From 3397f0cb483b40785678d2328da584c8a35c358c Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Tue, 22 Nov 2011 16:52:13 +0100
Subject: [PATCH] vvfat: Add migration blocker

vvfat caches more or less everything when in writable mode. For migration
to work, it would have to be invalidated. Block migration for now when
in writable mode (default is readonly).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/vvfat.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/block/vvfat.c b/block/vvfat.c
index 131680f6f..a310ce8c3 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -27,6 +27,7 @@
 #include "qemu-common.h"
 #include "block_int.h"
 #include "module.h"
+#include "migration.h"
 
 #ifndef S_IWGRP
 #define S_IWGRP 0
@@ -350,6 +351,8 @@ typedef struct BDRVVVFATState {
     array_t commits;
     const char* path;
     int downcase_short_names;
+
+    Error *migration_blocker;
 } BDRVVVFATState;
 
 /* take the sector position spos and convert it to Cylinder/Head/Sector position
@@ -1073,6 +1076,15 @@ DLOG(if (stderr == NULL) {
 
     //    assert(is_consistent(s));
     qemu_co_mutex_init(&s->lock);
+
+    /* Disable migration when vvfat is used rw */
+    if (s->qcow) {
+        error_set(&s->migration_blocker,
+                  QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED,
+                  "vvfat (rw)", bs->device_name, "live migration");
+        migrate_add_blocker(s->migration_blocker);
+    }
+
     return 0;
 }
 
@@ -2829,6 +2841,11 @@ static void vvfat_close(BlockDriverState *bs)
     array_free(&(s->directory));
     array_free(&(s->mapping));
     g_free(s->cluster_buffer);
+
+    if (s->qcow) {
+        migrate_del_blocker(s->migration_blocker);
+        error_free(s->migration_blocker);
+    }
 }
 
 static BlockDriver bdrv_vvfat = {