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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v2 18/27] tools/libxl: Convert a legacy stream if needed
For backwards compatibility, a legacy stream needs converting before it can be
read by the v2 stream logic.
This causes the v2 stream logic to need to juggle two parallel tasks.
check_stream_finished() is introduced for the purpose of joining the tasks in
both success and error cases.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CC: Ian Campbell <Ian.Campbell@xxxxxxxxxx>
CC: Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>
CC: Wei Liu <wei.liu2@xxxxxxxxxx>
---
tools/libxl/libxl_internal.h | 7 +++
tools/libxl/libxl_stream_read.c | 98 ++++++++++++++++++++++++++++++++++++++-
2 files changed, 104 insertions(+), 1 deletion(-)
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 68e7f02..1cf1884 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -3274,6 +3274,7 @@ struct libxl__stream_read_state {
/* filled by the user */
libxl__ao *ao;
int fd;
+ bool legacy;
void (*completion_callback)(libxl__egc *egc,
libxl__stream_read_state *srs,
int rc);
@@ -3281,6 +3282,12 @@ struct libxl__stream_read_state {
int rc;
bool running;
+ /* Active-stuff handling */
+ int joined_rc;
+
+ /* Conversion helper */
+ libxl__carefd *v2_carefd;
+
/* Main stream-reading data */
libxl__datacopier_state dc;
libxl__sr_hdr hdr;
diff --git a/tools/libxl/libxl_stream_read.c b/tools/libxl/libxl_stream_read.c
index 6f5d572..3011820 100644
--- a/tools/libxl/libxl_stream_read.c
+++ b/tools/libxl/libxl_stream_read.c
@@ -57,6 +57,10 @@
* - stream_write_emulator()
* - stream_write_emulator_done()
* - stream_continue()
+ *
+ * Depending on the contents of the stream, there are likely to be several
+ * parallel tasks being managed. check_stream_finished() is used to join all
+ * tasks in both success and error cases.
*/
/* Stream error/success handling. */
@@ -67,6 +71,16 @@ static void stream_failed(libxl__egc *egc,
static void stream_done(libxl__egc *egc,
libxl__stream_read_state *stream);
+/* Stream other-active-stuff handling. */
+/* libxl__xc_domain_restore_done() is logically grouped here. */
+#if defined(__x86_64__) || defined(__i386__)
+static void conversion_done(libxl__egc *egc,
+ libxl__conversion_helper_state *chs, int rc);
+#endif
+static void check_stream_finished(libxl__egc *egc,
+ libxl__stream_read_state *stream,
+ int rc, const char *what);
+
/* Event callbacks for main reading loop. */
static void stream_header_done(libxl__egc *egc,
libxl__datacopier_state *dc,
@@ -112,12 +126,40 @@ static int setup_read(libxl__stream_read_state *stream,
void libxl__stream_read_start(libxl__egc *egc,
libxl__stream_read_state *stream)
{
+ libxl__domain_create_state *dcs = CONTAINER_OF(stream, *dcs, srs);
libxl__datacopier_state *dc = &stream->dc;
+ STATE_AO_GC(stream->ao);
int ret = 0;
/* State initialisation. */
assert(!stream->running);
+ /*
+ * Initialise other moving parts so stream_check_finished() can correctly
+ * work out whether to tear them down.
+ */
+ libxl__conversion_helper_init(&dcs->chs);
+
+#if defined(__x86_64__) || defined(__i386__)
+ if (stream->legacy) {
+ /* Convert a legacy stream, if needed. */
+ dcs->chs.ao = stream->ao;
+ dcs->chs.legacy_fd = stream->fd;
+ dcs->chs.hvm =
+ (dcs->guest_config->b_info.type == LIBXL_DOMAIN_TYPE_HVM);
+ dcs->chs.v2_carefd = NULL;
+ dcs->chs.completion_callback = conversion_done;
+
+ libxl__convert_legacy_stream(egc, &dcs->chs);
+
+ assert(dcs->chs.v2_carefd);
+ stream->v2_carefd = dcs->chs.v2_carefd;
+ dcs->libxc_fd = stream->fd = libxl__carefd_fd(dcs->chs.v2_carefd);
+ }
+#endif
+
+ /* stream->fd is now guarenteed to be a v2 stream. */
+
memset(dc, 0, sizeof(*dc));
dc->ao = stream->ao;
dc->readfd = stream->fd;
@@ -183,7 +225,50 @@ static void stream_done(libxl__egc *egc,
free(rec);
}
- stream->completion_callback(egc, stream, stream->rc);
+ if (stream->v2_carefd)
+ libxl__carefd_close(stream->v2_carefd);
+
+ check_stream_finished(egc, stream, stream->rc, "stream");
+}
+
+static void check_stream_finished(libxl__egc *egc,
+ libxl__stream_read_state *stream,
+ int rc, const char *what)
+{
+ libxl__domain_create_state *dcs = CONTAINER_OF(stream, *dcs, srs);
+ STATE_AO_GC(stream->ao);
+
+ LOG(DEBUG, "Task '%s' joining (rc %d)", what, rc);
+
+ if (rc && !stream->joined_rc) {
+ bool skip = false;
+ /* First reported failure from joining tasks. Tear everything down */
+ stream->joined_rc = rc;
+
+ if (libxl__stream_read_inuse(&dcs->srs)) {
+ skip = true;
+ libxl__stream_read_abort(egc, &dcs->srs, rc);
+ }
+
+ if (libxl__convert_legacy_stream_inuse(&dcs->chs)) {
+ skip = true;
+ libxl__convert_legacy_stream_abort(egc, &dcs->chs, rc);
+ }
+
+ /* There is at least one more active task to join - wait for its
+ callback */
+ if ( skip )
+ return;
+ }
+
+ if (libxl__stream_read_inuse(&dcs->srs))
+ LOG(DEBUG, "stream still in use");
+ else if (libxl__convert_legacy_stream_inuse(&dcs->chs))
+ LOG(DEBUG, "conversion still in use");
+ else {
+ LOG(DEBUG, "Join complete: result %d", stream->joined_rc);
+ stream->completion_callback(egc, stream, stream->joined_rc);
+ }
}
static void stream_continue(libxl__egc *egc,
@@ -354,6 +439,17 @@ static void record_body_done(libxl__egc *egc,
stream_failed(egc, stream, ret);
}
+#if defined(__x86_64__) || defined(__i386__)
+static void conversion_done(libxl__egc *egc,
+ libxl__conversion_helper_state *chs, int rc)
+{
+ STATE_AO_GC(chs->ao);
+ libxl__domain_create_state *dcs = CONTAINER_OF(chs, *dcs, chs);
+
+ check_stream_finished(egc, &dcs->srs, rc, "conversion");
+}
+#endif
+
/*
* Returns a boolean indicating whether a further action should be set up by
* the caller. This is needed to prevent mutual recursion with
--
1.7.10.4
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