From: Ian Campbell <ian.campbell@citrix.com>
To: xen-devel@lists.xensource.com
Cc: Ian Campbell <ian.campbell@citrix.com>
Subject: [PATCH 3 of 7] libxl: convert an empty tap disk into a qdisk
Date: Thu, 07 Apr 2011 10:52:29 +0100 [thread overview]
Message-ID: <f5418873be3d097cbb37.1302169949@localhost.localdomain> (raw)
In-Reply-To: <patchbomb.1302169946@localhost.localdomain>
# HG changeset patch
# User Ian Campbell <ian.campbell@citrix.com>
# Date 1302167196 -3600
# Node ID f5418873be3d097cbb374009898ce9c74255e047
# Parent 76d363a113e5ee6111bc9e0eca5a314644ce6295
libxl: convert an empty tap disk into a qdisk
I'm not sure that empty disks which are is_cdrom are especially valid,
or that a cdrom can ever be handled by tapdisk anyway but try to do
something sane since it seems that xl's parse_disk_config() routine
could potentially generate such a configuration (although whether from
a valid input string or not I'm not sure).
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
diff -r 76d363a113e5 -r f5418873be3d tools/libxl/libxl.c
--- a/tools/libxl/libxl.c Thu Apr 07 10:06:35 2011 +0100
+++ b/tools/libxl/libxl.c Thu Apr 07 10:06:36 2011 +0100
@@ -983,6 +983,14 @@ int libxl_device_disk_add(libxl_ctx *ctx
if (disk->backend == DISK_BACKEND_TAP && !libxl__blktap_enabled(&gc))
disk->backend = DISK_BACKEND_QDISK;
+ /*
+ * blktap cannot handle empty disks (aka cdroms). Fall back to
+ * qdisk because qemu-xen creates the disk based on the xenstore
+ * entries.
+ */
+ if (disk->backend == DISK_BACKEND_TAP && disk->format == DISK_FORMAT_EMPTY)
+ disk->backend == DISK_BACKEND_QDISK;
+
switch (disk->backend) {
case DISK_BACKEND_PHY:
libxl__device_physdisk_major_minor(disk->pdev_path, &major, &minor);
@@ -995,7 +1003,7 @@ int libxl_device_disk_add(libxl_ctx *ctx
device.backend_kind = DEVICE_VBD;
break;
case DISK_BACKEND_TAP:
- if (disk->format != DISK_FORMAT_EMPTY) {
+ {
const char *dev = libxl__blktap_devpath(&gc,
disk->pdev_path, disk->format);
if (!dev) {
@@ -1003,8 +1011,8 @@ int libxl_device_disk_add(libxl_ctx *ctx
goto out_free;
}
flexarray_append(back, "tapdisk-params");
- flexarray_append(back, libxl__sprintf(&gc, "%s:%s",
- libxl__device_disk_string_of_format(disk->format),
+ flexarray_append(back, libxl__sprintf(&gc, "%s:%s",
+ libxl__device_disk_string_of_format(disk->format),
disk->pdev_path));
flexarray_append(back, "params");
flexarray_append(back, libxl__strdup(&gc, dev));
@@ -1013,8 +1021,6 @@ int libxl_device_disk_add(libxl_ctx *ctx
flexarray_append(back, "physical-device");
flexarray_append(back, libxl__sprintf(&gc, "%x:%x", major, minor));
device.backend_kind = DEVICE_VBD;
-
- break;
}
break;
case DISK_BACKEND_QDISK:
next prev parent reply other threads:[~2011-04-07 9:52 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-07 9:52 [PATCH 0 of 7] libxl: refactor tap disk handling Ian Campbell
2011-04-07 9:52 ` [PATCH 1 of 7] libxl: remove impossible check for backend != DISK_BACKEND_QDISK Ian Campbell
2011-04-07 9:52 ` [PATCH 2 of 7] libxl: make fallback from blktap2 to qdisk more explicit Ian Campbell
2011-04-07 9:52 ` Ian Campbell [this message]
2011-04-07 9:52 ` [PATCH 4 of 7] libxl: only a CDROM type disk can be empty Ian Campbell
2011-04-07 9:52 ` [PATCH 5 of 7] libxl: refactor DISK_BACKEND_PHY handling in libxl_device_disk_add Ian Campbell
2011-04-07 9:52 ` [PATCH 6 of 7] libxl: handle the tail end of a tap device using the phy backend handling code Ian Campbell
2011-04-07 9:52 ` [PATCH 7 of 7] libxl: Drop internal DEVICE_TAP backend type Ian Campbell
2011-04-08 15:46 ` Ian Jackson
2011-04-07 12:31 ` [PATCH 0 of 7] libxl: refactor tap disk handling Christoph Egger
2011-04-07 14:12 ` Ian Campbell
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