From bee9f65523218e3baeeecde9295c8fbe9bc08e0a Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 27 Jan 2022 16:02:50 +0000 Subject: netfs, cachefiles: Add a method to query presence of data in the cache Add a netfs_cache_ops method by which a network filesystem can ask the cache about what data it has available and where so that it can make a multipage read more efficient. Signed-off-by: David Howells cc: linux-cachefs@redhat.com Acked-by: Jeff Layton Reviewed-by: Rohith Surabattula Signed-off-by: Steve French --- include/linux/netfs.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include') diff --git a/include/linux/netfs.h b/include/linux/netfs.h index b46c39d98bbd..614f22213e21 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -244,6 +244,13 @@ struct netfs_cache_ops { int (*prepare_write)(struct netfs_cache_resources *cres, loff_t *_start, size_t *_len, loff_t i_size, bool no_space_allocated_yet); + + /* Query the occupancy of the cache in a region, returning where the + * next chunk of data starts and how long it is. + */ + int (*query_occupancy)(struct netfs_cache_resources *cres, + loff_t start, size_t len, size_t granularity, + loff_t *_data_start, size_t *_data_len); }; struct readahead_control; -- cgit v1.2.3