Dr. Greg Wettstein
2012-Aug-05 14:40 UTC
Xen 4.1.x backport request <e4781aedf817c5ab36f6f3077e44c43c566a2812>
Backport of the following patch from development:
# User Ian Campbell <[hidden email]>
# Date 1309968705 -3600
# Node ID e4781aedf817c5ab36f6f3077e44c43c566a2812
# Parent 05700ef33648e0777fb48ba965bf723264d56a31
libxl: attempt to cleanup tapdisk processes on disk backend destroy.
This patch properly terminates the tapdisk2 process(es) started
to service a virtual block device.
Without this patch 4.1.2 leaves a tapdisk2 process running for each
tap device created.
Signed-off-by: Greg Wettstein <greg@enjellic.com>
diff -r fa34499e8f6c tools/blktap2/control/tap-ctl-list.c
--- a/tools/blktap2/control/tap-ctl-list.c Mon Jul 30 13:38:58 2012 +0100
+++ b/tools/blktap2/control/tap-ctl-list.c Sun Aug 05 09:26:56 2012 -0500
@@ -506,17 +506,15 @@ out:
}
int
-tap_ctl_find_minor(const char *type, const char *path)
+tap_ctl_find(const char *type, const char *path, tap_list_t *tap)
{
tap_list_t **list, **_entry;
- int minor, err;
+ int ret = -ENOENT, err;
err = tap_ctl_list(&list);
if (err)
return err;
- minor = -1;
-
for (_entry = list; *_entry != NULL; ++_entry) {
tap_list_t *entry = *_entry;
@@ -526,11 +524,13 @@ tap_ctl_find_minor(const char *type, con
if (path && (!entry->path || strcmp(entry->path, path)))
continue;
- minor = entry->minor;
+ *tap = *entry;
+ tap->type = tap->path = NULL;
+ ret = 0;
break;
}
tap_ctl_free_list(list);
- return minor >= 0 ? minor : -ENOENT;
+ return ret;
}
diff -r fa34499e8f6c tools/blktap2/control/tap-ctl.h
--- a/tools/blktap2/control/tap-ctl.h Mon Jul 30 13:38:58 2012 +0100
+++ b/tools/blktap2/control/tap-ctl.h Sun Aug 05 09:26:56 2012 -0500
@@ -76,7 +76,7 @@ int tap_ctl_get_driver_id(const char *ha
int tap_ctl_list(tap_list_t ***list);
void tap_ctl_free_list(tap_list_t **list);
-int tap_ctl_find_minor(const char *type, const char *path);
+int tap_ctl_find(const char *type, const char *path, tap_list_t *tap);
int tap_ctl_allocate(int *minor, char **devname);
int tap_ctl_free(const int minor);
diff -r fa34499e8f6c tools/libxl/libxl_blktap2.c
--- a/tools/libxl/libxl_blktap2.c Mon Jul 30 13:38:58 2012 +0100
+++ b/tools/libxl/libxl_blktap2.c Sun Aug 05 09:26:56 2012 -0500
@@ -18,6 +18,8 @@
#include "tap-ctl.h"
+#include <string.h>
+
int libxl__blktap_enabled(libxl__gc *gc)
{
const char *msg;
@@ -30,12 +32,13 @@ const char *libxl__blktap_devpath(libxl_
{
const char *type;
char *params, *devname = NULL;
- int minor, err;
+ tap_list_t tap;
+ int err;
type = libxl__device_disk_string_of_format(format);
- minor = tap_ctl_find_minor(type, disk);
- if (minor >= 0) {
- devname = libxl__sprintf(gc, "/dev/xen/blktap-2/tapdev%d",
minor);
+ err = tap_ctl_find(type, disk, &tap);
+ if (err == 0) {
+ devname = libxl__sprintf(gc, "/dev/xen/blktap-2/tapdev%d",
tap.minor);
if (devname)
return devname;
}
@@ -49,3 +52,28 @@ const char *libxl__blktap_devpath(libxl_
return NULL;
}
+
+
+void libxl__device_destroy_tapdisk(libxl__gc *gc, char *be_path)
+{
+ char *path, *params, *type, *disk;
+ int err;
+ tap_list_t tap;
+
+ path = libxl__sprintf(gc, "%s/tapdisk-params", be_path);
+ if (!path) return;
+
+ params = libxl__xs_read(gc, XBT_NULL, path);
+ if (!params) return;
+
+ type = params;
+ disk = strchr(params, '':'');
+ if (!disk) return;
+
+ *disk++ = ''\0'';
+
+ err = tap_ctl_find(type, disk, &tap);
+ if (err < 0) return;
+
+ tap_ctl_destroy(tap.id, tap.minor);
+}
diff -r fa34499e8f6c tools/libxl/libxl_device.c
--- a/tools/libxl/libxl_device.c Mon Jul 30 13:38:58 2012 +0100
+++ b/tools/libxl/libxl_device.c Sun Aug 05 09:26:56 2012 -0500
@@ -250,6 +250,7 @@ int libxl__device_destroy(libxl_ctx *ctx
if (!state)
goto out;
if (atoi(state) != 4) {
+ libxl__device_destroy_tapdisk(&gc, be_path);
xs_rm(ctx->xsh, XBT_NULL, be_path);
goto out;
}
@@ -368,6 +369,7 @@ int libxl__devices_destroy(libxl_ctx *ct
}
}
}
+ libxl__device_destroy_tapdisk(&gc, be_path);
out:
libxl__free_all(&gc);
return 0;
diff -r fa34499e8f6c tools/libxl/libxl_internal.h
--- a/tools/libxl/libxl_internal.h Mon Jul 30 13:38:58 2012 +0100
+++ b/tools/libxl/libxl_internal.h Sun Aug 05 09:26:56 2012 -0500
@@ -314,6 +314,12 @@ _hidden const char *libxl__blktap_devpat
const char *disk,
libxl_disk_format format);
+/* libxl__device_destroy_tapdisk:
+ * Destroys any tapdisk process associated with the backend represented
+ * by be_path.
+ */
+_hidden void libxl__device_destroy_tapdisk(libxl__gc *gc, char *be_path);
+
_hidden char *libxl__uuid2string(libxl__gc *gc, const libxl_uuid uuid);
struct libxl__xen_console_reader {
diff -r fa34499e8f6c tools/libxl/libxl_noblktap2.c
--- a/tools/libxl/libxl_noblktap2.c Mon Jul 30 13:38:58 2012 +0100
+++ b/tools/libxl/libxl_noblktap2.c Sun Aug 05 09:26:56 2012 -0500
@@ -27,3 +27,7 @@ const char *libxl__blktap_devpath(libxl_
{
return NULL;
}
+
+void libxl__device_destroy_tapdisk(libxl__gc *gc, char *be_path)
+{
+}
As always,
Dr. G.W. Wettstein, Ph.D. Enjellic Systems Development, LLC.
4206 N. 19th Ave. Specializing in information infra-structure
Fargo, ND 58102 development.
PH: 701-281-1686
FAX: 701-281-3949 EMAIL: greg@enjellic.com
------------------------------------------------------------------------------
"My thoughts on the composition and effectiveness of the advisory
committee?
I think they are destined to accomplish about the same thing as what
you would get from locking 9 chimpanzees in a room with an armed
thermonuclear weapon and a can opener with orders to disarm it."
-- Dr. Greg Wettstein
Resurrection