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Commit 2cee6fbb authored by David Howells's avatar David Howells
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fscache: Remove the contents of the fscache driver, pending rewrite 

Remove the code that comprises the fscache driver as it's going to be
substantially rewritten, with the majority of the code being erased in the
rewrite.

A small piece of linux/fscache.h is left as that is #included by a bunch of
network filesystems.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/163819578724.215744.18210619052245724238.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/163906884814.143852.6727245089843862889.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/163967077097.1823006.1377665951499979089.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/164021485548.640689.13876080567388696162.stgit@warthog.procyon.org.uk/ # v4
parent 850cba06
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Showing with 13 additions and 7805 deletions
fs/9p/vfs_addr.c
View file @ 2cee6fbb
......@@ -76,9 +76,7 @@ static void v9fs_req_cleanup(struct address_space *mapping, void *priv)
*/
static bool v9fs_is_cache_enabled(struct inode *inode)
{
struct fscache_cookie *cookie = v9fs_inode_cookie(V9FS_I(inode));
return fscache_cookie_enabled(cookie) && !hlist_empty(&cookie->backing_objects);
return fscache_cookie_enabled(v9fs_inode_cookie(V9FS_I(inode)));
}
/**
......@@ -87,9 +85,13 @@ static bool v9fs_is_cache_enabled(struct inode *inode)
*/
static int v9fs_begin_cache_operation(struct netfs_read_request *rreq)
{
#ifdef CONFIG_9P_FSCACHE
struct fscache_cookie *cookie = v9fs_inode_cookie(V9FS_I(rreq->inode));
return fscache_begin_read_operation(rreq, cookie);
#else
return -ENOBUFS;
#endif
}
static const struct netfs_read_request_ops v9fs_req_ops = {
......
fs/Makefile
View file @ 2cee6fbb
......@@ -67,7 +67,6 @@ obj-$(CONFIG_DLM) += dlm/
# Do not add any filesystems before this line
obj-$(CONFIG_NETFS_SUPPORT) += netfs/
obj-$(CONFIG_FSCACHE) += fscache/
obj-$(CONFIG_REISERFS_FS) += reiserfs/
obj-$(CONFIG_EXT4_FS) += ext4/
# We place ext4 before ext2 so that clean ext3 root fs's do NOT mount using the
......
fs/afs/file.c
View file @ 2cee6fbb
......@@ -352,16 +352,18 @@ static void afs_init_rreq(struct netfs_read_request *rreq, struct file *file)
static bool afs_is_cache_enabled(struct inode *inode)
{
struct fscache_cookie *cookie = afs_vnode_cache(AFS_FS_I(inode));
return fscache_cookie_enabled(cookie) && !hlist_empty(&cookie->backing_objects);
return fscache_cookie_enabled(afs_vnode_cache(AFS_FS_I(inode)));
}
static int afs_begin_cache_operation(struct netfs_read_request *rreq)
{
#ifdef CONFIG_AFS_FSCACHE
struct afs_vnode *vnode = AFS_FS_I(rreq->inode);
return fscache_begin_read_operation(rreq, afs_vnode_cache(vnode));
#else
return -ENOBUFS;
#endif
}
static int afs_check_write_begin(struct file *file, loff_t pos, unsigned len,
......
fs/fscache/Kconfig
View file @ 2cee6fbb
# SPDX-License-Identifier: GPL-2.0-only
config FSCACHE
tristate "General filesystem local caching manager"
select NETFS_SUPPORT
help
This option enables a generic filesystem caching manager that can be
used by various network and other filesystems to cache data locally.
Different sorts of caches can be plugged in, depending on the
resources available.
See Documentation/filesystems/caching/fscache.rst for more information.
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:
/proc/fs/fscache/stats
The gathering of statistics adds a certain amount of overhead to
execution as there are a quite a few stats gathered, and on a
multi-CPU system these may be on cachelines that keep bouncing
between CPUs. On the other hand, the stats are very useful for
debugging purposes. Saying 'Y' here is recommended.
See Documentation/filesystems/caching/fscache.rst for more information.
config FSCACHE_DEBUG
bool "Debug FS-Cache"
depends on FSCACHE
help
This permits debugging to be dynamically enabled in the local caching
management module. If this is set, the debugging output may be
enabled by setting bits in /sys/modules/fscache/parameter/debug.
See Documentation/filesystems/caching/fscache.rst for more information.
config FSCACHE_OLD_API
bool
fs/fscache/Makefile deleted 100644 → 0
View file @ 850cba06
# SPDX-License-Identifier: GPL-2.0
#
# Makefile for general filesystem caching code
#
fscache-y := \
cache.o \
cookie.o \
fsdef.o \
io.o \
main.o \
netfs.o \
object.o \
operation.o \
page.o
fscache-$(CONFIG_PROC_FS) += proc.o
fscache-$(CONFIG_FSCACHE_STATS) += stats.o
obj-$(CONFIG_FSCACHE) := fscache.o
fs/fscache/cache.c deleted 100644 → 0
View file @ 850cba06
// SPDX-License-Identifier: GPL-2.0-or-later
/* FS-Cache cache handling
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#define FSCACHE_DEBUG_LEVEL CACHE
#include <linux/module.h>
#include <linux/slab.h>
#include "internal.h"
LIST_HEAD(fscache_cache_list);
DECLARE_RWSEM(fscache_addremove_sem);
DECLARE_WAIT_QUEUE_HEAD(fscache_cache_cleared_wq);
EXPORT_SYMBOL(fscache_cache_cleared_wq);
static LIST_HEAD(fscache_cache_tag_list);
/*
* look up a cache tag
*/
struct fscache_cache_tag *__fscache_lookup_cache_tag(const char *name)
{
struct fscache_cache_tag *tag, *xtag;
/* firstly check for the existence of the tag under read lock */
down_read(&fscache_addremove_sem);
list_for_each_entry(tag, &fscache_cache_tag_list, link) {
if (strcmp(tag->name, name) == 0) {
atomic_inc(&tag->usage);
up_read(&fscache_addremove_sem);
return tag;
}
}
up_read(&fscache_addremove_sem);
/* the tag does not exist - create a candidate */
xtag = kzalloc(sizeof(*xtag) + strlen(name) + 1, GFP_KERNEL);
if (!xtag)
/* return a dummy tag if out of memory */
return ERR_PTR(-ENOMEM);
atomic_set(&xtag->usage, 1);
strcpy(xtag->name, name);
/* write lock, search again and add if still not present */
down_write(&fscache_addremove_sem);
list_for_each_entry(tag, &fscache_cache_tag_list, link) {
if (strcmp(tag->name, name) == 0) {
atomic_inc(&tag->usage);
up_write(&fscache_addremove_sem);
kfree(xtag);
return tag;
}
}
list_add_tail(&xtag->link, &fscache_cache_tag_list);
up_write(&fscache_addremove_sem);
return xtag;
}
/*
* release a reference to a cache tag
*/
void __fscache_release_cache_tag(struct fscache_cache_tag *tag)
{
if (tag != ERR_PTR(-ENOMEM)) {
down_write(&fscache_addremove_sem);
if (atomic_dec_and_test(&tag->usage))
list_del_init(&tag->link);
else
tag = NULL;
up_write(&fscache_addremove_sem);
kfree(tag);
}
}
/*
* select a cache in which to store an object
* - the cache addremove semaphore must be at least read-locked by the caller
* - the object will never be an index
*/
struct fscache_cache *fscache_select_cache_for_object(
struct fscache_cookie *cookie)
{
struct fscache_cache_tag *tag;
struct fscache_object *object;
struct fscache_cache *cache;
_enter("");
if (list_empty(&fscache_cache_list)) {
_leave(" = NULL [no cache]");
return NULL;
}
/* we check the parent to determine the cache to use */
spin_lock(&cookie->lock);
/* the first in the parent's backing list should be the preferred
* cache */
if (!hlist_empty(&cookie->backing_objects)) {
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object, cookie_link);
cache = object->cache;
if (fscache_object_is_dying(object) ||
test_bit(FSCACHE_IOERROR, &cache->flags))
cache = NULL;
spin_unlock(&cookie->lock);
_leave(" = %s [parent]", cache ? cache->tag->name : "NULL");
return cache;
}
/* the parent is unbacked */
if (cookie->type != FSCACHE_COOKIE_TYPE_INDEX) {
/* cookie not an index and is unbacked */
spin_unlock(&cookie->lock);
_leave(" = NULL [cookie ub,ni]");
return NULL;
}
spin_unlock(&cookie->lock);
if (!cookie->def->select_cache)
goto no_preference;
/* ask the netfs for its preference */
tag = cookie->def->select_cache(cookie->parent->netfs_data,
cookie->netfs_data);
if (!tag)
goto no_preference;
if (tag == ERR_PTR(-ENOMEM)) {
_leave(" = NULL [nomem tag]");
return NULL;
}
if (!tag->cache) {
_leave(" = NULL [unbacked tag]");
return NULL;
}
if (test_bit(FSCACHE_IOERROR, &tag->cache->flags))
return NULL;
_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(" = %s [first]", cache->tag->name);
return cache;
}
/**
* fscache_init_cache - Initialise a cache record
* @cache: The cache record to be initialised
* @ops: The cache operations to be installed in that record
* @idfmt: Format string to define identifier
* @...: sprintf-style arguments
*
* Initialise a record of a cache and fill in the name.
*
* See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
void fscache_init_cache(struct fscache_cache *cache,
const struct fscache_cache_ops *ops,
const char *idfmt,
...)
{
va_list va;
memset(cache, 0, sizeof(*cache));
cache->ops = ops;
va_start(va, idfmt);
vsnprintf(cache->identifier, sizeof(cache->identifier), idfmt, va);
va_end(va);
INIT_WORK(&cache->op_gc, fscache_operation_gc);
INIT_LIST_HEAD(&cache->link);
INIT_LIST_HEAD(&cache->object_list);
INIT_LIST_HEAD(&cache->op_gc_list);
spin_lock_init(&cache->object_list_lock);
spin_lock_init(&cache->op_gc_list_lock);
}
EXPORT_SYMBOL(fscache_init_cache);
/**
* fscache_add_cache - Declare a cache as being open for business
* @cache: The record describing the cache
* @ifsdef: The record of the cache object describing the top-level index
* @tagname: The tag describing this cache
*
* Add a cache to the system, making it available for netfs's to use.
*
* See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
int fscache_add_cache(struct fscache_cache *cache,
struct fscache_object *ifsdef,
const char *tagname)
{
struct fscache_cache_tag *tag;
ASSERTCMP(ifsdef->cookie, ==, &fscache_fsdef_index);
BUG_ON(!cache->ops);
BUG_ON(!ifsdef);
cache->flags = 0;
ifsdef->event_mask =
((1 << NR_FSCACHE_OBJECT_EVENTS) - 1) &
~(1 << FSCACHE_OBJECT_EV_CLEARED);
__set_bit(FSCACHE_OBJECT_IS_AVAILABLE, &ifsdef->flags);
if (!tagname)
tagname = cache->identifier;
BUG_ON(!tagname[0]);
_enter("{%s.%s},,%s", cache->ops->name, cache->identifier, tagname);
/* we use the cache tag to uniquely identify caches */
tag = __fscache_lookup_cache_tag(tagname);
if (IS_ERR(tag))
goto nomem;
if (test_and_set_bit(FSCACHE_TAG_RESERVED, &tag->flags))
goto tag_in_use;
cache->kobj = kobject_create_and_add(tagname, fscache_root);
if (!cache->kobj)
goto error;
ifsdef->cache = cache;
cache->fsdef = ifsdef;
down_write(&fscache_addremove_sem);
tag->cache = cache;
cache->tag = tag;
/* add the cache to the list */
list_add(&cache->link, &fscache_cache_list);
/* add the cache's netfs definition index object to the cache's
* list */
spin_lock(&cache->object_list_lock);
list_add_tail(&ifsdef->cache_link, &cache->object_list);
spin_unlock(&cache->object_list_lock);
/* add the cache's netfs definition index object to the top level index
* cookie as a known backing object */
spin_lock(&fscache_fsdef_index.lock);
hlist_add_head(&ifsdef->cookie_link,
&fscache_fsdef_index.backing_objects);
refcount_inc(&fscache_fsdef_index.ref);
/* done */
spin_unlock(&fscache_fsdef_index.lock);
up_write(&fscache_addremove_sem);
pr_notice("Cache \"%s\" added (type %s)\n",
cache->tag->name, cache->ops->name);
kobject_uevent(cache->kobj, KOBJ_ADD);
_leave(" = 0 [%s]", cache->identifier);
return 0;
tag_in_use:
pr_err("Cache tag '%s' already in use\n", tagname);
__fscache_release_cache_tag(tag);
_leave(" = -EXIST");
return -EEXIST;
error:
__fscache_release_cache_tag(tag);
_leave(" = -EINVAL");
return -EINVAL;
nomem:
_leave(" = -ENOMEM");
return -ENOMEM;
}
EXPORT_SYMBOL(fscache_add_cache);
/**
* fscache_io_error - Note a cache I/O error
* @cache: The record describing the cache
*
* Note that an I/O error occurred in a cache and that it should no longer be
* used for anything. This also reports the error into the kernel log.
*
* See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
void fscache_io_error(struct fscache_cache *cache)
{
if (!test_and_set_bit(FSCACHE_IOERROR, &cache->flags))
pr_err("Cache '%s' stopped due to I/O error\n",
cache->ops->name);
}
EXPORT_SYMBOL(fscache_io_error);
/*
* request withdrawal of all the objects in a cache
* - all the objects being withdrawn are moved onto the supplied list
*/
static void fscache_withdraw_all_objects(struct fscache_cache *cache,
struct list_head *dying_objects)
{
struct fscache_object *object;
while (!list_empty(&cache->object_list)) {
spin_lock(&cache->object_list_lock);
if (!list_empty(&cache->object_list)) {
object = list_entry(cache->object_list.next,
struct fscache_object, cache_link);
list_move_tail(&object->cache_link, dying_objects);
_debug("withdraw %x", object->cookie->debug_id);
/* This must be done under object_list_lock to prevent
* a race with fscache_drop_object().
*/
fscache_raise_event(object, FSCACHE_OBJECT_EV_KILL);
}
spin_unlock(&cache->object_list_lock);
cond_resched();
}
}
/**
* fscache_withdraw_cache - Withdraw a cache from the active service
* @cache: The record describing the cache
*
* Withdraw a cache from service, unbinding all its cache objects from the
* netfs cookies they're currently representing.
*
* See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
void fscache_withdraw_cache(struct fscache_cache *cache)
{
LIST_HEAD(dying_objects);
_enter("");
pr_notice("Withdrawing cache \"%s\"\n",
cache->tag->name);
/* make the cache unavailable for cookie acquisition */
if (test_and_set_bit(FSCACHE_CACHE_WITHDRAWN, &cache->flags))
BUG();
down_write(&fscache_addremove_sem);
list_del_init(&cache->link);
cache->tag->cache = NULL;
up_write(&fscache_addremove_sem);
/* make sure all pages pinned by operations on behalf of the netfs are
* written to disk */
fscache_stat(&fscache_n_cop_sync_cache);
cache->ops->sync_cache(cache);
fscache_stat_d(&fscache_n_cop_sync_cache);
/* dissociate all the netfs pages backed by this cache from the block
* mappings in the cache */
fscache_stat(&fscache_n_cop_dissociate_pages);
cache->ops->dissociate_pages(cache);
fscache_stat_d(&fscache_n_cop_dissociate_pages);
/* we now have to destroy all the active objects pertaining to this
* cache - which we do by passing them off to thread pool to be
* disposed of */
_debug("destroy");
fscache_withdraw_all_objects(cache, &dying_objects);
/* wait for all extant objects to finish their outstanding operations
* and go away */
_debug("wait for finish");
wait_event(fscache_cache_cleared_wq,
atomic_read(&cache->object_count) == 0);
_debug("wait for clearance");
wait_event(fscache_cache_cleared_wq,
list_empty(&cache->object_list));
_debug("cleared");
ASSERT(list_empty(&dying_objects));
kobject_put(cache->kobj);
clear_bit(FSCACHE_TAG_RESERVED, &cache->tag->flags);
fscache_release_cache_tag(cache->tag);
cache->tag = NULL;
_leave("");
}
EXPORT_SYMBOL(fscache_withdraw_cache);
fs/fscache/cookie.c deleted 100644 → 0
View file @ 850cba06
// SPDX-License-Identifier: GPL-2.0-or-later
/* netfs cookie management
*
* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* See Documentation/filesystems/caching/netfs-api.rst for more information on
* the netfs API.
*/
#define FSCACHE_DEBUG_LEVEL COOKIE
#include <linux/module.h>
#include <linux/slab.h>
#include "internal.h"
struct kmem_cache *fscache_cookie_jar;
static atomic_t fscache_object_debug_id = ATOMIC_INIT(0);
#define fscache_cookie_hash_shift 15
static struct hlist_bl_head fscache_cookie_hash[1 << fscache_cookie_hash_shift];
static LIST_HEAD(fscache_cookies);
static DEFINE_RWLOCK(fscache_cookies_lock);
static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie,
loff_t object_size);
static int fscache_alloc_object(struct fscache_cache *cache,
struct fscache_cookie *cookie);
static int fscache_attach_object(struct fscache_cookie *cookie,
struct fscache_object *object);
static void fscache_print_cookie(struct fscache_cookie *cookie, char prefix)
{
struct fscache_object *object;
struct hlist_node *o;
const u8 *k;
unsigned loop;
pr_err("%c-cookie c=%08x [p=%08x fl=%lx nc=%u na=%u]\n",
prefix,
cookie->debug_id,
cookie->parent ? cookie->parent->debug_id : 0,
cookie->flags,
atomic_read(&cookie->n_children),
atomic_read(&cookie->n_active));
pr_err("%c-cookie d=%p{%s} n=%p\n",
prefix,
cookie->def,
cookie->def ? cookie->def->name : "?",
cookie->netfs_data);
o = READ_ONCE(cookie->backing_objects.first);
if (o) {
object = hlist_entry(o, struct fscache_object, cookie_link);
pr_err("%c-cookie o=%u\n", prefix, object->debug_id);
}
pr_err("%c-key=[%u] '", prefix, cookie->key_len);
k = (cookie->key_len <= sizeof(cookie->inline_key)) ?
cookie->inline_key : cookie->key;
for (loop = 0; loop < cookie->key_len; loop++)
pr_cont("%02x", k[loop]);
pr_cont("'\n");
}
void fscache_free_cookie(struct fscache_cookie *cookie)
{
if (cookie) {
BUG_ON(!hlist_empty(&cookie->backing_objects));
write_lock(&fscache_cookies_lock);
list_del(&cookie->proc_link);
write_unlock(&fscache_cookies_lock);
if (cookie->aux_len > sizeof(cookie->inline_aux))
kfree(cookie->aux);
if (cookie->key_len > sizeof(cookie->inline_key))
kfree(cookie->key);
kmem_cache_free(fscache_cookie_jar, cookie);
}
}
/*
* Set the index key in a cookie. The cookie struct has space for a 16-byte
* key plus length and hash, but if that's not big enough, it's instead a
* pointer to a buffer containing 3 bytes of hash, 1 byte of length and then
* the key data.
*/
static int fscache_set_key(struct fscache_cookie *cookie,
const void *index_key, size_t index_key_len)
{
u32 *buf;
int bufs;
bufs = DIV_ROUND_UP(index_key_len, sizeof(*buf));
if (index_key_len > sizeof(cookie->inline_key)) {
buf = kcalloc(bufs, sizeof(*buf), GFP_KERNEL);
if (!buf)
return -ENOMEM;
cookie->key = buf;
} else {
buf = (u32 *)cookie->inline_key;
}
memcpy(buf, index_key, index_key_len);
cookie->key_hash = fscache_hash(0, buf, bufs);
return 0;
}
static long fscache_compare_cookie(const struct fscache_cookie *a,
const struct fscache_cookie *b)
{
const void *ka, *kb;
if (a->key_hash != b->key_hash)
return (long)a->key_hash - (long)b->key_hash;
if (a->parent != b->parent)
return (long)a->parent - (long)b->parent;
if (a->key_len != b->key_len)
return (long)a->key_len - (long)b->key_len;
if (a->type != b->type)
return (long)a->type - (long)b->type;
if (a->key_len <= sizeof(a->inline_key)) {
ka = &a->inline_key;
kb = &b->inline_key;
} else {
ka = a->key;
kb = b->key;
}
return memcmp(ka, kb, a->key_len);
}
static atomic_t fscache_cookie_debug_id = ATOMIC_INIT(1);
/*
* Allocate a cookie.
*/
struct fscache_cookie *fscache_alloc_cookie(
struct fscache_cookie *parent,
const struct fscache_cookie_def *def,
const void *index_key, size_t index_key_len,
const void *aux_data, size_t aux_data_len,
void *netfs_data,
loff_t object_size)
{
struct fscache_cookie *cookie;
/* allocate and initialise a cookie */
cookie = kmem_cache_zalloc(fscache_cookie_jar, GFP_KERNEL);
if (!cookie)
return NULL;
cookie->key_len = index_key_len;
cookie->aux_len = aux_data_len;
if (fscache_set_key(cookie, index_key, index_key_len) < 0)
goto nomem;
if (cookie->aux_len <= sizeof(cookie->inline_aux)) {
memcpy(cookie->inline_aux, aux_data, cookie->aux_len);
} else {
cookie->aux = kmemdup(aux_data, cookie->aux_len, GFP_KERNEL);
if (!cookie->aux)
goto nomem;
}
refcount_set(&cookie->ref, 1);
atomic_set(&cookie->n_children, 0);
cookie->debug_id = atomic_inc_return(&fscache_cookie_debug_id);
/* We keep the active count elevated until relinquishment to prevent an
* attempt to wake up every time the object operations queue quiesces.
*/
atomic_set(&cookie->n_active, 1);
cookie->def = def;
cookie->parent = parent;
cookie->netfs_data = netfs_data;
cookie->flags = (1 << FSCACHE_COOKIE_NO_DATA_YET);
cookie->type = def->type;
spin_lock_init(&cookie->lock);
spin_lock_init(&cookie->stores_lock);
INIT_HLIST_HEAD(&cookie->backing_objects);
/* radix tree insertion won't use the preallocation pool unless it's
* told it may not wait */
INIT_RADIX_TREE(&cookie->stores, GFP_NOFS & ~__GFP_DIRECT_RECLAIM);
write_lock(&fscache_cookies_lock);
list_add_tail(&cookie->proc_link, &fscache_cookies);
write_unlock(&fscache_cookies_lock);
return cookie;
nomem:
fscache_free_cookie(cookie);
return NULL;
}
/*
* Attempt to insert the new cookie into the hash. If there's a collision, we
* return the old cookie if it's not in use and an error otherwise.
*/
struct fscache_cookie *fscache_hash_cookie(struct fscache_cookie *candidate)
{
struct fscache_cookie *cursor;
struct hlist_bl_head *h;
struct hlist_bl_node *p;
unsigned int bucket;
bucket = candidate->key_hash & (ARRAY_SIZE(fscache_cookie_hash) - 1);
h = &fscache_cookie_hash[bucket];
hlist_bl_lock(h);
hlist_bl_for_each_entry(cursor, p, h, hash_link) {
if (fscache_compare_cookie(candidate, cursor) == 0)
goto collision;
}
__set_bit(FSCACHE_COOKIE_ACQUIRED, &candidate->flags);
fscache_cookie_get(candidate->parent, fscache_cookie_get_acquire_parent);
atomic_inc(&candidate->parent->n_children);
hlist_bl_add_head(&candidate->hash_link, h);
hlist_bl_unlock(h);
return candidate;
collision:
if (test_and_set_bit(FSCACHE_COOKIE_ACQUIRED, &cursor->flags)) {
trace_fscache_cookie(cursor->debug_id, refcount_read(&cursor->ref),
fscache_cookie_collision);
pr_err("Duplicate cookie detected\n");
fscache_print_cookie(cursor, 'O');
fscache_print_cookie(candidate, 'N');
hlist_bl_unlock(h);
return NULL;
}
fscache_cookie_get(cursor, fscache_cookie_get_reacquire);
hlist_bl_unlock(h);
return cursor;
}
/*
* request a cookie to represent an object (index, datafile, xattr, etc)
* - parent specifies the parent object
* - the top level index cookie for each netfs is stored in the fscache_netfs
* struct upon registration
* - def points to the definition
* - the netfs_data will be passed to the functions pointed to in *def
* - all attached caches will be searched to see if they contain this object
* - index objects aren't stored on disk until there's a dependent file that
* needs storing
* - other objects are stored in a selected cache immediately, and all the
* indices forming the path to it are instantiated if necessary
* - we never let on to the netfs about errors
* - we may set a negative cookie pointer, but that's okay
*/
struct fscache_cookie *__fscache_acquire_cookie(
struct fscache_cookie *parent,
const struct fscache_cookie_def *def,
const void *index_key, size_t index_key_len,
const void *aux_data, size_t aux_data_len,
void *netfs_data,
loff_t object_size,
bool enable)
{
struct fscache_cookie *candidate, *cookie;
BUG_ON(!def);
_enter("{%s},{%s},%p,%u",
parent ? (char *) parent->def->name : "<no-parent>",
def->name, netfs_data, enable);
if (!index_key || !index_key_len || index_key_len > 255 || aux_data_len > 255)
return NULL;
if (!aux_data || !aux_data_len) {
aux_data = NULL;
aux_data_len = 0;
}
fscache_stat(&fscache_n_acquires);
/* if there's no parent cookie, then we don't create one here either */
if (!parent) {
fscache_stat(&fscache_n_acquires_null);
_leave(" [no parent]");
return NULL;
}
/* validate the definition */
BUG_ON(!def->name[0]);
BUG_ON(def->type == FSCACHE_COOKIE_TYPE_INDEX &&
parent->type != FSCACHE_COOKIE_TYPE_INDEX);
candidate = fscache_alloc_cookie(parent, def,
index_key, index_key_len,
aux_data, aux_data_len,
netfs_data, object_size);
if (!candidate) {
fscache_stat(&fscache_n_acquires_oom);
_leave(" [ENOMEM]");
return NULL;
}
cookie = fscache_hash_cookie(candidate);
if (!cookie) {
trace_fscache_cookie(candidate->debug_id, 1,
fscache_cookie_discard);
goto out;
}
if (cookie == candidate)
candidate = NULL;
switch (cookie->type) {
case FSCACHE_COOKIE_TYPE_INDEX:
fscache_stat(&fscache_n_cookie_index);
break;
case FSCACHE_COOKIE_TYPE_DATAFILE:
fscache_stat(&fscache_n_cookie_data);
break;
default:
fscache_stat(&fscache_n_cookie_special);
break;
}
trace_fscache_acquire(cookie);
if (enable) {
/* if the object is an index then we need do nothing more here
* - we create indices on disk when we need them as an index
* may exist in multiple caches */
if (cookie->type != FSCACHE_COOKIE_TYPE_INDEX) {
if (fscache_acquire_non_index_cookie(cookie, object_size) == 0) {
set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
} else {
atomic_dec(&parent->n_children);
fscache_cookie_put(cookie,
fscache_cookie_put_acquire_nobufs);
fscache_stat(&fscache_n_acquires_nobufs);
_leave(" = NULL");
return NULL;
}
} else {
set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
}
}
fscache_stat(&fscache_n_acquires_ok);
out:
fscache_free_cookie(candidate);
return cookie;
}
EXPORT_SYMBOL(__fscache_acquire_cookie);
/*
* Enable a cookie to permit it to accept new operations.
