[RFC PATCH 08/76] fscache: Remove store_limit* from struct fscache_object

From: David Howells
Date: Fri Nov 20 2020 - 10:05:06 EST


Remove the store_limit values from struct fscache_object and store the
object size in the cookie. The netfs can update this at will, and we don't
want to call back into the netfs to fetch it.

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

fs/cachefiles/interface.c | 10 ++--------
fs/fscache/cookie.c | 14 ++++++--------
fs/fscache/object.c | 2 --
include/linux/fscache-cache.h | 22 ----------------------
include/linux/fscache.h | 1 +
5 files changed, 9 insertions(+), 40 deletions(-)

diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c
index b7aa5c733cb7..a5d348581bcc 100644
--- a/fs/cachefiles/interface.c
+++ b/fs/cachefiles/interface.c
@@ -359,7 +359,7 @@ static int cachefiles_attr_changed(struct fscache_object *_object)
loff_t oi_size;
int ret;

- ni_size = _object->store_limit_l;
+ ni_size = _object->cookie->object_size;

_enter("{OBJ%x},[%llu]",
_object->debug_id, (unsigned long long) ni_size);
@@ -376,8 +376,6 @@ static int cachefiles_attr_changed(struct fscache_object *_object)

ASSERT(d_is_reg(object->backer));

- fscache_set_store_limit(&object->fscache, ni_size);
-
oi_size = i_size_read(d_backing_inode(object->backer));
if (oi_size == ni_size)
return 0;
@@ -406,7 +404,6 @@ static int cachefiles_attr_changed(struct fscache_object *_object)
cachefiles_end_secure(cache, saved_cred);

if (ret == -EIO) {
- fscache_set_store_limit(&object->fscache, 0);
cachefiles_io_error_obj(object, "Size set failed");
ret = -ENOBUFS;
}
@@ -431,7 +428,7 @@ static void cachefiles_invalidate_object(struct fscache_operation *op)
cache = container_of(object->fscache.cache,
struct cachefiles_cache, cache);

- ni_size = op->object->store_limit_l;
+ ni_size = op->object->cookie->object_size;

_enter("{OBJ%x},[%llu]",
op->object->debug_id, (unsigned long long)ni_size);
@@ -439,8 +436,6 @@ static void cachefiles_invalidate_object(struct fscache_operation *op)
if (object->backer) {
ASSERT(d_is_reg(object->backer));

- fscache_set_store_limit(&object->fscache, ni_size);
-
path.dentry = object->backer;
path.mnt = cache->mnt;

@@ -451,7 +446,6 @@ static void cachefiles_invalidate_object(struct fscache_operation *op)
cachefiles_end_secure(cache, saved_cred);

if (ret != 0) {
- fscache_set_store_limit(&object->fscache, 0);
if (ret == -EIO)
cachefiles_io_error_obj(object,
"Invalidate failed");
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 32c070c929b9..7811fe935b47 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -22,8 +22,7 @@ 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_acquire_non_index_cookie(struct fscache_cookie *cookie);
static int fscache_alloc_object(struct fscache_cache *cache,
struct fscache_cookie *cookie);
static int fscache_attach_object(struct fscache_cookie *cookie,
@@ -167,6 +166,7 @@ struct fscache_cookie *fscache_alloc_cookie(
cookie->advice = advice;
cookie->key_len = index_key_len;
cookie->aux_len = aux_data_len;
+ cookie->object_size = object_size;
strlcpy(cookie->type_name, type_name, sizeof(cookie->type_name));

if (fscache_set_key(cookie, index_key, index_key_len) < 0)
@@ -337,7 +337,7 @@ struct fscache_cookie *__fscache_acquire_cookie(
* - 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) {
+ if (fscache_acquire_non_index_cookie(cookie) == 0) {
set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
} else {
atomic_dec(&parent->n_children);
@@ -376,6 +376,7 @@ void __fscache_enable_cookie(struct fscache_cookie *cookie,
wait_on_bit_lock(&cookie->flags, FSCACHE_COOKIE_ENABLEMENT_LOCK,
TASK_UNINTERRUPTIBLE);

+ cookie->object_size = object_size;
fscache_update_aux(cookie, aux_data);

if (test_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags))
@@ -387,7 +388,7 @@ void __fscache_enable_cookie(struct fscache_cookie *cookie,
/* Wait for outstanding disablement to complete */
__fscache_wait_on_invalidate(cookie);

- if (fscache_acquire_non_index_cookie(cookie, object_size) == 0)
+ if (fscache_acquire_non_index_cookie(cookie) == 0)
set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
} else {
set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
@@ -404,8 +405,7 @@ EXPORT_SYMBOL(__fscache_enable_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)
+static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie)
{
struct fscache_object *object;
struct fscache_cache *cache;
@@ -456,8 +456,6 @@ static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie,
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);
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index bb551e29454d..e2e04ac2c0a1 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -319,8 +319,6 @@ void fscache_object_init(struct fscache_object *object,
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);
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index 0b395bcb4b16..fd07843e3d69 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -274,8 +274,6 @@ struct fscache_object {
#ifdef CONFIG_FSCACHE_OBJECT_LIST
struct rb_node objlist_link; /* link in global object list */
#endif
- pgoff_t store_limit; /* current storage limit */
- loff_t store_limit_l; /* current storage limit */
};

extern void fscache_object_init(struct fscache_object *, struct fscache_cookie *,
@@ -336,26 +334,6 @@ 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++;
-}
-
static inline void __fscache_use_cookie(struct fscache_cookie *cookie)
{
atomic_inc(&cookie->n_active);
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index a930532a39d0..f855f6d04667 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -83,6 +83,7 @@ struct fscache_cookie {
struct hlist_bl_node hash_link; /* Link in hash table */
struct list_head proc_link; /* Link in proc list */
char type_name[8]; /* Cookie type name */
+ loff_t object_size; /* Size of the netfs object */

unsigned long flags;
#define FSCACHE_COOKIE_LOOKING_UP 0 /* T if non-index cookie being looked up still */