
+ * sure it is arch independent and that it doesn't change as bits of the
+ * computed hash value might appear on disk.  The caller also guarantees that
+ * the hashed data will be a series of aligned 32-bit words.
+ */
+unsigned int fscache_hash(unsigned int salt, unsigned int *data, unsigned int n)
+{
+	unsigned int a, x = 0, y = salt;
+
+	for (; n; n--) {
+		a = *data++;
+		HASH_MIX(x, y, a);
+	}
+	return fold_hash(x, y);
+}
+
 /*
  * initialise the fs caching module
  */

fs/fscache/netfs.c

@@ -37,7 +37,7 @@ int __fscache_register_netfs(struct fscache_netfs *netfs)
 	if (!cookie)
 		goto already_registered;
 	if (cookie != candidate) {
-		trace_fscache_cookie(candidate, fscache_cookie_discard, 1);
+		trace_fscache_cookie(candidate->debug_id, 1, fscache_cookie_discard);
 		fscache_free_cookie(candidate);
 	}
 

fs/fscache/object.c

@@ -277,13 +277,10 @@ static void fscache_object_work_func(struct work_struct *work)
 {
 	struct fscache_object *object =
 		container_of(work, struct fscache_object, work);
-	unsigned long start;
 
 	_enter("{OBJ%x}", object->debug_id);
 
-	start = jiffies;
 	fscache_object_sm_dispatcher(object);
-	fscache_hist(fscache_objs_histogram, start);
 	fscache_put_object(object, fscache_obj_put_work);
 }
 
@@ -436,7 +433,6 @@ static const struct fscache_state *fscache_parent_ready(struct fscache_object *o
 	spin_lock(&parent->lock);
 	parent->n_ops++;
 	parent->n_obj_ops++;
-	object->lookup_jif = jiffies;
 	spin_unlock(&parent->lock);
 
 	_leave("");
@@ -522,7 +518,6 @@ void fscache_object_lookup_negative(struct fscache_object *object)
 		set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
 		clear_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
 
-		_debug("wake up lookup %p", &cookie->flags);
 		clear_bit_unlock(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags);
 		wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP);
 	}
@@ -596,7 +591,6 @@ static const struct fscache_state *fscache_object_available(struct fscache_objec
 	object->cache->ops->lookup_complete(object);
 	fscache_stat_d(&fscache_n_cop_lookup_complete);
 
-	fscache_hist(fscache_obj_instantiate_histogram, object->lookup_jif);
 	fscache_stat(&fscache_n_object_avail);
 
 	_leave("");
@@ -799,8 +793,6 @@ 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;

fs/fscache/operation.c

@@ -616,7 +616,6 @@ void fscache_op_work_func(struct work_struct *work)
 {
 	struct fscache_operation *op =
 		container_of(work, struct fscache_operation, work);
-	unsigned long start;
 
 	_enter("{OBJ%x OP%x,%d}",
 	       op->object->debug_id, op->debug_id, atomic_read(&op->usage));
@@ -624,9 +623,7 @@ void fscache_op_work_func(struct work_struct *work)
 	trace_fscache_op(op->object->cookie, op, fscache_op_work);
 
 	ASSERT(op->processor != NULL);
-	start = jiffies;
 	op->processor(op);
-	fscache_hist(fscache_ops_histogram, start);
 	fscache_put_operation(op);
 
 	_leave("");

fs/fscache/page.c

@@ -289,7 +289,6 @@ static void fscache_release_retrieval_op(struct fscache_operation *_op)
 	ASSERTIFCMP(op->op.state != FSCACHE_OP_ST_INITIALISED,
 		    atomic_read(&op->n_pages), ==, 0);
 
-	fscache_hist(fscache_retrieval_histogram, op->start_time);
 	if (op->context)
 		fscache_put_context(op->cookie, op->context);
 
