Introduce virDomainFSFreeze() and virDomainFSThaw() public API

These will freeze and thaw filesystems within guest specified by
@mountpoints parameters. The parameters can be NULL and 0, then all
mounted filesystems are frozen or thawed. @flags parameter, which are
currently not used, is for future extensions.

Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@hds.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

include/libvirt/libvirt.h.in

@@ -5279,6 +5279,16 @@ int virDomainFSTrim(virDomainPtr dom,
                     unsigned long long minimum,
                     unsigned int flags);
 
+int virDomainFSFreeze(virDomainPtr dom,
+                      const char **mountpoints,
+                      unsigned int nmountpoints,
+                      unsigned int flags);
+
+int virDomainFSThaw(virDomainPtr dom,
+                    const char **mountpoints,
+                    unsigned int nmountpoints,
+                    unsigned int flags);
+
 /**
  * virSchedParameterType:
  *

src/driver.h

@@ -1149,6 +1149,18 @@ typedef int
                                      unsigned int flags,
                                      int cancelled);
 
+typedef int
+(*virDrvDomainFSFreeze)(virDomainPtr dom,
+                        const char **mountpoints,
+                        unsigned int nmountpoints,
+                        unsigned int flags);
+
+typedef int
+(*virDrvDomainFSThaw)(virDomainPtr dom,
+                      const char **mountpoints,
+                      unsigned int nmountpoints,
+                      unsigned int flags);
+
 typedef struct _virDriver virDriver;
 typedef virDriver *virDriverPtr;
 
@@ -1363,6 +1375,8 @@ struct _virDriver {
     virDrvDomainMigrateFinish3Params domainMigrateFinish3Params;
     virDrvDomainMigrateConfirm3Params domainMigrateConfirm3Params;
     virDrvConnectGetCPUModelNames connectGetCPUModelNames;
+    virDrvDomainFSFreeze domainFSFreeze;
+    virDrvDomainFSThaw domainFSThaw;
 };
 
 

src/libvirt.c

@@ -20698,3 +20698,96 @@ virDomainFSTrim(virDomainPtr dom,
     virDispatchError(dom->conn);
     return -1;
 }
+
+/**
+ * virDomainFSFreeze:
+ * @dom: a domain object
+ * @mountpoints: list of mount points to be frozen
+ * @nmountpoints: the number of mount points specified in @mountpoints
+ * @flags: extra flags; not used yet, so callers should always pass 0
+ *
+ * Freeze specified filesystems within the guest (hence guest agent
+ * may be required depending on hypervisor used). If @mountpoints is NULL and
+ * @nmountpoints is 0, every mounted filesystem on the guest is frozen.
+ * In some environments (e.g. QEMU guest with guest agent which doesn't
+ * support mountpoints argument), @mountpoints may need to be NULL.
+ *
+ * Returns the number of frozen filesystems on success, -1 otherwise.
+ */
+int
+virDomainFSFreeze(virDomainPtr dom,
+                  const char **mountpoints,
+                  unsigned int nmountpoints,
+                  unsigned int flags)
+{
+    VIR_DOMAIN_DEBUG(dom, "mountpoints=%p, nmountpoints=%d, flags=%x",
+                     mountpoints, nmountpoints, flags);
+
+    virResetLastError();
+
+    virCheckDomainReturn(dom, -1);
+    virCheckReadOnlyGoto(dom->conn->flags, error);
+    if (nmountpoints)
+        virCheckNonNullArgGoto(mountpoints, error);
+    else
+        virCheckNullArgGoto(mountpoints, error);
+
+    if (dom->conn->driver->domainFSFreeze) {
+        int ret = dom->conn->driver->domainFSFreeze(
+            dom, mountpoints, nmountpoints, flags);
+        if (ret < 0)
+            goto error;
+        return ret;
+    }
+
+    virReportUnsupportedError();
+
+ error:
+    virDispatchError(dom->conn);
+    return -1;
+}
+
+/**
+ * virDomainFSThaw:
+ * @dom: a domain object
+ * @mountpoints: list of mount points to be thawed
+ * @nmountpoints: the number of mount points specified in @mountpoints
+ * @flags: extra flags; not used yet, so callers should always pass 0
+ *
+ * Thaw specified filesystems within the guest. If @mountpoints is NULL and
+ * @nmountpoints is 0, every mounted filesystem on the guest is thawed.
+ * In some drivers (e.g. QEMU driver), @mountpoints may need to be NULL.
+ *
+ * Returns the number of thawed filesystems on success, -1 otherwise.
+ */
+int
+virDomainFSThaw(virDomainPtr dom,
+                const char **mountpoints,
+                unsigned int nmountpoints,
+                unsigned int flags)
+{
+    VIR_DOMAIN_DEBUG(dom, "flags=%x", flags);
+
+    virResetLastError();
+
+    virCheckDomainReturn(dom, -1);
+    virCheckReadOnlyGoto(dom->conn->flags, error);
+    if (nmountpoints)
+        virCheckNonNullArgGoto(mountpoints, error);
+    else
+        virCheckNullArgGoto(mountpoints, error);
+
+    if (dom->conn->driver->domainFSThaw) {
+        int ret = dom->conn->driver->domainFSThaw(
+            dom, mountpoints, nmountpoints, flags);
+        if (ret < 0)
+            goto error;
+        return ret;
+    }
+
+    virReportUnsupportedError();
+
+ error:
+    virDispatchError(dom->conn);
+    return -1;
+}

src/libvirt_public.syms

@@ -650,5 +650,11 @@ LIBVIRT_1.2.3 {
         virDomainCoreDumpWithFormat;
 } LIBVIRT_1.2.1;
 
+LIBVIRT_1.2.5 {
+    global:
+        virDomainFSFreeze;
+        virDomainFSThaw;
+} LIBVIRT_1.2.3;
+
 
 # .... define new API here using predicted next version number ....