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-rw-r--r--Documentation/filesystems/caching/backend-api.txt38
1 files changed, 37 insertions, 1 deletions
diff --git a/Documentation/filesystems/caching/backend-api.txt b/Documentation/filesystems/caching/backend-api.txt
index 382d52cdaf2..d78bab9622c 100644
--- a/Documentation/filesystems/caching/backend-api.txt
+++ b/Documentation/filesystems/caching/backend-api.txt
@@ -308,6 +308,18 @@ performed on the denizens of the cache. These are held in a structure of type:
obtained by calling object->cookie->def->get_aux()/get_attr().
+ (*) Invalidate data object [mandatory]:
+
+ int (*invalidate_object)(struct fscache_operation *op)
+
+ This is called to invalidate a data object (as pointed to by op->object).
+ All the data stored for this object should be discarded and an
+ attr_changed operation should be performed. The caller will follow up
+ with an object update operation.
+
+ fscache_op_complete() must be called on op before returning.
+
+
(*) Discard object [mandatory]:
void (*drop_object)(struct fscache_object *object)
@@ -419,7 +431,10 @@ performed on the denizens of the cache. These are held in a structure of type:
If an I/O error occurs, fscache_io_error() should be called and -ENOBUFS
returned if possible or fscache_end_io() called with a suitable error
- code..
+ code.
+
+ fscache_put_retrieval() should be called after a page or pages are dealt
+ with. This will complete the operation when all pages are dealt with.
(*) Request pages be read from cache [mandatory]:
@@ -526,6 +541,27 @@ FS-Cache provides some utilities that a cache backend may make use of:
error value should be 0 if successful and an error otherwise.
+ (*) Record that one or more pages being retrieved or allocated have been dealt
+ with:
+
+ void fscache_retrieval_complete(struct fscache_retrieval *op,
+ int n_pages);
+
+ This is called to record the fact that one or more pages have been dealt
+ with and are no longer the concern of this operation. When the number of
+ pages remaining in the operation reaches 0, the operation will be
+ completed.
+
+
+ (*) Record operation completion:
+
+ void fscache_op_complete(struct fscache_operation *op);
+
+ This is called to record the completion of an operation. This deducts
+ this operation from the parent object's run state, potentially permitting
+ one or more pending operations to start running.
+
+
(*) Set highest store limit:
void fscache_set_store_limit(struct fscache_object *object,