@@ -324,7 +323,6 @@ struct fscache_retrieval *fscache_alloc_retrieval(
 	op->mapping	= mapping;
 	op->end_io_func	= end_io_func;
 	op->context	= context;
-	op->start_time	= jiffies;
 	INIT_LIST_HEAD(&op->to_do);
 
 	/* Pin the netfs read context in case we need to do the actual netfs
@@ -340,8 +338,6 @@ struct fscache_retrieval *fscache_alloc_retrieval(
  */
 int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)
 {
-	unsigned long jif;
-
 	_enter("");
 
 	if (!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) {
@@ -351,7 +347,6 @@ int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)
 
 	fscache_stat(&fscache_n_retrievals_wait);
 
-	jif = jiffies;
 	if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP,
 			TASK_INTERRUPTIBLE) != 0) {
 		fscache_stat(&fscache_n_retrievals_intr);
@@ -362,7 +357,6 @@ int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)
 	ASSERT(!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags));
 
 	smp_rmb();
-	fscache_hist(fscache_retrieval_delay_histogram, jif);
 	_leave(" = 0 [dly]");
 	return 0;
 }

fs/fscache/proc.c

@@ -21,18 +21,16 @@ int __init fscache_proc_init(void)
 	if (!proc_mkdir("fs/fscache", NULL))
 		goto error_dir;
 
+	if (!proc_create_seq("fs/fscache/cookies", S_IFREG | 0444, NULL,
+			     &fscache_cookies_seq_ops))
+		goto error_cookies;
+
 #ifdef CONFIG_FSCACHE_STATS
 	if (!proc_create_single("fs/fscache/stats", S_IFREG | 0444, NULL,
 			fscache_stats_show))
 		goto error_stats;
 #endif
 
-#ifdef CONFIG_FSCACHE_HISTOGRAM
-	if (!proc_create_seq("fs/fscache/histogram", S_IFREG | 0444, NULL,
-			 &fscache_histogram_ops))
-		goto error_histogram;
-#endif
-
 #ifdef CONFIG_FSCACHE_OBJECT_LIST
 	if (!proc_create("fs/fscache/objects", S_IFREG | 0444, NULL,
 			 &fscache_objlist_proc_ops))
@@ -45,14 +43,12 @@ int __init fscache_proc_init(void)
 #ifdef CONFIG_FSCACHE_OBJECT_LIST
 error_objects:
 #endif
-#ifdef CONFIG_FSCACHE_HISTOGRAM
-	remove_proc_entry("fs/fscache/histogram", NULL);
-error_histogram:
-#endif
 #ifdef CONFIG_FSCACHE_STATS
 	remove_proc_entry("fs/fscache/stats", NULL);
 error_stats:
 #endif
+	remove_proc_entry("fs/fscache/cookies", NULL);
+error_cookies:
 	remove_proc_entry("fs/fscache", NULL);
 error_dir:
 	_leave(" = -ENOMEM");
@@ -67,11 +63,9 @@ void fscache_proc_cleanup(void)
 #ifdef CONFIG_FSCACHE_OBJECT_LIST
 	remove_proc_entry("fs/fscache/objects", NULL);
 #endif
-#ifdef CONFIG_FSCACHE_HISTOGRAM
-	remove_proc_entry("fs/fscache/histogram", NULL);
-#endif
 #ifdef CONFIG_FSCACHE_STATS
 	remove_proc_entry("fs/fscache/stats", NULL);
 #endif
+	remove_proc_entry("fs/fscache/cookies", NULL);
 	remove_proc_entry("fs/fscache", NULL);
 }

include/linux/fscache-cache.h

@@ -147,7 +147,6 @@ struct fscache_retrieval {
 	fscache_rw_complete_t	end_io_func;	/* function to call on I/O completion */
 	void			*context;	/* netfs read context (pinned) */
 	struct list_head	to_do;		/* list of things to be done by the backend */
-	unsigned long		start_time;	/* time at which retrieval started */
 	atomic_t		n_pages;	/* number of pages to be retrieved */
 };
 
