splice: automatically detect whether vmsplice-to-user works

[fio.git] / engines / splice.c

diff --git a/engines/splice.c b/engines/splice.c
index f54b4414ae1851318ae79fb5aa40d67ea8e5b9f3..9386983c5daae1b899e491ae434ba0f4d26e1ed0 100644 (file)
--- a/engines/splice.c
+++ b/engines/splice.c
@@ -116,7 +116,6 @@ static int fio_splice_read(struct thread_data *td, struct io_u *io_u)
        return io_u->xfer_buflen;
 }
 
-
 /*
  * For splice writing, we can vmsplice our data buffer directly into a
  * pipe and then splice that to a file.
@@ -162,9 +161,17 @@ static int fio_spliceio_queue(struct thread_data *td, struct io_u *io_u)
        int ret;
 
        if (io_u->ddir == DDIR_READ) {
-               if (sd->vmsplice_to_user)
+               if (sd->vmsplice_to_user) {
                        ret = fio_splice_read(td, io_u);
-               else
+                       /*
+                        * This kernel doesn't support vmsplice to user
+                        * space. Reset the vmsplice_to_user flag, so that
+                        * we retry below and don't hit this path again.
+                        */
+                       if (ret == -EBADF)
+                               sd->vmsplice_to_user = 0;
+               }
+               if (!sd->vmsplice_to_user)
                        ret = fio_splice_read_old(td, io_u);
        } else if (io_u->ddir == DDIR_WRITE)
                ret = fio_splice_write(td, io_u);
@@ -209,9 +216,9 @@ static int fio_spliceio_init(struct thread_data *td)
        }
 
        /*
-        * need some check for enabling this, for now just leave it disabled
+        * Assume this work, we'll reset this if it doesn't
         */
-       sd->vmsplice_to_user = 0;
+       sd->vmsplice_to_user = 1;
 
        td->io_ops->data = sd;
        return 0;