glusterfs: discard (hole punch) support

Add support for the DISCARD file operation. Discard punches a hole
in a file in the provided range. Block de-allocation is implemented
via fallocate() (as requested via fuse and passed on to the brick
fs) but a separate fop is created within gluster to emphasize the
fact that discard changes file data (the discarded region is
replaced with zeroes) and must invalidate caches where appropriate.

BUG: 963678
Change-Id: I34633a0bfff2187afeab4292a15f3cc9adf261af
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-on: http://review.gluster.org/5090
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/rpc/xdr/src/glusterfs3-xdr.c b/rpc/xdr/src/glusterfs3-xdr.c
index 2ce0b84e..4e9791b2 100644
--- a/rpc/xdr/src/glusterfs3-xdr.c
+++ b/rpc/xdr/src/glusterfs3-xdr.c
@@ -1547,6 +1547,44 @@ xdr_gfs3_fallocate_rsp (XDR *xdrs, gfs3_fallocate_rsp *objp)
 }
 
 bool_t
+xdr_gfs3_discard_req (XDR *xdrs, gfs3_discard_req *objp)
+{
+	register int32_t *buf;
+        buf = NULL;
+
+	 if (!xdr_opaque (xdrs, objp->gfid, 16))
+		 return FALSE;
+	 if (!xdr_quad_t (xdrs, &objp->fd))
+		 return FALSE;
+	 if (!xdr_u_quad_t (xdrs, &objp->offset))
+		 return FALSE;
+	 if (!xdr_u_quad_t (xdrs, &objp->size))
+		 return FALSE;
+	 if (!xdr_bytes (xdrs, (char **)&objp->xdata.xdata_val, (u_int *) &objp->xdata.xdata_len, ~0))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
+xdr_gfs3_discard_rsp (XDR *xdrs, gfs3_discard_rsp *objp)
+{
+	register int32_t *buf;
+        buf = NULL;
+
+	 if (!xdr_int (xdrs, &objp->op_ret))
+		 return FALSE;
+	 if (!xdr_int (xdrs, &objp->op_errno))
+		 return FALSE;
+	 if (!xdr_gf_iatt (xdrs, &objp->statpre))
+		 return FALSE;
+	 if (!xdr_gf_iatt (xdrs, &objp->statpost))
+		 return FALSE;
+	 if (!xdr_bytes (xdrs, (char **)&objp->xdata.xdata_val, (u_int *) &objp->xdata.xdata_len, ~0))
+		 return FALSE;
+	return TRUE;
+}
+
+bool_t
 xdr_gfs3_rchecksum_req (XDR *xdrs, gfs3_rchecksum_req *objp)
 {
 	register int32_t *buf;