libvirt/0108-qemuDomainBuildNamespa...

114 lines
3.8 KiB
Diff

From: Michal Privoznik <mprivozn@redhat.com>
Date: Thu, 27 Apr 2017 16:29:21 +0200
Subject: [PATCH] qemuDomainBuildNamespace: Move /dev/* mountpoints later
When setting up mount namespace for a qemu domain the following
steps are executed:
1) get list of mountpoints under /dev/
2) move them to /var/run/libvirt/qemu/$domName.ext
3) start constructing new device tree under /var/run/libvirt/qemu/$domName.dev
4) move the mountpoint of the new device tree to /dev
5) restore original mountpoints from step 2)
Note the problem with this approach is that if some device in step
3) requires access to a mountpoint from step 2) it will fail as
the mountpoint is not there anymore. For instance consider the
following domain disk configuration:
<disk type='file' device='disk'>
<driver name='qemu' type='raw'/>
<source file='/dev/shm/vhostmd0'/>
<target dev='vdb' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/>
</disk>
In this case operation fails as we are unable to create vhostmd0
in the new device tree because after step 2) there is no /dev/shm
anymore. Leave aside fact that we shouldn't try to create devices
living in other mountpoints. That's a separate bug that will be
addressed later.
Currently, the order described above is rearranged to:
1) get list of mountpoints under /dev/
2) start constructing new device tree under /var/run/libvirt/qemu/$domName.dev
3) move them to /var/run/libvirt/qemu/$domName.ext
4) move the mountpoint of the new device tree to /dev
5) restore original mountpoints from step 3)
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Cedric Bosdonnat <cbosdonnat@suse.com>
(cherry picked from commit a7cc039dc796f541793955598377807af48341fb)
(cherry picked from commit 469bf7cb7a44a0798c63e4b5e4682d8e38bce66e)
---
src/qemu/qemu_domain.c | 48 ++++++++++++++++++++++++------------------------
1 file changed, 24 insertions(+), 24 deletions(-)
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 4a127cedf..64f18f493 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -7854,6 +7854,30 @@ qemuDomainBuildNamespace(virQEMUDriverConfigPtr cfg,
if (qemuDomainSetupDev(cfg, mgr, vm, devPath) < 0)
goto cleanup;
+ if (qemuDomainSetupAllDisks(cfg, vm, devPath) < 0)
+ goto cleanup;
+
+ if (qemuDomainSetupAllHostdevs(cfg, vm, devPath) < 0)
+ goto cleanup;
+
+ if (qemuDomainSetupAllMemories(cfg, vm, devPath) < 0)
+ goto cleanup;
+
+ if (qemuDomainSetupAllChardevs(cfg, vm, devPath) < 0)
+ goto cleanup;
+
+ if (qemuDomainSetupTPM(cfg, vm, devPath) < 0)
+ goto cleanup;
+
+ if (qemuDomainSetupAllGraphics(cfg, vm, devPath) < 0)
+ goto cleanup;
+
+ if (qemuDomainSetupAllInputs(cfg, vm, devPath) < 0)
+ goto cleanup;
+
+ if (qemuDomainSetupAllRNGs(cfg, vm, devPath) < 0)
+ goto cleanup;
+
/* Save some mount points because we want to share them with the host */
for (i = 0; i < ndevMountsPath; i++) {
struct stat sb;
@@ -7881,30 +7905,6 @@ qemuDomainBuildNamespace(virQEMUDriverConfigPtr cfg,
goto cleanup;
}
- if (qemuDomainSetupAllDisks(cfg, vm, devPath) < 0)
- goto cleanup;
-
- if (qemuDomainSetupAllHostdevs(cfg, vm, devPath) < 0)
- goto cleanup;
-
- if (qemuDomainSetupAllMemories(cfg, vm, devPath) < 0)
- goto cleanup;
-
- if (qemuDomainSetupAllChardevs(cfg, vm, devPath) < 0)
- goto cleanup;
-
- if (qemuDomainSetupTPM(cfg, vm, devPath) < 0)
- goto cleanup;
-
- if (qemuDomainSetupAllGraphics(cfg, vm, devPath) < 0)
- goto cleanup;
-
- if (qemuDomainSetupAllInputs(cfg, vm, devPath) < 0)
- goto cleanup;
-
- if (qemuDomainSetupAllRNGs(cfg, vm, devPath) < 0)
- goto cleanup;
-
if (virFileMoveMount(devPath, "/dev") < 0)
goto cleanup;