@@ -385,9 +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 */
 };

include/linux/fscache.h

@@ -123,15 +123,17 @@ struct fscache_netfs {
  * - indices are created on disk just-in-time
  */
 struct fscache_cookie {
-	atomic_t			usage;		/* number of users of this cookie */
+	refcount_t			ref;		/* number of users of this cookie */
 	atomic_t			n_children;	/* number of children of this cookie */
 	atomic_t			n_active;	/* number of active users of netfs ptrs */
+	unsigned int			debug_id;
 	spinlock_t			lock;
 	spinlock_t			stores_lock;	/* lock on page store tree */
 	struct hlist_head		backing_objects; /* object(s) backing this file/index */
 	const struct fscache_cookie_def	*def;		/* definition */
 	struct fscache_cookie		*parent;	/* parent of this entry */
 	struct hlist_bl_node		hash_link;	/* Link in hash table */
+	struct list_head		proc_link;	/* Link in proc list */
 	void				*netfs_data;	/* back pointer to netfs */
 	struct radix_tree_root		stores;		/* pages to be stored on this cookie */
 #define FSCACHE_COOKIE_PENDING_TAG	0		/* pages tag: pending write to cache */

include/linux/netfs.h

@@ -102,6 +102,7 @@ struct netfs_cache_resources {
 	const struct netfs_cache_ops	*ops;
 	void				*cache_priv;
 	void				*cache_priv2;
+	unsigned int			debug_id;	/* Cookie debug ID */
 };
 
 /*
@@ -137,7 +138,6 @@ struct netfs_read_request {
 	struct list_head	subrequests;	/* Requests to fetch I/O from disk or net */
 	void			*netfs_priv;	/* Private data for the netfs */
 	unsigned int		debug_id;
-	unsigned int		cookie_debug_id;
 	atomic_t		nr_rd_ops;	/* Number of read ops in progress */
 	atomic_t		nr_wr_ops;	/* Number of write ops in progress */
 	size_t			submitted;	/* Amount submitted for I/O so far */

include/trace/events/cachefiles.h

@@ -78,20 +78,20 @@ TRACE_EVENT(cachefiles_ref,
 
 	    /* Note that obj may be NULL */
 	    TP_STRUCT__entry(
-		    __field(struct cachefiles_object *,		obj		)
-		    __field(struct fscache_cookie *,		cookie		)
+		    __field(unsigned int,			obj		)
+		    __field(unsigned int,			cookie		)
 		    __field(enum cachefiles_obj_ref_trace,	why		)
 		    __field(int,				usage		)
 			     ),
 
 	    TP_fast_assign(
-		    __entry->obj	= obj;
-		    __entry->cookie	= cookie;
+		    __entry->obj	= obj->fscache.debug_id;
+		    __entry->cookie	= cookie->debug_id;
 		    __entry->usage	= usage;
 		    __entry->why	= why;
 			   ),
 
-	    TP_printk("c=%p o=%p u=%d %s",
+	    TP_printk("c=%08x o=%08x u=%d %s",
 		      __entry->cookie, __entry->obj, __entry->usage,
 		      __print_symbolic(__entry->why, cachefiles_obj_ref_traces))
 	    );
@@ -104,18 +104,18 @@ TRACE_EVENT(cachefiles_lookup,
 	    TP_ARGS(obj, de, inode),
 
 	    TP_STRUCT__entry(
-		    __field(struct cachefiles_object *,	obj	)
+		    __field(unsigned int,		obj	)
 		    __field(struct dentry *,		de	)
 		    __field(struct inode *,		inode	)
 			     ),
 
 	    TP_fast_assign(
-		    __entry->obj	= obj;
+		    __entry->obj	= obj->fscache.debug_id;
 		    __entry->de		= de;
 		    __entry->inode	= inode;
 			   ),
 