*/
void __fscache_enable_cookie(struct fscache_cookie *cookie,
const void *aux_data,
loff_t object_size,
bool (*can_enable)(void *data),
void *data)
{
_enter("%x", cookie->debug_id);
trace_fscache_enable(cookie);
wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK,
TASK_UNINTERRUPTIBLE);
fscache_update_aux(cookie, aux_data);
if (test_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags))
goto out_unlock;
if (can_enable && !can_enable(data)) {
/* The netfs decided it didn't want to enable after all */
} else if (cookie->type != FSCACHE_COOKIE_TYPE_INDEX) {
/* Wait for outstanding disablement to complete */
__fscache_wait_on_invalidate(cookie);
if (fscache_acquire_non_index_cookie(cookie, object_size) == 0)
set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
} else {
set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
}
out_unlock:
clear_bit_unlock(FSCACHE_COOKIE_ENABLEMENT_LOCK, &cookie->flags);
wake_up_bit(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK);
}
EXPORT_SYMBOL(__fscache_enable_cookie);
/*
* acquire a non-index cookie
* - this must make sure the index chain is instantiated and instantiate the
* object representation too
*/
static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie,
loff_t object_size)
{
struct fscache_object *object;
struct fscache_cache *cache;
int ret;
_enter("");
set_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
/* now we need to see whether the backing objects for this cookie yet
* exist, if not there'll be nothing to search */
down_read(&fscache_addremove_sem);
if (list_empty(&fscache_cache_list)) {
up_read(&fscache_addremove_sem);
_leave(" = 0 [no caches]");
return 0;
}
/* select a cache in which to store the object */
cache = fscache_select_cache_for_object(cookie->parent);
if (!cache) {
up_read(&fscache_addremove_sem);
fscache_stat(&fscache_n_acquires_no_cache);
_leave(" = -ENOMEDIUM [no cache]");
return -ENOMEDIUM;
}
_debug("cache %s", cache->tag->name);
set_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags);
/* ask the cache to allocate objects for this cookie and its parent
* chain */
ret = fscache_alloc_object(cache, cookie);
if (ret < 0) {
up_read(&fscache_addremove_sem);
_leave(" = %d", ret);
return ret;
}
spin_lock(&cookie->lock);
if (hlist_empty(&cookie->backing_objects)) {
spin_unlock(&cookie->lock);
goto unavailable;
}
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object, cookie_link);
fscache_set_store_limit(object, object_size);
/* initiate the process of looking up all the objects in the chain
* (done by fscache_initialise_object()) */
fscache_raise_event(object, FSCACHE_OBJECT_EV_NEW_CHILD);
spin_unlock(&cookie->lock);
/* we may be required to wait for lookup to complete at this point */
if (!fscache_defer_lookup) {
wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP,
TASK_UNINTERRUPTIBLE);
if (test_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags))
goto unavailable;
}
up_read(&fscache_addremove_sem);
_leave(" = 0 [deferred]");
return 0;
unavailable:
up_read(&fscache_addremove_sem);
_leave(" = -ENOBUFS");
return -ENOBUFS;
}
/*
* recursively allocate cache object records for a cookie/cache combination
* - caller must be holding the addremove sem
*/
static int fscache_alloc_object(struct fscache_cache *cache,
struct fscache_cookie *cookie)
{
struct fscache_object *object;
int ret;
_enter("%s,%x{%s}", cache->tag->name, cookie->debug_id, cookie->def->name);
spin_lock(&cookie->lock);
hlist_for_each_entry(object, &cookie->backing_objects,
cookie_link) {
if (object->cache == cache)
goto object_already_extant;
}
spin_unlock(&cookie->lock);
/* ask the cache to allocate an object (we may end up with duplicate
* objects at this stage, but we sort that out later) */
fscache_stat(&fscache_n_cop_alloc_object);
object = cache->ops->alloc_object(cache, cookie);
fscache_stat_d(&fscache_n_cop_alloc_object);
if (IS_ERR(object)) {
fscache_stat(&fscache_n_object_no_alloc);
ret = PTR_ERR(object);
goto error;
}
ASSERTCMP(object->cookie, ==, cookie);
fscache_stat(&fscache_n_object_alloc);
object->debug_id = atomic_inc_return(&fscache_object_debug_id);
_debug("ALLOC OBJ%x: %s {%lx}",
object->debug_id, cookie->def->name, object->events);
ret = fscache_alloc_object(cache, cookie->parent);
if (ret < 0)
goto error_put;
/* only attach if we managed to allocate all we needed, otherwise
* discard the object we just allocated and instead use the one
* attached to the cookie */
if (fscache_attach_object(cookie, object) < 0) {
fscache_stat(&fscache_n_cop_put_object);
cache->ops->put_object(object, fscache_obj_put_attach_fail);
fscache_stat_d(&fscache_n_cop_put_object);
}
_leave(" = 0");
return 0;
object_already_extant:
ret = -ENOBUFS;
if (fscache_object_is_dying(object) ||
fscache_cache_is_broken(object)) {
spin_unlock(&cookie->lock);
goto error;
}
spin_unlock(&cookie->lock);
_leave(" = 0 [found]");
return 0;
error_put:
fscache_stat(&fscache_n_cop_put_object);
cache->ops->put_object(object, fscache_obj_put_alloc_fail);
fscache_stat_d(&fscache_n_cop_put_object);
error:
_leave(" = %d", ret);
return ret;
}
/*
* attach a cache object to a cookie
*/
static int fscache_attach_object(struct fscache_cookie *cookie,
struct fscache_object *object)
{
struct fscache_object *p;
struct fscache_cache *cache = object->cache;
int ret;
_enter("{%s},{OBJ%x}", cookie->def->name, object->debug_id);
ASSERTCMP(object->cookie, ==, cookie);
spin_lock(&cookie->lock);
/* there may be multiple initial creations of this object, but we only
* want one */
ret = -EEXIST;
hlist_for_each_entry(p, &cookie->backing_objects, cookie_link) {
if (p->cache == object->cache) {
if (fscache_object_is_dying(p))
ret = -ENOBUFS;
goto cant_attach_object;
}
}
/* pin the parent object */
spin_lock_nested(&cookie->parent->lock, 1);
hlist_for_each_entry(p, &cookie->parent->backing_objects,
cookie_link) {
if (p->cache == object->cache) {
if (fscache_object_is_dying(p)) {
ret = -ENOBUFS;
spin_unlock(&cookie->parent->lock);
goto cant_attach_object;
}
object->parent = p;
spin_lock(&p->lock);
p->n_children++;
spin_unlock(&p->lock);
break;
}
}
spin_unlock(&cookie->parent->lock);
/* attach to the cache's object list */
if (list_empty(&object->cache_link)) {
spin_lock(&cache->object_list_lock);
list_add(&object->cache_link, &cache->object_list);
spin_unlock(&cache->object_list_lock);
}
/* Attach to the cookie. The object already has a ref on it. */
hlist_add_head(&object->cookie_link, &cookie->backing_objects);
ret = 0;
cant_attach_object:
spin_unlock(&cookie->lock);
_leave(" = %d", ret);
return ret;
}
/*
* Invalidate an object. Callable with spinlocks held.
*/
void __fscache_invalidate(struct fscache_cookie *cookie)
{
struct fscache_object *object;
_enter("{%s}", cookie->def->name);
fscache_stat(&fscache_n_invalidates);
/* Only permit invalidation of data files. Invalidating an index will
* require the caller to release all its attachments to the tree rooted
* there, and if it's doing that, it may as well just retire the
* cookie.
*/
ASSERTCMP(cookie->type, ==, FSCACHE_COOKIE_TYPE_DATAFILE);
/* If there's an object, we tell the object state machine to handle the
* invalidation on our behalf, otherwise there's nothing to do.
*/
if (!hlist_empty(&cookie->backing_objects)) {
spin_lock(&cookie->lock);
if (fscache_cookie_enabled(cookie) &&
!hlist_empty(&cookie->backing_objects) &&
!test_and_set_bit(FSCACHE_COOKIE_INVALIDATING,
&cookie->flags)) {
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object,
cookie_link);
if (fscache_object_is_live(object))
fscache_raise_event(
object, FSCACHE_OBJECT_EV_INVALIDATE);
}
spin_unlock(&cookie->lock);
}
_leave("");
}
EXPORT_SYMBOL(__fscache_invalidate);
/*
* Wait for object invalidation to complete.
*/
void __fscache_wait_on_invalidate(struct fscache_cookie *cookie)
{
_enter("%x", cookie->debug_id);
wait_on_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING,
TASK_UNINTERRUPTIBLE);
_leave("");
}
EXPORT_SYMBOL(__fscache_wait_on_invalidate);
/*
* update the index entries backing a cookie
*/
void __fscache_update_cookie(struct fscache_cookie *cookie, const void *aux_data)
{
struct fscache_object *object;
fscache_stat(&fscache_n_updates);
if (!cookie) {
fscache_stat(&fscache_n_updates_null);
_leave(" [no cookie]");
return;
}
_enter("{%s}", cookie->def->name);
spin_lock(&cookie->lock);
fscache_update_aux(cookie, aux_data);
if (fscache_cookie_enabled(cookie)) {
/* update the index entry on disk in each cache backing this
* cookie.
*/
hlist_for_each_entry(object,
&cookie->backing_objects, cookie_link) {
fscache_raise_event(object, FSCACHE_OBJECT_EV_UPDATE);
}
}
spin_unlock(&cookie->lock);
_leave("");
}
EXPORT_SYMBOL(__fscache_update_cookie);
/*
* Disable a cookie to stop it from accepting new requests from the netfs.
*/
void __fscache_disable_cookie(struct fscache_cookie *cookie,
const void *aux_data,
bool invalidate)
{
struct fscache_object *object;
bool awaken = false;
_enter("%x,%u", cookie->debug_id, invalidate);
trace_fscache_disable(cookie);
ASSERTCMP(atomic_read(&cookie->n_active), >, 0);
if (atomic_read(&cookie->n_children) != 0) {
pr_err("Cookie '%s' still has children\n",
cookie->def->name);
BUG();
}
wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK,
TASK_UNINTERRUPTIBLE);
fscache_update_aux(cookie, aux_data);
if (!test_and_clear_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags))
goto out_unlock_enable;
/* If the cookie is being invalidated, wait for that to complete first
* so that we can reuse the flag.
*/
__fscache_wait_on_invalidate(cookie);
/* Dispose of the backing objects */
set_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags);
spin_lock(&cookie->lock);
if (!hlist_empty(&cookie->backing_objects)) {
hlist_for_each_entry(object, &cookie->backing_objects, cookie_link) {
if (invalidate)
set_bit(FSCACHE_OBJECT_RETIRED, &object->flags);
clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
fscache_raise_event(object, FSCACHE_OBJECT_EV_KILL);
}
} else {
if (test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags))
awaken = true;
}
spin_unlock(&cookie->lock);
if (awaken)
wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING);
/* Wait for cessation of activity requiring access to the netfs (when
* n_active reaches 0). This makes sure outstanding reads and writes
* have completed.
*/
if (!atomic_dec_and_test(&cookie->n_active)) {
wait_var_event(&cookie->n_active,
!atomic_read(&cookie->n_active));
}
/* Make sure any pending writes are cancelled. */
if (cookie->type != FSCACHE_COOKIE_TYPE_INDEX)
fscache_invalidate_writes(cookie);
/* Reset the cookie state if it wasn't relinquished */
if (!test_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags)) {
atomic_inc(&cookie->n_active);
set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
}
out_unlock_enable:
clear_bit_unlock(FSCACHE_COOKIE_ENABLEMENT_LOCK, &cookie->flags);
wake_up_bit(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK);
_leave("");
}
EXPORT_SYMBOL(__fscache_disable_cookie);
/*
* release a cookie back to the cache
* - the object will be marked as recyclable on disk if retire is true
* - all dependents of this cookie must have already been unregistered
* (indices/files/pages)
*/
void __fscache_relinquish_cookie(struct fscache_cookie *cookie,
const void *aux_data,
bool retire)
{
fscache_stat(&fscache_n_relinquishes);
if (retire)
fscache_stat(&fscache_n_relinquishes_retire);
if (!cookie) {
fscache_stat(&fscache_n_relinquishes_null);
_leave(" [no cookie]");
return;
}
_enter("%x{%s,%d},%d",
cookie->debug_id, cookie->def->name,
atomic_read(&cookie->n_active), retire);
trace_fscache_relinquish(cookie, retire);
/* No further netfs-accessing operations on this cookie permitted */
if (test_and_set_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags))
BUG();
__fscache_disable_cookie(cookie, aux_data, retire);
/* Clear pointers back to the netfs */
cookie->netfs_data = NULL;
cookie->def = NULL;
BUG_ON(!radix_tree_empty(&cookie->stores));
if (cookie->parent) {
ASSERTCMP(refcount_read(&cookie->parent->ref), >, 0);
ASSERTCMP(atomic_read(&cookie->parent->n_children), >, 0);
atomic_dec(&cookie->parent->n_children);
}
/* Dispose of the netfs's link to the cookie */
fscache_cookie_put(cookie, fscache_cookie_put_relinquish);
_leave("");
}
EXPORT_SYMBOL(__fscache_relinquish_cookie);
/*
* Remove a cookie from the hash table.
*/
static void fscache_unhash_cookie(struct fscache_cookie *cookie)
{
struct hlist_bl_head *h;
unsigned int bucket;
bucket = cookie->key_hash & (ARRAY_SIZE(fscache_cookie_hash) - 1);
h = &fscache_cookie_hash[bucket];
hlist_bl_lock(h);
hlist_bl_del(&cookie->hash_link);
hlist_bl_unlock(h);
}
/*
* Drop a reference to a cookie.
*/
void fscache_cookie_put(struct fscache_cookie *cookie,
enum fscache_cookie_trace where)
{
struct fscache_cookie *parent;
int ref;
_enter("%x", cookie->debug_id);
do {
unsigned int cookie_debug_id = cookie->debug_id;
bool zero = __refcount_dec_and_test(&cookie->ref, &ref);
trace_fscache_cookie(cookie_debug_id, ref - 1, where);
if (!zero)
return;
parent = cookie->parent;
fscache_unhash_cookie(cookie);
fscache_free_cookie(cookie);
cookie = parent;
where = fscache_cookie_put_parent;
} while (cookie);
_leave("");
}
/*
* Get a reference to a cookie.
*/
struct fscache_cookie *fscache_cookie_get(struct fscache_cookie *cookie,
enum fscache_cookie_trace where)
{
int ref;
__refcount_inc(&cookie->ref, &ref);
trace_fscache_cookie(cookie->debug_id, ref + 1, where);
return cookie;
}
/*
* check the consistency between the netfs inode and the backing cache
*
* NOTE: it only serves no-index type
*/
int __fscache_check_consistency(struct fscache_cookie *cookie,
const void *aux_data)
{
struct fscache_operation *op;
struct fscache_object *object;
bool wake_cookie = false;
int ret;
_enter("%p,", cookie);
ASSERTCMP(cookie->type, ==, FSCACHE_COOKIE_TYPE_DATAFILE);
if (fscache_wait_for_deferred_lookup(cookie) < 0)
return -ERESTARTSYS;
if (hlist_empty(&cookie->backing_objects))
return 0;
op = kzalloc(sizeof(*op), GFP_NOIO | __GFP_NOMEMALLOC | __GFP_NORETRY);
if (!op)
return -ENOMEM;
fscache_operation_init(cookie, op, NULL, NULL, NULL);
op->flags = FSCACHE_OP_MYTHREAD |
(1 << FSCACHE_OP_WAITING) |
(1 << FSCACHE_OP_UNUSE_COOKIE);
trace_fscache_page_op(cookie, NULL, op, fscache_page_op_check_consistency);
spin_lock(&cookie->lock);
fscache_update_aux(cookie, aux_data);
if (!fscache_cookie_enabled(cookie) ||
hlist_empty(&cookie->backing_objects))
goto inconsistent;
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object, cookie_link);
if (test_bit(FSCACHE_IOERROR, &object->cache->flags))
goto inconsistent;
op->debug_id = atomic_inc_return(&fscache_op_debug_id);
__fscache_use_cookie(cookie);
if (fscache_submit_op(object, op) < 0)
goto submit_failed;
/* the work queue now carries its own ref on the object */
spin_unlock(&cookie->lock);
ret = fscache_wait_for_operation_activation(object, op, NULL, NULL);
if (ret == 0) {
/* ask the cache to honour the operation */
ret = object->cache->ops->check_consistency(op);
fscache_op_complete(op, false);
} else if (ret == -ENOBUFS) {
ret = 0;
}
fscache_put_operation(op);
_leave(" = %d", ret);
return ret;
submit_failed:
wake_cookie = __fscache_unuse_cookie(cookie);
inconsistent:
spin_unlock(&cookie->lock);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
kfree(op);
_leave(" = -ESTALE");
return -ESTALE;
}
EXPORT_SYMBOL(__fscache_check_consistency);
/*
* Generate a list of extant cookies in /proc/fs/fscache/cookies
*/
static int fscache_cookies_seq_show(struct seq_file *m, void *v)
{
struct fscache_cookie *cookie;
unsigned int keylen = 0, auxlen = 0;
char _type[3], *type;
u8 *p;
if (v == &fscache_cookies) {
seq_puts(m,
"COOKIE PARENT USAGE CHILD ACT TY FL DEF NETFS_DATA\n"
"======== ======== ===== ===== === == === ================ ==========\n"
);
return 0;
}
cookie = list_entry(v, struct fscache_cookie, proc_link);
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 %08x %5u %5u %3u %s %03lx %-16s %px",
cookie->debug_id,
cookie->parent ? cookie->parent->debug_id : 0,
refcount_read(&cookie->ref),
atomic_read(&cookie->n_children),
atomic_read(&cookie->n_active),
type,
cookie->flags,
cookie->def->name,
cookie->netfs_data);
keylen = cookie->key_len;
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) {
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");
return 0;
}
static void *fscache_cookies_seq_start(struct seq_file *m, loff_t *_pos)
__acquires(fscache_cookies_lock)
{
read_lock(&fscache_cookies_lock);
return seq_list_start_head(&fscache_cookies, *_pos);
}
static void *fscache_cookies_seq_next(struct seq_file *m, void *v, loff_t *_pos)
{
return seq_list_next(v, &fscache_cookies, _pos);
}
static void fscache_cookies_seq_stop(struct seq_file *m, void *v)
__releases(rcu)
{
read_unlock(&fscache_cookies_lock);
}
const struct seq_operations fscache_cookies_seq_ops = {
.start = fscache_cookies_seq_start,
.next = fscache_cookies_seq_next,
.stop = fscache_cookies_seq_stop,
.show = fscache_cookies_seq_show,
};
fs/fscache/fsdef.c deleted 100644 → 0
View file @ 850cba06
// SPDX-License-Identifier: GPL-2.0-or-later
/* Filesystem index definition
*
* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#define FSCACHE_DEBUG_LEVEL CACHE
#include <linux/module.h>
#include "internal.h"
static
enum fscache_checkaux fscache_fsdef_netfs_check_aux(void *cookie_netfs_data,
const void *data,
uint16_t datalen,
loff_t object_size);
/*
* The root index is owned by FS-Cache itself.
*
* When a netfs requests caching facilities, FS-Cache will, if one doesn't
* already exist, create an entry in the root index with the key being the name
* of the netfs ("AFS" for example), and the auxiliary data holding the index
* structure version supplied by the netfs:
*
* FSDEF
* |
* +-----------+
* | |
* NFS AFS
* [v=1] [v=1]
*
* If an entry with the appropriate name does already exist, the version is
* compared. If the version is different, the entire subtree from that entry
* will be discarded and a new entry created.
*
* The new entry will be an index, and a cookie referring to it will be passed
* to the netfs. This is then the root handle by which the netfs accesses the
* cache. It can create whatever objects it likes in that index, including
* further indices.
*/
static struct fscache_cookie_def fscache_fsdef_index_def = {
.name = ".FS-Cache",
.type = FSCACHE_COOKIE_TYPE_INDEX,
};
struct fscache_cookie fscache_fsdef_index = {
.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,
.def = &fscache_fsdef_index_def,
.flags = 1 << FSCACHE_COOKIE_ENABLED,
.type = FSCACHE_COOKIE_TYPE_INDEX,
};
EXPORT_SYMBOL(fscache_fsdef_index);
/*
* Definition of an entry in the root index. Each entry is an index, keyed to
* a specific netfs and only applicable to a particular version of the index
* structure used by that netfs.
*/
struct fscache_cookie_def fscache_fsdef_netfs_def = {
.name = "FSDEF.netfs",
.type = FSCACHE_COOKIE_TYPE_INDEX,
.check_aux = fscache_fsdef_netfs_check_aux,
};
/*
* check that the index structure version number stored in the auxiliary data
* matches the one the netfs gave us
*/
static enum fscache_checkaux fscache_fsdef_netfs_check_aux(
void *cookie_netfs_data,
const void *data,
uint16_t datalen,
loff_t object_size)
{
struct fscache_netfs *netfs = cookie_netfs_data;
uint32_t version;
_enter("{%s},,%hu", netfs->name, datalen);
if (datalen != sizeof(version)) {
_leave(" = OBSOLETE [dl=%d v=%zu]", datalen, sizeof(version));
return FSCACHE_CHECKAUX_OBSOLETE;
}
memcpy(&version, data, sizeof(version));
if (version != netfs->version) {
_leave(" = OBSOLETE [ver=%x net=%x]", version, netfs->version);
return FSCACHE_CHECKAUX_OBSOLETE;
}
_leave(" = OKAY");
return FSCACHE_CHECKAUX_OKAY;
}
fs/fscache/internal.h deleted 100644 → 0
View file @ 850cba06
/* SPDX-License-Identifier: GPL-2.0-or-later */
/* Internal definitions for FS-Cache
*
* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
/*
* Lock order, in the order in which multiple locks should be obtained:
* - fscache_addremove_sem
* - cookie->lock
* - cookie->parent->lock
* - cache->object_list_lock
* - object->lock
* - object->parent->lock
* - cookie->stores_lock
* - fscache_thread_lock
*
*/
#ifdef pr_fmt
#undef pr_fmt
#endif
#define pr_fmt(fmt) "FS-Cache: " fmt
#include <linux/fscache-cache.h>
#include <trace/events/fscache.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#define FSCACHE_MIN_THREADS 4
#define FSCACHE_MAX_THREADS 32
/*
* cache.c
*/
extern struct list_head fscache_cache_list;
extern struct rw_semaphore fscache_addremove_sem;
extern struct fscache_cache *fscache_select_cache_for_object(
struct fscache_cookie *);
/*
* 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 *,
const struct fscache_cookie_def *,
const void *, size_t,
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;
/*
* main.c
*/
extern unsigned fscache_defer_lookup;
extern unsigned fscache_defer_create;
extern unsigned fscache_debug;
extern struct kobject *fscache_root;
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);
}
/*
* object.c
*/
extern void fscache_enqueue_object(struct fscache_object *);
/*
* operation.c
*/
extern int fscache_submit_exclusive_op(struct fscache_object *,
struct fscache_operation *);
extern int fscache_submit_op(struct fscache_object *,
struct fscache_operation *);
extern int fscache_cancel_op(struct fscache_operation *, bool);
extern void fscache_cancel_all_ops(struct fscache_object *);
extern void fscache_abort_object(struct fscache_object *);
extern void fscache_start_operations(struct fscache_object *);
extern void fscache_operation_gc(struct work_struct *);
/*
* page.c
*/
extern int fscache_wait_for_deferred_lookup(struct fscache_cookie *);
extern int fscache_wait_for_operation_activation(struct fscache_object *,
struct fscache_operation *,
atomic_t *,
atomic_t *);
extern void fscache_invalidate_writes(struct fscache_cookie *);
struct fscache_retrieval *fscache_alloc_retrieval(struct fscache_cookie *cookie,
struct address_space *mapping,
fscache_rw_complete_t end_io_func,
void *context);
/*
* proc.c
*/
#ifdef CONFIG_PROC_FS
extern int __init fscache_proc_init(void);
extern void fscache_proc_cleanup(void);
#else
#define fscache_proc_init() (0)
#define fscache_proc_cleanup() do {} while (0)
#endif
/*
* stats.c
*/
#ifdef CONFIG_FSCACHE_STATS
extern atomic_t fscache_n_ops_processed[FSCACHE_MAX_THREADS];
extern atomic_t fscache_n_objs_processed[FSCACHE_MAX_THREADS];
extern atomic_t fscache_n_op_pend;
extern atomic_t fscache_n_op_run;
extern atomic_t fscache_n_op_enqueue;
extern atomic_t fscache_n_op_deferred_release;
extern atomic_t fscache_n_op_initialised;
extern atomic_t fscache_n_op_release;
extern atomic_t fscache_n_op_gc;
extern atomic_t fscache_n_op_cancelled;
extern atomic_t fscache_n_op_rejected;
extern atomic_t fscache_n_attr_changed;
extern atomic_t fscache_n_attr_changed_ok;
extern atomic_t fscache_n_attr_changed_nobufs;
extern atomic_t fscache_n_attr_changed_nomem;
extern atomic_t fscache_n_attr_changed_calls;
extern atomic_t fscache_n_allocs;
extern atomic_t fscache_n_allocs_ok;
extern atomic_t fscache_n_allocs_wait;
extern atomic_t fscache_n_allocs_nobufs;
extern atomic_t fscache_n_allocs_intr;
extern atomic_t fscache_n_allocs_object_dead;
extern atomic_t fscache_n_alloc_ops;
extern atomic_t fscache_n_alloc_op_waits;
extern atomic_t fscache_n_retrievals;
extern atomic_t fscache_n_retrievals_ok;
extern atomic_t fscache_n_retrievals_wait;
extern atomic_t fscache_n_retrievals_nodata;
extern atomic_t fscache_n_retrievals_nobufs;
extern atomic_t fscache_n_retrievals_intr;
extern atomic_t fscache_n_retrievals_nomem;
extern atomic_t fscache_n_retrievals_object_dead;
extern atomic_t fscache_n_retrieval_ops;
extern atomic_t fscache_n_retrieval_op_waits;
extern atomic_t fscache_n_stores;
extern atomic_t fscache_n_stores_ok;
extern atomic_t fscache_n_stores_again;
extern atomic_t fscache_n_stores_nobufs;
extern atomic_t fscache_n_stores_oom;
extern atomic_t fscache_n_store_ops;
extern atomic_t fscache_n_store_calls;
extern atomic_t fscache_n_store_pages;
extern atomic_t fscache_n_store_radix_deletes;
extern atomic_t fscache_n_store_pages_over_limit;
extern atomic_t fscache_n_store_vmscan_not_storing;
extern atomic_t fscache_n_store_vmscan_gone;
extern atomic_t fscache_n_store_vmscan_busy;
extern atomic_t fscache_n_store_vmscan_cancelled;
extern atomic_t fscache_n_store_vmscan_wait;
extern atomic_t fscache_n_marks;
extern atomic_t fscache_n_uncaches;
extern atomic_t fscache_n_acquires;
extern atomic_t fscache_n_acquires_null;
extern atomic_t fscache_n_acquires_no_cache;
extern atomic_t fscache_n_acquires_ok;
extern atomic_t fscache_n_acquires_nobufs;
extern atomic_t fscache_n_acquires_oom;
extern atomic_t fscache_n_invalidates;
extern atomic_t fscache_n_invalidates_run;
extern atomic_t fscache_n_updates;
extern atomic_t fscache_n_updates_null;
extern atomic_t fscache_n_updates_run;
extern atomic_t fscache_n_relinquishes;
extern atomic_t fscache_n_relinquishes_null;
extern atomic_t fscache_n_relinquishes_waitcrt;
extern atomic_t fscache_n_relinquishes_retire;
extern atomic_t fscache_n_cookie_index;
extern atomic_t fscache_n_cookie_data;
extern atomic_t fscache_n_cookie_special;
extern atomic_t fscache_n_object_alloc;
extern atomic_t fscache_n_object_no_alloc;
extern atomic_t fscache_n_object_lookups;
extern atomic_t fscache_n_object_lookups_negative;
extern atomic_t fscache_n_object_lookups_positive;
extern atomic_t fscache_n_object_lookups_timed_out;
extern atomic_t fscache_n_object_created;
extern atomic_t fscache_n_object_avail;
extern atomic_t fscache_n_object_dead;
extern atomic_t fscache_n_checkaux_none;
extern atomic_t fscache_n_checkaux_okay;
extern atomic_t fscache_n_checkaux_update;
extern atomic_t fscache_n_checkaux_obsolete;
extern atomic_t fscache_n_cop_alloc_object;
extern atomic_t fscache_n_cop_lookup_object;
extern atomic_t fscache_n_cop_lookup_complete;
extern atomic_t fscache_n_cop_grab_object;
extern atomic_t fscache_n_cop_invalidate_object;
extern atomic_t fscache_n_cop_update_object;
extern atomic_t fscache_n_cop_drop_object;
extern atomic_t fscache_n_cop_put_object;
extern atomic_t fscache_n_cop_sync_cache;
extern atomic_t fscache_n_cop_attr_changed;
extern atomic_t fscache_n_cop_read_or_alloc_page;
extern atomic_t fscache_n_cop_read_or_alloc_pages;
extern atomic_t fscache_n_cop_allocate_page;
extern atomic_t fscache_n_cop_allocate_pages;
extern atomic_t fscache_n_cop_write_page;
extern atomic_t fscache_n_cop_uncache_page;
extern atomic_t fscache_n_cop_dissociate_pages;
extern atomic_t fscache_n_cache_no_space_reject;
extern atomic_t fscache_n_cache_stale_objects;
extern atomic_t fscache_n_cache_retired_objects;
extern atomic_t fscache_n_cache_culled_objects;
static inline void fscache_stat(atomic_t *stat)
{
atomic_inc(stat);
}
static inline void fscache_stat_d(atomic_t *stat)
{
atomic_dec(stat);
}
#define __fscache_stat(stat) (stat)
int fscache_stats_show(struct seq_file *m, void *v);
#else
#define __fscache_stat(stat) (NULL)
#define fscache_stat(stat) do {} while (0)
#define fscache_stat_d(stat) do {} while (0)
#endif
/*
* raise an event on an object
* - if the event is not masked for that object, then the object is
* queued for attention by the thread pool.
*/
static inline void fscache_raise_event(struct fscache_object *object,
unsigned event)
{
BUG_ON(event >= NR_FSCACHE_OBJECT_EVENTS);
#if 0
printk("*** fscache_raise_event(OBJ%d{%lx},%x)\n",
object->debug_id, object->event_mask, (1 << event));
#endif
if (!test_and_set_bit(event, &object->events) &&
test_bit(event, &object->event_mask))
fscache_enqueue_object(object);
}
/*
* get an extra reference to a netfs retrieval context
*/
static inline
void *fscache_get_context(struct fscache_cookie *cookie, void *context)
{
if (cookie->def->get_context)
cookie->def->get_context(cookie->netfs_data, context);
return context;
}
/*
* release a reference to a netfs retrieval context
*/
static inline
void fscache_put_context(struct fscache_cookie *cookie, void *context)
{
if (cookie->def->put_context)
cookie->def->put_context(cookie->netfs_data, context);
}
/*
* Update the auxiliary data on a cookie.
