fscache: Pass object size in rather than calling back for it

Pass the object size in to fscache_acquire_cookie() and
fscache_write_page() rather than the netfs providing a callback by which it
can be received.  This makes it easier to update the size of the object
when a new page is written that extends the object.

The current object size is also passed by fscache to the check_aux
function, obviating the need to store it in the aux data.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Anna Schumaker <anna.schumaker@netapp.com>
Tested-by: Steve Dickson <steved@redhat.com>

4 files changed, 21 insertions, 13 deletions

diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 4d6210082a60..8ca9a932d225 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -21,7 +21,8 @@ struct kmem_cache *fscache_cookie_jar;
 
 static atomic_t fscache_object_debug_id = ATOMIC_INIT(0);
 
-static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie);
+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,
@@ -61,6 +62,7 @@ struct fscache_cookie *__fscache_acquire_cookie(
 	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 *cookie;
@@ -160,7 +162,7 @@ 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) == 0) {
+			if (fscache_acquire_non_index_cookie(cookie, object_size) == 0) {
 				set_bit(FSCACHE_COOKIE_ENABLED, &cookie->flags);
 			} else {
 				atomic_dec(&parent->n_children);
@@ -194,6 +196,7 @@ EXPORT_SYMBOL(__fscache_acquire_cookie);
  */
 void __fscache_enable_cookie(struct fscache_cookie *cookie,
 			     const void *aux_data,
+			     loff_t object_size,
 			     bool (*can_enable)(void *data),
 			     void *data)
 {
@@ -215,7 +218,7 @@ 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) == 0)
+		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);
@@ -232,11 +235,11 @@ 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)
+static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie,
+					    loff_t object_size)
 {
 	struct fscache_object *object;
 	struct fscache_cache *cache;
-	uint64_t i_size;
 	int ret;
 
 	_enter("");
@@ -275,9 +278,6 @@ static int fscache_acquire_non_index_cookie(struct fscache_cookie *cookie)
 		return ret;
 	}
 
-	/* pass on how big the object we're caching is supposed to be */
-	cookie->def->get_attr(cookie->netfs_data, &i_size);
-
 	spin_lock(&cookie->lock);
 	if (hlist_empty(&cookie->backing_objects)) {
 		spin_unlock(&cookie->lock);
@@ -287,7 +287,7 @@ 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, i_size);
+	fscache_set_store_limit(object, object_size);
 
 	/* initiate the process of looking up all the objects in the chain
 	 * (done by fscache_initialise_object()) */
diff --git a/fs/fscache/fsdef.c b/fs/fscache/fsdef.c
index 1122e97d56e8..aa46e48d8c75 100644
--- a/fs/fscache/fsdef.c
+++ b/fs/fscache/fsdef.c
@@ -16,7 +16,8 @@
 static
 enum fscache_checkaux fscache_fsdef_netfs_check_aux(void *cookie_netfs_data,
 						    const void *data,
-						    uint16_t datalen);
+						    uint16_t datalen,
+						    loff_t object_size);
 
 /*
  * The root index is owned by FS-Cache itself.
@@ -76,7 +77,8 @@ struct fscache_cookie_def fscache_fsdef_netfs_def = {
 static enum fscache_checkaux fscache_fsdef_netfs_check_aux(
 	void *cookie_netfs_data,
 	const void *data,
-	uint16_t datalen)
+	uint16_t datalen,
+	loff_t object_size)
 {
 	struct fscache_netfs *netfs = cookie_netfs_data;
 	uint32_t version;
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index a7b28f876fde..1085ca12e25c 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -922,7 +922,8 @@ static void fscache_dequeue_object(struct fscache_object *object)
  * and creation).
  */
 enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
-					const void *data, uint16_t datalen)
+					const void *data, uint16_t datalen,
+					loff_t object_size)
 {
 	enum fscache_checkaux result;
 
@@ -932,7 +933,7 @@ enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
 	}
 
 	result = object->cookie->def->check_aux(object->cookie->netfs_data,
-						data, datalen);
+						data, datalen, object_size);
 	switch (result) {
 		/* entry okay as is */
 	case FSCACHE_CHECKAUX_OKAY:
diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index 810b33aced1c..111349f67d98 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -963,6 +963,7 @@ void fscache_invalidate_writes(struct fscache_cookie *cookie)
  */
 int __fscache_write_page(struct fscache_cookie *cookie,
 			 struct page *page,
+			 loff_t object_size,
 			 gfp_t gfp)
 {
 	struct fscache_storage *op;
@@ -1014,6 +1015,10 @@ int __fscache_write_page(struct fscache_cookie *cookie,
 	/* 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);