commit e5e6268348972aaf415d7931bbd808b3fdba6cb1
author Denis V. Lunev <den@openvz.org> Fri Aug 04 18:10:13 2017 +0300
committer Kevin Wolf <kwolf@redhat.com> Tue Aug 08 15:19:16 2017 +0200
tree b16ad4431a5205398cdd584a213282590e764668
parent d8b83e37c381cf86ecd907301b7dcc65baaa0aea

parallels: drop check that bdrv_truncate() is working

This would be actually strange and error prone. If truncate() nowadays
will fail, there is something fatally wrong. Let's check for that during
the actual work.

The only fallback case is when the file is not zero initialized. In this
case we should switch to preallocation via fallocate().

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Markus Armbruster <armbru@redhat.com>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Max Reitz <mreitz@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/parallels.c

diff --git a/block/parallels.c b/block/parallels.c
index 6794e53..e1e06d2 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -703,9 +703,7 @@
         goto fail_options;
     }
 
-    if (!(flags & BDRV_O_RESIZE) || !bdrv_has_zero_init(bs->file->bs) ||
-            bdrv_truncate(bs->file, bdrv_getlength(bs->file->bs),
-                          PREALLOC_MODE_OFF, NULL) != 0) {
+    if (!bdrv_has_zero_init(bs->file->bs)) {
         s->prealloc_mode = PRL_PREALLOC_MODE_FALLOCATE;
     }