[libvirt] [PATCH v2 2/2] qemu: Also treat directories properly when using namespaces

[Martin Kletzander]

When recreating folders with namespaces, the directory type was not
being handled at all.  It's not special, we probably just didn't know
that that can be used as a volume path as well.  The code failed
gracefully, but we want to allow that so that we can use <disk
type='dir'> in domains again.

Partially-resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1443434

Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
---
 src/qemu/qemu_domain.c | 40 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 5 deletions(-)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 2c77a6442467..2549f9bf3290 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -7855,6 +7855,7 @@ qemuDomainCreateDeviceRecursive(const char *device,
     bool isLink = false;
     bool isDev = false;
     bool isReg = false;
+    bool isDir = false;
     bool create = false;
 #ifdef WITH_SELINUX
     char *tcon = NULL;
@@ -7879,6 +7880,7 @@ qemuDomainCreateDeviceRecursive(const char *device,
     isLink = S_ISLNK(sb.st_mode);
     isDev = S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode);
     isReg = S_ISREG(sb.st_mode) || S_ISFIFO(sb.st_mode) || S_ISSOCK(sb.st_mode);
+    isDir = S_ISDIR(sb.st_mode);
 
     /* Here, @device might be whatever path in the system. We
      * should create the path in the namespace iff it's "/dev"
@@ -7996,6 +7998,10 @@ qemuDomainCreateDeviceRecursive(const char *device,
             goto cleanup;
         /* Just create the file here so that code below sets
          * proper owner and mode. Bind mount only after that. */
+    } else if (isDir) {
+        if (create &&
+            virFileMakePathWithMode(devicePath, sb.st_mode) < 0)
+            goto cleanup;
     } else {
         virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
                        _("unsupported device type %s 0%o"),
@@ -8057,7 +8063,7 @@ qemuDomainCreateDeviceRecursive(const char *device,
 #endif
 
     /* Finish mount process started earlier. */
-    if (isReg &&
+    if ((isReg || isDir) &&
         virFileBindMountDevice(device, devicePath) < 0)
         goto cleanup;
 
@@ -8686,6 +8692,7 @@ qemuDomainAttachDeviceMknodHelper(pid_t pid ATTRIBUTE_UNUSED,
     bool isLink = S_ISLNK(data->sb.st_mode);
     bool isDev = S_ISCHR(data->sb.st_mode) || S_ISBLK(data->sb.st_mode);
     bool isReg = S_ISREG(data->sb.st_mode) || S_ISFIFO(data->sb.st_mode) || S_ISSOCK(data->sb.st_mode);
+    bool isDir = S_ISDIR(data->sb.st_mode);
 
     qemuSecurityPostFork(data->driver->securityManager);
 
@@ -8741,6 +8748,23 @@ qemuDomainAttachDeviceMknodHelper(pid_t pid ATTRIBUTE_UNUSED,
         delDevice = true;
         /* Just create the file here so that code below sets
          * proper owner and mode. Move the mount only after that. */
+    } else if (isDir) {
+        /* We are not cleaning up disks on virDomainDetachDevice
+         * because disk might be still in use by different disk
+         * as its backing chain. This might however clash here.
+         * Therefore do the cleanup here. */
+        if (umount(data->file) < 0 &&
+            errno != ENOENT && errno != EINVAL) {
+            virReportSystemError(errno,
+                                 _("Unable to umount %s"),
+                                 data->file);
+            goto cleanup;
+        }
+        if (virFileMakePathWithMode(data->file, data->sb.st_mode) < 0)
+            goto cleanup;
+        delDevice = true;
+        /* Just create the folder here so that code below sets
+         * proper owner and mode. Move the mount only after that. */
     } else {
         virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
                        _("unsupported device type %s 0%o"),
@@ -8788,14 +8812,18 @@ qemuDomainAttachDeviceMknodHelper(pid_t pid ATTRIBUTE_UNUSED,
 # endif
 
     /* Finish mount process started earlier. */
-    if (isReg &&
+    if ((isReg || isDir) &&
         virFileMoveMount(data->target, data->file) < 0)
         goto cleanup;
 
     ret = 0;
  cleanup:
-    if (ret < 0 && delDevice)
-        unlink(data->file);
+    if (ret < 0 && delDevice) {
+        if (isDir)
+            virFileDeleteTree(data->file);
+        else
+            unlink(data->file);
+    }
 # ifdef WITH_SELINUX
     freecon(data->tcon);
 # endif
@@ -8818,6 +8846,7 @@ qemuDomainAttachDeviceMknodRecursive(virQEMUDriverPtr driver,
     char *target = NULL;
     bool isLink;
     bool isReg;
+    bool isDir;
 
     if (!ttl) {
         virReportSystemError(ELOOP,
@@ -8840,8 +8869,9 @@ qemuDomainAttachDeviceMknodRecursive(virQEMUDriverPtr driver,
 
     isLink = S_ISLNK(data.sb.st_mode);
     isReg = S_ISREG(data.sb.st_mode) || S_ISFIFO(data.sb.st_mode) || S_ISSOCK(data.sb.st_mode);
+    isDir = S_ISDIR(data.sb.st_mode);
 
-    if (isReg && STRPREFIX(file, DEVPREFIX)) {
+    if ((isReg || isDir) && STRPREFIX(file, DEVPREFIX)) {
         cfg = virQEMUDriverGetConfig(driver);
         if (!(target = qemuDomainGetPreservedMountPath(cfg, vm, file)))
             goto cleanup;
-- 
2.14.1