*/
static inline
void fscache_update_aux(struct fscache_cookie *cookie, const void *aux_data)
{
void *p;
if (!aux_data)
return;
if (cookie->aux_len <= sizeof(cookie->inline_aux))
p = cookie->inline_aux;
else
p = cookie->aux;
if (memcmp(p, aux_data, cookie->aux_len) != 0) {
memcpy(p, aux_data, cookie->aux_len);
set_bit(FSCACHE_COOKIE_AUX_UPDATED, &cookie->flags);
}
}
/*****************************************************************************/
/*
* debug tracing
*/
#define dbgprintk(FMT, ...) \
printk(KERN_DEBUG "[%-6.6s] "FMT"\n", current->comm, ##__VA_ARGS__)
#define kenter(FMT, ...) dbgprintk("==> %s("FMT")", __func__, ##__VA_ARGS__)
#define kleave(FMT, ...) dbgprintk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
#define kdebug(FMT, ...) dbgprintk(FMT, ##__VA_ARGS__)
#define kjournal(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
#ifdef __KDEBUG
#define _enter(FMT, ...) kenter(FMT, ##__VA_ARGS__)
#define _leave(FMT, ...) kleave(FMT, ##__VA_ARGS__)
#define _debug(FMT, ...) kdebug(FMT, ##__VA_ARGS__)
#elif defined(CONFIG_FSCACHE_DEBUG)
#define _enter(FMT, ...) \
do { \
if (__do_kdebug(ENTER)) \
kenter(FMT, ##__VA_ARGS__); \
} while (0)
#define _leave(FMT, ...) \
do { \
if (__do_kdebug(LEAVE)) \
kleave(FMT, ##__VA_ARGS__); \
} while (0)
#define _debug(FMT, ...) \
do { \
if (__do_kdebug(DEBUG)) \
kdebug(FMT, ##__VA_ARGS__); \
} while (0)
#else
#define _enter(FMT, ...) no_printk("==> %s("FMT")", __func__, ##__VA_ARGS__)
#define _leave(FMT, ...) no_printk("<== %s()"FMT"", __func__, ##__VA_ARGS__)
#define _debug(FMT, ...) no_printk(FMT, ##__VA_ARGS__)
#endif
/*
* determine whether a particular optional debugging point should be logged
* - we need to go through three steps to persuade cpp to correctly join the
* shorthand in FSCACHE_DEBUG_LEVEL with its prefix
*/
#define ____do_kdebug(LEVEL, POINT) \
unlikely((fscache_debug & \
(FSCACHE_POINT_##POINT << (FSCACHE_DEBUG_ ## LEVEL * 3))))
#define ___do_kdebug(LEVEL, POINT) \
____do_kdebug(LEVEL, POINT)
#define __do_kdebug(POINT) \
___do_kdebug(FSCACHE_DEBUG_LEVEL, POINT)
#define FSCACHE_DEBUG_CACHE 0
#define FSCACHE_DEBUG_COOKIE 1
#define FSCACHE_DEBUG_PAGE 2
#define FSCACHE_DEBUG_OPERATION 3
#define FSCACHE_POINT_ENTER 1
#define FSCACHE_POINT_LEAVE 2
#define FSCACHE_POINT_DEBUG 4
#ifndef FSCACHE_DEBUG_LEVEL
#define FSCACHE_DEBUG_LEVEL CACHE
#endif
/*
* assertions
*/
#if 1 /* defined(__KDEBUGALL) */
#define ASSERT(X) \
do { \
if (unlikely(!(X))) { \
pr_err("\n"); \
pr_err("Assertion failed\n"); \
BUG(); \
} \
} while (0)
#define ASSERTCMP(X, OP, Y) \
do { \
if (unlikely(!((X) OP (Y)))) { \
pr_err("\n"); \
pr_err("Assertion failed\n"); \
pr_err("%lx " #OP " %lx is false\n", \
(unsigned long)(X), (unsigned long)(Y)); \
BUG(); \
} \
} while (0)
#define ASSERTIF(C, X) \
do { \
if (unlikely((C) && !(X))) { \
pr_err("\n"); \
pr_err("Assertion failed\n"); \
BUG(); \
} \
} while (0)
#define ASSERTIFCMP(C, X, OP, Y) \
do { \
if (unlikely((C) && !((X) OP (Y)))) { \
pr_err("\n"); \
pr_err("Assertion failed\n"); \
pr_err("%lx " #OP " %lx is false\n", \
(unsigned long)(X), (unsigned long)(Y)); \
BUG(); \
} \
} while (0)
#else
#define ASSERT(X) do {} while (0)
#define ASSERTCMP(X, OP, Y) do {} while (0)
#define ASSERTIF(C, X) do {} while (0)
#define ASSERTIFCMP(C, X, OP, Y) do {} while (0)
#endif /* assert or not */
fs/fscache/io.c deleted 100644 → 0
View file @ 850cba06
// SPDX-License-Identifier: GPL-2.0-or-later
/* Cache data I/O routines
*
* Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#define FSCACHE_DEBUG_LEVEL PAGE
#include <linux/module.h>
#define FSCACHE_USE_NEW_IO_API
#include <linux/fscache-cache.h>
#include <linux/slab.h>
#include <linux/netfs.h>
#include "internal.h"
/*
* Start a cache read operation.
* - we return:
* -ENOMEM - out of memory, some pages may be being read
* -ERESTARTSYS - interrupted, some pages may be being read
* -ENOBUFS - no backing object or space available in which to cache any
* pages not being read
* -ENODATA - no data available in the backing object for some or all of
* the pages
* 0 - dispatched a read on all pages
*/
int __fscache_begin_read_operation(struct netfs_read_request *rreq,
struct fscache_cookie *cookie)
{
struct fscache_retrieval *op;
struct fscache_object *object;
bool wake_cookie = false;
int ret;
_enter("rr=%08x", rreq->debug_id);
fscache_stat(&fscache_n_retrievals);
if (hlist_empty(&cookie->backing_objects))
goto nobufs;
if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) {
_leave(" = -ENOBUFS [invalidating]");
return -ENOBUFS;
}
ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
if (fscache_wait_for_deferred_lookup(cookie) < 0)
return -ERESTARTSYS;
op = fscache_alloc_retrieval(cookie, NULL, NULL, NULL);
if (!op)
return -ENOMEM;
trace_fscache_page_op(cookie, NULL, &op->op, fscache_page_op_retr_multi);
spin_lock(&cookie->lock);
if (!fscache_cookie_enabled(cookie) ||
hlist_empty(&cookie->backing_objects))
goto nobufs_unlock;
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object, cookie_link);
__fscache_use_cookie(cookie);
atomic_inc(&object->n_reads);
__set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
if (fscache_submit_op(object, &op->op) < 0)
goto nobufs_unlock_dec;
spin_unlock(&cookie->lock);
fscache_stat(&fscache_n_retrieval_ops);
/* we wait for the operation to become active, and then process it
* *here*, in this thread, and not in the thread pool */
ret = fscache_wait_for_operation_activation(
object, &op->op,
__fscache_stat(&fscache_n_retrieval_op_waits),
__fscache_stat(&fscache_n_retrievals_object_dead));
if (ret < 0)
goto error;
/* ask the cache to honour the operation */
ret = object->cache->ops->begin_read_operation(rreq, op);
error:
if (ret == -ENOMEM)
fscache_stat(&fscache_n_retrievals_nomem);
else if (ret == -ERESTARTSYS)
fscache_stat(&fscache_n_retrievals_intr);
else if (ret == -ENODATA)
fscache_stat(&fscache_n_retrievals_nodata);
else if (ret < 0)
fscache_stat(&fscache_n_retrievals_nobufs);
else
fscache_stat(&fscache_n_retrievals_ok);
fscache_put_retrieval(op);
_leave(" = %d", ret);
return ret;
nobufs_unlock_dec:
atomic_dec(&object->n_reads);
wake_cookie = __fscache_unuse_cookie(cookie);
nobufs_unlock:
spin_unlock(&cookie->lock);
fscache_put_retrieval(op);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
nobufs:
fscache_stat(&fscache_n_retrievals_nobufs);
_leave(" = -ENOBUFS");
return -ENOBUFS;
}
EXPORT_SYMBOL(__fscache_begin_read_operation);
fs/fscache/main.c deleted 100644 → 0
View file @ 850cba06
// SPDX-License-Identifier: GPL-2.0-or-later
/* General filesystem local caching manager
*
* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#define FSCACHE_DEBUG_LEVEL CACHE
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/completion.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#define CREATE_TRACE_POINTS
#include "internal.h"
MODULE_DESCRIPTION("FS Cache Manager");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
unsigned fscache_defer_lookup = 1;
module_param_named(defer_lookup, fscache_defer_lookup, uint,
S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(fscache_defer_lookup,
"Defer cookie lookup to background thread");
unsigned fscache_defer_create = 1;
module_param_named(defer_create, fscache_defer_create, uint,
S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(fscache_defer_create,
"Defer cookie creation to background thread");
unsigned fscache_debug;
module_param_named(debug, fscache_debug, uint,
S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(fscache_debug,
"FS-Cache debugging mask");
struct kobject *fscache_root;
struct workqueue_struct *fscache_object_wq;
struct workqueue_struct *fscache_op_wq;
DEFINE_PER_CPU(wait_queue_head_t, fscache_object_cong_wait);
/* these values serve as lower bounds, will be adjusted in fscache_init() */
static unsigned fscache_object_max_active = 4;
static unsigned fscache_op_max_active = 2;
#ifdef CONFIG_SYSCTL
static struct ctl_table_header *fscache_sysctl_header;
static int fscache_max_active_sysctl(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos)
{
struct workqueue_struct **wqp = table->extra1;
unsigned int *datap = table->data;
int ret;
ret = proc_dointvec(table, write, buffer, lenp, ppos);
if (ret == 0)
workqueue_set_max_active(*wqp, *datap);
return ret;
}
static struct ctl_table fscache_sysctls[] = {
{
.procname = "object_max_active",
.data = &fscache_object_max_active,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = fscache_max_active_sysctl,
.extra1 = &fscache_object_wq,
},
{
.procname = "operation_max_active",
.data = &fscache_op_max_active,
.maxlen = sizeof(unsigned),
.mode = 0644,
.proc_handler = fscache_max_active_sysctl,
.extra1 = &fscache_op_wq,
},
{}
};
static struct ctl_table fscache_sysctls_root[] = {
{
.procname = "fscache",
.mode = 0555,
.child = fscache_sysctls,
},
{}
};
#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
*/
static int __init fscache_init(void)
{
unsigned int nr_cpus = num_possible_cpus();
unsigned int cpu;
int ret;
fscache_object_max_active =
clamp_val(nr_cpus,
fscache_object_max_active, WQ_UNBOUND_MAX_ACTIVE);
ret = -ENOMEM;
fscache_object_wq = alloc_workqueue("fscache_object", WQ_UNBOUND,
fscache_object_max_active);
if (!fscache_object_wq)
goto error_object_wq;
fscache_op_max_active =
clamp_val(fscache_object_max_active / 2,
fscache_op_max_active, WQ_UNBOUND_MAX_ACTIVE);
ret = -ENOMEM;
fscache_op_wq = alloc_workqueue("fscache_operation", WQ_UNBOUND,
fscache_op_max_active);
if (!fscache_op_wq)
goto error_op_wq;
for_each_possible_cpu(cpu)
init_waitqueue_head(&per_cpu(fscache_object_cong_wait, cpu));
ret = fscache_proc_init();
if (ret < 0)
goto error_proc;
#ifdef CONFIG_SYSCTL
ret = -ENOMEM;
fscache_sysctl_header = register_sysctl_table(fscache_sysctls_root);
if (!fscache_sysctl_header)
goto error_sysctl;
#endif
fscache_cookie_jar = kmem_cache_create("fscache_cookie_jar",
sizeof(struct fscache_cookie),
0, 0, NULL);
if (!fscache_cookie_jar) {
pr_notice("Failed to allocate a cookie jar\n");
ret = -ENOMEM;
goto error_cookie_jar;
}
fscache_root = kobject_create_and_add("fscache", kernel_kobj);
if (!fscache_root)
goto error_kobj;
pr_notice("Loaded\n");
return 0;
error_kobj:
kmem_cache_destroy(fscache_cookie_jar);
error_cookie_jar:
#ifdef CONFIG_SYSCTL
unregister_sysctl_table(fscache_sysctl_header);
error_sysctl:
#endif
fscache_proc_cleanup();
error_proc:
destroy_workqueue(fscache_op_wq);
error_op_wq:
destroy_workqueue(fscache_object_wq);
error_object_wq:
return ret;
}
fs_initcall(fscache_init);
/*
* clean up on module removal
*/
static void __exit fscache_exit(void)
{
_enter("");
kobject_put(fscache_root);
kmem_cache_destroy(fscache_cookie_jar);
#ifdef CONFIG_SYSCTL
unregister_sysctl_table(fscache_sysctl_header);
#endif
fscache_proc_cleanup();
destroy_workqueue(fscache_op_wq);
destroy_workqueue(fscache_object_wq);
pr_notice("Unloaded\n");
}
module_exit(fscache_exit);
fs/fscache/netfs.c deleted 100644 → 0
View file @ 850cba06
// SPDX-License-Identifier: GPL-2.0-or-later
/* FS-Cache netfs (client) registration
*
* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#define FSCACHE_DEBUG_LEVEL COOKIE
#include <linux/module.h>
#include <linux/slab.h>
#include "internal.h"
/*
* register a network filesystem for caching
*/
int __fscache_register_netfs(struct fscache_netfs *netfs)
{
struct fscache_cookie *candidate, *cookie;
_enter("{%s}", netfs->name);
/* allocate a cookie for the primary index */
candidate = fscache_alloc_cookie(&fscache_fsdef_index,
&fscache_fsdef_netfs_def,
netfs->name, strlen(netfs->name),
&netfs->version, sizeof(netfs->version),
netfs, 0);
if (!candidate) {
_leave(" = -ENOMEM");
return -ENOMEM;
}
candidate->flags = 1 << FSCACHE_COOKIE_ENABLED;
/* check the netfs type is not already present */
cookie = fscache_hash_cookie(candidate);
if (!cookie)
goto already_registered;
if (cookie != candidate) {
trace_fscache_cookie(candidate->debug_id, 1, fscache_cookie_discard);
fscache_free_cookie(candidate);
}
fscache_cookie_get(cookie->parent, fscache_cookie_get_register_netfs);
atomic_inc(&cookie->parent->n_children);
netfs->primary_index = cookie;
pr_notice("Netfs '%s' registered for caching\n", netfs->name);
trace_fscache_netfs(netfs);
_leave(" = 0");
return 0;
already_registered:
fscache_cookie_put(candidate, fscache_cookie_put_dup_netfs);
_leave(" = -EEXIST");
return -EEXIST;
}
EXPORT_SYMBOL(__fscache_register_netfs);
/*
* unregister a network filesystem from the cache
* - all cookies must have been released first
*/
void __fscache_unregister_netfs(struct fscache_netfs *netfs)
{
_enter("{%s.%u}", netfs->name, netfs->version);
fscache_relinquish_cookie(netfs->primary_index, NULL, false);
pr_notice("Netfs '%s' unregistered from caching\n", netfs->name);
_leave("");
}
EXPORT_SYMBOL(__fscache_unregister_netfs);
fs/fscache/object.c deleted 100644 → 0
View file @ 850cba06
// SPDX-License-Identifier: GPL-2.0-or-later
/* FS-Cache object state machine handler
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* See Documentation/filesystems/caching/object.rst for a description of the
* object state machine and the in-kernel representations.
*/
#define FSCACHE_DEBUG_LEVEL COOKIE
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/prefetch.h>
#include "internal.h"
static const struct fscache_state *fscache_abort_initialisation(struct fscache_object *, int);
static const struct fscache_state *fscache_kill_dependents(struct fscache_object *, int);
static const struct fscache_state *fscache_drop_object(struct fscache_object *, int);
static const struct fscache_state *fscache_initialise_object(struct fscache_object *, int);
static const struct fscache_state *fscache_invalidate_object(struct fscache_object *, int);
static const struct fscache_state *fscache_jumpstart_dependents(struct fscache_object *, int);
static const struct fscache_state *fscache_kill_object(struct fscache_object *, int);
static const struct fscache_state *fscache_lookup_failure(struct fscache_object *, int);
static const struct fscache_state *fscache_look_up_object(struct fscache_object *, int);
static const struct fscache_state *fscache_object_available(struct fscache_object *, int);
static const struct fscache_state *fscache_parent_ready(struct fscache_object *, int);
static const struct fscache_state *fscache_update_object(struct fscache_object *, int);
static const struct fscache_state *fscache_object_dead(struct fscache_object *, int);
#define __STATE_NAME(n) fscache_osm_##n
#define STATE(n) (&__STATE_NAME(n))
/*
* Define a work state. Work states are execution states. No event processing
* is performed by them. The function attached to a work state returns a
* pointer indicating the next state to which the state machine should
* transition. Returning NO_TRANSIT repeats the current state, but goes back
* to the scheduler first.
*/
#define WORK_STATE(n, sn, f) \
const struct fscache_state __STATE_NAME(n) = { \
.name = #n, \
.short_name = sn, \
.work = f \
}
/*
* Returns from work states.
*/
#define transit_to(state) ({ prefetch(&STATE(state)->work); STATE(state); })
#define NO_TRANSIT ((struct fscache_state *)NULL)
/*
* Define a wait state. Wait states are event processing states. No execution
* is performed by them. Wait states are just tables of "if event X occurs,
* clear it and transition to state Y". The dispatcher returns to the
* scheduler if none of the events in which the wait state has an interest are
* currently pending.
*/
#define WAIT_STATE(n, sn, ...) \
const struct fscache_state __STATE_NAME(n) = { \
.name = #n, \
.short_name = sn, \
.work = NULL, \
.transitions = { __VA_ARGS__, { 0, NULL } } \
}
#define TRANSIT_TO(state, emask) \
{ .events = (emask), .transit_to = STATE(state) }
/*
* The object state machine.
*/
static WORK_STATE(INIT_OBJECT, "INIT", fscache_initialise_object);
static WORK_STATE(PARENT_READY, "PRDY", fscache_parent_ready);
static WORK_STATE(ABORT_INIT, "ABRT", fscache_abort_initialisation);
static WORK_STATE(LOOK_UP_OBJECT, "LOOK", fscache_look_up_object);
static WORK_STATE(OBJECT_AVAILABLE, "AVBL", fscache_object_available);
static WORK_STATE(JUMPSTART_DEPS, "JUMP", fscache_jumpstart_dependents);
static WORK_STATE(INVALIDATE_OBJECT, "INVL", fscache_invalidate_object);
static WORK_STATE(UPDATE_OBJECT, "UPDT", fscache_update_object);
static WORK_STATE(LOOKUP_FAILURE, "LCFL", fscache_lookup_failure);
static WORK_STATE(KILL_OBJECT, "KILL", fscache_kill_object);
static WORK_STATE(KILL_DEPENDENTS, "KDEP", fscache_kill_dependents);
static WORK_STATE(DROP_OBJECT, "DROP", fscache_drop_object);
static WORK_STATE(OBJECT_DEAD, "DEAD", fscache_object_dead);
static WAIT_STATE(WAIT_FOR_INIT, "?INI",
TRANSIT_TO(INIT_OBJECT, 1 << FSCACHE_OBJECT_EV_NEW_CHILD));
static WAIT_STATE(WAIT_FOR_PARENT, "?PRN",
TRANSIT_TO(PARENT_READY, 1 << FSCACHE_OBJECT_EV_PARENT_READY));
static WAIT_STATE(WAIT_FOR_CMD, "?CMD",
TRANSIT_TO(INVALIDATE_OBJECT, 1 << FSCACHE_OBJECT_EV_INVALIDATE),
TRANSIT_TO(UPDATE_OBJECT, 1 << FSCACHE_OBJECT_EV_UPDATE),
TRANSIT_TO(JUMPSTART_DEPS, 1 << FSCACHE_OBJECT_EV_NEW_CHILD));
static WAIT_STATE(WAIT_FOR_CLEARANCE, "?CLR",
TRANSIT_TO(KILL_OBJECT, 1 << FSCACHE_OBJECT_EV_CLEARED));
/*
* Out-of-band event transition tables. These are for handling unexpected
* events, such as an I/O error. If an OOB event occurs, the state machine
* clears and disables the event and forces a transition to the nominated work
* state (acurrently executing work states will complete first).
*
* In such a situation, object->state remembers the state the machine should
* have been in/gone to and returning NO_TRANSIT returns to that.
*/
static const struct fscache_transition fscache_osm_init_oob[] = {
TRANSIT_TO(ABORT_INIT,
(1 << FSCACHE_OBJECT_EV_ERROR) |
(1 << FSCACHE_OBJECT_EV_KILL)),
{ 0, NULL }
};
static const struct fscache_transition fscache_osm_lookup_oob[] = {
TRANSIT_TO(LOOKUP_FAILURE,
(1 << FSCACHE_OBJECT_EV_ERROR) |
(1 << FSCACHE_OBJECT_EV_KILL)),
{ 0, NULL }
};
static const struct fscache_transition fscache_osm_run_oob[] = {
TRANSIT_TO(KILL_OBJECT,
(1 << FSCACHE_OBJECT_EV_ERROR) |
(1 << FSCACHE_OBJECT_EV_KILL)),
{ 0, NULL }
};
static int fscache_get_object(struct fscache_object *,
enum fscache_obj_ref_trace);
static void fscache_put_object(struct fscache_object *,
enum fscache_obj_ref_trace);
static bool fscache_enqueue_dependents(struct fscache_object *, int);
static void fscache_dequeue_object(struct fscache_object *);
static void fscache_update_aux_data(struct fscache_object *);
/*
* we need to notify the parent when an op completes that we had outstanding
* upon it
*/
static inline void fscache_done_parent_op(struct fscache_object *object)
{
struct fscache_object *parent = object->parent;
_enter("OBJ%x {OBJ%x,%x}",
object->debug_id, parent->debug_id, parent->n_ops);
spin_lock_nested(&parent->lock, 1);
parent->n_obj_ops--;
parent->n_ops--;
if (parent->n_ops == 0)
fscache_raise_event(parent, FSCACHE_OBJECT_EV_CLEARED);
spin_unlock(&parent->lock);
}
/*
* Object state machine dispatcher.
*/
static void fscache_object_sm_dispatcher(struct fscache_object *object)
{
const struct fscache_transition *t;
const struct fscache_state *state, *new_state;
unsigned long events, event_mask;
bool oob;
int event = -1;
ASSERT(object != NULL);
_enter("{OBJ%x,%s,%lx}",
object->debug_id, object->state->name, object->events);
event_mask = object->event_mask;
restart:
object->event_mask = 0; /* Mask normal event handling */
state = object->state;
restart_masked:
events = object->events;
/* Handle any out-of-band events (typically an error) */
if (events & object->oob_event_mask) {
_debug("{OBJ%x} oob %lx",
object->debug_id, events & object->oob_event_mask);
oob = true;
for (t = object->oob_table; t->events; t++) {
if (events & t->events) {
state = t->transit_to;
ASSERT(state->work != NULL);
event = fls(events & t->events) - 1;
__clear_bit(event, &object->oob_event_mask);
clear_bit(event, &object->events);
goto execute_work_state;
}
}
}
oob = false;
/* Wait states are just transition tables */
if (!state->work) {
if (events & event_mask) {
for (t = state->transitions; t->events; t++) {
if (events & t->events) {
new_state = t->transit_to;
event = fls(events & t->events) - 1;
trace_fscache_osm(object, state,
true, false, event);
clear_bit(event, &object->events);
_debug("{OBJ%x} ev %d: %s -> %s",
object->debug_id, event,
state->name, new_state->name);
object->state = state = new_state;
goto execute_work_state;
}
}
/* The event mask didn't include all the tabled bits */
BUG();
}
/* Randomly woke up */
goto unmask_events;
}
execute_work_state:
_debug("{OBJ%x} exec %s", object->debug_id, state->name);
trace_fscache_osm(object, state, false, oob, event);
new_state = state->work(object, event);
event = -1;
if (new_state == NO_TRANSIT) {
_debug("{OBJ%x} %s notrans", object->debug_id, state->name);
if (unlikely(state == STATE(OBJECT_DEAD))) {
_leave(" [dead]");
return;
}
fscache_enqueue_object(object);
event_mask = object->oob_event_mask;
goto unmask_events;
}
_debug("{OBJ%x} %s -> %s",
object->debug_id, state->name, new_state->name);
object->state = state = new_state;
if (state->work) {
if (unlikely(state == STATE(OBJECT_DEAD))) {
_leave(" [dead]");
return;
}
goto restart_masked;
}
/* Transited to wait state */
event_mask = object->oob_event_mask;
for (t = state->transitions; t->events; t++)
event_mask |= t->events;
unmask_events:
object->event_mask = event_mask;
smp_mb();
events = object->events;
if (events & event_mask)
goto restart;
_leave(" [msk %lx]", event_mask);
}
/*
* execute an object
*/
static void fscache_object_work_func(struct work_struct *work)
{
struct fscache_object *object =
container_of(work, struct fscache_object, work);
_enter("{OBJ%x}", object->debug_id);
fscache_object_sm_dispatcher(object);
fscache_put_object(object, fscache_obj_put_work);
}
/**
* fscache_object_init - Initialise a cache object description
* @object: Object description
* @cookie: Cookie object will be attached to
* @cache: Cache in which backing object will be found
*
* Initialise a cache object description to its basic values.
*
* See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
void fscache_object_init(struct fscache_object *object,
struct fscache_cookie *cookie,
struct fscache_cache *cache)
{
const struct fscache_transition *t;
atomic_inc(&cache->object_count);
object->state = STATE(WAIT_FOR_INIT);
object->oob_table = fscache_osm_init_oob;
object->flags = 1 << FSCACHE_OBJECT_IS_LIVE;
spin_lock_init(&object->lock);
INIT_LIST_HEAD(&object->cache_link);
INIT_HLIST_NODE(&object->cookie_link);
INIT_WORK(&object->work, fscache_object_work_func);
INIT_LIST_HEAD(&object->dependents);
INIT_LIST_HEAD(&object->dep_link);
INIT_LIST_HEAD(&object->pending_ops);
object->n_children = 0;
object->n_ops = object->n_in_progress = object->n_exclusive = 0;
object->events = 0;
object->store_limit = 0;
object->store_limit_l = 0;
object->cache = cache;
object->cookie = cookie;
fscache_cookie_get(cookie, fscache_cookie_get_attach_object);
object->parent = NULL;
#ifdef CONFIG_FSCACHE_OBJECT_LIST
RB_CLEAR_NODE(&object->objlist_link);
#endif
object->oob_event_mask = 0;
for (t = object->oob_table; t->events; t++)
object->oob_event_mask |= t->events;
object->event_mask = object->oob_event_mask;
for (t = object->state->transitions; t->events; t++)
object->event_mask |= t->events;
}
EXPORT_SYMBOL(fscache_object_init);
/*
* Mark the object as no longer being live, making sure that we synchronise
* against op submission.
*/
static inline void fscache_mark_object_dead(struct fscache_object *object)
{
spin_lock(&object->lock);
clear_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
spin_unlock(&object->lock);
}
/*
* Abort object initialisation before we start it.
*/
static const struct fscache_state *fscache_abort_initialisation(struct fscache_object *object,
int event)
{
_enter("{OBJ%x},%d", object->debug_id, event);
object->oob_event_mask = 0;
fscache_dequeue_object(object);
return transit_to(KILL_OBJECT);
}
/*
* initialise an object
* - check the specified object's parent to see if we can make use of it
* immediately to do a creation
* - we may need to start the process of creating a parent and we need to wait
* for the parent's lookup and creation to complete if it's not there yet
*/
static const struct fscache_state *fscache_initialise_object(struct fscache_object *object,
int event)
{
struct fscache_object *parent;
bool success;
_enter("{OBJ%x},%d", object->debug_id, event);
ASSERT(list_empty(&object->dep_link));
parent = object->parent;
if (!parent) {
_leave(" [no parent]");
return transit_to(DROP_OBJECT);
}
_debug("parent: %s of:%lx", parent->state->name, parent->flags);
if (fscache_object_is_dying(parent)) {
_leave(" [bad parent]");
return transit_to(DROP_OBJECT);
}
if (fscache_object_is_available(parent)) {
_leave(" [ready]");
return transit_to(PARENT_READY);
}
_debug("wait");
spin_lock(&parent->lock);
fscache_stat(&fscache_n_cop_grab_object);
success = false;
if (fscache_object_is_live(parent) &&
object->cache->ops->grab_object(object, fscache_obj_get_add_to_deps)) {
list_add(&object->dep_link, &parent->dependents);
success = true;
}
fscache_stat_d(&fscache_n_cop_grab_object);
spin_unlock(&parent->lock);
if (!success) {
_leave(" [grab failed]");
return transit_to(DROP_OBJECT);
}
/* fscache_acquire_non_index_cookie() uses this
* to wake the chain up */
fscache_raise_event(parent, FSCACHE_OBJECT_EV_NEW_CHILD);
_leave(" [wait]");
return transit_to(WAIT_FOR_PARENT);
}
/*
* Once the parent object is ready, we should kick off our lookup op.
