Re: [libvirt] [PATCH 3/3] Do proper escaping of cgroup resource partitions

On 04/26/2013 04:45 AM, Daniel P. Berrange wrote: > From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; > > If a user cgroup name begins with "cgroup.", "_" or with any of > the controllers from /proc/cgroups followed by a dot, then they > need to be prefixed with a single underscore. eg if there is > an object "cpu.service", then this would end up as "_cpu.service" > in the cgroup filesystem tree, however, "waldo.service" would > stay "waldo.service", at least as long as nobody comes up with > a cgroup controller called "waldo". Do we also need to consider cgroup names beginning with leading '.'? > > Since we require a '.XXXX' suffix on all partitions, there is > no scope for clashing with the kernel 'tasks' and 'release_agent' > files. > > Signed-off-by: Daniel P. Berrange <berrange(a)redhat.com&gt; > --- > src/util/vircgroup.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++ > tests/vircgroupmock.c | 27 +++++++++++++--- > tests/vircgrouptest.c | 54 ++++++++++++++++++++++++++++++++ > 3 files changed, 163 insertions(+), 4 deletions(-) > #if defined HAVE_MNTENT_H && defined HAVE_GETMNTENT_R > +static int virCgroupNeedEscape(const char *path) NeedsEscape sounds a bit better than NeedEscape, if you want to make the tweak. > +static int virCgroupEscape(char **path) > +{ > + size_t len = strlen(*path); > + int rc; > + > + if ((rc = virCgroupNeedEscape(*path)) <= 0) > + return rc; > + From here... > + if (VIR_REALLOC_N(*path, len + 2) < 0) > + return -ENOMEM; > + > + memmove((*path) + 1, > + *path, > + len + 1); > + (*path)[0] = '_'; ...to here could be simplified to: char escape = '_'; VIR_INSERT_ELEMENT(*path, 0, len, escape);