Re: [libvirt] [PATCH 3/4] Trim /proc & /sys subtrees before mounting new instances

On 05/11/2012 12:48 PM, Daniel P. Berrange wrote: >From: "Daniel P. Berrange&quot;&lt;berrange(a)redhat.com&gt; > >Both /proc and /sys may have sub-mounts in them from the host >OS. We must explicitly unmount them all before mounting the >new instance over that location. If we don't then /proc/mounts >will show the sub-mounts as existing, even though nothing will >be able to access them, due to the over-mount. > >Signed-off-by: Daniel P. Berrange&lt;berrange(a)redhat.com&gt; >--- > src/lxc/lxc_container.c | 61 ++++++++++++++++++++++++++++++++++++----------- > 1 file changed, 47 insertions(+), 14 deletions(-) > >@@ -1054,13 +1057,36 @@ static int lxcContainerUnmountOldFS(void) > qsort(mounts, nmounts, sizeof(mounts[0]), > lxcContainerChildMountSort); > >+ *mountsret = mounts; >+ *nmountsret = nmounts; >+ ret = 0; >+ >+cleanup: >+ endmntent(procmnt); >+ return ret; >+} >+ >+static int lxcContainerUnmountSubtree(const char *prefix, >+ bool isOldRootFS) >+{ >+ char **mounts = NULL; >+ size_t nmounts = 0; >+ size_t i; >+ int saveErrno; >+ const char *failedUmount = NULL; >+ int ret = -1; >+ >+ VIR_DEBUG("Unmount subtreee from %s", prefix); >+ >+ if (lxcContainerGetSubtree(prefix,&mounts,&nmounts)< 0) >+ return -1; > for (i = 0 ; i< nmounts ; i++) { > VIR_DEBUG("Umount %s", mounts[i]); > if (umount(mounts[i])< 0) { > char ebuf[1024]; > failedUmount = mounts[i]; > saveErrno = errno; >- VIR_WARN("Failed to unmount '%s', trying to detach root '%s': %s", >+ VIR_WARN("Failed to unmount '%s', trying to detach subtree '%s': %s", > failedUmount, mounts[nmounts-1], > virStrerror(errno, ebuf, sizeof(ebuf))); > break; This may be an existing issue - should the code not try to continue unmounting rather than break'ing follwing error above? Would leaving the loop here leave stale mounts behind?