*/
static const struct fscache_state *fscache_parent_ready(struct fscache_object *object,
int event)
{
struct fscache_object *parent = object->parent;
_enter("{OBJ%x},%d", object->debug_id, event);
ASSERT(parent != NULL);
spin_lock(&parent->lock);
parent->n_ops++;
parent->n_obj_ops++;
spin_unlock(&parent->lock);
_leave("");
return transit_to(LOOK_UP_OBJECT);
}
/*
* look an object up in the cache from which it was allocated
* - we hold an "access lock" on the parent object, so the parent object cannot
* be withdrawn by either party till we've finished
*/
static const struct fscache_state *fscache_look_up_object(struct fscache_object *object,
int event)
{
struct fscache_cookie *cookie = object->cookie;
struct fscache_object *parent = object->parent;
int ret;
_enter("{OBJ%x},%d", object->debug_id, event);
object->oob_table = fscache_osm_lookup_oob;
ASSERT(parent != NULL);
ASSERTCMP(parent->n_ops, >, 0);
ASSERTCMP(parent->n_obj_ops, >, 0);
/* make sure the parent is still available */
ASSERT(fscache_object_is_available(parent));
if (fscache_object_is_dying(parent) ||
test_bit(FSCACHE_IOERROR, &object->cache->flags) ||
!fscache_use_cookie(object)) {
_leave(" [unavailable]");
return transit_to(LOOKUP_FAILURE);
}
_debug("LOOKUP \"%s\" in \"%s\"",
cookie->def->name, object->cache->tag->name);
fscache_stat(&fscache_n_object_lookups);
fscache_stat(&fscache_n_cop_lookup_object);
ret = object->cache->ops->lookup_object(object);
fscache_stat_d(&fscache_n_cop_lookup_object);
fscache_unuse_cookie(object);
if (ret == -ETIMEDOUT) {
/* probably stuck behind another object, so move this one to
* the back of the queue */
fscache_stat(&fscache_n_object_lookups_timed_out);
_leave(" [timeout]");
return NO_TRANSIT;
}
if (ret < 0) {
_leave(" [error]");
return transit_to(LOOKUP_FAILURE);
}
_leave(" [ok]");
return transit_to(OBJECT_AVAILABLE);
}
/**
* fscache_object_lookup_negative - Note negative cookie lookup
* @object: Object pointing to cookie to mark
*
* Note negative lookup, permitting those waiting to read data from an already
* existing backing object to continue as there's no data for them to read.
*/
void fscache_object_lookup_negative(struct fscache_object *object)
{
struct fscache_cookie *cookie = object->cookie;
_enter("{OBJ%x,%s}", object->debug_id, object->state->name);
if (!test_and_set_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)) {
fscache_stat(&fscache_n_object_lookups_negative);
/* Allow write requests to begin stacking up and read requests to begin
* returning ENODATA.
*/
set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
clear_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
clear_bit_unlock(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags);
wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP);
}
_leave("");
}
EXPORT_SYMBOL(fscache_object_lookup_negative);
/**
* fscache_obtained_object - Note successful object lookup or creation
* @object: Object pointing to cookie to mark
*
* Note successful lookup and/or creation, permitting those waiting to write
* data to a backing object to continue.
*
* Note that after calling this, an object's cookie may be relinquished by the
* netfs, and so must be accessed with object lock held.
*/
void fscache_obtained_object(struct fscache_object *object)
{
struct fscache_cookie *cookie = object->cookie;
_enter("{OBJ%x,%s}", object->debug_id, object->state->name);
/* if we were still looking up, then we must have a positive lookup
* result, in which case there may be data available */
if (!test_and_set_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags)) {
fscache_stat(&fscache_n_object_lookups_positive);
/* We do (presumably) have data */
clear_bit_unlock(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
clear_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
/* Allow write requests to begin stacking up and read requests
* to begin shovelling data.
*/
clear_bit_unlock(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags);
wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP);
} else {
fscache_stat(&fscache_n_object_created);
}
set_bit(FSCACHE_OBJECT_IS_AVAILABLE, &object->flags);
_leave("");
}
EXPORT_SYMBOL(fscache_obtained_object);
/*
* handle an object that has just become available
*/
static const struct fscache_state *fscache_object_available(struct fscache_object *object,
int event)
{
_enter("{OBJ%x},%d", object->debug_id, event);
object->oob_table = fscache_osm_run_oob;
spin_lock(&object->lock);
fscache_done_parent_op(object);
if (object->n_in_progress == 0) {
if (object->n_ops > 0) {
ASSERTCMP(object->n_ops, >=, object->n_obj_ops);
fscache_start_operations(object);
} else {
ASSERT(list_empty(&object->pending_ops));
}
}
spin_unlock(&object->lock);
fscache_stat(&fscache_n_cop_lookup_complete);
object->cache->ops->lookup_complete(object);
fscache_stat_d(&fscache_n_cop_lookup_complete);
fscache_stat(&fscache_n_object_avail);
_leave("");
return transit_to(JUMPSTART_DEPS);
}
/*
* Wake up this object's dependent objects now that we've become available.
*/
static const struct fscache_state *fscache_jumpstart_dependents(struct fscache_object *object,
int event)
{
_enter("{OBJ%x},%d", object->debug_id, event);
if (!fscache_enqueue_dependents(object, FSCACHE_OBJECT_EV_PARENT_READY))
return NO_TRANSIT; /* Not finished; requeue */
return transit_to(WAIT_FOR_CMD);
}
/*
* Handle lookup or creation failute.
*/
static const struct fscache_state *fscache_lookup_failure(struct fscache_object *object,
int event)
{
struct fscache_cookie *cookie;
_enter("{OBJ%x},%d", object->debug_id, event);
object->oob_event_mask = 0;
fscache_stat(&fscache_n_cop_lookup_complete);
object->cache->ops->lookup_complete(object);
fscache_stat_d(&fscache_n_cop_lookup_complete);
set_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->flags);
cookie = object->cookie;
set_bit(FSCACHE_COOKIE_UNAVAILABLE, &cookie->flags);
if (test_and_clear_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags))
wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP);
fscache_done_parent_op(object);
return transit_to(KILL_OBJECT);
}
/*
* Wait for completion of all active operations on this object and the death of
* all child objects of this object.
*/
static const struct fscache_state *fscache_kill_object(struct fscache_object *object,
int event)
{
_enter("{OBJ%x,%d,%d},%d",
object->debug_id, object->n_ops, object->n_children, event);
fscache_mark_object_dead(object);
object->oob_event_mask = 0;
if (test_bit(FSCACHE_OBJECT_RETIRED, &object->flags)) {
/* Reject any new read/write ops and abort any that are pending. */
clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
fscache_cancel_all_ops(object);
}
if (list_empty(&object->dependents) &&
object->n_ops == 0 &&
object->n_children == 0)
return transit_to(DROP_OBJECT);
if (object->n_in_progress == 0) {
spin_lock(&object->lock);
if (object->n_ops > 0 && object->n_in_progress == 0)
fscache_start_operations(object);
spin_unlock(&object->lock);
}
if (!list_empty(&object->dependents))
return transit_to(KILL_DEPENDENTS);
return transit_to(WAIT_FOR_CLEARANCE);
}
/*
* Kill dependent objects.
*/
static const struct fscache_state *fscache_kill_dependents(struct fscache_object *object,
int event)
{
_enter("{OBJ%x},%d", object->debug_id, event);
if (!fscache_enqueue_dependents(object, FSCACHE_OBJECT_EV_KILL))
return NO_TRANSIT; /* Not finished */
return transit_to(WAIT_FOR_CLEARANCE);
}
/*
* Drop an object's attachments
*/
static const struct fscache_state *fscache_drop_object(struct fscache_object *object,
int event)
{
struct fscache_object *parent = object->parent;
struct fscache_cookie *cookie = object->cookie;
struct fscache_cache *cache = object->cache;
bool awaken = false;
_enter("{OBJ%x,%d},%d", object->debug_id, object->n_children, event);
ASSERT(cookie != NULL);
ASSERT(!hlist_unhashed(&object->cookie_link));
if (test_bit(FSCACHE_COOKIE_AUX_UPDATED, &cookie->flags)) {
_debug("final update");
fscache_update_aux_data(object);
}
/* Make sure the cookie no longer points here and that the netfs isn't
* waiting for us.
*/
spin_lock(&cookie->lock);
hlist_del_init(&object->cookie_link);
if (hlist_empty(&cookie->backing_objects) &&
test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags))
awaken = true;
spin_unlock(&cookie->lock);
if (awaken)
wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING);
if (test_and_clear_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags))
wake_up_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP);
/* Prevent a race with our last child, which has to signal EV_CLEARED
* before dropping our spinlock.
*/
spin_lock(&object->lock);
spin_unlock(&object->lock);
/* Discard from the cache's collection of objects */
spin_lock(&cache->object_list_lock);
list_del_init(&object->cache_link);
spin_unlock(&cache->object_list_lock);
fscache_stat(&fscache_n_cop_drop_object);
cache->ops->drop_object(object);
fscache_stat_d(&fscache_n_cop_drop_object);
/* The parent object wants to know when all it dependents have gone */
if (parent) {
_debug("release parent OBJ%x {%d}",
parent->debug_id, parent->n_children);
spin_lock(&parent->lock);
parent->n_children--;
if (parent->n_children == 0)
fscache_raise_event(parent, FSCACHE_OBJECT_EV_CLEARED);
spin_unlock(&parent->lock);
object->parent = NULL;
}
/* this just shifts the object release to the work processor */
fscache_put_object(object, fscache_obj_put_drop_obj);
fscache_stat(&fscache_n_object_dead);
_leave("");
return transit_to(OBJECT_DEAD);
}
/*
* get a ref on an object
*/
static int fscache_get_object(struct fscache_object *object,
enum fscache_obj_ref_trace why)
{
int ret;
fscache_stat(&fscache_n_cop_grab_object);
ret = object->cache->ops->grab_object(object, why) ? 0 : -EAGAIN;
fscache_stat_d(&fscache_n_cop_grab_object);
return ret;
}
/*
* Discard a ref on an object
*/
static void fscache_put_object(struct fscache_object *object,
enum fscache_obj_ref_trace why)
{
fscache_stat(&fscache_n_cop_put_object);
object->cache->ops->put_object(object, why);
fscache_stat_d(&fscache_n_cop_put_object);
}
/**
* 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 *object)
{
/* We can get rid of the cookie now */
fscache_cookie_put(object->cookie, fscache_cookie_put_object);
object->cookie = NULL;
}
EXPORT_SYMBOL(fscache_object_destroy);
/*
* enqueue an object for metadata-type processing
*/
void fscache_enqueue_object(struct fscache_object *object)
{
_enter("{OBJ%x}", object->debug_id);
if (fscache_get_object(object, fscache_obj_get_queue) >= 0) {
wait_queue_head_t *cong_wq =
&get_cpu_var(fscache_object_cong_wait);
if (queue_work(fscache_object_wq, &object->work)) {
if (fscache_object_congested())
wake_up(cong_wq);
} else
fscache_put_object(object, fscache_obj_put_queue);
put_cpu_var(fscache_object_cong_wait);
}
}
/**
* fscache_object_sleep_till_congested - Sleep until object wq is congested
* @timeoutp: Scheduler sleep timeout
*
* Allow an object handler to sleep until the object workqueue is congested.
*
* The caller must set up a wake up event before calling this and must have set
* the appropriate sleep mode (such as TASK_UNINTERRUPTIBLE) and tested its own
* condition before calling this function as no test is made here.
*
* %true is returned if the object wq is congested, %false otherwise.
*/
bool fscache_object_sleep_till_congested(signed long *timeoutp)
{
wait_queue_head_t *cong_wq = this_cpu_ptr(&fscache_object_cong_wait);
DEFINE_WAIT(wait);
if (fscache_object_congested())
return true;
add_wait_queue_exclusive(cong_wq, &wait);
if (!fscache_object_congested())
*timeoutp = schedule_timeout(*timeoutp);
finish_wait(cong_wq, &wait);
return fscache_object_congested();
}
EXPORT_SYMBOL_GPL(fscache_object_sleep_till_congested);
/*
* Enqueue the dependents of an object for metadata-type processing.
*
* If we don't manage to finish the list before the scheduler wants to run
* again then return false immediately. We return true if the list was
* cleared.
*/
static bool fscache_enqueue_dependents(struct fscache_object *object, int event)
{
struct fscache_object *dep;
bool ret = true;
_enter("{OBJ%x}", object->debug_id);
if (list_empty(&object->dependents))
return true;
spin_lock(&object->lock);
while (!list_empty(&object->dependents)) {
dep = list_entry(object->dependents.next,
struct fscache_object, dep_link);
list_del_init(&dep->dep_link);
fscache_raise_event(dep, event);
fscache_put_object(dep, fscache_obj_put_enq_dep);
if (!list_empty(&object->dependents) && need_resched()) {
ret = false;
break;
}
}
spin_unlock(&object->lock);
return ret;
}
/*
* remove an object from whatever queue it's waiting on
*/
static void fscache_dequeue_object(struct fscache_object *object)
{
_enter("{OBJ%x}", object->debug_id);
if (!list_empty(&object->dep_link)) {
spin_lock(&object->parent->lock);
list_del_init(&object->dep_link);
spin_unlock(&object->parent->lock);
}
_leave("");
}
/**
* fscache_check_aux - Ask the netfs whether an object on disk is still valid
* @object: The object to ask about
* @data: The auxiliary data for the object
* @datalen: The size of the auxiliary data
* @object_size: The size of the object according to the server.
*
* This function consults the netfs about the coherency state of an object.
* The caller must be holding a ref on cookie->n_active (held by
* fscache_look_up_object() on behalf of the cache backend during object lookup
* and creation).
*/
enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
const void *data, uint16_t datalen,
loff_t object_size)
{
enum fscache_checkaux result;
if (!object->cookie->def->check_aux) {
fscache_stat(&fscache_n_checkaux_none);
return FSCACHE_CHECKAUX_OKAY;
}
result = object->cookie->def->check_aux(object->cookie->netfs_data,
data, datalen, object_size);
switch (result) {
/* entry okay as is */
case FSCACHE_CHECKAUX_OKAY:
fscache_stat(&fscache_n_checkaux_okay);
break;
/* entry requires update */
case FSCACHE_CHECKAUX_NEEDS_UPDATE:
fscache_stat(&fscache_n_checkaux_update);
break;
/* entry requires deletion */
case FSCACHE_CHECKAUX_OBSOLETE:
fscache_stat(&fscache_n_checkaux_obsolete);
break;
default:
BUG();
}
return result;
}
EXPORT_SYMBOL(fscache_check_aux);
/*
* Asynchronously invalidate an object.
*/
static const struct fscache_state *_fscache_invalidate_object(struct fscache_object *object,
int event)
{
struct fscache_operation *op;
struct fscache_cookie *cookie = object->cookie;
_enter("{OBJ%x},%d", object->debug_id, event);
/* We're going to need the cookie. If the cookie is not available then
* retire the object instead.
*/
if (!fscache_use_cookie(object)) {
ASSERT(radix_tree_empty(&object->cookie->stores));
set_bit(FSCACHE_OBJECT_RETIRED, &object->flags);
_leave(" [no cookie]");
return transit_to(KILL_OBJECT);
}
/* Reject any new read/write ops and abort any that are pending. */
fscache_invalidate_writes(cookie);
clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
fscache_cancel_all_ops(object);
/* Now we have to wait for in-progress reads and writes */
op = kzalloc(sizeof(*op), GFP_KERNEL);
if (!op)
goto nomem;
fscache_operation_init(cookie, op, object->cache->ops->invalidate_object,
NULL, NULL);
op->flags = FSCACHE_OP_ASYNC |
(1 << FSCACHE_OP_EXCLUSIVE) |
(1 << FSCACHE_OP_UNUSE_COOKIE);
trace_fscache_page_op(cookie, NULL, op, fscache_page_op_invalidate);
spin_lock(&cookie->lock);
if (fscache_submit_exclusive_op(object, op) < 0)
goto submit_op_failed;
spin_unlock(&cookie->lock);
fscache_put_operation(op);
/* Once we've completed the invalidation, we know there will be no data
* stored in the cache and thus we can reinstate the data-check-skip
* optimisation.
*/
set_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
/* We can allow read and write requests to come in once again. They'll
* queue up behind our exclusive invalidation operation.
*/
if (test_and_clear_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags))
wake_up_bit(&cookie->flags, FSCACHE_COOKIE_INVALIDATING);
_leave(" [ok]");
return transit_to(UPDATE_OBJECT);
nomem:
fscache_mark_object_dead(object);
fscache_unuse_cookie(object);
_leave(" [ENOMEM]");
return transit_to(KILL_OBJECT);
submit_op_failed:
fscache_mark_object_dead(object);
spin_unlock(&cookie->lock);
fscache_unuse_cookie(object);
kfree(op);
_leave(" [EIO]");
return transit_to(KILL_OBJECT);
}
static const struct fscache_state *fscache_invalidate_object(struct fscache_object *object,
int event)
{
const struct fscache_state *s;
fscache_stat(&fscache_n_invalidates_run);
fscache_stat(&fscache_n_cop_invalidate_object);
s = _fscache_invalidate_object(object, event);
fscache_stat_d(&fscache_n_cop_invalidate_object);
return s;
}
/*
* Update auxiliary data.
*/
static void fscache_update_aux_data(struct fscache_object *object)
{
fscache_stat(&fscache_n_updates_run);
fscache_stat(&fscache_n_cop_update_object);
object->cache->ops->update_object(object);
fscache_stat_d(&fscache_n_cop_update_object);
}
/*
* Asynchronously update an object.
*/
static const struct fscache_state *fscache_update_object(struct fscache_object *object,
int event)
{
_enter("{OBJ%x},%d", object->debug_id, event);
fscache_update_aux_data(object);
_leave("");
return transit_to(WAIT_FOR_CMD);
}
/**
* fscache_object_retrying_stale - Note retrying stale object
* @object: The object that will be retried
*
* Note that an object lookup found an on-disk object that was adjudged to be
* stale and has been deleted. The lookup will be retried.
*/
void fscache_object_retrying_stale(struct fscache_object *object)
{
fscache_stat(&fscache_n_cache_no_space_reject);
}
EXPORT_SYMBOL(fscache_object_retrying_stale);
/**
* fscache_object_mark_killed - Note that an object was killed
* @object: The object that was culled
* @why: The reason the object was killed.
*
* Note that an object was killed. Returns true if the object was
* already marked killed, false if it wasn't.
*/
void fscache_object_mark_killed(struct fscache_object *object,
enum fscache_why_object_killed why)
{
if (test_and_set_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->flags)) {
pr_err("Error: Object already killed by cache [%s]\n",
object->cache->identifier);
return;
}
switch (why) {
case FSCACHE_OBJECT_NO_SPACE:
fscache_stat(&fscache_n_cache_no_space_reject);
break;
case FSCACHE_OBJECT_IS_STALE:
fscache_stat(&fscache_n_cache_stale_objects);
break;
case FSCACHE_OBJECT_WAS_RETIRED:
fscache_stat(&fscache_n_cache_retired_objects);
break;
case FSCACHE_OBJECT_WAS_CULLED:
fscache_stat(&fscache_n_cache_culled_objects);
break;
}
}
EXPORT_SYMBOL(fscache_object_mark_killed);
/*
* The object is dead. We can get here if an object gets queued by an event
* that would lead to its death (such as EV_KILL) when the dispatcher is
* already running (and so can be requeued) but hasn't yet cleared the event
* mask.
*/
static const struct fscache_state *fscache_object_dead(struct fscache_object *object,
int event)
{
if (!test_and_set_bit(FSCACHE_OBJECT_RUN_AFTER_DEAD,
&object->flags))
return NO_TRANSIT;
WARN(true, "FS-Cache object redispatched after death");
return NO_TRANSIT;
}
fs/fscache/operation.c deleted 100644 → 0
View file @ 850cba06
// SPDX-License-Identifier: GPL-2.0-or-later
/* FS-Cache worker operation management routines
*
* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* See Documentation/filesystems/caching/operations.rst
*/
#define FSCACHE_DEBUG_LEVEL OPERATION
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include "internal.h"
atomic_t fscache_op_debug_id;
EXPORT_SYMBOL(fscache_op_debug_id);
static void fscache_operation_dummy_cancel(struct fscache_operation *op)
{
}
/**
* fscache_operation_init - Do basic initialisation of an operation
* @cookie: The cookie to operate on
* @op: The operation to initialise
* @processor: The function to perform the operation
* @cancel: A function to handle operation cancellation
* @release: The release function to assign
*
* Do basic initialisation of an operation. The caller must still set flags,
* object and processor if needed.
*/
void fscache_operation_init(struct fscache_cookie *cookie,
struct fscache_operation *op,
fscache_operation_processor_t processor,
fscache_operation_cancel_t cancel,
fscache_operation_release_t release)
{
INIT_WORK(&op->work, fscache_op_work_func);
atomic_set(&op->usage, 1);
op->state = FSCACHE_OP_ST_INITIALISED;
op->debug_id = atomic_inc_return(&fscache_op_debug_id);
op->processor = processor;
op->cancel = cancel ?: fscache_operation_dummy_cancel;
op->release = release;
INIT_LIST_HEAD(&op->pend_link);
fscache_stat(&fscache_n_op_initialised);
trace_fscache_op(cookie, op, fscache_op_init);
}
EXPORT_SYMBOL(fscache_operation_init);
/**
* fscache_enqueue_operation - Enqueue an operation for processing
* @op: The operation to enqueue
*
* Enqueue an operation for processing by the FS-Cache thread pool.
*
* This will get its own ref on the object.
*/
void fscache_enqueue_operation(struct fscache_operation *op)
{
struct fscache_cookie *cookie = op->object->cookie;
_enter("{OBJ%x OP%x,%u}",
op->object->debug_id, op->debug_id, atomic_read(&op->usage));
ASSERT(list_empty(&op->pend_link));
ASSERT(op->processor != NULL);
ASSERT(fscache_object_is_available(op->object));
ASSERTCMP(atomic_read(&op->usage), >, 0);
ASSERTIFCMP(op->state != FSCACHE_OP_ST_IN_PROGRESS,
op->state, ==, FSCACHE_OP_ST_CANCELLED);
fscache_stat(&fscache_n_op_enqueue);
switch (op->flags & FSCACHE_OP_TYPE) {
case FSCACHE_OP_ASYNC:
trace_fscache_op(cookie, op, fscache_op_enqueue_async);
_debug("queue async");
atomic_inc(&op->usage);
if (!queue_work(fscache_op_wq, &op->work))
fscache_put_operation(op);
break;
case FSCACHE_OP_MYTHREAD:
trace_fscache_op(cookie, op, fscache_op_enqueue_mythread);
_debug("queue for caller's attention");
break;
default:
pr_err("Unexpected op type %lx", op->flags);
BUG();
break;
}
}
EXPORT_SYMBOL(fscache_enqueue_operation);
/*
* start an op running
*/
static void fscache_run_op(struct fscache_object *object,
struct fscache_operation *op)
{
ASSERTCMP(op->state, ==, FSCACHE_OP_ST_PENDING);
op->state = FSCACHE_OP_ST_IN_PROGRESS;
object->n_in_progress++;
if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
if (op->processor)
fscache_enqueue_operation(op);
else
trace_fscache_op(object->cookie, op, fscache_op_run);
fscache_stat(&fscache_n_op_run);
}
/*
* report an unexpected submission
*/
static void fscache_report_unexpected_submission(struct fscache_object *object,
struct fscache_operation *op,
const struct fscache_state *ostate)
{
static bool once_only;
struct fscache_operation *p;
unsigned n;
if (once_only)
return;
once_only = true;
kdebug("unexpected submission OP%x [OBJ%x %s]",
op->debug_id, object->debug_id, object->state->name);
kdebug("objstate=%s [%s]", object->state->name, ostate->name);
kdebug("objflags=%lx", object->flags);
kdebug("objevent=%lx [%lx]", object->events, object->event_mask);
kdebug("ops=%u inp=%u exc=%u",
object->n_ops, object->n_in_progress, object->n_exclusive);
if (!list_empty(&object->pending_ops)) {
n = 0;
list_for_each_entry(p, &object->pending_ops, pend_link) {
ASSERTCMP(p->object, ==, object);
kdebug("%p %p", op->processor, op->release);
n++;
}
kdebug("n=%u", n);
}
dump_stack();
}
/*
* submit an exclusive operation for an object
* - other ops are excluded from running simultaneously with this one
* - this gets any extra refs it needs on an op
*/
int fscache_submit_exclusive_op(struct fscache_object *object,
struct fscache_operation *op)
{
const struct fscache_state *ostate;
unsigned long flags;
int ret;
_enter("{OBJ%x OP%x},", object->debug_id, op->debug_id);
trace_fscache_op(object->cookie, op, fscache_op_submit_ex);
ASSERTCMP(op->state, ==, FSCACHE_OP_ST_INITIALISED);
ASSERTCMP(atomic_read(&op->usage), >, 0);
spin_lock(&object->lock);
ASSERTCMP(object->n_ops, >=, object->n_in_progress);
ASSERTCMP(object->n_ops, >=, object->n_exclusive);
ASSERT(list_empty(&op->pend_link));
ostate = object->state;
smp_rmb();
op->state = FSCACHE_OP_ST_PENDING;
flags = READ_ONCE(object->flags);
if (unlikely(!(flags & BIT(FSCACHE_OBJECT_IS_LIVE)))) {
fscache_stat(&fscache_n_op_rejected);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
} else if (unlikely(fscache_cache_is_broken(object))) {
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -EIO;
} else if (flags & BIT(FSCACHE_OBJECT_IS_AVAILABLE)) {
op->object = object;
object->n_ops++;
object->n_exclusive++; /* reads and writes must wait */
if (object->n_in_progress > 0) {
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
} else if (!list_empty(&object->pending_ops)) {
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
fscache_start_operations(object);
} else {
ASSERTCMP(object->n_in_progress, ==, 0);
fscache_run_op(object, op);
}
/* need to issue a new write op after this */
clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
ret = 0;
} else if (flags & BIT(FSCACHE_OBJECT_IS_LOOKED_UP)) {
op->object = object;
object->n_ops++;
object->n_exclusive++; /* reads and writes must wait */
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
ret = 0;
} else if (flags & BIT(FSCACHE_OBJECT_KILLED_BY_CACHE)) {
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
} else {
fscache_report_unexpected_submission(object, op, ostate);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
}
spin_unlock(&object->lock);
return ret;
}
/*
* submit an operation for an object
* - objects may be submitted only in the following states:
* - during object creation (write ops may be submitted)
* - whilst the object is active
* - after an I/O error incurred in one of the two above states (op rejected)
* - this gets any extra refs it needs on an op
*/
int fscache_submit_op(struct fscache_object *object,
struct fscache_operation *op)
{
const struct fscache_state *ostate;
unsigned long flags;
int ret;
_enter("{OBJ%x OP%x},{%u}",
object->debug_id, op->debug_id, atomic_read(&op->usage));
trace_fscache_op(object->cookie, op, fscache_op_submit);
ASSERTCMP(op->state, ==, FSCACHE_OP_ST_INITIALISED);
ASSERTCMP(atomic_read(&op->usage), >, 0);
spin_lock(&object->lock);
ASSERTCMP(object->n_ops, >=, object->n_in_progress);
ASSERTCMP(object->n_ops, >=, object->n_exclusive);
ASSERT(list_empty(&op->pend_link));
ostate = object->state;
smp_rmb();
op->state = FSCACHE_OP_ST_PENDING;
flags = READ_ONCE(object->flags);
if (unlikely(!(flags & BIT(FSCACHE_OBJECT_IS_LIVE)))) {
fscache_stat(&fscache_n_op_rejected);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
} else if (unlikely(fscache_cache_is_broken(object))) {
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -EIO;
} else if (flags & BIT(FSCACHE_OBJECT_IS_AVAILABLE)) {
op->object = object;
object->n_ops++;
if (object->n_exclusive > 0) {
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
} else if (!list_empty(&object->pending_ops)) {
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
fscache_start_operations(object);
} else {
ASSERTCMP(object->n_exclusive, ==, 0);
fscache_run_op(object, op);
}
ret = 0;
} else if (flags & BIT(FSCACHE_OBJECT_IS_LOOKED_UP)) {
op->object = object;
object->n_ops++;
atomic_inc(&op->usage);
list_add_tail(&op->pend_link, &object->pending_ops);
fscache_stat(&fscache_n_op_pend);
ret = 0;
} else if (flags & BIT(FSCACHE_OBJECT_KILLED_BY_CACHE)) {
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
} else {
fscache_report_unexpected_submission(object, op, ostate);
ASSERT(!fscache_object_is_active(object));
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
ret = -ENOBUFS;
}
spin_unlock(&object->lock);
return ret;
}
/*
* queue an object for withdrawal on error, aborting all following asynchronous
* operations
*/
void fscache_abort_object(struct fscache_object *object)
{
_enter("{OBJ%x}", object->debug_id);
fscache_raise_event(object, FSCACHE_OBJECT_EV_ERROR);
}
/*
* Jump start the operation processing on an object. The caller must hold
* object->lock.
