[libvirt PATCH v3 03/18] qemu: expand nbdkit capabilities

[Jonathon Jongsma]

In order to add caching of the nbdkit capabilities, we will need to
compare against file modification times, etc. So look up this
information when creating the nbdkit caps.

Add a nbdkit_moddir build option to allow the builder to specify the
location to look for nbdkit plugins and filters.

Signed-off-by: Jonathon Jongsma <jjongsma at redhat.com>
---
 meson.build            |  6 ++++++
 meson_options.txt      |  1 +
 src/qemu/qemu_nbdkit.c | 40 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 47 insertions(+)

diff --git a/meson.build b/meson.build
index 93de355430..e4581e74dd 100644
--- a/meson.build
+++ b/meson.build
@@ -1731,6 +1731,12 @@ if not get_option('driver_qemu').disabled()
       qemu_dbus_daemon_path = '/usr/bin/dbus-daemon'
     endif
     conf.set_quoted('QEMU_DBUS_DAEMON', qemu_dbus_daemon_path)
+
+    nbdkit_moddir = get_option('nbdkit_moddir')
+    if nbdkit_moddir == ''
+      nbdkit_moddir = libdir / 'nbdkit'
+    endif
+    conf.set_quoted('NBDKIT_MODDIR', nbdkit_moddir)
   endif
 endif
 
diff --git a/meson_options.txt b/meson_options.txt
index 861c5577d2..d5ea4376e0 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -71,6 +71,7 @@ option('driver_vbox', type: 'feature', value: 'auto', description: 'VirtualBox X
 option('vbox_xpcomc_dir', type: 'string', value: '', description: 'Location of directory containing VirtualBox XPCOMC library')
 option('driver_vmware', type: 'feature', value: 'auto', description: 'VMware driver')
 option('driver_vz', type: 'feature', value: 'auto', description: 'Virtuozzo driver')
+option('nbdkit_moddir', type: 'string', value: '', description: 'set the directory where nbdkit modules are located')
 
 option('secdriver_apparmor', type: 'feature', value: 'auto', description: 'use AppArmor security driver')
 option('apparmor_profiles', type: 'feature', value: 'auto', description: 'install apparmor profiles')
diff --git a/src/qemu/qemu_nbdkit.c b/src/qemu/qemu_nbdkit.c
index 7a7248c1ef..5de1021d89 100644
--- a/src/qemu/qemu_nbdkit.c
+++ b/src/qemu/qemu_nbdkit.c
@@ -41,6 +41,9 @@
 
 VIR_LOG_INIT("qemu.nbdkit");
 
+#define NBDKIT_PLUGINDIR NBDKIT_MODDIR "/plugins"
+#define NBDKIT_FILTERDIR NBDKIT_MODDIR "/filters"
+
 VIR_ENUM_IMPL(qemuNbdkitCaps,
     QEMU_NBDKIT_CAPS_LAST,
     /* 0 */
@@ -54,6 +57,11 @@ struct _qemuNbdkitCaps {
 
     char *path;
     char *version;
+    time_t ctime;
+    time_t libvirtCtime;
+    time_t pluginDirMtime;
+    time_t filterDirMtime;
+    unsigned int libvirtVersion;
 
     virBitmap *flags;
 };
@@ -178,9 +186,41 @@ qemuNbdkitCapsNew(const char *path)
 }
 
 
+static time_t
+qemuNbdkitGetDirMtime(const char *moddir)
+{
+    struct stat st;
+
+    if (stat(moddir, &st) < 0) {
+        VIR_DEBUG("Failed to stat nbdkit module directory '%s': %s",
+                  moddir,
+                  g_strerror(errno));
+        return 0;
+    }
+
+    return st.st_mtime;
+}
+
+
 G_GNUC_UNUSED static void
 qemuNbdkitCapsQuery(qemuNbdkitCaps *caps)
 {
+    struct stat st;
+
+    if (stat(caps->path, &st) < 0) {
+        VIR_DEBUG("Failed to stat nbdkit binary '%s': %s",
+                  caps->path,
+                  g_strerror(errno));
+        caps->ctime  = 0;
+        return;
+    }
+
+    caps->ctime = st.st_ctime;
+    caps->filterDirMtime = qemuNbdkitGetDirMtime(NBDKIT_FILTERDIR);
+    caps->pluginDirMtime = qemuNbdkitGetDirMtime(NBDKIT_PLUGINDIR);
+    caps->libvirtCtime = virGetSelfLastChanged();
+    caps->libvirtVersion = LIBVIR_VERSION_NUMBER;
+
     qemuNbdkitCapsQueryPlugins(caps);
     qemuNbdkitCapsQueryFilters(caps);
     qemuNbdkitCapsQueryVersion(caps);
-- 
2.37.3