CacheFiles: Implement interface to check cache consistency (5002d7be) · Commits · 戴 / test

fs/cachefiles/interface.c

+26 −0

Original line number	Diff line number	Diff line
		@@ -377,6 +377,31 @@ static void cachefiles_sync_cache(struct fscache_cache *_cache)
		ret);
		}

		/*
		* check if the backing cache is updated to FS-Cache
		* - called by FS-Cache when evaluates if need to invalidate the cache
		*/
		static bool cachefiles_check_consistency(struct fscache_operation *op)
		{
		struct cachefiles_object *object;
		struct cachefiles_cache *cache;
		const struct cred *saved_cred;
		int ret;

		_enter("{OBJ%x}", op->object->debug_id);

		object = container_of(op->object, struct cachefiles_object, fscache);
		cache = container_of(object->fscache.cache,
		struct cachefiles_cache, cache);

		cachefiles_begin_secure(cache, &saved_cred);
		ret = cachefiles_check_auxdata(object);
		cachefiles_end_secure(cache, saved_cred);

		_leave(" = %d", ret);
		return ret;
		}

		/*
		* notification the attributes on an object have changed
		* - called with reads/writes excluded by FS-Cache
		@@ -522,4 +547,5 @@ const struct fscache_cache_ops cachefiles_cache_ops = {
		.write_page = cachefiles_write_page,
		.uncache_page = cachefiles_uncache_page,
		.dissociate_pages = cachefiles_dissociate_pages,
		.check_consistency = cachefiles_check_consistency,
		};

+1 −0

Original line number	Diff line number	Diff line
		@@ -235,6 +235,7 @@ extern int cachefiles_set_object_xattr(struct cachefiles_object *object,
		struct cachefiles_xattr *auxdata);
		extern int cachefiles_update_object_xattr(struct cachefiles_object *object,
		struct cachefiles_xattr *auxdata);
		extern int cachefiles_check_auxdata(struct cachefiles_object *object);
		extern int cachefiles_check_object_xattr(struct cachefiles_object *object,
		struct cachefiles_xattr *auxdata);
		extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,

+36 −0

Original line number	Diff line number	Diff line
		@@ -156,6 +156,42 @@ int cachefiles_update_object_xattr(struct cachefiles_object *object,
		return ret;
		}

		/*
		* check the consistency between the backing cache and the FS-Cache cookie
		*/
		int cachefiles_check_auxdata(struct cachefiles_object *object)
		{
		struct cachefiles_xattr *auxbuf;
		struct dentry *dentry = object->dentry;
		unsigned int dlen;
		int ret;

		ASSERT(dentry);
		ASSERT(dentry->d_inode);
		ASSERT(object->fscache.cookie->def->check_aux);

		auxbuf = kmalloc(sizeof(struct cachefiles_xattr) + 512, GFP_KERNEL);
		if (!auxbuf)
		return -ENOMEM;

		auxbuf->len = vfs_getxattr(dentry, cachefiles_xattr_cache,
		&auxbuf->type, 512 + 1);
		if (auxbuf->len < 1)
		return -ESTALE;

		if (auxbuf->type != object->fscache.cookie->def->type)
		return -ESTALE;

		dlen = auxbuf->len - 1;
		ret = fscache_check_aux(&object->fscache, &auxbuf->data, dlen);

		kfree(auxbuf);
		if (ret != FSCACHE_CHECKAUX_OKAY)
		return -ESTALE;

		return 0;
		}

		/*
		* check the state xattr on a cache file
		* - return -ESTALE if the object should be deleted