*/
void fscache_start_operations(struct fscache_object *object)
{
struct fscache_operation *op;
bool stop = false;
while (!list_empty(&object->pending_ops) && !stop) {
op = list_entry(object->pending_ops.next,
struct fscache_operation, pend_link);
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags)) {
if (object->n_in_progress > 0)
break;
stop = true;
}
list_del_init(&op->pend_link);
fscache_run_op(object, op);
/* the pending queue was holding a ref on the object */
fscache_put_operation(op);
}
ASSERTCMP(object->n_in_progress, <=, object->n_ops);
_debug("woke %d ops on OBJ%x",
object->n_in_progress, object->debug_id);
}
/*
* cancel an operation that's pending on an object
*/
int fscache_cancel_op(struct fscache_operation *op,
bool cancel_in_progress_op)
{
struct fscache_object *object = op->object;
bool put = false;
int ret;
_enter("OBJ%x OP%x}", op->object->debug_id, op->debug_id);
trace_fscache_op(object->cookie, op, fscache_op_cancel);
ASSERTCMP(op->state, >=, FSCACHE_OP_ST_PENDING);
ASSERTCMP(op->state, !=, FSCACHE_OP_ST_CANCELLED);
ASSERTCMP(atomic_read(&op->usage), >, 0);
spin_lock(&object->lock);
ret = -EBUSY;
if (op->state == FSCACHE_OP_ST_PENDING) {
ASSERT(!list_empty(&op->pend_link));
list_del_init(&op->pend_link);
put = true;
fscache_stat(&fscache_n_op_cancelled);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
object->n_exclusive--;
if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
ret = 0;
} else if (op->state == FSCACHE_OP_ST_IN_PROGRESS && cancel_in_progress_op) {
ASSERTCMP(object->n_in_progress, >, 0);
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
object->n_exclusive--;
object->n_in_progress--;
if (object->n_in_progress == 0)
fscache_start_operations(object);
fscache_stat(&fscache_n_op_cancelled);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
object->n_exclusive--;
if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
ret = 0;
}
if (put)
fscache_put_operation(op);
spin_unlock(&object->lock);
_leave(" = %d", ret);
return ret;
}
/*
* Cancel all pending operations on an object
*/
void fscache_cancel_all_ops(struct fscache_object *object)
{
struct fscache_operation *op;
_enter("OBJ%x", object->debug_id);
spin_lock(&object->lock);
while (!list_empty(&object->pending_ops)) {
op = list_entry(object->pending_ops.next,
struct fscache_operation, pend_link);
fscache_stat(&fscache_n_op_cancelled);
list_del_init(&op->pend_link);
trace_fscache_op(object->cookie, op, fscache_op_cancel_all);
ASSERTCMP(op->state, ==, FSCACHE_OP_ST_PENDING);
op->cancel(op);
op->state = FSCACHE_OP_ST_CANCELLED;
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
object->n_exclusive--;
if (test_and_clear_bit(FSCACHE_OP_WAITING, &op->flags))
wake_up_bit(&op->flags, FSCACHE_OP_WAITING);
fscache_put_operation(op);
cond_resched_lock(&object->lock);
}
spin_unlock(&object->lock);
_leave("");
}
/*
* Record the completion or cancellation of an in-progress operation.
*/
void fscache_op_complete(struct fscache_operation *op, bool cancelled)
{
struct fscache_object *object = op->object;
_enter("OBJ%x", object->debug_id);
ASSERTCMP(op->state, ==, FSCACHE_OP_ST_IN_PROGRESS);
ASSERTCMP(object->n_in_progress, >, 0);
ASSERTIFCMP(test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags),
object->n_exclusive, >, 0);
ASSERTIFCMP(test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags),
object->n_in_progress, ==, 1);
spin_lock(&object->lock);
if (!cancelled) {
trace_fscache_op(object->cookie, op, fscache_op_completed);
op->state = FSCACHE_OP_ST_COMPLETE;
} else {
op->cancel(op);
trace_fscache_op(object->cookie, op, fscache_op_cancelled);
op->state = FSCACHE_OP_ST_CANCELLED;
}
if (test_bit(FSCACHE_OP_EXCLUSIVE, &op->flags))
object->n_exclusive--;
object->n_in_progress--;
if (object->n_in_progress == 0)
fscache_start_operations(object);
spin_unlock(&object->lock);
_leave("");
}
EXPORT_SYMBOL(fscache_op_complete);
/*
* release an operation
* - queues pending ops if this is the last in-progress op
*/
void fscache_put_operation(struct fscache_operation *op)
{
struct fscache_object *object;
struct fscache_cache *cache;
_enter("{OBJ%x OP%x,%d}",
op->object ? op->object->debug_id : 0,
op->debug_id, atomic_read(&op->usage));
ASSERTCMP(atomic_read(&op->usage), >, 0);
if (!atomic_dec_and_test(&op->usage))
return;
trace_fscache_op(op->object ? op->object->cookie : NULL, op, fscache_op_put);
_debug("PUT OP");
ASSERTIFCMP(op->state != FSCACHE_OP_ST_INITIALISED &&
op->state != FSCACHE_OP_ST_COMPLETE,
op->state, ==, FSCACHE_OP_ST_CANCELLED);
fscache_stat(&fscache_n_op_release);
if (op->release) {
op->release(op);
op->release = NULL;
}
op->state = FSCACHE_OP_ST_DEAD;
object = op->object;
if (likely(object)) {
if (test_bit(FSCACHE_OP_DEC_READ_CNT, &op->flags))
atomic_dec(&object->n_reads);
if (test_bit(FSCACHE_OP_UNUSE_COOKIE, &op->flags))
fscache_unuse_cookie(object);
/* now... we may get called with the object spinlock held, so we
* complete the cleanup here only if we can immediately acquire the
* lock, and defer it otherwise */
if (!spin_trylock(&object->lock)) {
_debug("defer put");
fscache_stat(&fscache_n_op_deferred_release);
cache = object->cache;
spin_lock(&cache->op_gc_list_lock);
list_add_tail(&op->pend_link, &cache->op_gc_list);
spin_unlock(&cache->op_gc_list_lock);
schedule_work(&cache->op_gc);
_leave(" [defer]");
return;
}
ASSERTCMP(object->n_ops, >, 0);
object->n_ops--;
if (object->n_ops == 0)
fscache_raise_event(object, FSCACHE_OBJECT_EV_CLEARED);
spin_unlock(&object->lock);
}
kfree(op);
_leave(" [done]");
}
EXPORT_SYMBOL(fscache_put_operation);
/*
* garbage collect operations that have had their release deferred
*/
void fscache_operation_gc(struct work_struct *work)
{
struct fscache_operation *op;
struct fscache_object *object;
struct fscache_cache *cache =
container_of(work, struct fscache_cache, op_gc);
int count = 0;
_enter("");
do {
spin_lock(&cache->op_gc_list_lock);
if (list_empty(&cache->op_gc_list)) {
spin_unlock(&cache->op_gc_list_lock);
break;
}
op = list_entry(cache->op_gc_list.next,
struct fscache_operation, pend_link);
list_del(&op->pend_link);
spin_unlock(&cache->op_gc_list_lock);
object = op->object;
trace_fscache_op(object->cookie, op, fscache_op_gc);
spin_lock(&object->lock);
_debug("GC DEFERRED REL OBJ%x OP%x",
object->debug_id, op->debug_id);
fscache_stat(&fscache_n_op_gc);
ASSERTCMP(atomic_read(&op->usage), ==, 0);
ASSERTCMP(op->state, ==, FSCACHE_OP_ST_DEAD);
ASSERTCMP(object->n_ops, >, 0);
object->n_ops--;
if (object->n_ops == 0)
fscache_raise_event(object, FSCACHE_OBJECT_EV_CLEARED);
spin_unlock(&object->lock);
kfree(op);
} while (count++ < 20);
if (!list_empty(&cache->op_gc_list))
schedule_work(&cache->op_gc);
_leave("");
}
/*
* execute an operation using fs_op_wq to provide processing context -
* the caller holds a ref to this object, so we don't need to hold one
*/
void fscache_op_work_func(struct work_struct *work)
{
struct fscache_operation *op =
container_of(work, struct fscache_operation, work);
_enter("{OBJ%x OP%x,%d}",
op->object->debug_id, op->debug_id, atomic_read(&op->usage));
trace_fscache_op(op->object->cookie, op, fscache_op_work);
ASSERT(op->processor != NULL);
op->processor(op);
fscache_put_operation(op);
_leave("");
}
fs/fscache/page.c deleted 100644 → 0
View file @ 850cba06
// SPDX-License-Identifier: GPL-2.0-or-later
/* Cache page management and data I/O routines
*
* Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#define FSCACHE_DEBUG_LEVEL PAGE
#include <linux/module.h>
#include <linux/fscache-cache.h>
#include <linux/buffer_head.h>
#include <linux/pagevec.h>
#include <linux/slab.h>
#include "internal.h"
/*
* check to see if a page is being written to the cache
*/
bool __fscache_check_page_write(struct fscache_cookie *cookie, struct page *page)
{
void *val;
rcu_read_lock();
val = radix_tree_lookup(&cookie->stores, page->index);
rcu_read_unlock();
trace_fscache_check_page(cookie, page, val, 0);
return val != NULL;
}
EXPORT_SYMBOL(__fscache_check_page_write);
/*
* wait for a page to finish being written to the cache
*/
void __fscache_wait_on_page_write(struct fscache_cookie *cookie, struct page *page)
{
wait_queue_head_t *wq = bit_waitqueue(&cookie->flags, 0);
trace_fscache_page(cookie, page, fscache_page_write_wait);
wait_event(*wq, !__fscache_check_page_write(cookie, page));
}
EXPORT_SYMBOL(__fscache_wait_on_page_write);
/*
* wait for a page to finish being written to the cache. Put a timeout here
* since we might be called recursively via parent fs.
*/
static
bool release_page_wait_timeout(struct fscache_cookie *cookie, struct page *page)
{
wait_queue_head_t *wq = bit_waitqueue(&cookie->flags, 0);
return wait_event_timeout(*wq, !__fscache_check_page_write(cookie, page),
HZ);
}
/*
* decide whether a page can be released, possibly by cancelling a store to it
* - we're allowed to sleep if __GFP_DIRECT_RECLAIM is flagged
*/
bool __fscache_maybe_release_page(struct fscache_cookie *cookie,
struct page *page,
gfp_t gfp)
{
struct page *xpage;
void *val;
_enter("%p,%p,%x", cookie, page, gfp);
trace_fscache_page(cookie, page, fscache_page_maybe_release);
try_again:
rcu_read_lock();
val = radix_tree_lookup(&cookie->stores, page->index);
if (!val) {
rcu_read_unlock();
fscache_stat(&fscache_n_store_vmscan_not_storing);
__fscache_uncache_page(cookie, page);
return true;
}
/* see if the page is actually undergoing storage - if so we can't get
* rid of it till the cache has finished with it */
if (radix_tree_tag_get(&cookie->stores, page->index,
FSCACHE_COOKIE_STORING_TAG)) {
rcu_read_unlock();
goto page_busy;
}
/* the page is pending storage, so we attempt to cancel the store and
* discard the store request so that the page can be reclaimed */
spin_lock(&cookie->stores_lock);
rcu_read_unlock();
if (radix_tree_tag_get(&cookie->stores, page->index,
FSCACHE_COOKIE_STORING_TAG)) {
/* the page started to undergo storage whilst we were looking,
* so now we can only wait or return */
spin_unlock(&cookie->stores_lock);
goto page_busy;
}
xpage = radix_tree_delete(&cookie->stores, page->index);
trace_fscache_page(cookie, page, fscache_page_radix_delete);
spin_unlock(&cookie->stores_lock);
if (xpage) {
fscache_stat(&fscache_n_store_vmscan_cancelled);
fscache_stat(&fscache_n_store_radix_deletes);
ASSERTCMP(xpage, ==, page);
} else {
fscache_stat(&fscache_n_store_vmscan_gone);
}
wake_up_bit(&cookie->flags, 0);
trace_fscache_wake_cookie(cookie);
if (xpage)
put_page(xpage);
__fscache_uncache_page(cookie, page);
return true;
page_busy:
/* We will wait here if we're allowed to, but that could deadlock the
* allocator as the work threads writing to the cache may all end up
* sleeping on memory allocation, so we may need to impose a timeout
* too. */
if (!(gfp & __GFP_DIRECT_RECLAIM) || !(gfp & __GFP_FS)) {
fscache_stat(&fscache_n_store_vmscan_busy);
return false;
}
fscache_stat(&fscache_n_store_vmscan_wait);
if (!release_page_wait_timeout(cookie, page))
_debug("fscache writeout timeout page: %p{%lx}",
page, page->index);
gfp &= ~__GFP_DIRECT_RECLAIM;
goto try_again;
}
EXPORT_SYMBOL(__fscache_maybe_release_page);
/*
* note that a page has finished being written to the cache
*/
static void fscache_end_page_write(struct fscache_object *object,
struct page *page)
{
struct fscache_cookie *cookie;
struct page *xpage = NULL, *val;
spin_lock(&object->lock);
cookie = object->cookie;
if (cookie) {
/* delete the page from the tree if it is now no longer
* pending */
spin_lock(&cookie->stores_lock);
radix_tree_tag_clear(&cookie->stores, page->index,
FSCACHE_COOKIE_STORING_TAG);
trace_fscache_page(cookie, page, fscache_page_radix_clear_store);
if (!radix_tree_tag_get(&cookie->stores, page->index,
FSCACHE_COOKIE_PENDING_TAG)) {
fscache_stat(&fscache_n_store_radix_deletes);
xpage = radix_tree_delete(&cookie->stores, page->index);
trace_fscache_page(cookie, page, fscache_page_radix_delete);
trace_fscache_page(cookie, page, fscache_page_write_end);
val = radix_tree_lookup(&cookie->stores, page->index);
trace_fscache_check_page(cookie, page, val, 1);
} else {
trace_fscache_page(cookie, page, fscache_page_write_end_pend);
}
spin_unlock(&cookie->stores_lock);
wake_up_bit(&cookie->flags, 0);
trace_fscache_wake_cookie(cookie);
} else {
trace_fscache_page(cookie, page, fscache_page_write_end_noc);
}
spin_unlock(&object->lock);
if (xpage)
put_page(xpage);
}
/*
* actually apply the changed attributes to a cache object
*/
static void fscache_attr_changed_op(struct fscache_operation *op)
{
struct fscache_object *object = op->object;
int ret;
_enter("{OBJ%x OP%x}", object->debug_id, op->debug_id);
fscache_stat(&fscache_n_attr_changed_calls);
if (fscache_object_is_active(object)) {
fscache_stat(&fscache_n_cop_attr_changed);
ret = object->cache->ops->attr_changed(object);
fscache_stat_d(&fscache_n_cop_attr_changed);
if (ret < 0)
fscache_abort_object(object);
fscache_op_complete(op, ret < 0);
} else {
fscache_op_complete(op, true);
}
_leave("");
}
/*
* notification that the attributes on an object have changed
*/
int __fscache_attr_changed(struct fscache_cookie *cookie)
{
struct fscache_operation *op;
struct fscache_object *object;
bool wake_cookie = false;
_enter("%p", cookie);
ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
fscache_stat(&fscache_n_attr_changed);
op = kzalloc(sizeof(*op), GFP_KERNEL);
if (!op) {
fscache_stat(&fscache_n_attr_changed_nomem);
_leave(" = -ENOMEM");
return -ENOMEM;
}
fscache_operation_init(cookie, op, fscache_attr_changed_op, NULL, NULL);
trace_fscache_page_op(cookie, NULL, op, fscache_page_op_attr_changed);
op->flags = FSCACHE_OP_ASYNC |
(1 << FSCACHE_OP_EXCLUSIVE) |
(1 << FSCACHE_OP_UNUSE_COOKIE);
spin_lock(&cookie->lock);
if (!fscache_cookie_enabled(cookie) ||
hlist_empty(&cookie->backing_objects))
goto nobufs;
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object, cookie_link);
__fscache_use_cookie(cookie);
if (fscache_submit_exclusive_op(object, op) < 0)
goto nobufs_dec;
spin_unlock(&cookie->lock);
fscache_stat(&fscache_n_attr_changed_ok);
fscache_put_operation(op);
_leave(" = 0");
return 0;
nobufs_dec:
wake_cookie = __fscache_unuse_cookie(cookie);
nobufs:
spin_unlock(&cookie->lock);
fscache_put_operation(op);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
fscache_stat(&fscache_n_attr_changed_nobufs);
_leave(" = %d", -ENOBUFS);
return -ENOBUFS;
}
EXPORT_SYMBOL(__fscache_attr_changed);
/*
* Handle cancellation of a pending retrieval op
*/
static void fscache_do_cancel_retrieval(struct fscache_operation *_op)
{
struct fscache_retrieval *op =
container_of(_op, struct fscache_retrieval, op);
atomic_set(&op->n_pages, 0);
}
/*
* release a retrieval op reference
*/
static void fscache_release_retrieval_op(struct fscache_operation *_op)
{
struct fscache_retrieval *op =
container_of(_op, struct fscache_retrieval, op);
_enter("{OP%x}", op->op.debug_id);
ASSERTIFCMP(op->op.state != FSCACHE_OP_ST_INITIALISED,
atomic_read(&op->n_pages), ==, 0);
if (op->context)
fscache_put_context(op->cookie, op->context);
_leave("");
}
/*
* allocate a retrieval op
*/
struct fscache_retrieval *fscache_alloc_retrieval(
struct fscache_cookie *cookie,
struct address_space *mapping,
fscache_rw_complete_t end_io_func,
void *context)
{
struct fscache_retrieval *op;
/* allocate a retrieval operation and attempt to submit it */
op = kzalloc(sizeof(*op), GFP_NOIO);
if (!op) {
fscache_stat(&fscache_n_retrievals_nomem);
return NULL;
}
fscache_operation_init(cookie, &op->op, NULL,
fscache_do_cancel_retrieval,
fscache_release_retrieval_op);
op->op.flags = FSCACHE_OP_MYTHREAD |
(1UL << FSCACHE_OP_WAITING) |
(1UL << FSCACHE_OP_UNUSE_COOKIE);
op->cookie = cookie;
op->mapping = mapping;
op->end_io_func = end_io_func;
op->context = context;
INIT_LIST_HEAD(&op->to_do);
/* Pin the netfs read context in case we need to do the actual netfs
* read because we've encountered a cache read failure.
*/
if (context)
fscache_get_context(op->cookie, context);
return op;
}
/*
* wait for a deferred lookup to complete
*/
int fscache_wait_for_deferred_lookup(struct fscache_cookie *cookie)
{
_enter("");
if (!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags)) {
_leave(" = 0 [imm]");
return 0;
}
fscache_stat(&fscache_n_retrievals_wait);
if (wait_on_bit(&cookie->flags, FSCACHE_COOKIE_LOOKING_UP,
TASK_INTERRUPTIBLE) != 0) {
fscache_stat(&fscache_n_retrievals_intr);
_leave(" = -ERESTARTSYS");
return -ERESTARTSYS;
}
ASSERT(!test_bit(FSCACHE_COOKIE_LOOKING_UP, &cookie->flags));
smp_rmb();
_leave(" = 0 [dly]");
return 0;
}
/*
* wait for an object to become active (or dead)
*/
int fscache_wait_for_operation_activation(struct fscache_object *object,
struct fscache_operation *op,
atomic_t *stat_op_waits,
atomic_t *stat_object_dead)
{
int ret;
if (!test_bit(FSCACHE_OP_WAITING, &op->flags))
goto check_if_dead;
_debug(">>> WT");
if (stat_op_waits)
fscache_stat(stat_op_waits);
if (wait_on_bit(&op->flags, FSCACHE_OP_WAITING,
TASK_INTERRUPTIBLE) != 0) {
trace_fscache_op(object->cookie, op, fscache_op_signal);
ret = fscache_cancel_op(op, false);
if (ret == 0)
return -ERESTARTSYS;
/* it's been removed from the pending queue by another party,
* so we should get to run shortly */
wait_on_bit(&op->flags, FSCACHE_OP_WAITING,
TASK_UNINTERRUPTIBLE);
}
_debug("<<< GO");
check_if_dead:
if (op->state == FSCACHE_OP_ST_CANCELLED) {
if (stat_object_dead)
fscache_stat(stat_object_dead);
_leave(" = -ENOBUFS [cancelled]");
return -ENOBUFS;
}
if (unlikely(fscache_object_is_dying(object) ||
fscache_cache_is_broken(object))) {
enum fscache_operation_state state = op->state;
trace_fscache_op(object->cookie, op, fscache_op_signal);
fscache_cancel_op(op, true);
if (stat_object_dead)
fscache_stat(stat_object_dead);
_leave(" = -ENOBUFS [obj dead %d]", state);
return -ENOBUFS;
}
return 0;
}
/*
* read a page from the cache or allocate a block in which to store it
* - we return:
* -ENOMEM - out of memory, nothing done
* -ERESTARTSYS - interrupted
* -ENOBUFS - no backing object available in which to cache the block
* -ENODATA - no data available in the backing object for this block
* 0 - dispatched a read - it'll call end_io_func() when finished
*/
int __fscache_read_or_alloc_page(struct fscache_cookie *cookie,
struct page *page,
fscache_rw_complete_t end_io_func,
void *context,
gfp_t gfp)
{
struct fscache_retrieval *op;
struct fscache_object *object;
bool wake_cookie = false;
int ret;
_enter("%p,%p,,,", cookie, page);
fscache_stat(&fscache_n_retrievals);
if (hlist_empty(&cookie->backing_objects))
goto nobufs;
if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) {
_leave(" = -ENOBUFS [invalidating]");
return -ENOBUFS;
}
ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
ASSERTCMP(page, !=, NULL);
if (fscache_wait_for_deferred_lookup(cookie) < 0)
return -ERESTARTSYS;
op = fscache_alloc_retrieval(cookie, page->mapping,
end_io_func, context);
if (!op) {
_leave(" = -ENOMEM");
return -ENOMEM;
}
atomic_set(&op->n_pages, 1);
trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_retr_one);
spin_lock(&cookie->lock);
if (!fscache_cookie_enabled(cookie) ||
hlist_empty(&cookie->backing_objects))
goto nobufs_unlock;
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object, cookie_link);
ASSERT(test_bit(FSCACHE_OBJECT_IS_LOOKED_UP, &object->flags));
__fscache_use_cookie(cookie);
atomic_inc(&object->n_reads);
__set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
if (fscache_submit_op(object, &op->op) < 0)
goto nobufs_unlock_dec;
spin_unlock(&cookie->lock);
fscache_stat(&fscache_n_retrieval_ops);
/* we wait for the operation to become active, and then process it
* *here*, in this thread, and not in the thread pool */
ret = fscache_wait_for_operation_activation(
object, &op->op,
__fscache_stat(&fscache_n_retrieval_op_waits),
__fscache_stat(&fscache_n_retrievals_object_dead));
if (ret < 0)
goto error;
/* ask the cache to honour the operation */
if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) {
fscache_stat(&fscache_n_cop_allocate_page);
ret = object->cache->ops->allocate_page(op, page, gfp);
fscache_stat_d(&fscache_n_cop_allocate_page);
if (ret == 0)
ret = -ENODATA;
} else {
fscache_stat(&fscache_n_cop_read_or_alloc_page);
ret = object->cache->ops->read_or_alloc_page(op, page, gfp);
fscache_stat_d(&fscache_n_cop_read_or_alloc_page);
}
error:
if (ret == -ENOMEM)
fscache_stat(&fscache_n_retrievals_nomem);
else if (ret == -ERESTARTSYS)
fscache_stat(&fscache_n_retrievals_intr);
else if (ret == -ENODATA)
fscache_stat(&fscache_n_retrievals_nodata);
else if (ret < 0)
fscache_stat(&fscache_n_retrievals_nobufs);
else
fscache_stat(&fscache_n_retrievals_ok);
fscache_put_retrieval(op);
_leave(" = %d", ret);
return ret;
nobufs_unlock_dec:
atomic_dec(&object->n_reads);
wake_cookie = __fscache_unuse_cookie(cookie);
nobufs_unlock:
spin_unlock(&cookie->lock);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
fscache_put_retrieval(op);
nobufs:
fscache_stat(&fscache_n_retrievals_nobufs);
_leave(" = -ENOBUFS");
return -ENOBUFS;
}
EXPORT_SYMBOL(__fscache_read_or_alloc_page);
/*
* read a list of page from the cache or allocate a block in which to store
* them
* - we return:
* -ENOMEM - out of memory, some pages may be being read
* -ERESTARTSYS - interrupted, some pages may be being read
* -ENOBUFS - no backing object or space available in which to cache any
* pages not being read
* -ENODATA - no data available in the backing object for some or all of
* the pages
* 0 - dispatched a read on all pages
*
* end_io_func() will be called for each page read from the cache as it is
* finishes being read
*
* any pages for which a read is dispatched will be removed from pages and
* nr_pages
*/
int __fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
struct address_space *mapping,
struct list_head *pages,
unsigned *nr_pages,
fscache_rw_complete_t end_io_func,
void *context,
gfp_t gfp)
{
struct fscache_retrieval *op;
struct fscache_object *object;
bool wake_cookie = false;
int ret;
_enter("%p,,%d,,,", cookie, *nr_pages);
fscache_stat(&fscache_n_retrievals);
if (hlist_empty(&cookie->backing_objects))
goto nobufs;
if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) {
_leave(" = -ENOBUFS [invalidating]");
return -ENOBUFS;
}
ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
ASSERTCMP(*nr_pages, >, 0);
ASSERT(!list_empty(pages));
if (fscache_wait_for_deferred_lookup(cookie) < 0)
return -ERESTARTSYS;
op = fscache_alloc_retrieval(cookie, mapping, end_io_func, context);
if (!op)
return -ENOMEM;
atomic_set(&op->n_pages, *nr_pages);
trace_fscache_page_op(cookie, NULL, &op->op, fscache_page_op_retr_multi);
spin_lock(&cookie->lock);
if (!fscache_cookie_enabled(cookie) ||
hlist_empty(&cookie->backing_objects))
goto nobufs_unlock;
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object, cookie_link);
__fscache_use_cookie(cookie);
atomic_inc(&object->n_reads);
__set_bit(FSCACHE_OP_DEC_READ_CNT, &op->op.flags);
if (fscache_submit_op(object, &op->op) < 0)
goto nobufs_unlock_dec;
spin_unlock(&cookie->lock);
fscache_stat(&fscache_n_retrieval_ops);
/* we wait for the operation to become active, and then process it
* *here*, in this thread, and not in the thread pool */
ret = fscache_wait_for_operation_activation(
object, &op->op,
__fscache_stat(&fscache_n_retrieval_op_waits),
__fscache_stat(&fscache_n_retrievals_object_dead));
if (ret < 0)
goto error;
/* ask the cache to honour the operation */
if (test_bit(FSCACHE_COOKIE_NO_DATA_YET, &object->cookie->flags)) {
fscache_stat(&fscache_n_cop_allocate_pages);
ret = object->cache->ops->allocate_pages(
op, pages, nr_pages, gfp);
fscache_stat_d(&fscache_n_cop_allocate_pages);
} else {
fscache_stat(&fscache_n_cop_read_or_alloc_pages);
ret = object->cache->ops->read_or_alloc_pages(
op, pages, nr_pages, gfp);
fscache_stat_d(&fscache_n_cop_read_or_alloc_pages);
}
error:
if (ret == -ENOMEM)
fscache_stat(&fscache_n_retrievals_nomem);
else if (ret == -ERESTARTSYS)
fscache_stat(&fscache_n_retrievals_intr);
else if (ret == -ENODATA)
fscache_stat(&fscache_n_retrievals_nodata);
else if (ret < 0)
fscache_stat(&fscache_n_retrievals_nobufs);
else
fscache_stat(&fscache_n_retrievals_ok);
fscache_put_retrieval(op);
_leave(" = %d", ret);
return ret;
nobufs_unlock_dec:
atomic_dec(&object->n_reads);
wake_cookie = __fscache_unuse_cookie(cookie);
nobufs_unlock:
spin_unlock(&cookie->lock);
fscache_put_retrieval(op);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
nobufs:
fscache_stat(&fscache_n_retrievals_nobufs);
_leave(" = -ENOBUFS");
return -ENOBUFS;
}
EXPORT_SYMBOL(__fscache_read_or_alloc_pages);
/*
* allocate a block in the cache on which to store a page
* - we return:
* -ENOMEM - out of memory, nothing done
* -ERESTARTSYS - interrupted
* -ENOBUFS - no backing object available in which to cache the block
* 0 - block allocated
*/
int __fscache_alloc_page(struct fscache_cookie *cookie,
struct page *page,
gfp_t gfp)
{
struct fscache_retrieval *op;
struct fscache_object *object;
bool wake_cookie = false;
int ret;
_enter("%p,%p,,,", cookie, page);
fscache_stat(&fscache_n_allocs);
if (hlist_empty(&cookie->backing_objects))
goto nobufs;
ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
ASSERTCMP(page, !=, NULL);
if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) {
_leave(" = -ENOBUFS [invalidating]");
return -ENOBUFS;
}
if (fscache_wait_for_deferred_lookup(cookie) < 0)
return -ERESTARTSYS;
op = fscache_alloc_retrieval(cookie, page->mapping, NULL, NULL);
if (!op)
return -ENOMEM;
atomic_set(&op->n_pages, 1);
trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_alloc_one);
spin_lock(&cookie->lock);
if (!fscache_cookie_enabled(cookie) ||
hlist_empty(&cookie->backing_objects))
goto nobufs_unlock;
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object, cookie_link);
__fscache_use_cookie(cookie);
if (fscache_submit_op(object, &op->op) < 0)
goto nobufs_unlock_dec;
spin_unlock(&cookie->lock);
fscache_stat(&fscache_n_alloc_ops);
ret = fscache_wait_for_operation_activation(
object, &op->op,
__fscache_stat(&fscache_n_alloc_op_waits),
__fscache_stat(&fscache_n_allocs_object_dead));
if (ret < 0)
goto error;
/* ask the cache to honour the operation */
fscache_stat(&fscache_n_cop_allocate_page);
ret = object->cache->ops->allocate_page(op, page, gfp);
fscache_stat_d(&fscache_n_cop_allocate_page);
error:
if (ret == -ERESTARTSYS)
fscache_stat(&fscache_n_allocs_intr);
else if (ret < 0)
fscache_stat(&fscache_n_allocs_nobufs);
else
fscache_stat(&fscache_n_allocs_ok);
fscache_put_retrieval(op);
_leave(" = %d", ret);
return ret;
nobufs_unlock_dec:
wake_cookie = __fscache_unuse_cookie(cookie);
nobufs_unlock:
spin_unlock(&cookie->lock);
fscache_put_retrieval(op);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
nobufs:
fscache_stat(&fscache_n_allocs_nobufs);
_leave(" = -ENOBUFS");
return -ENOBUFS;
}
EXPORT_SYMBOL(__fscache_alloc_page);
/*
* Unmark pages allocate in the readahead code path (via:
* fscache_readpages_or_alloc) after delegating to the base filesystem
*/
void __fscache_readpages_cancel(struct fscache_cookie *cookie,
struct list_head *pages)
{
struct page *page;
list_for_each_entry(page, pages, lru) {
if (PageFsCache(page))
__fscache_uncache_page(cookie, page);
}
}
EXPORT_SYMBOL(__fscache_readpages_cancel);
/*
* release a write op reference
*/
static void fscache_release_write_op(struct fscache_operation *_op)
{
_enter("{OP%x}", _op->debug_id);
}
/*
* perform the background storage of a page into the cache
*/
static void fscache_write_op(struct fscache_operation *_op)
{
struct fscache_storage *op =
container_of(_op, struct fscache_storage, op);
struct fscache_object *object = op->op.object;
struct fscache_cookie *cookie;
struct page *page;
unsigned n;
void *results[1];
int ret;
_enter("{OP%x,%d}", op->op.debug_id, atomic_read(&op->op.usage));
again:
spin_lock(&object->lock);
cookie = object->cookie;
if (!fscache_object_is_active(object)) {
/* If we get here, then the on-disk cache object likely no
* longer exists, so we should just cancel this write
* operation.
