[net/9p] Preparation and helper functions for zero copy
This patch prepares p9_fcall structure for zero copy. Added
fields send the payload buffer information to the transport layer.
In addition it adds a 'private' field for the transport layer to
store mapped/pinned page information so that it can be freed/unpinned
during req_done.
This patch also creates trans_common.[ch] to house helper functions.
It adds the following helper functions.
p9_release_req_pages - Release pages after the transaction.
p9_nr_pages - Return number of pages needed to accomodate the payload.
payload_gup - Translates user buffer into kernel pages.
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/net/9p/protocol.c b/net/9p/protocol.c
index 1e308f2..d888847 100644
--- a/net/9p/protocol.c
+++ b/net/9p/protocol.c
@@ -606,6 +606,10 @@
{
pdu->offset = 0;
pdu->size = 0;
+ pdu->private = NULL;
+ pdu->pubuf = NULL;
+ pdu->pkbuf = NULL;
+ pdu->pbuf_size = 0;
}
int p9dirent_read(char *buf, int len, struct p9_dirent *dirent,