[libvirt] [PATCH] qemu: mkdir memory_backing_dir on startup

[Michal Privoznik]

In 48d9e6cdcc and friends we've allowed users to back guest
memory by a file inside the host. And in order to keep things
manageable the memory_backing_dir variable was introduced to
qemu.conf to specify the directory where the files are kept.
However, libvirt's policy is that directories are created on
domain startup if they don't exist. We've missed this one.

Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
---
 src/qemu/qemu_driver.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 67f54282a..fcab7ddf8 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -706,6 +706,11 @@ qemuStateInitialize(bool privileged,
                              cfg->nvramDir);
         goto error;
     }
+    if (virFileMakePath(cfg->memoryBackingDir) < 0) {
+        virReportSystemError(errno, _("Failed to create memory backing dir %s"),
+                             cfg->memoryBackingDir);
+        goto error;
+    }
 
     qemu_driver->qemuImgBinary = virFindFileInPath("qemu-img");
 
@@ -830,6 +835,13 @@ qemuStateInitialize(bool privileged,
                                  (int) cfg->group);
             goto error;
         }
+        if (chown(cfg->memoryBackingDir, cfg->user, cfg->group) < 0) {
+            virReportSystemError(errno,
+                                 _("unable to set ownership of '%s' to %d:%d"),
+                                 cfg->memoryBackingDir, (int) cfg->user,
+                                 (int) cfg->group);
+            goto error;
+        }
 
         run_uid = cfg->user;
         run_gid = cfg->group;
-- 
2.13.0