*/
spin_unlock(&object->lock);
fscache_op_complete(&op->op, true);
_leave(" [inactive]");
return;
}
if (!cookie) {
/* If we get here, then the cookie belonging to the object was
* detached, probably by the cookie being withdrawn due to
* memory pressure, which means that the pages we might write
* to the cache from no longer exist - therefore, we can just
* cancel this write operation.
*/
spin_unlock(&object->lock);
fscache_op_complete(&op->op, true);
_leave(" [cancel] op{f=%lx s=%u} obj{s=%s f=%lx}",
_op->flags, _op->state, object->state->short_name,
object->flags);
return;
}
spin_lock(&cookie->stores_lock);
fscache_stat(&fscache_n_store_calls);
/* find a page to store */
results[0] = NULL;
page = NULL;
n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0, 1,
FSCACHE_COOKIE_PENDING_TAG);
trace_fscache_gang_lookup(cookie, &op->op, results, n, op->store_limit);
if (n != 1)
goto superseded;
page = results[0];
_debug("gang %d [%lx]", n, page->index);
radix_tree_tag_set(&cookie->stores, page->index,
FSCACHE_COOKIE_STORING_TAG);
radix_tree_tag_clear(&cookie->stores, page->index,
FSCACHE_COOKIE_PENDING_TAG);
trace_fscache_page(cookie, page, fscache_page_radix_pend2store);
spin_unlock(&cookie->stores_lock);
spin_unlock(&object->lock);
if (page->index >= op->store_limit)
goto discard_page;
fscache_stat(&fscache_n_store_pages);
fscache_stat(&fscache_n_cop_write_page);
ret = object->cache->ops->write_page(op, page);
fscache_stat_d(&fscache_n_cop_write_page);
trace_fscache_wrote_page(cookie, page, &op->op, ret);
fscache_end_page_write(object, page);
if (ret < 0) {
fscache_abort_object(object);
fscache_op_complete(&op->op, true);
} else {
fscache_enqueue_operation(&op->op);
}
_leave("");
return;
discard_page:
fscache_stat(&fscache_n_store_pages_over_limit);
trace_fscache_wrote_page(cookie, page, &op->op, -ENOBUFS);
fscache_end_page_write(object, page);
goto again;
superseded:
/* this writer is going away and there aren't any more things to
* write */
_debug("cease");
spin_unlock(&cookie->stores_lock);
clear_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags);
spin_unlock(&object->lock);
fscache_op_complete(&op->op, false);
_leave("");
}
/*
* Clear the pages pending writing for invalidation
*/
void fscache_invalidate_writes(struct fscache_cookie *cookie)
{
struct page *page;
void *results[16];
int n, i;
_enter("");
for (;;) {
spin_lock(&cookie->stores_lock);
n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0,
ARRAY_SIZE(results),
FSCACHE_COOKIE_PENDING_TAG);
if (n == 0) {
spin_unlock(&cookie->stores_lock);
break;
}
for (i = n - 1; i >= 0; i--) {
page = results[i];
radix_tree_delete(&cookie->stores, page->index);
trace_fscache_page(cookie, page, fscache_page_radix_delete);
trace_fscache_page(cookie, page, fscache_page_inval);
}
spin_unlock(&cookie->stores_lock);
for (i = n - 1; i >= 0; i--)
put_page(results[i]);
}
wake_up_bit(&cookie->flags, 0);
trace_fscache_wake_cookie(cookie);
_leave("");
}
/*
* request a page be stored in the cache
* - returns:
* -ENOMEM - out of memory, nothing done
* -ENOBUFS - no backing object available in which to cache the page
* 0 - dispatched a write - it'll call end_io_func() when finished
*
* if the cookie still has a backing object at this point, that object can be
* in one of a few states with respect to storage processing:
*
* (1) negative lookup, object not yet created (FSCACHE_COOKIE_CREATING is
* set)
*
* (a) no writes yet
*
* (b) writes deferred till post-creation (mark page for writing and
* return immediately)
*
* (2) negative lookup, object created, initial fill being made from netfs
*
* (a) fill point not yet reached this page (mark page for writing and
* return)
*
* (b) fill point passed this page (queue op to store this page)
*
* (3) object extant (queue op to store this page)
*
* any other state is invalid
*/
int __fscache_write_page(struct fscache_cookie *cookie,
struct page *page,
loff_t object_size,
gfp_t gfp)
{
struct fscache_storage *op;
struct fscache_object *object;
bool wake_cookie = false;
int ret;
_enter("%p,%x,", cookie, (u32) page->flags);
ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
ASSERT(PageFsCache(page));
fscache_stat(&fscache_n_stores);
if (test_bit(FSCACHE_COOKIE_INVALIDATING, &cookie->flags)) {
_leave(" = -ENOBUFS [invalidating]");
return -ENOBUFS;
}
op = kzalloc(sizeof(*op), GFP_NOIO | __GFP_NOMEMALLOC | __GFP_NORETRY);
if (!op)
goto nomem;
fscache_operation_init(cookie, &op->op, fscache_write_op, NULL,
fscache_release_write_op);
op->op.flags = FSCACHE_OP_ASYNC |
(1 << FSCACHE_OP_WAITING) |
(1 << FSCACHE_OP_UNUSE_COOKIE);
ret = radix_tree_maybe_preload(gfp & ~__GFP_HIGHMEM);
if (ret < 0)
goto nomem_free;
trace_fscache_page_op(cookie, page, &op->op, fscache_page_op_write_one);
ret = -ENOBUFS;
spin_lock(&cookie->lock);
if (!fscache_cookie_enabled(cookie) ||
hlist_empty(&cookie->backing_objects))
goto nobufs;
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object, cookie_link);
if (test_bit(FSCACHE_IOERROR, &object->cache->flags))
goto nobufs;
trace_fscache_page(cookie, page, fscache_page_write);
/* add the page to the pending-storage radix tree on the backing
* object */
spin_lock(&object->lock);
if (object->store_limit_l != object_size)
fscache_set_store_limit(object, object_size);
spin_lock(&cookie->stores_lock);
_debug("store limit %llx", (unsigned long long) object->store_limit);
ret = radix_tree_insert(&cookie->stores, page->index, page);
if (ret < 0) {
if (ret == -EEXIST)
goto already_queued;
_debug("insert failed %d", ret);
goto nobufs_unlock_obj;
}
trace_fscache_page(cookie, page, fscache_page_radix_insert);
radix_tree_tag_set(&cookie->stores, page->index,
FSCACHE_COOKIE_PENDING_TAG);
trace_fscache_page(cookie, page, fscache_page_radix_set_pend);
get_page(page);
/* we only want one writer at a time, but we do need to queue new
* writers after exclusive ops */
if (test_and_set_bit(FSCACHE_OBJECT_PENDING_WRITE, &object->flags))
goto already_pending;
spin_unlock(&cookie->stores_lock);
spin_unlock(&object->lock);
op->op.debug_id = atomic_inc_return(&fscache_op_debug_id);
op->store_limit = object->store_limit;
__fscache_use_cookie(cookie);
if (fscache_submit_op(object, &op->op) < 0)
goto submit_failed;
spin_unlock(&cookie->lock);
radix_tree_preload_end();
fscache_stat(&fscache_n_store_ops);
fscache_stat(&fscache_n_stores_ok);
/* the work queue now carries its own ref on the object */
fscache_put_operation(&op->op);
_leave(" = 0");
return 0;
already_queued:
fscache_stat(&fscache_n_stores_again);
already_pending:
spin_unlock(&cookie->stores_lock);
spin_unlock(&object->lock);
spin_unlock(&cookie->lock);
radix_tree_preload_end();
fscache_put_operation(&op->op);
fscache_stat(&fscache_n_stores_ok);
_leave(" = 0");
return 0;
submit_failed:
spin_lock(&cookie->stores_lock);
radix_tree_delete(&cookie->stores, page->index);
trace_fscache_page(cookie, page, fscache_page_radix_delete);
spin_unlock(&cookie->stores_lock);
wake_cookie = __fscache_unuse_cookie(cookie);
put_page(page);
ret = -ENOBUFS;
goto nobufs;
nobufs_unlock_obj:
spin_unlock(&cookie->stores_lock);
spin_unlock(&object->lock);
nobufs:
spin_unlock(&cookie->lock);
radix_tree_preload_end();
fscache_put_operation(&op->op);
if (wake_cookie)
__fscache_wake_unused_cookie(cookie);
fscache_stat(&fscache_n_stores_nobufs);
_leave(" = -ENOBUFS");
return -ENOBUFS;
nomem_free:
fscache_put_operation(&op->op);
nomem:
fscache_stat(&fscache_n_stores_oom);
_leave(" = -ENOMEM");
return -ENOMEM;
}
EXPORT_SYMBOL(__fscache_write_page);
/*
* remove a page from the cache
*/
void __fscache_uncache_page(struct fscache_cookie *cookie, struct page *page)
{
struct fscache_object *object;
_enter(",%p", page);
ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);
ASSERTCMP(page, !=, NULL);
fscache_stat(&fscache_n_uncaches);
/* cache withdrawal may beat us to it */
if (!PageFsCache(page))
goto done;
trace_fscache_page(cookie, page, fscache_page_uncache);
/* get the object */
spin_lock(&cookie->lock);
if (hlist_empty(&cookie->backing_objects)) {
ClearPageFsCache(page);
goto done_unlock;
}
object = hlist_entry(cookie->backing_objects.first,
struct fscache_object, cookie_link);
/* there might now be stuff on disk we could read */
clear_bit(FSCACHE_COOKIE_NO_DATA_YET, &cookie->flags);
/* only invoke the cache backend if we managed to mark the page
* uncached here; this deals with synchronisation vs withdrawal */
if (TestClearPageFsCache(page) &&
object->cache->ops->uncache_page) {
/* the cache backend releases the cookie lock */
fscache_stat(&fscache_n_cop_uncache_page);
object->cache->ops->uncache_page(object, page);
fscache_stat_d(&fscache_n_cop_uncache_page);
goto done;
}
done_unlock:
spin_unlock(&cookie->lock);
done:
_leave("");
}
EXPORT_SYMBOL(__fscache_uncache_page);
/**
* fscache_mark_page_cached - Mark a page as being cached
* @op: The retrieval op pages are being marked for
* @page: The page to be marked
*
* Mark a netfs page as being cached. After this is called, the netfs
* must call fscache_uncache_page() to remove the mark.
*/
void fscache_mark_page_cached(struct fscache_retrieval *op, struct page *page)
{
struct fscache_cookie *cookie = op->op.object->cookie;
#ifdef CONFIG_FSCACHE_STATS
atomic_inc(&fscache_n_marks);
#endif
trace_fscache_page(cookie, page, fscache_page_cached);
_debug("- mark %p{%lx}", page, page->index);
if (TestSetPageFsCache(page)) {
static bool once_only;
if (!once_only) {
once_only = true;
pr_warn("Cookie type %s marked page %lx multiple times\n",
cookie->def->name, page->index);
}
}
if (cookie->def->mark_page_cached)
cookie->def->mark_page_cached(cookie->netfs_data,
op->mapping, page);
}
EXPORT_SYMBOL(fscache_mark_page_cached);
/**
* fscache_mark_pages_cached - Mark pages as being cached
* @op: The retrieval op pages are being marked for
* @pagevec: The pages to be marked
*
* Mark a bunch of netfs pages as being cached. After this is called,
* the netfs must call fscache_uncache_page() to remove the mark.
*/
void fscache_mark_pages_cached(struct fscache_retrieval *op,
struct pagevec *pagevec)
{
unsigned long loop;
for (loop = 0; loop < pagevec->nr; loop++)
fscache_mark_page_cached(op, pagevec->pages[loop]);
pagevec_reinit(pagevec);
}
EXPORT_SYMBOL(fscache_mark_pages_cached);
/*
* Uncache all the pages in an inode that are marked PG_fscache, assuming them
* to be associated with the given cookie.
*/
void __fscache_uncache_all_inode_pages(struct fscache_cookie *cookie,
struct inode *inode)
{
struct address_space *mapping = inode->i_mapping;
struct pagevec pvec;
pgoff_t next;
int i;
_enter("%p,%p", cookie, inode);
if (!mapping || mapping->nrpages == 0) {
_leave(" [no pages]");
return;
}
pagevec_init(&pvec);
next = 0;
do {
if (!pagevec_lookup(&pvec, mapping, &next))
break;
for (i = 0; i < pagevec_count(&pvec); i++) {
struct page *page = pvec.pages[i];
if (PageFsCache(page)) {
__fscache_wait_on_page_write(cookie, page);
__fscache_uncache_page(cookie, page);
}
}
pagevec_release(&pvec);
cond_resched();
} while (next);
_leave("");
}
EXPORT_SYMBOL(__fscache_uncache_all_inode_pages);
fs/fscache/proc.c deleted 100644 → 0
View file @ 850cba06
// SPDX-License-Identifier: GPL-2.0-or-later
/* FS-Cache statistics viewing interface
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#define FSCACHE_DEBUG_LEVEL OPERATION
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "internal.h"
/*
* initialise the /proc/fs/fscache/ directory
*/
int __init fscache_proc_init(void)
{
_enter("");
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_OBJECT_LIST
if (!proc_create("fs/fscache/objects", S_IFREG | 0444, NULL,
&fscache_objlist_proc_ops))
goto error_objects;
#endif
_leave(" = 0");
return 0;
#ifdef CONFIG_FSCACHE_OBJECT_LIST
error_objects:
#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");
return -ENOMEM;
}
/*
* clean up the /proc/fs/fscache/ directory
*/
void fscache_proc_cleanup(void)
{
#ifdef CONFIG_FSCACHE_OBJECT_LIST
remove_proc_entry("fs/fscache/objects", 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);
}
fs/fscache/stats.c deleted 100644 → 0
View file @ 850cba06
// SPDX-License-Identifier: GPL-2.0-or-later
/* FS-Cache statistics
*
* Copyright (C) 2007 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"
/*
* operation counters
*/
atomic_t fscache_n_op_pend;
atomic_t fscache_n_op_run;
atomic_t fscache_n_op_enqueue;
atomic_t fscache_n_op_deferred_release;
atomic_t fscache_n_op_initialised;
atomic_t fscache_n_op_release;
atomic_t fscache_n_op_gc;
atomic_t fscache_n_op_cancelled;
atomic_t fscache_n_op_rejected;
atomic_t fscache_n_attr_changed;
atomic_t fscache_n_attr_changed_ok;
atomic_t fscache_n_attr_changed_nobufs;
atomic_t fscache_n_attr_changed_nomem;
atomic_t fscache_n_attr_changed_calls;
atomic_t fscache_n_allocs;
atomic_t fscache_n_allocs_ok;
atomic_t fscache_n_allocs_wait;
atomic_t fscache_n_allocs_nobufs;
atomic_t fscache_n_allocs_intr;
atomic_t fscache_n_allocs_object_dead;
atomic_t fscache_n_alloc_ops;
atomic_t fscache_n_alloc_op_waits;
atomic_t fscache_n_retrievals;
atomic_t fscache_n_retrievals_ok;
atomic_t fscache_n_retrievals_wait;
atomic_t fscache_n_retrievals_nodata;
atomic_t fscache_n_retrievals_nobufs;
atomic_t fscache_n_retrievals_intr;
atomic_t fscache_n_retrievals_nomem;
atomic_t fscache_n_retrievals_object_dead;
atomic_t fscache_n_retrieval_ops;
atomic_t fscache_n_retrieval_op_waits;
atomic_t fscache_n_stores;
atomic_t fscache_n_stores_ok;
atomic_t fscache_n_stores_again;
atomic_t fscache_n_stores_nobufs;
atomic_t fscache_n_stores_oom;
atomic_t fscache_n_store_ops;
atomic_t fscache_n_store_calls;
atomic_t fscache_n_store_pages;
atomic_t fscache_n_store_radix_deletes;
atomic_t fscache_n_store_pages_over_limit;
atomic_t fscache_n_store_vmscan_not_storing;
atomic_t fscache_n_store_vmscan_gone;
atomic_t fscache_n_store_vmscan_busy;
atomic_t fscache_n_store_vmscan_cancelled;
atomic_t fscache_n_store_vmscan_wait;
atomic_t fscache_n_marks;
atomic_t fscache_n_uncaches;
atomic_t fscache_n_acquires;
atomic_t fscache_n_acquires_null;
atomic_t fscache_n_acquires_no_cache;
atomic_t fscache_n_acquires_ok;
atomic_t fscache_n_acquires_nobufs;
atomic_t fscache_n_acquires_oom;
atomic_t fscache_n_invalidates;
atomic_t fscache_n_invalidates_run;
atomic_t fscache_n_updates;
atomic_t fscache_n_updates_null;
atomic_t fscache_n_updates_run;
atomic_t fscache_n_relinquishes;
atomic_t fscache_n_relinquishes_null;
atomic_t fscache_n_relinquishes_waitcrt;
atomic_t fscache_n_relinquishes_retire;
atomic_t fscache_n_cookie_index;
atomic_t fscache_n_cookie_data;
atomic_t fscache_n_cookie_special;
atomic_t fscache_n_object_alloc;
atomic_t fscache_n_object_no_alloc;
atomic_t fscache_n_object_lookups;
atomic_t fscache_n_object_lookups_negative;
atomic_t fscache_n_object_lookups_positive;
atomic_t fscache_n_object_lookups_timed_out;
atomic_t fscache_n_object_created;
atomic_t fscache_n_object_avail;
atomic_t fscache_n_object_dead;
atomic_t fscache_n_checkaux_none;
atomic_t fscache_n_checkaux_okay;
atomic_t fscache_n_checkaux_update;
atomic_t fscache_n_checkaux_obsolete;
atomic_t fscache_n_cop_alloc_object;
atomic_t fscache_n_cop_lookup_object;
atomic_t fscache_n_cop_lookup_complete;
atomic_t fscache_n_cop_grab_object;
atomic_t fscache_n_cop_invalidate_object;
atomic_t fscache_n_cop_update_object;
atomic_t fscache_n_cop_drop_object;
atomic_t fscache_n_cop_put_object;
atomic_t fscache_n_cop_sync_cache;
atomic_t fscache_n_cop_attr_changed;
atomic_t fscache_n_cop_read_or_alloc_page;
atomic_t fscache_n_cop_read_or_alloc_pages;
atomic_t fscache_n_cop_allocate_page;
atomic_t fscache_n_cop_allocate_pages;
atomic_t fscache_n_cop_write_page;
atomic_t fscache_n_cop_uncache_page;
atomic_t fscache_n_cop_dissociate_pages;
atomic_t fscache_n_cache_no_space_reject;
atomic_t fscache_n_cache_stale_objects;
atomic_t fscache_n_cache_retired_objects;
atomic_t fscache_n_cache_culled_objects;
/*
* display the general statistics
*/
int fscache_stats_show(struct seq_file *m, void *v)
{
seq_puts(m, "FS-Cache statistics\n");
seq_printf(m, "Cookies: idx=%u dat=%u spc=%u\n",
atomic_read(&fscache_n_cookie_index),
atomic_read(&fscache_n_cookie_data),
atomic_read(&fscache_n_cookie_special));
seq_printf(m, "Objects: alc=%u nal=%u avl=%u ded=%u\n",
atomic_read(&fscache_n_object_alloc),
atomic_read(&fscache_n_object_no_alloc),
atomic_read(&fscache_n_object_avail),
atomic_read(&fscache_n_object_dead));
seq_printf(m, "ChkAux : non=%u ok=%u upd=%u obs=%u\n",
atomic_read(&fscache_n_checkaux_none),
atomic_read(&fscache_n_checkaux_okay),
atomic_read(&fscache_n_checkaux_update),
atomic_read(&fscache_n_checkaux_obsolete));
seq_printf(m, "Pages : mrk=%u unc=%u\n",
atomic_read(&fscache_n_marks),
atomic_read(&fscache_n_uncaches));
seq_printf(m, "Acquire: n=%u nul=%u noc=%u ok=%u nbf=%u"
" oom=%u\n",
atomic_read(&fscache_n_acquires),
atomic_read(&fscache_n_acquires_null),
atomic_read(&fscache_n_acquires_no_cache),
atomic_read(&fscache_n_acquires_ok),
atomic_read(&fscache_n_acquires_nobufs),
atomic_read(&fscache_n_acquires_oom));
seq_printf(m, "Lookups: n=%u neg=%u pos=%u crt=%u tmo=%u\n",
atomic_read(&fscache_n_object_lookups),
atomic_read(&fscache_n_object_lookups_negative),
atomic_read(&fscache_n_object_lookups_positive),
atomic_read(&fscache_n_object_created),
atomic_read(&fscache_n_object_lookups_timed_out));
seq_printf(m, "Invals : n=%u run=%u\n",
atomic_read(&fscache_n_invalidates),
atomic_read(&fscache_n_invalidates_run));
seq_printf(m, "Updates: n=%u nul=%u run=%u\n",
atomic_read(&fscache_n_updates),
atomic_read(&fscache_n_updates_null),
atomic_read(&fscache_n_updates_run));
seq_printf(m, "Relinqs: n=%u nul=%u wcr=%u rtr=%u\n",
atomic_read(&fscache_n_relinquishes),
atomic_read(&fscache_n_relinquishes_null),
atomic_read(&fscache_n_relinquishes_waitcrt),
atomic_read(&fscache_n_relinquishes_retire));
seq_printf(m, "AttrChg: n=%u ok=%u nbf=%u oom=%u run=%u\n",
atomic_read(&fscache_n_attr_changed),
atomic_read(&fscache_n_attr_changed_ok),
atomic_read(&fscache_n_attr_changed_nobufs),
atomic_read(&fscache_n_attr_changed_nomem),
atomic_read(&fscache_n_attr_changed_calls));
seq_printf(m, "Allocs : n=%u ok=%u wt=%u nbf=%u int=%u\n",
atomic_read(&fscache_n_allocs),
atomic_read(&fscache_n_allocs_ok),
atomic_read(&fscache_n_allocs_wait),
atomic_read(&fscache_n_allocs_nobufs),
atomic_read(&fscache_n_allocs_intr));
seq_printf(m, "Allocs : ops=%u owt=%u abt=%u\n",
atomic_read(&fscache_n_alloc_ops),
atomic_read(&fscache_n_alloc_op_waits),
atomic_read(&fscache_n_allocs_object_dead));
seq_printf(m, "Retrvls: n=%u ok=%u wt=%u nod=%u nbf=%u"
" int=%u oom=%u\n",
atomic_read(&fscache_n_retrievals),
atomic_read(&fscache_n_retrievals_ok),
atomic_read(&fscache_n_retrievals_wait),
atomic_read(&fscache_n_retrievals_nodata),
atomic_read(&fscache_n_retrievals_nobufs),
atomic_read(&fscache_n_retrievals_intr),
atomic_read(&fscache_n_retrievals_nomem));
seq_printf(m, "Retrvls: ops=%u owt=%u abt=%u\n",
atomic_read(&fscache_n_retrieval_ops),
atomic_read(&fscache_n_retrieval_op_waits),
atomic_read(&fscache_n_retrievals_object_dead));
seq_printf(m, "Stores : n=%u ok=%u agn=%u nbf=%u oom=%u\n",
atomic_read(&fscache_n_stores),
atomic_read(&fscache_n_stores_ok),
atomic_read(&fscache_n_stores_again),
atomic_read(&fscache_n_stores_nobufs),
atomic_read(&fscache_n_stores_oom));
seq_printf(m, "Stores : ops=%u run=%u pgs=%u rxd=%u olm=%u\n",
atomic_read(&fscache_n_store_ops),
atomic_read(&fscache_n_store_calls),
atomic_read(&fscache_n_store_pages),
atomic_read(&fscache_n_store_radix_deletes),
atomic_read(&fscache_n_store_pages_over_limit));
seq_printf(m, "VmScan : nos=%u gon=%u bsy=%u can=%u wt=%u\n",
atomic_read(&fscache_n_store_vmscan_not_storing),
atomic_read(&fscache_n_store_vmscan_gone),
atomic_read(&fscache_n_store_vmscan_busy),
atomic_read(&fscache_n_store_vmscan_cancelled),
atomic_read(&fscache_n_store_vmscan_wait));
seq_printf(m, "Ops : pend=%u run=%u enq=%u can=%u rej=%u\n",
atomic_read(&fscache_n_op_pend),
atomic_read(&fscache_n_op_run),
atomic_read(&fscache_n_op_enqueue),
atomic_read(&fscache_n_op_cancelled),
atomic_read(&fscache_n_op_rejected));
seq_printf(m, "Ops : ini=%u dfr=%u rel=%u gc=%u\n",
atomic_read(&fscache_n_op_initialised),
atomic_read(&fscache_n_op_deferred_release),
atomic_read(&fscache_n_op_release),
atomic_read(&fscache_n_op_gc));
seq_printf(m, "CacheOp: alo=%d luo=%d luc=%d gro=%d\n",
atomic_read(&fscache_n_cop_alloc_object),
atomic_read(&fscache_n_cop_lookup_object),
atomic_read(&fscache_n_cop_lookup_complete),
atomic_read(&fscache_n_cop_grab_object));
seq_printf(m, "CacheOp: inv=%d upo=%d dro=%d pto=%d atc=%d syn=%d\n",
atomic_read(&fscache_n_cop_invalidate_object),
atomic_read(&fscache_n_cop_update_object),
atomic_read(&fscache_n_cop_drop_object),
atomic_read(&fscache_n_cop_put_object),
atomic_read(&fscache_n_cop_attr_changed),
atomic_read(&fscache_n_cop_sync_cache));
seq_printf(m, "CacheOp: rap=%d ras=%d alp=%d als=%d wrp=%d ucp=%d dsp=%d\n",
atomic_read(&fscache_n_cop_read_or_alloc_page),
atomic_read(&fscache_n_cop_read_or_alloc_pages),
atomic_read(&fscache_n_cop_allocate_page),
atomic_read(&fscache_n_cop_allocate_pages),
atomic_read(&fscache_n_cop_write_page),
atomic_read(&fscache_n_cop_uncache_page),
atomic_read(&fscache_n_cop_dissociate_pages));
seq_printf(m, "CacheEv: nsp=%d stl=%d rtr=%d cul=%d\n",
atomic_read(&fscache_n_cache_no_space_reject),
atomic_read(&fscache_n_cache_stale_objects),
atomic_read(&fscache_n_cache_retired_objects),
atomic_read(&fscache_n_cache_culled_objects));
netfs_stats_show(m);
return 0;
}
include/linux/fscache-cache.h
View file @ 2cee6fbb
/* SPDX-License-Identifier: GPL-2.0-or-later */
/* General filesystem caching backing cache interface
*
* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Copyright (C) 2021 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* NOTE!!! See:
......@@ -15,551 +15,5 @@
#define _LINUX_FSCACHE_CACHE_H
#include <linux/fscache.h>
#include <linux/sched.h>
#include <linux/workqueue.h>
#define NR_MAXCACHES BITS_PER_LONG
struct fscache_cache;
struct fscache_cache_ops;
struct fscache_object;
struct fscache_operation;
enum fscache_obj_ref_trace {
fscache_obj_get_add_to_deps,
fscache_obj_get_queue,
fscache_obj_put_alloc_fail,
fscache_obj_put_attach_fail,
fscache_obj_put_drop_obj,
fscache_obj_put_enq_dep,
fscache_obj_put_queue,
fscache_obj_put_work,
fscache_obj_ref__nr_traces
};
/*
* cache tag definition
*/
struct fscache_cache_tag {
struct list_head link;
struct fscache_cache *cache; /* cache referred to by this tag */
unsigned long flags;
#define FSCACHE_TAG_RESERVED 0 /* T if tag is reserved for a cache */
atomic_t usage;
char name[]; /* tag name */
};
/*
* cache definition
*/
struct fscache_cache {
const struct fscache_cache_ops *ops;
struct fscache_cache_tag *tag; /* tag representing this cache */
struct kobject *kobj; /* system representation of this cache */
struct list_head link; /* link in list of caches */
size_t max_index_size; /* maximum size of index data */
char identifier[36]; /* cache label */
/* node management */
struct work_struct op_gc; /* operation garbage collector */
struct list_head object_list; /* list of data/index objects */
struct list_head op_gc_list; /* list of ops to be deleted */
spinlock_t object_list_lock;
spinlock_t op_gc_list_lock;
atomic_t object_count; /* no. of live objects in this cache */
struct fscache_object *fsdef; /* object for the fsdef index */
unsigned long flags;
#define FSCACHE_IOERROR 0 /* cache stopped on I/O error */
#define FSCACHE_CACHE_WITHDRAWN 1 /* cache has been withdrawn */
};
extern wait_queue_head_t fscache_cache_cleared_wq;
/*
* operation to be applied to a cache object
* - retrieval initiation operations are done in the context of the process
* that issued them, and not in an async thread pool
*/
typedef void (*fscache_operation_release_t)(struct fscache_operation *op);
typedef void (*fscache_operation_processor_t)(struct fscache_operation *op);
typedef void (*fscache_operation_cancel_t)(struct fscache_operation *op);
enum fscache_operation_state {
FSCACHE_OP_ST_BLANK, /* Op is not yet submitted */
FSCACHE_OP_ST_INITIALISED, /* Op is initialised */
FSCACHE_OP_ST_PENDING, /* Op is blocked from running */
FSCACHE_OP_ST_IN_PROGRESS, /* Op is in progress */
FSCACHE_OP_ST_COMPLETE, /* Op is complete */
FSCACHE_OP_ST_CANCELLED, /* Op has been cancelled */
FSCACHE_OP_ST_DEAD /* Op is now dead */
};
struct fscache_operation {
struct work_struct work; /* record for async ops */
struct list_head pend_link; /* link in object->pending_ops */
struct fscache_object *object; /* object to be operated upon */
unsigned long flags;
#define FSCACHE_OP_TYPE 0x000f /* operation type */
#define FSCACHE_OP_ASYNC 0x0001 /* - async op, processor may sleep for disk */
#define FSCACHE_OP_MYTHREAD 0x0002 /* - processing is done be issuing thread, not pool */
#define FSCACHE_OP_WAITING 4 /* cleared when op is woken */
#define FSCACHE_OP_EXCLUSIVE 5 /* exclusive op, other ops must wait */
#define FSCACHE_OP_DEC_READ_CNT 6 /* decrement object->n_reads on destruction */
#define FSCACHE_OP_UNUSE_COOKIE 7 /* call fscache_unuse_cookie() on completion */
#define FSCACHE_OP_KEEP_FLAGS 0x00f0 /* flags to keep when repurposing an op */
enum fscache_operation_state state;
atomic_t usage;
unsigned debug_id; /* debugging ID */
/* operation processor callback
* - can be NULL if FSCACHE_OP_WAITING is going to be used to perform
* the op in a non-pool thread */
fscache_operation_processor_t processor;
/* Operation cancellation cleanup (optional) */
fscache_operation_cancel_t cancel;
/* operation releaser */
fscache_operation_release_t release;
};
extern atomic_t fscache_op_debug_id;
extern void fscache_op_work_func(struct work_struct *work);
extern void fscache_enqueue_operation(struct fscache_operation *);
extern void fscache_op_complete(struct fscache_operation *, bool);
extern void fscache_put_operation(struct fscache_operation *);
extern void fscache_operation_init(struct fscache_cookie *,
struct fscache_operation *,
fscache_operation_processor_t,
fscache_operation_cancel_t,
fscache_operation_release_t);
/*
* data read operation
*/
struct fscache_retrieval {
struct fscache_operation op;
struct fscache_cookie *cookie; /* The netfs cookie */
struct address_space *mapping; /* netfs pages */
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 */
atomic_t n_pages; /* number of pages to be retrieved */
};
typedef int (*fscache_page_retrieval_func_t)(struct fscache_retrieval *op,
struct page *page,
gfp_t gfp);
typedef int (*fscache_pages_retrieval_func_t)(struct fscache_retrieval *op,
struct list_head *pages,
unsigned *nr_pages,
gfp_t gfp);
/**
* fscache_get_retrieval - Get an extra reference on a retrieval operation
* @op: The retrieval operation to get a reference on
*
* Get an extra reference on a retrieval operation.