-	    TP_printk("o=%p d=%p i=%p",
+	    TP_printk("o=%08x d=%p i=%p",
 		      __entry->obj, __entry->de, __entry->inode)
 	    );
 
@@ -126,18 +126,18 @@ TRACE_EVENT(cachefiles_mkdir,
 	    TP_ARGS(obj, de, ret),
 
 	    TP_STRUCT__entry(
-		    __field(struct cachefiles_object *,	obj	)
+		    __field(unsigned int,		obj	)
 		    __field(struct dentry *,		de	)
 		    __field(int,			ret	)
 			     ),
 
 	    TP_fast_assign(
-		    __entry->obj	= obj;
+		    __entry->obj	= obj->fscache.debug_id;
 		    __entry->de		= de;
 		    __entry->ret	= ret;
 			   ),
 
-	    TP_printk("o=%p d=%p r=%u",
+	    TP_printk("o=%08x d=%p r=%u",
 		      __entry->obj, __entry->de, __entry->ret)
 	    );
 
@@ -148,18 +148,18 @@ TRACE_EVENT(cachefiles_create,
 	    TP_ARGS(obj, de, ret),
 
 	    TP_STRUCT__entry(
-		    __field(struct cachefiles_object *,	obj	)
+		    __field(unsigned int,		obj	)
 		    __field(struct dentry *,		de	)
 		    __field(int,			ret	)
 			     ),
 
 	    TP_fast_assign(
-		    __entry->obj	= obj;
+		    __entry->obj	= obj->fscache.debug_id;
 		    __entry->de		= de;
 		    __entry->ret	= ret;
 			   ),
 
-	    TP_printk("o=%p d=%p r=%u",
+	    TP_printk("o=%08x d=%p r=%u",
 		      __entry->obj, __entry->de, __entry->ret)
 	    );
 
@@ -172,18 +172,18 @@ TRACE_EVENT(cachefiles_unlink,
 
 	    /* Note that obj may be NULL */
 	    TP_STRUCT__entry(
-		    __field(struct cachefiles_object *,	obj		)
+		    __field(unsigned int,		obj		)
 		    __field(struct dentry *,		de		)
 		    __field(enum fscache_why_object_killed, why		)
 			     ),
 
 	    TP_fast_assign(
-		    __entry->obj	= obj;
+		    __entry->obj	= obj->fscache.debug_id;
 		    __entry->de		= de;
 		    __entry->why	= why;
 			   ),
 
-	    TP_printk("o=%p d=%p w=%s",
+	    TP_printk("o=%08x d=%p w=%s",
 		      __entry->obj, __entry->de,
 		      __print_symbolic(__entry->why, cachefiles_obj_kill_traces))
 	    );
@@ -198,20 +198,20 @@ TRACE_EVENT(cachefiles_rename,
 
 	    /* Note that obj may be NULL */
 	    TP_STRUCT__entry(
-		    __field(struct cachefiles_object *,	obj		)
+		    __field(unsigned int,		obj		)
 		    __field(struct dentry *,		de		)
 		    __field(struct dentry *,		to		)
 		    __field(enum fscache_why_object_killed, why		)
 			     ),
 
 	    TP_fast_assign(
-		    __entry->obj	= obj;
+		    __entry->obj	= obj->fscache.debug_id;
 		    __entry->de		= de;
 		    __entry->to		= to;
 		    __entry->why	= why;
 			   ),
 
-	    TP_printk("o=%p d=%p t=%p w=%s",
+	    TP_printk("o=%08x d=%p t=%p w=%s",
 		      __entry->obj, __entry->de, __entry->to,
 		      __print_symbolic(__entry->why, cachefiles_obj_kill_traces))
 	    );
@@ -224,16 +224,16 @@ TRACE_EVENT(cachefiles_mark_active,
 
