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authorDavid Howells <dhowells@redhat.com>2015-02-20 00:47:31 +0100
committerDavid Howells <dhowells@redhat.com>2015-02-24 11:05:27 +0100
commit182d919b84902eece162c63ed3d476c8016b4197 (patch)
treec2f02f26cdcaa4718121c94e8b050a598fab5f8c /Documentation/filesystems/caching/backend-api.txt
parentMerge tag 'locks-v3.20-2' of git://git.samba.org/jlayton/linux (diff)
downloadlinux-182d919b84902eece162c63ed3d476c8016b4197.tar.xz
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FS-Cache: Count culled objects and objects rejected due to lack of space
Count the number of objects that get culled by the cache backend and the number of objects that the cache backend declines to instantiate due to lack of space in the cache. These numbers are made available through /proc/fs/fscache/stats Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Steve Dickson <steved@redhat.com> Acked-by: Jeff Layton <jeff.layton@primarydata.com>
Diffstat (limited to 'Documentation/filesystems/caching/backend-api.txt')
-rw-r--r--Documentation/filesystems/caching/backend-api.txt23
1 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/filesystems/caching/backend-api.txt b/Documentation/filesystems/caching/backend-api.txt
index 277d1e810670..c0bd5677271b 100644
--- a/Documentation/filesystems/caching/backend-api.txt
+++ b/Documentation/filesystems/caching/backend-api.txt
@@ -676,6 +676,29 @@ FS-Cache provides some utilities that a cache backend may make use of:
as possible.
+ (*) Indicate that a stale object was found and discarded:
+
+ void fscache_object_retrying_stale(struct fscache_object *object);
+
+ This is called to indicate that the lookup procedure found an object in
+ the cache that the netfs decided was stale. The object has been
+ discarded from the cache and the lookup will be performed again.
+
+
+ (*) Indicate that the caching backend killed an object:
+
+ void fscache_object_mark_killed(struct fscache_object *object,
+ enum fscache_why_object_killed why);
+
+ This is called to indicate that the cache backend preemptively killed an
+ object. The why parameter should be set to indicate the reason:
+
+ FSCACHE_OBJECT_IS_STALE - the object was stale and needs discarding.
+ FSCACHE_OBJECT_NO_SPACE - there was insufficient cache space
+ FSCACHE_OBJECT_WAS_RETIRED - the object was retired when relinquished.
+ FSCACHE_OBJECT_WAS_CULLED - the object was culled to make space.
+
+
(*) Get and release references on a retrieval record:
void fscache_get_retrieval(struct fscache_retrieval *op);