*/
static inline
struct fscache_retrieval *fscache_get_retrieval(struct fscache_retrieval *op)
{
atomic_inc(&op->op.usage);
return op;
}
/**
* fscache_enqueue_retrieval - Enqueue a retrieval operation for processing
* @op: The retrieval operation affected
*
* Enqueue a retrieval operation for processing by the FS-Cache thread pool.
*/
static inline void fscache_enqueue_retrieval(struct fscache_retrieval *op)
{
fscache_enqueue_operation(&op->op);
}
/**
* fscache_retrieval_complete - Record (partial) completion of a retrieval
* @op: The retrieval operation affected
* @n_pages: The number of pages to account for
*/
static inline void fscache_retrieval_complete(struct fscache_retrieval *op,
int n_pages)
{
if (atomic_sub_return_relaxed(n_pages, &op->n_pages) <= 0)
fscache_op_complete(&op->op, false);
}
/**
* fscache_put_retrieval - Drop a reference to a retrieval operation
* @op: The retrieval operation affected
*
* Drop a reference to a retrieval operation.
*/
static inline void fscache_put_retrieval(struct fscache_retrieval *op)
{
fscache_put_operation(&op->op);
}
/*
* cached page storage work item
* - used to do three things:
* - batch writes to the cache
* - do cache writes asynchronously
* - defer writes until cache object lookup completion
*/
struct fscache_storage {
struct fscache_operation op;
pgoff_t store_limit; /* don't write more than this */
};
/*
* cache operations
*/
struct fscache_cache_ops {
/* name of cache provider */
const char *name;
/* allocate an object record for a cookie */
struct fscache_object *(*alloc_object)(struct fscache_cache *cache,
struct fscache_cookie *cookie);
/* look up the object for a cookie
* - return -ETIMEDOUT to be requeued
*/
int (*lookup_object)(struct fscache_object *object);
/* finished looking up */
void (*lookup_complete)(struct fscache_object *object);
/* increment the usage count on this object (may fail if unmounting) */
struct fscache_object *(*grab_object)(struct fscache_object *object,
enum fscache_obj_ref_trace why);
/* pin an object in the cache */
int (*pin_object)(struct fscache_object *object);
/* unpin an object in the cache */
void (*unpin_object)(struct fscache_object *object);
/* check the consistency between the backing cache and the FS-Cache
* cookie */
int (*check_consistency)(struct fscache_operation *op);
/* store the updated auxiliary data on an object */
void (*update_object)(struct fscache_object *object);
/* Invalidate an object */
void (*invalidate_object)(struct fscache_operation *op);
/* discard the resources pinned by an object and effect retirement if
* necessary */
void (*drop_object)(struct fscache_object *object);
/* dispose of a reference to an object */
void (*put_object)(struct fscache_object *object,
enum fscache_obj_ref_trace why);
/* sync a cache */
void (*sync_cache)(struct fscache_cache *cache);
/* notification that the attributes of a non-index object (such as
* i_size) have changed */
int (*attr_changed)(struct fscache_object *object);
/* reserve space for an object's data and associated metadata */
int (*reserve_space)(struct fscache_object *object, loff_t i_size);
/* request a backing block for a page be read or allocated in the
* cache */
fscache_page_retrieval_func_t read_or_alloc_page;
/* request backing blocks for a list of pages be read or allocated in
* the cache */
fscache_pages_retrieval_func_t read_or_alloc_pages;
/* request a backing block for a page be allocated in the cache so that
* it can be written directly */
fscache_page_retrieval_func_t allocate_page;
/* request backing blocks for pages be allocated in the cache so that
* they can be written directly */
fscache_pages_retrieval_func_t allocate_pages;
/* write a page to its backing block in the cache */
int (*write_page)(struct fscache_storage *op, struct page *page);
/* detach backing block from a page (optional)
* - must release the cookie lock before returning
* - may sleep
*/
void (*uncache_page)(struct fscache_object *object,
struct page *page);
/* dissociate a cache from all the pages it was backing */
void (*dissociate_pages)(struct fscache_cache *cache);
/* Begin a read operation for the netfs lib */
int (*begin_read_operation)(struct netfs_read_request *rreq,
struct fscache_retrieval *op);
};
extern struct fscache_cookie fscache_fsdef_index;
/*
* Event list for fscache_object::{event_mask,events}
*/
enum {
FSCACHE_OBJECT_EV_NEW_CHILD, /* T if object has a new child */
FSCACHE_OBJECT_EV_PARENT_READY, /* T if object's parent is ready */
FSCACHE_OBJECT_EV_UPDATE, /* T if object should be updated */
FSCACHE_OBJECT_EV_INVALIDATE, /* T if cache requested object invalidation */
FSCACHE_OBJECT_EV_CLEARED, /* T if accessors all gone */
FSCACHE_OBJECT_EV_ERROR, /* T if fatal error occurred during processing */
FSCACHE_OBJECT_EV_KILL, /* T if netfs relinquished or cache withdrew object */
NR_FSCACHE_OBJECT_EVENTS
};
#define FSCACHE_OBJECT_EVENTS_MASK ((1UL << NR_FSCACHE_OBJECT_EVENTS) - 1)
/*
* States for object state machine.
*/
struct fscache_transition {
unsigned long events;
const struct fscache_state *transit_to;
};
struct fscache_state {
char name[24];
char short_name[8];
const struct fscache_state *(*work)(struct fscache_object *object,
int event);
const struct fscache_transition transitions[];
};
/*
* on-disk cache file or index handle
*/
struct fscache_object {
const struct fscache_state *state; /* Object state machine state */
const struct fscache_transition *oob_table; /* OOB state transition table */
int debug_id; /* debugging ID */
int n_children; /* number of child objects */
int n_ops; /* number of extant ops on object */
int n_obj_ops; /* number of object ops outstanding on object */
int n_in_progress; /* number of ops in progress */
int n_exclusive; /* number of exclusive ops queued or in progress */
atomic_t n_reads; /* number of read ops in progress */
spinlock_t lock; /* state and operations lock */
unsigned long lookup_jif; /* time at which lookup started */
unsigned long oob_event_mask; /* OOB events this object is interested in */
unsigned long event_mask; /* events this object is interested in */
unsigned long events; /* events to be processed by this object
* (order is important - using fls) */
unsigned long flags;
#define FSCACHE_OBJECT_LOCK 0 /* T if object is busy being processed */
#define FSCACHE_OBJECT_PENDING_WRITE 1 /* T if object has pending write */
#define FSCACHE_OBJECT_WAITING 2 /* T if object is waiting on its parent */
#define FSCACHE_OBJECT_IS_LIVE 3 /* T if object is not withdrawn or relinquished */
#define FSCACHE_OBJECT_IS_LOOKED_UP 4 /* T if object has been looked up */
#define FSCACHE_OBJECT_IS_AVAILABLE 5 /* T if object has become active */
#define FSCACHE_OBJECT_RETIRED 6 /* T if object was retired on relinquishment */
#define FSCACHE_OBJECT_KILLED_BY_CACHE 7 /* T if object was killed by the cache */
#define FSCACHE_OBJECT_RUN_AFTER_DEAD 8 /* T if object has been dispatched after death */
struct list_head cache_link; /* link in cache->object_list */
struct hlist_node cookie_link; /* link in cookie->backing_objects */
struct fscache_cache *cache; /* cache that supplied this object */
struct fscache_cookie *cookie; /* netfs's file/index object */
struct fscache_object *parent; /* parent object */
struct work_struct work; /* attention scheduling record */
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 */
pgoff_t store_limit; /* current storage limit */
loff_t store_limit_l; /* current storage limit */
};
extern void fscache_object_init(struct fscache_object *, struct fscache_cookie *,
struct fscache_cache *);
extern void fscache_object_destroy(struct fscache_object *);
extern void fscache_object_lookup_negative(struct fscache_object *object);
extern void fscache_obtained_object(struct fscache_object *object);
static inline bool fscache_object_is_live(struct fscache_object *object)
{
return test_bit(FSCACHE_OBJECT_IS_LIVE, &object->flags);
}
static inline bool fscache_object_is_dying(struct fscache_object *object)
{
return !fscache_object_is_live(object);
}
static inline bool fscache_object_is_available(struct fscache_object *object)
{
return test_bit(FSCACHE_OBJECT_IS_AVAILABLE, &object->flags);
}
static inline bool fscache_cache_is_broken(struct fscache_object *object)
{
return test_bit(FSCACHE_IOERROR, &object->cache->flags);
}
static inline bool fscache_object_is_active(struct fscache_object *object)
{
return fscache_object_is_available(object) &&
fscache_object_is_live(object) &&
!fscache_cache_is_broken(object);
}
/**
* fscache_object_destroyed - Note destruction of an object in a cache
* @cache: The cache from which the object came
*
* Note the destruction and deallocation of an object record in a cache.
*/
static inline void fscache_object_destroyed(struct fscache_cache *cache)
{
if (atomic_dec_and_test(&cache->object_count))
wake_up_all(&fscache_cache_cleared_wq);
}
/**
* fscache_object_lookup_error - Note an object encountered an error
* @object: The object on which the error was encountered
*
* Note that an object encountered a fatal error (usually an I/O error) and
* that it should be withdrawn as soon as possible.
*/
static inline void fscache_object_lookup_error(struct fscache_object *object)
{
set_bit(FSCACHE_OBJECT_EV_ERROR, &object->events);
}
/**
* fscache_set_store_limit - Set the maximum size to be stored in an object
* @object: The object to set the maximum on
* @i_size: The limit to set in bytes
*
* Set the maximum size an object is permitted to reach, implying the highest
* byte that may be written. Intended to be called by the attr_changed() op.
*
* See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
static inline
void fscache_set_store_limit(struct fscache_object *object, loff_t i_size)
{
object->store_limit_l = i_size;
object->store_limit = i_size >> PAGE_SHIFT;
if (i_size & ~PAGE_MASK)
object->store_limit++;
}
/**
* fscache_end_io - End a retrieval operation on a page
* @op: The FS-Cache operation covering the retrieval
* @page: The page that was to be fetched
* @error: The error code (0 if successful)
*
* Note the end of an operation to retrieve a page, as covered by a particular
* operation record.
*/
static inline void fscache_end_io(struct fscache_retrieval *op,
struct page *page, int error)
{
op->end_io_func(page, op->context, error);
}
static inline void __fscache_use_cookie(struct fscache_cookie *cookie)
{
atomic_inc(&cookie->n_active);
}
/**
* fscache_use_cookie - Request usage of cookie attached to an object
* @object: Object description
*
* Request usage of the cookie attached to an object. NULL is returned if the
* relinquishment had reduced the cookie usage count to 0.
*/
static inline bool fscache_use_cookie(struct fscache_object *object)
{
struct fscache_cookie *cookie = object->cookie;
return atomic_inc_not_zero(&cookie->n_active) != 0;
}
static inline bool __fscache_unuse_cookie(struct fscache_cookie *cookie)
{
return atomic_dec_and_test(&cookie->n_active);
}
static inline void __fscache_wake_unused_cookie(struct fscache_cookie *cookie)
{
wake_up_var(&cookie->n_active);
}
/**
* fscache_unuse_cookie - Cease usage of cookie attached to an object
* @object: Object description
*
* Cease usage of the cookie attached to an object. When the users count
* reaches zero then the cookie relinquishment will be permitted to proceed.
*/
static inline void fscache_unuse_cookie(struct fscache_object *object)
{
struct fscache_cookie *cookie = object->cookie;
if (__fscache_unuse_cookie(cookie))
__fscache_wake_unused_cookie(cookie);
}
/*
* out-of-line cache backend functions
*/
extern __printf(3, 4)
void fscache_init_cache(struct fscache_cache *cache,
const struct fscache_cache_ops *ops,
const char *idfmt, ...);
extern int fscache_add_cache(struct fscache_cache *cache,
struct fscache_object *fsdef,
const char *tagname);
extern void fscache_withdraw_cache(struct fscache_cache *cache);
extern void fscache_io_error(struct fscache_cache *cache);
extern void fscache_mark_page_cached(struct fscache_retrieval *op,
struct page *page);
extern void fscache_mark_pages_cached(struct fscache_retrieval *op,
struct pagevec *pagevec);
extern bool fscache_object_sleep_till_congested(signed long *timeoutp);
extern enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
const void *data,
uint16_t datalen,
loff_t object_size);
extern void fscache_object_retrying_stale(struct fscache_object *object);
enum fscache_why_object_killed {
FSCACHE_OBJECT_IS_STALE,
FSCACHE_OBJECT_NO_SPACE,
FSCACHE_OBJECT_WAS_RETIRED,
FSCACHE_OBJECT_WAS_CULLED,
};
extern void fscache_object_mark_killed(struct fscache_object *object,
enum fscache_why_object_killed why);
#endif /* _LINUX_FSCACHE_CACHE_H */
include/linux/fscache.h
View file @ 2cee6fbb
......@@ -15,861 +15,14 @@
#define _LINUX_FSCACHE_H
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/pagemap.h>
#include <linux/pagevec.h>
#include <linux/list_bl.h>
#include <linux/netfs.h>
#if defined(CONFIG_FSCACHE) || defined(CONFIG_FSCACHE_MODULE)
#define fscache_available() (1)
#define fscache_cookie_valid(cookie) (cookie)
#define fscache_cookie_enabled(cookie) (cookie)
#else
#define fscache_available() (0)
#define fscache_cookie_valid(cookie) (0)
#define fscache_cookie_enabled(cookie) (0)
#endif
/* pattern used to fill dead space in an index entry */
#define FSCACHE_INDEX_DEADFILL_PATTERN 0x79
struct pagevec;
struct fscache_cache_tag;
struct fscache_cookie;
struct fscache_netfs;
struct netfs_read_request;
typedef void (*fscache_rw_complete_t)(struct page *page,
void *context,
int error);
/* result of index entry consultation */
enum fscache_checkaux {
FSCACHE_CHECKAUX_OKAY, /* entry okay as is */
FSCACHE_CHECKAUX_NEEDS_UPDATE, /* entry requires update */
FSCACHE_CHECKAUX_OBSOLETE, /* entry requires deletion */
};
/*
* fscache cookie definition
*/
struct fscache_cookie_def {
/* name of cookie type */
char name[16];
/* cookie type */
uint8_t type;
#define FSCACHE_COOKIE_TYPE_INDEX 0
#define FSCACHE_COOKIE_TYPE_DATAFILE 1
/* select the cache into which to insert an entry in this index
* - optional
* - should return a cache identifier or NULL to cause the cache to be
* inherited from the parent if possible or the first cache picked
* for a non-index file if not
*/
struct fscache_cache_tag *(*select_cache)(
const void *parent_netfs_data,
const void *cookie_netfs_data);
/* consult the netfs about the state of an object
* - this function can be absent if the index carries no state data
* - the netfs data from the cookie being used as the target is
* presented, as is the auxiliary data and the object size
*/
enum fscache_checkaux (*check_aux)(void *cookie_netfs_data,
const void *data,
uint16_t datalen,
loff_t object_size);
/* get an extra reference on a read context
* - this function can be absent if the completion function doesn't
* require a context
*/
void (*get_context)(void *cookie_netfs_data, void *context);
/* release an extra reference on a read context
* - this function can be absent if the completion function doesn't
* require a context
*/
void (*put_context)(void *cookie_netfs_data, void *context);
/* indicate page that now have cache metadata retained
* - this function should mark the specified page as now being cached
* - the page will have been marked with PG_fscache before this is
* called, so this is optional
*/
void (*mark_page_cached)(void *cookie_netfs_data,
struct address_space *mapping,
struct page *page);
};
/*
* fscache cached network filesystem type
* - name, version and ops must be filled in before registration
* - all other fields will be set during registration
*/
struct fscache_netfs {
uint32_t version; /* indexing version */
const char *name; /* filesystem name */
struct fscache_cookie *primary_index;
};
/*
* data file or index object cookie
* - a file will only appear in one cache
* - a request to cache a file may or may not be honoured, subject to
* constraints such as disk space
* - indices are created on disk just-in-time
*/
struct fscache_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 */
#define FSCACHE_COOKIE_STORING_TAG 1 /* pages tag: writing to cache */
unsigned long flags;
#define FSCACHE_COOKIE_LOOKING_UP 0 /* T if non-index cookie being looked up still */
#define FSCACHE_COOKIE_NO_DATA_YET 1 /* T if new object with no cached data yet */
#define FSCACHE_COOKIE_UNAVAILABLE 2 /* T if cookie is unavailable (error, etc) */
#define FSCACHE_COOKIE_INVALIDATING 3 /* T if cookie is being invalidated */
#define FSCACHE_COOKIE_RELINQUISHED 4 /* T if cookie has been relinquished */
#define FSCACHE_COOKIE_ENABLED 5 /* T if cookie is enabled */
#define FSCACHE_COOKIE_ENABLEMENT_LOCK 6 /* T if cookie is being en/disabled */
#define FSCACHE_COOKIE_AUX_UPDATED 8 /* T if the auxiliary data was updated */
#define FSCACHE_COOKIE_ACQUIRED 9 /* T if cookie is in use */
#define FSCACHE_COOKIE_RELINQUISHING 10 /* T if cookie is being relinquished */
u8 type; /* Type of object */
u8 key_len; /* Length of index key */
u8 aux_len; /* Length of auxiliary data */
u32 key_hash; /* Hash of parent, type, key, len */
union {
void *key; /* Index key */
u8 inline_key[16]; /* - If the key is short enough */
};
union {
void *aux; /* Auxiliary data */
u8 inline_aux[8]; /* - If the aux data is short enough */
};
};
static inline bool fscache_cookie_enabled(struct fscache_cookie *cookie)
{
return fscache_cookie_valid(cookie) && test_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
}
/*
* slow-path functions for when there is actually caching available, and the
* netfs does actually have a valid token
* - these are not to be called directly
* - these are undefined symbols when FS-Cache is not configured and the
* optimiser takes care of not using them
*/
extern int __fscache_register_netfs(struct fscache_netfs *);
extern void __fscache_unregister_netfs(struct fscache_netfs *);
extern struct fscache_cache_tag *__fscache_lookup_cache_tag(const char *);
extern void __fscache_release_cache_tag(struct fscache_cache_tag *);
extern struct fscache_cookie *__fscache_acquire_cookie(
struct fscache_cookie *,
const struct fscache_cookie_def *,
const void *, size_t,
const void *, size_t,
void *, loff_t, bool);
extern void __fscache_relinquish_cookie(struct fscache_cookie *, const void *, bool);
extern int __fscache_check_consistency(struct fscache_cookie *, const void *);
extern void __fscache_update_cookie(struct fscache_cookie *, const void *);
extern int __fscache_attr_changed(struct fscache_cookie *);
extern void __fscache_invalidate(struct fscache_cookie *);
extern void __fscache_wait_on_invalidate(struct fscache_cookie *);
#ifdef FSCACHE_USE_NEW_IO_API
extern int __fscache_begin_read_operation(struct netfs_read_request *, struct fscache_cookie *);
#else
extern int __fscache_read_or_alloc_page(struct fscache_cookie *,
struct page *,
fscache_rw_complete_t,
void *,
gfp_t);
extern int __fscache_read_or_alloc_pages(struct fscache_cookie *,
struct address_space *,
struct list_head *,
unsigned *,
fscache_rw_complete_t,
void *,
gfp_t);
extern int __fscache_alloc_page(struct fscache_cookie *, struct page *, gfp_t);
extern int __fscache_write_page(struct fscache_cookie *, struct page *, loff_t, gfp_t);
extern void __fscache_uncache_page(struct fscache_cookie *, struct page *);
extern bool __fscache_check_page_write(struct fscache_cookie *, struct page *);
extern void __fscache_wait_on_page_write(struct fscache_cookie *, struct page *);
extern bool __fscache_maybe_release_page(struct fscache_cookie *, struct page *,
gfp_t);
extern void __fscache_uncache_all_inode_pages(struct fscache_cookie *,
struct inode *);
extern void __fscache_readpages_cancel(struct fscache_cookie *cookie,
struct list_head *pages);
#endif /* FSCACHE_USE_NEW_IO_API */
extern void __fscache_disable_cookie(struct fscache_cookie *, const void *, bool);
extern void __fscache_enable_cookie(struct fscache_cookie *, const void *, loff_t,
bool (*)(void *), void *);
/**
* fscache_register_netfs - Register a filesystem as desiring caching services
* @netfs: The description of the filesystem
*
* Register a filesystem as desiring caching services if they're available.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
int fscache_register_netfs(struct fscache_netfs *netfs)
{
if (fscache_available())
return __fscache_register_netfs(netfs);
else
return 0;
}
/**
* fscache_unregister_netfs - Indicate that a filesystem no longer desires
* caching services
* @netfs: The description of the filesystem
*
* Indicate that a filesystem no longer desires caching services for the
* moment.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
void fscache_unregister_netfs(struct fscache_netfs *netfs)
{
if (fscache_available())
__fscache_unregister_netfs(netfs);
}
/**
* fscache_lookup_cache_tag - Look up a cache tag
* @name: The name of the tag to search for
*
* Acquire a specific cache referral tag that can be used to select a specific
* cache in which to cache an index.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
struct fscache_cache_tag *fscache_lookup_cache_tag(const char *name)
{
if (fscache_available())
return __fscache_lookup_cache_tag(name);
else
return NULL;
}
/**
* fscache_release_cache_tag - Release a cache tag
* @tag: The tag to release
*
* Release a reference to a cache referral tag previously looked up.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
void fscache_release_cache_tag(struct fscache_cache_tag *tag)
{
if (fscache_available())
__fscache_release_cache_tag(tag);
}
/**
* fscache_acquire_cookie - Acquire a cookie to represent a cache object
* @parent: The cookie that's to be the parent of this one
* @def: A description of the cache object, including callback operations
* @index_key: The index key for this cookie
* @index_key_len: Size of the index key
* @aux_data: The auxiliary data for the cookie (may be NULL)
* @aux_data_len: Size of the auxiliary data buffer
* @netfs_data: An arbitrary piece of data to be kept in the cookie to
* represent the cache object to the netfs
* @object_size: The initial size of object
* @enable: Whether or not to enable a data cookie immediately
*
* This function is used to inform FS-Cache about part of an index hierarchy
* that can be used to locate files. This is done by requesting a cookie for
* each index in the path to the file.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
struct fscache_cookie *fscache_acquire_cookie(
struct fscache_cookie *parent,
const struct fscache_cookie_def *def,
const void *index_key,
size_t index_key_len,
const void *aux_data,
size_t aux_data_len,
void *netfs_data,
loff_t object_size,
bool enable)
{
if (fscache_cookie_valid(parent) && fscache_cookie_enabled(parent))
return __fscache_acquire_cookie(parent, def,
index_key, index_key_len,
aux_data, aux_data_len,
netfs_data, object_size, enable);
else
return NULL;
}
/**
* fscache_relinquish_cookie - Return the cookie to the cache, maybe discarding
* it
* @cookie: The cookie being returned
* @aux_data: The updated auxiliary data for the cookie (may be NULL)
* @retire: True if the cache object the cookie represents is to be discarded
*
* This function returns a cookie to the cache, forcibly discarding the
* associated cache object if retire is set to true. The opportunity is
* provided to update the auxiliary data in the cache before the object is
* disconnected.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
void fscache_relinquish_cookie(struct fscache_cookie *cookie,
const void *aux_data,
bool retire)
{
if (fscache_cookie_valid(cookie))
__fscache_relinquish_cookie(cookie, aux_data, retire);
}
/**
* fscache_check_consistency - Request validation of a cache's auxiliary data
* @cookie: The cookie representing the cache object
* @aux_data: The updated auxiliary data for the cookie (may be NULL)
*
* Request an consistency check from fscache, which passes the request to the
* backing cache. The auxiliary data on the cookie will be updated first if
* @aux_data is set.
*
* Returns 0 if consistent and -ESTALE if inconsistent. May also
* return -ENOMEM and -ERESTARTSYS.
