Re: [libvirt] [dbus PATCH 14/25] Implement FSFreeze method for Domain Interface

On Tue, Apr 17, 2018 at 02:04:33PM +0200, Katerina Koukiou wrote: > Signed-off-by: Katerina Koukiou <kkoukiou(a)redhat.com&gt; > --- > data/org.libvirt.Domain.xml | 7 +++++++ > src/domain.c | 40 > ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 47 insertions(+) > > diff --git a/data/org.libvirt.Domain.xml > b/data/org.libvirt.Domain.xml > index fb2bcce..66cf5e2 100644 > --- a/data/org.libvirt.Domain.xml > +++ b/data/org.libvirt.Domain.xml > @@ -135,6 +135,13 @@ > <arg name="xml" type="s" direction="in"/> > <arg name="flags" type="u" direction="in"/> > </method> > + <method name="FSFreeze"> > + <annotation name="org.gtk.GDBus.DocString" > + value="See https://libvirt.org/html/libvirt-libvirt-domain > .html#virDomainFSFreeze"/>; > + <arg name="mountpoints" type="as" direction="in"/> > + <arg name="flags" type="u" direction="in"/> > + <arg name="frozenFilesystems" type="u" direction="out"/> > + </method> > <method name="GetBlkioParameters"> > <annotation name="org.gtk.GDBus.DocString" > value="See https://libvirt.org/html/libvirt-libvirt-domain > .html#virDomainGetBlkioParameters"/>; > diff --git a/src/domain.c b/src/domain.c > index 2fd8343..04115d1 100644 > --- a/src/domain.c > +++ b/src/domain.c > @@ -693,6 +693,45 @@ virtDBusDomainDetachDevice(GVariant *inArgs, > virtDBusUtilSetLastVirtError(error); > } > > +static void > +virtDBusDomainFSFreeze(GVariant *inArgs, > + GUnixFDList *inFDs G_GNUC_UNUSED, > + const gchar *objectPath, > + gpointer userData, > + GVariant **outArgs, > + GUnixFDList **outFDs G_GNUC_UNUSED, > + GError **error) > +{ > + virtDBusConnect *connect = userData; > + g_autoptr(virDomain) domain = NULL; > + g_autofree const gchar **mountpoints = NULL; > + GVariantIter *iter; > + gsize nmountpoints = 0; > + guint flags; > + gint ret; > + > + g_variant_get(inArgs, "(asu)", &iter, &flags); > + > + nmountpoints = g_variant_iter_n_children(iter); > + if (nmountpoints) { > + mountpoints = g_new0(const gchar*, nmountpoints + 1); > + while (g_variant_iter_loop(iter, "s", > &mountpoints[nmountpoints-1])) > + nmountpoints++; > + nmountpoints--; > + g_variant_iter_free(iter); > + } This code will not work for nmountpoints >= 2. At the first line you get a number of mountpoints, let's say it's 2 ("/root", "/home"). Then you allocate nmountpoints + 1 array of strings, the array should have only nmountpoints elements. The while loop is the place where it actually fails: 1 cycle: g_variant_iter_loop(iter, "s", &mountpoints[3-1]) - this will not fail because mountpoints[2] is still allocated 2 cycle: g_variant_iter_loop(iter, "s", &mountpoints[4-1]) - there the program crashes because mountpoints[3] is not allocated Another issue here is that using "s" as signature makes a copy of the string and it needs to be freed, in this case "&s" would be better. One possible way how the code can look like: const gchar **tmp; nmountpoints = g_variant_iter_n_children(iter); if (nmountpoints > 0) { mountpoints = g_new0(const gchar*, nmountpoints); tmp = mountpoints; while (g_variant_iter_loop(iter, "&s", tmp)) tmp++; g_variant_iter_free(iter); }

> + > + domain = virtDBusDomainGetVirDomain(connect, objectPath, > error); > + if (!domain) > + return; > + > + ret = virDomainFSFreeze(domain, (const gchar **)mountpoints, > nmountpoints, flags); There is no need to typecast mountpoints and the line is too long. > + if (ret < 0) > + virtDBusUtilSetLastVirtError(error); Missing return. Pavel