[libvirt] [PATCH v4] qemu: fix broken autostart symlink after renaming domain.

[Erik Skultety]

On Thu, Jul 19, 2018 at 01:21:48AM -0300, Julio Faracco wrote:
> If a domain is configured to start on boot, it has a symlink to the
> domain definition inside the autostart directory. If you rename this
> domain, the definition is renamed too. The symlink need to be pointed to
> this renamed file. This commit recreates the symlink after renaming the
> XML file.
>
> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1594985
>
> Signed-off-by: Julio Faracco <jcfaracco at gmail.com>
> ---
>  src/qemu/qemu_driver.c | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
>
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 25170f6f26..09af231dfc 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -20917,6 +20917,8 @@ qemuDomainRenameCallback(virDomainObjPtr vm,
>      char *old_dom_name = NULL;
>      char *new_dom_cfg_file = NULL;
>      char *old_dom_cfg_file = NULL;
> +    char *new_dom_autostart_link = NULL;
> +    char *old_dom_autostart_link = NULL;
>
>      virCheckFlags(0, ret);
>
> @@ -20937,6 +20939,14 @@ qemuDomainRenameCallback(virDomainObjPtr vm,
>                                                   vm->def->name)))
>          goto cleanup;
>
> +    if (vm->autostart) {
> +        if (!(new_dom_autostart_link = virDomainConfigFile(cfg->autostartDir,
> +                                                          new_dom_name)) ||
> +            !(old_dom_autostart_link = virDomainConfigFile(cfg->autostartDir,
> +                                                          vm->def->name)))
> +            goto cleanup;
> +    }
> +
>      event_old = virDomainEventLifecycleNewFromObj(vm,
>                                              VIR_DOMAIN_EVENT_UNDEFINED,
>                                              VIR_DOMAIN_EVENT_UNDEFINED_RENAMED);
> @@ -20949,6 +20959,23 @@ qemuDomainRenameCallback(virDomainObjPtr vm,
>      if (virDomainSaveConfig(cfg->configDir, driver->caps, vm->def) < 0)
>          goto rollback;
>
> +    if (vm->autostart) {
> +        if (virFileIsLink(old_dom_autostart_link) &&
> +            unlink(old_dom_autostart_link) < 0) {
> +            virReportSystemError(errno,
> +                                 _("Failed to delete symlink '%s'"),
> +                                 old_dom_autostart_link);
> +            goto rollback;
> +        }
> +
> +        if (symlink(new_dom_cfg_file, new_dom_autostart_link) < 0) {
> +            virReportSystemError(errno,
> +                                 _("Failed to create symlink '%s to '%s'"),
> +                                 new_dom_autostart_link, new_dom_cfg_file);
> +            goto rollback;

If ^this symlink fails, you don't restore the original. The only thing your
code really needs is to move some bits around, the logic is fine otherwise.
I've done that, you can see the diff of the changes I performed in the attached
diff and pushed the patch.

Thanks,
Erik

> +        }
> +    }
> +
>      if (virFileExists(old_dom_cfg_file) &&
>          unlink(old_dom_cfg_file) < 0) {
>          virReportSystemError(errno,
> @@ -20963,6 +20990,8 @@ qemuDomainRenameCallback(virDomainObjPtr vm,
>      ret = 0;
>
>   cleanup:
> +    VIR_FREE(old_dom_autostart_link);
> +    VIR_FREE(new_dom_autostart_link);
>      VIR_FREE(old_dom_cfg_file);
>      VIR_FREE(new_dom_cfg_file);
>      VIR_FREE(old_dom_name);
> @@ -20982,6 +21011,11 @@ qemuDomainRenameCallback(virDomainObjPtr vm,
>      if (virFileExists(new_dom_cfg_file))
>          unlink(new_dom_cfg_file);
>
> +    if (vm->autostart) {
> +        if (virFileExists(new_dom_autostart_link))
> +            unlink(new_dom_autostart_link);
> +    }
> +
>      goto cleanup;
>  }
>
> --
> 2.17.1
>
> --
> libvir-list mailing list
> libvir-list at redhat.com
> https://www.redhat.com/mailman/listinfo/libvir-list
-------------- next part --------------
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 09af231dfc..b5e6fe8132 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -20945,6 +20945,13 @@ qemuDomainRenameCallback(virDomainObjPtr vm,
             !(old_dom_autostart_link = virDomainConfigFile(cfg->autostartDir,
                                                           vm->def->name)))
             goto cleanup;
+
+        if (symlink(new_dom_cfg_file, new_dom_autostart_link) < 0) {
+            virReportSystemError(errno,
+                                 _("Failed to create symlink '%s to '%s'"),
+                                 new_dom_autostart_link, new_dom_cfg_file);
+            goto cleanup;
+        }
     }
 
     event_old = virDomainEventLifecycleNewFromObj(vm,
@@ -20959,23 +20966,6 @@ qemuDomainRenameCallback(virDomainObjPtr vm,
     if (virDomainSaveConfig(cfg->configDir, driver->caps, vm->def) < 0)
         goto rollback;
 
-    if (vm->autostart) {
-        if (virFileIsLink(old_dom_autostart_link) &&
-            unlink(old_dom_autostart_link) < 0) {
-            virReportSystemError(errno,
-                                 _("Failed to delete symlink '%s'"),
-                                 old_dom_autostart_link);
-            goto rollback;
-        }
-
-        if (symlink(new_dom_cfg_file, new_dom_autostart_link) < 0) {
-            virReportSystemError(errno,
-                                 _("Failed to create symlink '%s to '%s'"),
-                                 new_dom_autostart_link, new_dom_cfg_file);
-            goto rollback;
-        }
-    }
-
     if (virFileExists(old_dom_cfg_file) &&
         unlink(old_dom_cfg_file) < 0) {
         virReportSystemError(errno,
@@ -20984,6 +20974,16 @@ qemuDomainRenameCallback(virDomainObjPtr vm,
         goto rollback;
     }
 
+    if (vm->autostart) {
+        if (virFileIsLink(old_dom_autostart_link) &&
+            unlink(old_dom_autostart_link) < 0) {
+            virReportSystemError(errno,
+                                 _("Failed to delete symlink '%s'"),
+                                 old_dom_autostart_link);
+            goto rollback;
+        }
+    }
+
     event_new = virDomainEventLifecycleNewFromObj(vm,
                                               VIR_DOMAIN_EVENT_DEFINED,
                                               VIR_DOMAIN_EVENT_DEFINED_RENAMED);
@@ -21011,10 +21011,9 @@ qemuDomainRenameCallback(virDomainObjPtr vm,
     if (virFileExists(new_dom_cfg_file))
         unlink(new_dom_cfg_file);
 
-    if (vm->autostart) {
-        if (virFileExists(new_dom_autostart_link))
-            unlink(new_dom_autostart_link);
-    }
+    if (vm->autostart &&
+        virFileExists(new_dom_autostart_link))
+        unlink(new_dom_autostart_link);
 
     goto cleanup;
 }