diff mbox series

[16/21] parallels: Truncate images on the last used cluster

Message ID 20231228094153.370291-16-alexander.ivanov@virtuozzo.com (mailing list archive)
State New, archived
Headers show
Series [01/21] parallels: Set s->used_bmap to NULL in parallels_free_used_bitmap() | expand

Commit Message

Alexander Ivanov Dec. 28, 2023, 9:41 a.m. UTC 
On an image closing there can be unused clusters in the end of the image.
Truncate these clusters and update data_end field.

Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
---
 block/parallels.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/block/parallels.c b/block/parallels.c
index fb7bc5e555..136865d53e 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -1454,6 +1454,23 @@  fail:
     return ret;
 }
 
+static int GRAPH_RDLOCK parallels_truncate_unused_clusters(BlockDriverState *bs)
+{
+    BDRVParallelsState *s = bs->opaque;
+    uint64_t end_off = 0;
+    if (s->used_bmap_size > 0) {
+        end_off = find_last_bit(s->used_bmap, s->used_bmap_size);
+        if (end_off == s->used_bmap_size) {
+            end_off = 0;
+        } else {
+            end_off = (end_off + 1) * s->cluster_size;
+        }
+    }
+    end_off += s->data_start * BDRV_SECTOR_SIZE;
+    s->data_end = end_off / BDRV_SECTOR_SIZE;
+    return bdrv_truncate(bs->file, end_off, true, PREALLOC_MODE_OFF, 0, NULL);
+}
+
 static int GRAPH_RDLOCK parallels_inactivate(BlockDriverState *bs)
 {
     BDRVParallelsState *s = bs->opaque;
@@ -1471,8 +1488,7 @@  static int GRAPH_RDLOCK parallels_inactivate(BlockDriverState *bs)
     parallels_update_header(bs);
 
     /* errors are ignored, so we might as well pass exact=true */
-    ret = bdrv_truncate(bs->file, s->data_end << BDRV_SECTOR_BITS,
-                        true, PREALLOC_MODE_OFF, 0, NULL);
+    ret = parallels_truncate_unused_clusters(bs);
     if (ret < 0) {
         error_report("Failed to truncate image: %s", strerror(-ret));
     }