fuse: add retrieve request

Userspace filesystem can request data to be retrieved from the inode's
mapping.  This request is synchronous and the retrieved data is queued
as a new request.  If the write to the fuse device returns an error
then the retrieve request was not completed and a reply will not be
sent.

Only present pages are returned in the retrieve reply.  Retrieving
stops when it finds a non-present page and only data prior to that is
returned.

This request doesn't change the dirty state of pages.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 61267d8d527b..57d4a3a0f102 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -272,6 +272,7 @@ struct fuse_req {
                         struct fuse_write_in in;
                         struct fuse_write_out out;
                 } write;
+                struct fuse_notify_retrieve_in retrieve_in;
                 struct fuse_lk_in lk_in;
         } misc;