From da9803bc8812f5bd3b26baaa90e515b843c65ff7 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 21 Aug 2013 17:29:38 -0400 Subject: FS-Cache: Add interface to check consistency of a cached object Extend the fscache netfs API so that the netfs can ask as to whether a cache object is up to date with respect to its corresponding netfs object: int fscache_check_consistency(struct fscache_cookie *cookie) This will call back to the netfs to check whether the auxiliary data associated with a cookie is correct. It returns 0 if it is and -ESTALE if it isn't; it may also return -ENOMEM and -ERESTARTSYS. The backends now have to implement a mandatory operation pointer: int (*check_consistency)(struct fscache_object *object) that corresponds to the above API call. FS-Cache takes care of pinning the object and the cookie in memory and managing this call with respect to the object state. Original-author: Hongyi Jia Signed-off-by: David Howells cc: Hongyi Jia cc: Milosz Tanski --- include/linux/fscache-cache.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/fscache-cache.h') diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h index a9ff9a36b86d..7823e9ef995e 100644 --- a/include/linux/fscache-cache.h +++ b/include/linux/fscache-cache.h @@ -251,6 +251,10 @@ struct fscache_cache_ops { /* 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 */ + bool (*check_consistency)(struct fscache_operation *op); + /* store the updated auxiliary data on an object */ void (*update_object)(struct fscache_object *object); -- cgit v1.2.1