 	    /* Note that obj may be NULL */
 	    TP_STRUCT__entry(
-		    __field(struct cachefiles_object *,	obj		)
+		    __field(unsigned int,		obj		)
 		    __field(struct dentry *,		de		)
 			     ),
 
 	    TP_fast_assign(
-		    __entry->obj	= obj;
+		    __entry->obj	= obj->fscache.debug_id;
 		    __entry->de		= de;
 			   ),
 
-	    TP_printk("o=%p d=%p",
+	    TP_printk("o=%08x d=%p",
 		      __entry->obj, __entry->de)
 	    );
 
@@ -246,22 +246,22 @@ TRACE_EVENT(cachefiles_wait_active,
 
 	    /* Note that obj may be NULL */
 	    TP_STRUCT__entry(
-		    __field(struct cachefiles_object *,	obj		)
+		    __field(unsigned int,		obj		)
+		    __field(unsigned int,		xobj		)
 		    __field(struct dentry *,		de		)
-		    __field(struct cachefiles_object *,	xobj		)
 		    __field(u16,			flags		)
 		    __field(u16,			fsc_flags	)
 			     ),
 
 	    TP_fast_assign(
-		    __entry->obj	= obj;
+		    __entry->obj	= obj->fscache.debug_id;
 		    __entry->de		= de;
-		    __entry->xobj	= xobj;
+		    __entry->xobj	= xobj->fscache.debug_id;
 		    __entry->flags	= xobj->flags;
 		    __entry->fsc_flags	= xobj->fscache.flags;
 			   ),
 
-	    TP_printk("o=%p d=%p wo=%p wf=%x wff=%x",
+	    TP_printk("o=%08x d=%p wo=%08x wf=%x wff=%x",
 		      __entry->obj, __entry->de, __entry->xobj,
 		      __entry->flags, __entry->fsc_flags)
 	    );
@@ -275,18 +275,18 @@ TRACE_EVENT(cachefiles_mark_inactive,
 
 	    /* Note that obj may be NULL */
 	    TP_STRUCT__entry(
-		    __field(struct cachefiles_object *,	obj		)
+		    __field(unsigned int,		obj		)
 		    __field(struct dentry *,		de		)
 		    __field(struct inode *,		inode		)
 			     ),
 
 	    TP_fast_assign(
-		    __entry->obj	= obj;
+		    __entry->obj	= obj->fscache.debug_id;
 		    __entry->de		= de;
 		    __entry->inode	= inode;
 			   ),
 
-	    TP_printk("o=%p d=%p i=%p",
+	    TP_printk("o=%08x d=%p i=%p",
 		      __entry->obj, __entry->de, __entry->inode)
 	    );
 
@@ -299,18 +299,18 @@ TRACE_EVENT(cachefiles_mark_buried,
 
 	    /* Note that obj may be NULL */
 	    TP_STRUCT__entry(
-		    __field(struct cachefiles_object *,	obj		)
+		    __field(unsigned int,		obj		)
 		    __field(struct dentry *,		de		)
 		    __field(enum fscache_why_object_killed, why		)
 			     ),
 
 	    TP_fast_assign(
-		    __entry->obj	= obj;
+		    __entry->obj	= obj->fscache.debug_id;
 		    __entry->de		= de;
 		    __entry->why	= why;
 			   ),
 
-	    TP_printk("o=%p d=%p w=%s",
+	    TP_printk("o=%08x d=%p w=%s",
 		      __entry->obj, __entry->de,
 		      __print_symbolic(__entry->why, cachefiles_obj_kill_traces))
 	    );

include/trace/events/netfs.h

@@ -139,7 +139,7 @@ TRACE_EVENT(netfs_read,
 
 	    TP_fast_assign(
 		    __entry->rreq	= rreq->debug_id;
-		    __entry->cookie	= rreq->cookie_debug_id;
+		    __entry->cookie	= rreq->cache_resources.debug_id;
 		    __entry->start	= start;
 		    __entry->len	= len;
 		    __entry->what	= what;