[Libguestfs] [PATCH] api: add_drive - add QEMU detect-zeroes support

[Maros Zatko]

See: https://lists.gnu.org/archive/html/qemu-devel/2012-07/msg03747.html
Related do RHBZ#1130506.
---
 generator/actions.ml   |  2 +-
 src/drives.c           | 11 +++++++++--
 src/guestfs-internal.h |  1 +
 src/launch-direct.c    |  8 +++++---
 4 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/generator/actions.ml b/generator/actions.ml
index fb971d3..4bdd913 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -1318,7 +1318,7 @@ not all belong to a single logical operating system
 
   { defaults with
     name = "add_drive";
-    style = RErr, [String "filename"], [OBool "readonly"; OString "format"; OString "iface"; OString "name"; OString "label"; OString "protocol"; OStringList "server"; OString "username"; OString "secret"; OString "cachemode"; OString "discard"; OBool "copyonread"];
+    style = RErr, [String "filename"], [OBool "readonly"; OString "format"; OString "iface"; OString "name"; OString "label"; OString "protocol"; OStringList "server"; OString "username"; OString "secret"; OString "cachemode"; OString "discard"; OBool "copyonread"; OBool "detectzeros"];
     once_had_no_optargs = true;
     blocking = false;
     fish_alias = ["add"];
diff --git a/src/drives.c b/src/drives.c
index ad747ab..d1e680a 100644
--- a/src/drives.c
+++ b/src/drives.c
@@ -63,6 +63,7 @@ struct drive_create_data {
   const char *cachemode;
   enum discard discard;
   bool copyonread;
+  bool detectzeros;
 };
 
 COMPILE_REGEXP (re_hostname_port, "(.*):(\\d+)$", 0)
@@ -116,6 +117,7 @@ create_drive_file (guestfs_h *g,
   drv->cachemode = data->cachemode ? safe_strdup (g, data->cachemode) : NULL;
   drv->discard = data->discard;
   drv->copyonread = data->copyonread;
+  drv->detectzeros = data->detectzeros;
 
   if (data->readonly) {
     if (create_overlay (g, drv) == -1) {
@@ -152,6 +154,7 @@ create_drive_non_file (guestfs_h *g,
   drv->cachemode = data->cachemode ? safe_strdup (g, data->cachemode) : NULL;
   drv->discard = data->discard;
   drv->copyonread = data->copyonread;
+  drv->detectzeros = data->detectzeros;
 
   if (data->readonly) {
     if (create_overlay (g, drv) == -1) {
@@ -504,7 +507,7 @@ static char *
 drive_to_string (guestfs_h *g, const struct drive *drv)
 {
   return safe_asprintf
-    (g, "%s%s%s%s protocol=%s%s%s%s%s%s%s%s%s%s%s",
+    (g, "%s%s%s%s protocol=%s%s%s%s%s%s%s%s%s%s%s%s",
      drv->src.u.path,
      drv->readonly ? " readonly" : "",
      drv->src.format ? " format=" : "",
@@ -520,7 +523,8 @@ drive_to_string (guestfs_h *g, const struct drive *drv)
      drv->cachemode ? : "",
      drv->discard == discard_disable ? "" :
      drv->discard == discard_enable ? " discard=enable" : " discard=besteffort",
-     drv->copyonread ? " copyonread" : "");
+     drv->copyonread ? " copyonread" : "",
+     drv->detectzeros ? " detect-zeroes=on" : "");
 }
 
 /* Add struct drive to the g->drives vector at the given index. */
@@ -746,6 +750,9 @@ guestfs_impl_add_drive_opts (guestfs_h *g, const char *filename,
   data.servers = NULL;
   data.exportname = filename;
 
+  data.detectzeros = optargs->bitmask & GUESTFS_ADD_DRIVE_OPTS_DETECTZEROS_BITMASK
+    ? optargs->detectzeros : false;
+
   data.readonly = optargs->bitmask & GUESTFS_ADD_DRIVE_OPTS_READONLY_BITMASK
     ? optargs->readonly : false;
   data.format = optargs->bitmask & GUESTFS_ADD_DRIVE_OPTS_FORMAT_BITMASK
diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h
index 43cdd4d..456ac6a 100644
--- a/src/guestfs-internal.h
+++ b/src/guestfs-internal.h
@@ -269,6 +269,7 @@ struct drive {
   char *cachemode;
   enum discard discard;
   bool copyonread;
+  bool detectzeros;
 };
 
 /* Extra hv parameters (from guestfs_config). */
diff --git a/src/launch-direct.c b/src/launch-direct.c
index 5753236..f208f11 100644
--- a/src/launch-direct.c
+++ b/src/launch-direct.c
@@ -512,7 +512,7 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
        * the if=... at the end.
        */
       param = safe_asprintf
-        (g, "file=%s%s,cache=%s%s%s%s%s%s%s,id=hd%zu",
+        (g, "file=%s%s,cache=%s%s%s%s%s%s%s%s,id=hd%zu",
          escaped_file,
          drv->readonly ? ",snapshot=on" : "",
          drv->cachemode ? drv->cachemode : "writeback",
@@ -521,6 +521,7 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
          drv->src.format ? drv->src.format : "",
          drv->disk_label ? ",serial=" : "",
          drv->disk_label ? drv->disk_label : "",
+         drv->detectzeros ? ",detect-zeroes=on" : "",
          drv->copyonread ? ",copy-on-read=on" : "",
          i);
     }
@@ -528,11 +529,12 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
       /* Writable qcow2 overlay on top of read-only drive. */
       escaped_file = qemu_escape_param (g, drv->overlay);
       param = safe_asprintf
-        (g, "file=%s,cache=unsafe,format=qcow2%s%s,id=hd%zu",
+        (g, "file=%s,cache=unsafe,format=qcow2%s%s,id=hd%zu,detect-zeroes=%s",
          escaped_file,
          drv->disk_label ? ",serial=" : "",
          drv->disk_label ? drv->disk_label : "",
-         i);
+         i,
+         drv->detectzeros ? "on" : "off");
     }
 
     /* If there's an explicit 'iface', use it.  Otherwise default to
-- 
1.9.3