Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2019-08-19' into staging

Block patches:
- preallocation=falloc/full support for LUKS
- Various minor fixes

# gpg: Signature made Mon 19 Aug 2019 16:36:45 BST
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2019-08-19:
  doc: Preallocation does not require writing zeroes
  iotests: Fix 141 when run with qed
  vpc: Do not return RAW from block_status
  vmdk: Make block_status recurse for flat extents
  vdi: Make block_status recurse for fixed images
  iotests: Full mirror to existing non-zero image
  iotests: Test convert -n to pre-filled image
  iotests: Convert to preallocated encrypted qcow2
  vhdx: Fix .bdrv_has_zero_init()
  vdi: Fix .bdrv_has_zero_init()
  qcow2: Fix .bdrv_has_zero_init()
  block: Use bdrv_has_zero_init_truncate()
  block: Implement .bdrv_has_zero_init_truncate()
  block: Add bdrv_has_zero_init_truncate()
  mirror: Fix bdrv_has_zero_init() use
  qemu-img: Fix bdrv_has_zero_init() use in convert
  LUKS: support preallocation

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/qemu-img.c b/qemu-img.c
index c920e3564c..7daa05e51a 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -1578,6 +1578,7 @@ typedef struct ImgConvertState {
     bool has_zero_init;
     bool compressed;
     bool unallocated_blocks_are_zero;
+    bool target_is_new;
     bool target_has_backing;
     int64_t target_backing_sectors; /* negative if unknown */
     bool wr_in_order;
@@ -1975,9 +1976,11 @@ static int convert_do_copy(ImgConvertState *s)
     int64_t sector_num = 0;
 
     /* Check whether we have zero initialisation or can get it efficiently */
-    s->has_zero_init = s->min_sparse && !s->target_has_backing
-                     ? bdrv_has_zero_init(blk_bs(s->target))
-                     : false;
+    if (s->target_is_new && s->min_sparse && !s->target_has_backing) {
+        s->has_zero_init = bdrv_has_zero_init(blk_bs(s->target));
+    } else {
+        s->has_zero_init = false;
+    }
 
     if (!s->has_zero_init && !s->target_has_backing &&
         bdrv_can_write_zeroes_with_unmap(blk_bs(s->target)))
@@ -2428,6 +2431,8 @@ static int img_convert(int argc, char **argv)
         }
     }
 
+    s.target_is_new = !skip_create;
+
     flags = s.min_sparse ? (BDRV_O_RDWR | BDRV_O_UNMAP) : BDRV_O_RDWR;
     ret = bdrv_parse_cache_mode(cache, &flags, &writethrough);
     if (ret < 0) {