*/
static inline
int fscache_check_consistency(struct fscache_cookie *cookie,
const void *aux_data)
{
if (fscache_cookie_valid(cookie) && fscache_cookie_enabled(cookie))
return __fscache_check_consistency(cookie, aux_data);
else
return 0;
}
/**
* fscache_update_cookie - Request that a cache object be updated
* @cookie: The cookie representing the cache object
* @aux_data: The updated auxiliary data for the cookie (may be NULL)
*
* Request an update of the index data for the cache object associated with the
* cookie. The auxiliary data on the cookie will be updated first if @aux_data
* is set.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
void fscache_update_cookie(struct fscache_cookie *cookie, const void *aux_data)
{
if (fscache_cookie_valid(cookie) && fscache_cookie_enabled(cookie))
__fscache_update_cookie(cookie, aux_data);
}
/**
* fscache_pin_cookie - Pin a data-storage cache object in its cache
* @cookie: The cookie representing the cache object
*
* Permit data-storage cache objects to be pinned in the cache.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
int fscache_pin_cookie(struct fscache_cookie *cookie)
{
return -ENOBUFS;
}
/**
* fscache_pin_cookie - Unpin a data-storage cache object in its cache
* @cookie: The cookie representing the cache object
*
* Permit data-storage cache objects to be unpinned from the cache.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
void fscache_unpin_cookie(struct fscache_cookie *cookie)
{
}
/**
* fscache_attr_changed - Notify cache that an object's attributes changed
* @cookie: The cookie representing the cache object
*
* Send a notification to the cache indicating that an object's attributes have
* changed. This includes the data size. These attributes will be obtained
* through the get_attr() cookie definition op.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
int fscache_attr_changed(struct fscache_cookie *cookie)
{
if (fscache_cookie_valid(cookie) && fscache_cookie_enabled(cookie))
return __fscache_attr_changed(cookie);
else
return -ENOBUFS;
}
/**
* fscache_invalidate - Notify cache that an object needs invalidation
* @cookie: The cookie representing the cache object
*
* Notify the cache that an object is needs to be invalidated and that it
* should abort any retrievals or stores it is doing on the cache. The object
* is then marked non-caching until such time as the invalidation is complete.
*
* This can be called with spinlocks held.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
void fscache_invalidate(struct fscache_cookie *cookie)
{
if (fscache_cookie_valid(cookie) && fscache_cookie_enabled(cookie))
__fscache_invalidate(cookie);
}
/**
* fscache_wait_on_invalidate - Wait for invalidation to complete
* @cookie: The cookie representing the cache object
*
* Wait for the invalidation of an object to complete.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
void fscache_wait_on_invalidate(struct fscache_cookie *cookie)
{
if (fscache_cookie_valid(cookie))
__fscache_wait_on_invalidate(cookie);
}
/**
* fscache_reserve_space - Reserve data space for a cached object
* @cookie: The cookie representing the cache object
* @i_size: The amount of space to be reserved
*
* Reserve an amount of space in the cache for the cache object attached to a
* cookie so that a write to that object within the space can always be
* honoured.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
int fscache_reserve_space(struct fscache_cookie *cookie, loff_t size)
{
return -ENOBUFS;
}
#ifdef FSCACHE_USE_NEW_IO_API
/**
* fscache_begin_read_operation - Begin a read operation for the netfs lib
* @rreq: The read request being undertaken
* @cookie: The cookie representing the cache object
*
* Begin a read operation on behalf of the netfs helper library. @rreq
* indicates the read request to which the operation state should be attached;
* @cookie indicates the cache object that will be accessed.
*
* This is intended to be called from the ->begin_cache_operation() netfs lib
* operation as implemented by the network filesystem.
*
* Returns:
* * 0 - Success
* * -ENOBUFS - No caching available
* * Other error code from the cache, such as -ENOMEM.
*/
static inline
int fscache_begin_read_operation(struct netfs_read_request *rreq,
struct fscache_cookie *cookie)
{
if (fscache_cookie_valid(cookie) && fscache_cookie_enabled(cookie))
return __fscache_begin_read_operation(rreq, cookie);
return -ENOBUFS;
}
#else /* FSCACHE_USE_NEW_IO_API */
/**
* fscache_read_or_alloc_page - Read a page from the cache or allocate a block
* in which to store it
* @cookie: The cookie representing the cache object
* @page: The netfs page to fill if possible
* @end_io_func: The callback to invoke when and if the page is filled
* @context: An arbitrary piece of data to pass on to end_io_func()
* @gfp: The conditions under which memory allocation should be made
*
* Read a page from the cache, or if that's not possible make a potential
* one-block reservation in the cache into which the page may be stored once
* fetched from the server.
*
* If the page is not backed by the cache object, or if it there's some reason
* it can't be, -ENOBUFS will be returned and nothing more will be done for
* that page.
*
* Else, if that page is backed by the cache, a read will be initiated directly
* to the netfs's page and 0 will be returned by this function. The
* end_io_func() callback will be invoked when the operation terminates on a
* completion or failure. Note that the callback may be invoked before the
* return.
*
* Else, if the page is unbacked, -ENODATA is returned and a block may have
* been allocated in the cache.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
int fscache_read_or_alloc_page(struct fscache_cookie *cookie,
struct page *page,
fscache_rw_complete_t end_io_func,
void *context,
gfp_t gfp)
{
if (fscache_cookie_valid(cookie) && fscache_cookie_enabled(cookie))
return __fscache_read_or_alloc_page(cookie, page, end_io_func,
context, gfp);
else
return -ENOBUFS;
}
/**
* fscache_read_or_alloc_pages - Read pages from the cache and/or allocate
* blocks in which to store them
* @cookie: The cookie representing the cache object
* @mapping: The netfs inode mapping to which the pages will be attached
* @pages: A list of potential netfs pages to be filled
* @nr_pages: Number of pages to be read and/or allocated
* @end_io_func: The callback to invoke when and if each page is filled
* @context: An arbitrary piece of data to pass on to end_io_func()
* @gfp: The conditions under which memory allocation should be made
*
* Read a set of pages from the cache, or if that's not possible, attempt to
* make a potential one-block reservation for each page in the cache into which
* that page may be stored once fetched from the server.
*
* If some pages are not backed by the cache object, or if it there's some
* reason they can't be, -ENOBUFS will be returned and nothing more will be
* done for that pages.
*
* Else, if some of the pages are backed by the cache, a read will be initiated
* directly to the netfs's page and 0 will be returned by this function. The
* end_io_func() callback will be invoked when the operation terminates on a
* completion or failure. Note that the callback may be invoked before the
* return.
*
* Else, if a page is unbacked, -ENODATA is returned and a block may have
* been allocated in the cache.
*
* Because the function may want to return all of -ENOBUFS, -ENODATA and 0 in
* regard to different pages, the return values are prioritised in that order.
* Any pages submitted for reading are removed from the pages list.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
int fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
struct address_space *mapping,
struct list_head *pages,
unsigned *nr_pages,
fscache_rw_complete_t end_io_func,
void *context,
gfp_t gfp)
{
if (fscache_cookie_valid(cookie) && fscache_cookie_enabled(cookie))
return __fscache_read_or_alloc_pages(cookie, mapping, pages,
nr_pages, end_io_func,
context, gfp);
else
return -ENOBUFS;
}
/**
* fscache_alloc_page - Allocate a block in which to store a page
* @cookie: The cookie representing the cache object
* @page: The netfs page to allocate a page for
* @gfp: The conditions under which memory allocation should be made
*
* Request Allocation a block in the cache in which to store a netfs page
* without retrieving any contents from the cache.
*
* If the page is not backed by a file then -ENOBUFS will be returned and
* nothing more will be done, and no reservation will be made.
*
* Else, a block will be allocated if one wasn't already, and 0 will be
* returned
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
int fscache_alloc_page(struct fscache_cookie *cookie,
struct page *page,
gfp_t gfp)
{
if (fscache_cookie_valid(cookie) && fscache_cookie_enabled(cookie))
return __fscache_alloc_page(cookie, page, gfp);
else
return -ENOBUFS;
}
/**
* fscache_readpages_cancel - Cancel read/alloc on pages
* @cookie: The cookie representing the inode's cache object.
* @pages: The netfs pages that we canceled write on in readpages()
*
* Uncache/unreserve the pages reserved earlier in readpages() via
* fscache_readpages_or_alloc() and similar. In most successful caches in
* readpages() this doesn't do anything. In cases when the underlying netfs's
* readahead failed we need to clean up the pagelist (unmark and uncache).
*
* This function may sleep as it may have to clean up disk state.
*/
static inline
void fscache_readpages_cancel(struct fscache_cookie *cookie,
struct list_head *pages)
{
if (fscache_cookie_valid(cookie))
__fscache_readpages_cancel(cookie, pages);
}
/**
* fscache_write_page - Request storage of a page in the cache
* @cookie: The cookie representing the cache object
* @page: The netfs page to store
* @object_size: Updated size of object
* @gfp: The conditions under which memory allocation should be made
*
* Request the contents of the netfs page be written into the cache. This
* request may be ignored if no cache block is currently allocated, in which
* case it will return -ENOBUFS.
*
* If a cache block was already allocated, a write will be initiated and 0 will
* be returned. The PG_fscache_write page bit is set immediately and will then
* be cleared at the completion of the write to indicate the success or failure
* of the operation. Note that the completion may happen before the return.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
int fscache_write_page(struct fscache_cookie *cookie,
struct page *page,
loff_t object_size,
gfp_t gfp)
{
if (fscache_cookie_valid(cookie) && fscache_cookie_enabled(cookie))
return __fscache_write_page(cookie, page, object_size, gfp);
else
return -ENOBUFS;
}
/**
* fscache_uncache_page - Indicate that caching is no longer required on a page
* @cookie: The cookie representing the cache object
* @page: The netfs page that was being cached.
*
* Tell the cache that we no longer want a page to be cached and that it should
* remove any knowledge of the netfs page it may have.
*
* Note that this cannot cancel any outstanding I/O operations between this
* page and the cache.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
void fscache_uncache_page(struct fscache_cookie *cookie,
struct page *page)
{
if (fscache_cookie_valid(cookie))
__fscache_uncache_page(cookie, page);
}
/**
* fscache_check_page_write - Ask if a page is being writing to the cache
* @cookie: The cookie representing the cache object
* @page: The netfs page that is being cached.
*
* Ask the cache if a page is being written to the cache.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
bool fscache_check_page_write(struct fscache_cookie *cookie,
struct page *page)
{
if (fscache_cookie_valid(cookie))
return __fscache_check_page_write(cookie, page);
return false;
}
/**
* fscache_wait_on_page_write - Wait for a page to complete writing to the cache
* @cookie: The cookie representing the cache object
* @page: The netfs page that is being cached.
*
* Ask the cache to wake us up when a page is no longer being written to the
* cache.
*
* See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
void fscache_wait_on_page_write(struct fscache_cookie *cookie,
struct page *page)
{
if (fscache_cookie_valid(cookie))
__fscache_wait_on_page_write(cookie, page);
}
/**
* fscache_maybe_release_page - Consider releasing a page, cancelling a store
* @cookie: The cookie representing the cache object
* @page: The netfs page that is being cached.
* @gfp: The gfp flags passed to releasepage()
*
* Consider releasing a page for the vmscan algorithm, on behalf of the netfs's
* releasepage() call. A storage request on the page may cancelled if it is
* not currently being processed.
*
* The function returns true if the page no longer has a storage request on it,
* and false if a storage request is left in place. If true is returned, the
* page will have been passed to fscache_uncache_page(). If false is returned
* the page cannot be freed yet.
*/
static inline
bool fscache_maybe_release_page(struct fscache_cookie *cookie,
struct page *page,
gfp_t gfp)
{
if (fscache_cookie_valid(cookie) && PageFsCache(page))
return __fscache_maybe_release_page(cookie, page, gfp);
return true;
}
/**
* fscache_uncache_all_inode_pages - Uncache all an inode's pages
* @cookie: The cookie representing the inode's cache object.
* @inode: The inode to uncache pages from.
*
* Uncache all the pages in an inode that are marked PG_fscache, assuming them
* to be associated with the given cookie.
*
* This function may sleep. It will wait for pages that are being written out
* and will wait whilst the PG_fscache mark is removed by the cache.
*/
static inline
void fscache_uncache_all_inode_pages(struct fscache_cookie *cookie,
struct inode *inode)
{
if (fscache_cookie_valid(cookie))
__fscache_uncache_all_inode_pages(cookie, inode);
}
#endif /* FSCACHE_USE_NEW_IO_API */
/**
* fscache_disable_cookie - Disable a cookie
* @cookie: The cookie representing the cache object
* @aux_data: The updated auxiliary data for the cookie (may be NULL)
* @invalidate: Invalidate the backing object
*
* Disable a cookie from accepting further alloc, read, write, invalidate,
* update or acquire operations. Outstanding operations can still be waited
* upon and pages can still be uncached and the cookie relinquished.
*
* This will not return until all outstanding operations have completed.
*
* If @invalidate is set, then the backing object will be invalidated and
* detached, otherwise it will just be detached.
*
* If @aux_data is set, then auxiliary data will be updated from that.
*/
static inline
void fscache_disable_cookie(struct fscache_cookie *cookie,
const void *aux_data,
bool invalidate)
{
if (fscache_cookie_valid(cookie) && fscache_cookie_enabled(cookie))
__fscache_disable_cookie(cookie, aux_data, invalidate);
}
/**
* fscache_enable_cookie - Reenable a cookie
* @cookie: The cookie representing the cache object
* @aux_data: The updated auxiliary data for the cookie (may be NULL)
* @object_size: Current size of object
* @can_enable: A function to permit enablement once lock is held
* @data: Data for can_enable()
*
* Reenable a previously disabled cookie, allowing it to accept further alloc,
* read, write, invalidate, update or acquire operations. An attempt will be
* made to immediately reattach the cookie to a backing object. If @aux_data
* is set, the auxiliary data attached to the cookie will be updated.
*
* The can_enable() function is called (if not NULL) once the enablement lock
* is held to rule on whether enablement is still permitted to go ahead.
*/
static inline
void fscache_enable_cookie(struct fscache_cookie *cookie,
const void *aux_data,
loff_t object_size,
bool (*can_enable)(void *data),
void *data)
{
if (fscache_cookie_valid(cookie) && !fscache_cookie_enabled(cookie))
__fscache_enable_cookie(cookie, aux_data, object_size,
can_enable, data);
}
#endif /* _LINUX_FSCACHE_H */
include/trace/events/fscache.h deleted 100644 → 0
View file @ 850cba06
/* SPDX-License-Identifier: GPL-2.0-or-later */
/* FS-Cache tracepoints
*
* Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#undef TRACE_SYSTEM
#define TRACE_SYSTEM fscache
#if !defined(_TRACE_FSCACHE_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_FSCACHE_H
#include <linux/fscache.h>
#include <linux/tracepoint.h>
/*
* Define enums for tracing information.
*/
#ifndef __FSCACHE_DECLARE_TRACE_ENUMS_ONCE_ONLY
#define __FSCACHE_DECLARE_TRACE_ENUMS_ONCE_ONLY
enum fscache_cookie_trace {
fscache_cookie_collision,
fscache_cookie_discard,
fscache_cookie_get_acquire_parent,
fscache_cookie_get_attach_object,
fscache_cookie_get_reacquire,
fscache_cookie_get_register_netfs,
fscache_cookie_put_acquire_nobufs,
fscache_cookie_put_dup_netfs,
fscache_cookie_put_relinquish,
fscache_cookie_put_object,
fscache_cookie_put_parent,
};
enum fscache_page_trace {
fscache_page_cached,
fscache_page_inval,
fscache_page_maybe_release,
fscache_page_radix_clear_store,
fscache_page_radix_delete,
fscache_page_radix_insert,
fscache_page_radix_pend2store,
fscache_page_radix_set_pend,
fscache_page_uncache,
fscache_page_write,
fscache_page_write_end,
fscache_page_write_end_pend,
fscache_page_write_end_noc,
fscache_page_write_wait,
fscache_page_trace__nr
};
enum fscache_op_trace {
fscache_op_cancel,
fscache_op_cancel_all,
fscache_op_cancelled,
fscache_op_completed,
fscache_op_enqueue_async,
fscache_op_enqueue_mythread,
fscache_op_gc,
fscache_op_init,
fscache_op_put,
fscache_op_run,
fscache_op_signal,
fscache_op_submit,
fscache_op_submit_ex,
fscache_op_work,
fscache_op_trace__nr
};
enum fscache_page_op_trace {
fscache_page_op_alloc_one,
fscache_page_op_attr_changed,
fscache_page_op_check_consistency,
fscache_page_op_invalidate,
fscache_page_op_retr_multi,
fscache_page_op_retr_one,
fscache_page_op_write_one,
fscache_page_op_trace__nr
};
#endif
/*
* Declare tracing information enums and their string mappings for display.
*/
#define fscache_cookie_traces \
EM(fscache_cookie_collision, "*COLLISION*") \
EM(fscache_cookie_discard, "DISCARD") \
EM(fscache_cookie_get_acquire_parent, "GET prn") \
EM(fscache_cookie_get_attach_object, "GET obj") \
EM(fscache_cookie_get_reacquire, "GET raq") \
EM(fscache_cookie_get_register_netfs, "GET net") \
EM(fscache_cookie_put_acquire_nobufs, "PUT nbf") \
EM(fscache_cookie_put_dup_netfs, "PUT dnt") \
EM(fscache_cookie_put_relinquish, "PUT rlq") \
EM(fscache_cookie_put_object, "PUT obj") \
E_(fscache_cookie_put_parent, "PUT prn")
#define fscache_page_traces \
EM(fscache_page_cached, "Cached ") \
EM(fscache_page_inval, "InvalPg") \
EM(fscache_page_maybe_release, "MayRels") \
EM(fscache_page_uncache, "Uncache") \
EM(fscache_page_radix_clear_store, "RxCStr ") \
EM(fscache_page_radix_delete, "RxDel ") \
EM(fscache_page_radix_insert, "RxIns ") \
EM(fscache_page_radix_pend2store, "RxP2S ") \
EM(fscache_page_radix_set_pend, "RxSPend ") \
EM(fscache_page_write, "WritePg") \
EM(fscache_page_write_end, "EndPgWr") \
EM(fscache_page_write_end_pend, "EndPgWP") \
EM(fscache_page_write_end_noc, "EndPgNC") \
E_(fscache_page_write_wait, "WtOnWrt")
#define fscache_op_traces \
EM(fscache_op_cancel, "Cancel1") \
EM(fscache_op_cancel_all, "CancelA") \
EM(fscache_op_cancelled, "Canclld") \
EM(fscache_op_completed, "Complet") \
EM(fscache_op_enqueue_async, "EnqAsyn") \
EM(fscache_op_enqueue_mythread, "EnqMyTh") \
EM(fscache_op_gc, "GC ") \
EM(fscache_op_init, "Init ") \
EM(fscache_op_put, "Put ") \
EM(fscache_op_run, "Run ") \
EM(fscache_op_signal, "Signal ") \
EM(fscache_op_submit, "Submit ") \
EM(fscache_op_submit_ex, "SubmitX") \
E_(fscache_op_work, "Work ")
#define fscache_page_op_traces \
EM(fscache_page_op_alloc_one, "Alloc1 ") \
EM(fscache_page_op_attr_changed, "AttrChg") \
EM(fscache_page_op_check_consistency, "CheckCn") \
EM(fscache_page_op_invalidate, "Inval ") \
EM(fscache_page_op_retr_multi, "RetrMul") \
EM(fscache_page_op_retr_one, "Retr1 ") \
E_(fscache_page_op_write_one, "Write1 ")
/*
* Export enum symbols via userspace.
*/
#undef EM
#undef E_
#define EM(a, b) TRACE_DEFINE_ENUM(a);
#define E_(a, b) TRACE_DEFINE_ENUM(a);
fscache_cookie_traces;
/*
* Now redefine the EM() and E_() macros to map the enums to the strings that
* will be printed in the output.
*/
#undef EM
#undef E_
#define EM(a, b) { a, b },
#define E_(a, b) { a, b }
TRACE_EVENT(fscache_cookie,
TP_PROTO(unsigned int cookie_debug_id,
int ref,
enum fscache_cookie_trace where),
TP_ARGS(cookie_debug_id, ref, where),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(enum fscache_cookie_trace, where )
__field(int, ref )
),
TP_fast_assign(
__entry->cookie = cookie_debug_id;
__entry->where = where;
__entry->ref = ref;
),
TP_printk("%s c=%08x r=%d",
__print_symbolic(__entry->where, fscache_cookie_traces),
__entry->cookie, __entry->ref)
);
TRACE_EVENT(fscache_netfs,
TP_PROTO(struct fscache_netfs *netfs),
TP_ARGS(netfs),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__array(char, name, 8 )
),
TP_fast_assign(
__entry->cookie = netfs->primary_index->debug_id;
strncpy(__entry->name, netfs->name, 8);
__entry->name[7] = 0;
),
TP_printk("c=%08x n=%s",
__entry->cookie, __entry->name)
);
TRACE_EVENT(fscache_acquire,
TP_PROTO(struct fscache_cookie *cookie),
TP_ARGS(cookie),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(unsigned int, parent )
__array(char, name, 8 )
__field(int, p_ref )
__field(int, p_n_children )
__field(u8, p_flags )
),
TP_fast_assign(
__entry->cookie = cookie->debug_id;
__entry->parent = cookie->parent->debug_id;
__entry->p_ref = refcount_read(&cookie->parent->ref);
__entry->p_n_children = atomic_read(&cookie->parent->n_children);
__entry->p_flags = cookie->parent->flags;
memcpy(__entry->name, cookie->def->name, 8);
__entry->name[7] = 0;
),
TP_printk("c=%08x p=%08x pr=%d pc=%d pf=%02x n=%s",
__entry->cookie, __entry->parent, __entry->p_ref,
__entry->p_n_children, __entry->p_flags, __entry->name)
);
TRACE_EVENT(fscache_relinquish,
TP_PROTO(struct fscache_cookie *cookie, bool retire),
TP_ARGS(cookie, retire),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(unsigned int, parent )
__field(int, ref )
__field(int, n_children )
__field(int, n_active )
__field(u8, flags )
__field(bool, retire )
),
TP_fast_assign(
__entry->cookie = cookie->debug_id;
__entry->parent = cookie->parent->debug_id;
__entry->ref = refcount_read(&cookie->ref);
__entry->n_children = atomic_read(&cookie->n_children);
__entry->n_active = atomic_read(&cookie->n_active);
__entry->flags = cookie->flags;
__entry->retire = retire;
),
TP_printk("c=%08x r=%d p=%08x Nc=%d Na=%d f=%02x r=%u",
__entry->cookie, __entry->ref,
__entry->parent, __entry->n_children, __entry->n_active,
__entry->flags, __entry->retire)
);
TRACE_EVENT(fscache_enable,
TP_PROTO(struct fscache_cookie *cookie),
TP_ARGS(cookie),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(int, ref )
__field(int, n_children )
__field(int, n_active )
__field(u8, flags )
),
TP_fast_assign(
__entry->cookie = cookie->debug_id;
__entry->ref = refcount_read(&cookie->ref);
__entry->n_children = atomic_read(&cookie->n_children);
__entry->n_active = atomic_read(&cookie->n_active);
__entry->flags = cookie->flags;
),
TP_printk("c=%08x r=%d Nc=%d Na=%d f=%02x",
__entry->cookie, __entry->ref,
__entry->n_children, __entry->n_active, __entry->flags)
);
TRACE_EVENT(fscache_disable,
TP_PROTO(struct fscache_cookie *cookie),
TP_ARGS(cookie),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(int, ref )
__field(int, n_children )
__field(int, n_active )
__field(u8, flags )
),
TP_fast_assign(
__entry->cookie = cookie->debug_id;
__entry->ref = refcount_read(&cookie->ref);
__entry->n_children = atomic_read(&cookie->n_children);
__entry->n_active = atomic_read(&cookie->n_active);
__entry->flags = cookie->flags;
),
TP_printk("c=%08x r=%d Nc=%d Na=%d f=%02x",
__entry->cookie, __entry->ref,
__entry->n_children, __entry->n_active, __entry->flags)
);
TRACE_EVENT(fscache_osm,
TP_PROTO(struct fscache_object *object,
const struct fscache_state *state,
bool wait, bool oob, s8 event_num),
TP_ARGS(object, state, wait, oob, event_num),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(unsigned int, object )
__array(char, state, 8 )
__field(bool, wait )
__field(bool, oob )
__field(s8, event_num )
),
TP_fast_assign(
__entry->cookie = object->cookie->debug_id;
__entry->object = object->debug_id;
__entry->wait = wait;
__entry->oob = oob;
__entry->event_num = event_num;
memcpy(__entry->state, state->short_name, 8);
),
TP_printk("c=%08x o=%08d %s %s%sev=%d",
__entry->cookie,
__entry->object,
__entry->state,
__print_symbolic(__entry->wait,
{ true, "WAIT" },
{ false, "WORK" }),
__print_symbolic(__entry->oob,
{ true, " OOB " },
{ false, " " }),
__entry->event_num)
);
TRACE_EVENT(fscache_page,
TP_PROTO(struct fscache_cookie *cookie, struct page *page,
enum fscache_page_trace why),
TP_ARGS(cookie, page, why),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(pgoff_t, page )
__field(enum fscache_page_trace, why )
),
TP_fast_assign(
__entry->cookie = cookie->debug_id;
__entry->page = page->index;
__entry->why = why;
),
TP_printk("c=%08x %s pg=%lx",
__entry->cookie,
__print_symbolic(__entry->why, fscache_page_traces),
__entry->page)
);
TRACE_EVENT(fscache_check_page,
TP_PROTO(struct fscache_cookie *cookie, struct page *page,
void *val, int n),
TP_ARGS(cookie, page, val, n),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(void *, page )
__field(void *, val )
__field(int, n )
),
TP_fast_assign(
__entry->cookie = cookie->debug_id;
__entry->page = page;
__entry->val = val;
__entry->n = n;
),
TP_printk("c=%08x pg=%p val=%p n=%d",
__entry->cookie, __entry->page, __entry->val, __entry->n)
);
TRACE_EVENT(fscache_wake_cookie,
TP_PROTO(struct fscache_cookie *cookie),
TP_ARGS(cookie),
TP_STRUCT__entry(
__field(unsigned int, cookie )
),
TP_fast_assign(
__entry->cookie = cookie->debug_id;
),
TP_printk("c=%08x", __entry->cookie)
);
TRACE_EVENT(fscache_op,
TP_PROTO(struct fscache_cookie *cookie, struct fscache_operation *op,
enum fscache_op_trace why),
TP_ARGS(cookie, op, why),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(unsigned int, op )
__field(enum fscache_op_trace, why )
),
TP_fast_assign(
__entry->cookie = cookie ? cookie->debug_id : 0;
__entry->op = op->debug_id;
__entry->why = why;
),
TP_printk("c=%08x op=%08x %s",
__entry->cookie, __entry->op,
__print_symbolic(__entry->why, fscache_op_traces))
);
TRACE_EVENT(fscache_page_op,
TP_PROTO(struct fscache_cookie *cookie, struct page *page,
struct fscache_operation *op, enum fscache_page_op_trace what),
TP_ARGS(cookie, page, op, what),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(unsigned int, op )
__field(pgoff_t, page )
__field(enum fscache_page_op_trace, what )
),
TP_fast_assign(
__entry->cookie = cookie->debug_id;
__entry->page = page ? page->index : 0;
__entry->op = op->debug_id;
__entry->what = what;
),
TP_printk("c=%08x %s pg=%lx op=%08x",
__entry->cookie,
__print_symbolic(__entry->what, fscache_page_op_traces),
__entry->page, __entry->op)
);
TRACE_EVENT(fscache_wrote_page,
TP_PROTO(struct fscache_cookie *cookie, struct page *page,
struct fscache_operation *op, int ret),
TP_ARGS(cookie, page, op, ret),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(unsigned int, op )
__field(pgoff_t, page )
__field(int, ret )
),
TP_fast_assign(
__entry->cookie = cookie->debug_id;
__entry->page = page->index;
__entry->op = op->debug_id;
__entry->ret = ret;
),
TP_printk("c=%08x pg=%lx op=%08x ret=%d",
__entry->cookie, __entry->page, __entry->op, __entry->ret)
);
TRACE_EVENT(fscache_gang_lookup,
TP_PROTO(struct fscache_cookie *cookie, struct fscache_operation *op,
void **results, int n, pgoff_t store_limit),
TP_ARGS(cookie, op, results, n, store_limit),
TP_STRUCT__entry(
__field(unsigned int, cookie )
__field(unsigned int, op )
__field(pgoff_t, results0 )
__field(int, n )
__field(pgoff_t, store_limit )
),
TP_fast_assign(
__entry->cookie = cookie->debug_id;
__entry->op = op->debug_id;
__entry->results0 = results[0] ? ((struct page *)results[0])->index : (pgoff_t)-1;
__entry->n = n;
__entry->store_limit = store_limit;
),
TP_printk("c=%08x op=%08x r0=%lx n=%d sl=%lx",
__entry->cookie, __entry->op, __entry->results0, __entry->n,
__entry->store_limit)
);
#endif /* _TRACE_FSCACHE_H */
/* This part must be outside protection */
#include <trace/define_trace.h>
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