[net/9p] Read side zerocopy changes for 9P2000.L protocol.

[platform/kernel/linux-rpi.git] / net / 9p / client.c

diff --git a/net/9p/client.c b/net/9p/client.c
index a848bca..82079f9 100644 (file)
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1270,7 +1270,15 @@ p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
        if (count < rsize)
                rsize = count;
 
-       req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, rsize);
+       /* Don't bother zerocopy form small IO (< 1024) */
+       if (((clnt->trans_mod->pref & P9_TRANS_PREF_PAYLOAD_MASK) ==
+                       P9_TRANS_PREF_PAYLOAD_SEP) && (rsize > 1024)) {
+               req = p9_client_rpc(clnt, P9_TREAD, "dqE", fid->fid, offset,
+                               rsize, data, udata);
+       } else {
+               req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset,
+                               rsize);
+       }
        if (IS_ERR(req)) {
                err = PTR_ERR(req);
                goto error;
@@ -1284,13 +1292,15 @@ p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
 
        P9_DPRINTK(P9_DEBUG_9P, "<<< RREAD count %d\n", count);
 
-       if (data) {
-               memmove(data, dataptr, count);
-       } else {
-               err = copy_to_user(udata, dataptr, count);
-               if (err) {
-                       err = -EFAULT;
-                       goto free_and_error;
+       if (!req->tc->pbuf_size) {
+               if (data) {
+                       memmove(data, dataptr, count);
+               } else {
+                       err = copy_to_user(udata, dataptr, count);
+                       if (err) {
+                               err = -EFAULT;
+                               goto free_and_error;
+                       }
                }
        }
        p9_free_req(clnt, req);