3:44 p.m.
The NBD protocol is adding an extension to let servers advertise
initialization state to the client: whether the image contains holes,
and whether it is known to read as all zeroes. For Ocaml, the changes
are just copy-and-paste, but I wasn't sure how to test them beyond a
successful build.
Signed-off-by: Eric Blake <eblake(a)redhat.com>
---
plugins/ocaml/NBDKit.ml | 14 +++++++++++-
plugins/ocaml/NBDKit.mli | 5 ++++-
plugins/ocaml/ocaml.c | 47 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 64 insertions(+), 2 deletions(-)
diff --git a/plugins/ocaml/NBDKit.ml b/plugins/ocaml/NBDKit.ml
index 85c30a1..2db011f 100644
--- a/plugins/ocaml/NBDKit.ml
+++ b/plugins/ocaml/NBDKit.ml
@@ -100,6 +100,9 @@ type 'a plugin = {
can_fast_zero : ('a -> bool) option;
preconnect : (bool -> unit) option;
+
+ init_sparse : ('a -> bool) option;
+ init_zero : ('a -> bool) option;
}
let default_callbacks = {
@@ -149,6 +152,9 @@ let default_callbacks = {
can_fast_zero = None;
preconnect = None;
+
+ init_sparse = None;
+ init_zero = None;
}
external set_name : string -> unit = "ocaml_nbdkit_set_name"
"noalloc"
@@ -198,6 +204,9 @@ external set_can_fast_zero : ('a -> bool) -> unit =
"ocaml_nbdkit_set_can_fast_z
external set_preconnect : (bool -> unit) -> unit =
"ocaml_nbdkit_set_preconnect"
+external set_init_sparse : ('a -> bool) -> unit =
"ocaml_nbdkit_set_init_sparse"
+external set_init_zero : ('a -> bool) -> unit =
"ocaml_nbdkit_set_init_zero"
+
let may f = function None -> () | Some a -> f a
let register_plugin plugin =
@@ -265,7 +274,10 @@ let register_plugin plugin =
may set_can_fast_zero plugin.can_fast_zero;
- may set_preconnect plugin.preconnect
+ may set_preconnect plugin.preconnect;
+
+ may set_init_sparse plugin.init_sparse;
+ may set_init_zero plugin.init_zero;
external _set_error : int -> unit = "ocaml_nbdkit_set_error"
"noalloc"
diff --git a/plugins/ocaml/NBDKit.mli b/plugins/ocaml/NBDKit.mli
index 4cdf911..966b1bb 100644
--- a/plugins/ocaml/NBDKit.mli
+++ b/plugins/ocaml/NBDKit.mli
@@ -105,12 +105,15 @@ type 'a plugin = {
can_fast_zero : ('a -> bool) option;
preconnect : (bool -> unit) option;
+
+ init_sparse : ('a -> bool) option;
+ init_zero : ('a -> bool) option;
}
(** The plugin fields and callbacks. ['a] is the handle type. *)
val default_callbacks : 'a plugin
(** The plugin with all fields set to [None], so you can write
- [{ defaults_callbacks with field1 = Some foo1; field2 = Some foo2 }] *)
+ [{ default_callbacks with field1 = Some foo1; field2 = Some foo2 }] *)
val register_plugin : 'a plugin -> unit
(** Register the plugin with nbdkit. *)
diff --git a/plugins/ocaml/ocaml.c b/plugins/ocaml/ocaml.c
index a7d188f..db88f68 100644
--- a/plugins/ocaml/ocaml.c
+++ b/plugins/ocaml/ocaml.c
@@ -138,6 +138,9 @@ static value can_fast_zero_fn;
static value preconnect_fn;
+static value init_sparse_fn;
+static value init_zero_fn;
+
/*----------------------------------------------------------------------*/
/* Wrapper functions that translate calls from C (ie. nbdkit) to OCaml. */
@@ -747,6 +750,44 @@ preconnect_wrapper (int readonly)
CAMLreturnT (int, 1);
}
+static int
+init_sparse_wrapper (void *h)
+{
+ CAMLparam0 ();
+ CAMLlocal1 (rv);
+
+ caml_leave_blocking_section ();
+
+ rv = caml_callback_exn (init_sparse_fn, *(value *) h);
+ if (Is_exception_result (rv)) {
+ nbdkit_error ("%s", caml_format_exception (Extract_exception (rv)));
+ caml_enter_blocking_section ();
+ CAMLreturnT (int, -1);
+ }
+
+ caml_enter_blocking_section ();
+ CAMLreturnT (int, Bool_val (rv));
+}
+
+static int
+init_zero_wrapper (void *h)
+{
+ CAMLparam0 ();
+ CAMLlocal1 (rv);
+
+ caml_leave_blocking_section ();
+
+ rv = caml_callback_exn (init_zero_fn, *(value *) h);
+ if (Is_exception_result (rv)) {
+ nbdkit_error ("%s", caml_format_exception (Extract_exception (rv)));
+ caml_enter_blocking_section ();
+ CAMLreturnT (int, -1);
+ }
+
+ caml_enter_blocking_section ();
+ CAMLreturnT (int, Bool_val (rv));
+}
+
/*----------------------------------------------------------------------*/
/* set_* functions called from OCaml code at load time to initialize
* fields in the plugin struct.
@@ -838,6 +879,9 @@ SET(can_fast_zero)
SET(preconnect)
+SET(init_sparse)
+SET(init_zero)
+
#undef SET
static void
@@ -886,6 +930,9 @@ remove_roots (void)
REMOVE (preconnect);
+ REMOVE (init_sparse);
+ REMOVE (init_zero);
+
#undef REMOVE
}
--
2.24.1