commit 6f5ef23a3ff09919b73eef8196969685cb2383ee
author Kevin Wolf <kwolf@redhat.com> Thu Feb 09 14:45:37 2017 +0100
committer Kevin Wolf <kwolf@redhat.com> Tue Feb 28 20:47:50 2017 +0100
tree a7127f58abc2a2a2b7a16f83dbbe7746d5b75d65
parent 887354bd13ecb7ff68ec26892806c97512b77877

migration/block: Use real permissions

Request BLK_PERM_CONSISTENT_READ for the source of block migration, and
handle potential permission errors as good as we can in this place
(which is not very good, but it matches the other failure cases).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>

migration/block.c

diff --git a/migration/block.c b/migration/block.c
index d259936..1941bc2 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -379,7 +379,7 @@
     }
 }
 
-static void init_blk_migration(QEMUFile *f)
+static int init_blk_migration(QEMUFile *f)
 {
     BlockDriverState *bs;
     BlkMigDevState *bmds;
@@ -390,6 +390,8 @@
         BlkMigDevState *bmds;
         BlockDriverState *bs;
     } *bmds_bs;
+    Error *local_err = NULL;
+    int ret;
 
     block_mig_state.submitted = 0;
     block_mig_state.read_done = 0;
@@ -411,12 +413,12 @@
 
         sectors = bdrv_nb_sectors(bs);
         if (sectors <= 0) {
+            ret = sectors;
             goto out;
         }
 
         bmds = g_new0(BlkMigDevState, 1);
-        /* FIXME Use real permissions */
-        bmds->blk = blk_new(0, BLK_PERM_ALL);
+        bmds->blk = blk_new(BLK_PERM_CONSISTENT_READ, BLK_PERM_ALL);
         bmds->blk_name = g_strdup(bdrv_get_device_name(bs));
         bmds->bulk_completed = 0;
         bmds->total_sectors = sectors;
@@ -446,7 +448,11 @@
         BlockDriverState *bs = bmds_bs[i].bs;
 
         if (bmds) {
-            blk_insert_bs(bmds->blk, bs, &error_abort);
+            ret = blk_insert_bs(bmds->blk, bs, &local_err);
+            if (ret < 0) {
+                error_report_err(local_err);
+                goto out;
+            }
 
             alloc_aio_bitmap(bmds);
             error_setg(&bmds->blocker, "block device is in use by migration");
@@ -454,8 +460,10 @@
         }
     }
 
+    ret = 0;
 out:
     g_free(bmds_bs);
+    return ret;
 }
 
 /* Called with no lock taken.  */
@@ -706,7 +714,11 @@
             block_mig_state.submitted, block_mig_state.transferred);
 
     qemu_mutex_lock_iothread();
-    init_blk_migration(f);
+    ret = init_blk_migration(f);
+    if (ret < 0) {
+        qemu_mutex_unlock_iothread();
+        return ret;
+    }
 
     /* start track dirty blocks */
     ret = set_dirty_tracking();