From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Date: Tue, 29 Oct 2019 15:09:34 +0000 (+0300)
Subject: block/block-copy: fix s->copy_size for compressed cluster
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=dcfbece68441bfbe6803de60ab5a8045196094b4;p=qemu.git

block/block-copy: fix s->copy_size for compressed cluster

0e2402452f1f20429 allowed writes larger than cluster, but that's
unsupported for compressed write. Fix it.

Fixes: 0e2402452f1f20429
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20191029150934.26416-1-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
---

diff --git a/block/block-copy.c b/block/block-copy.c
index c39cc9cffe..79798a1567 100644
--- a/block/block-copy.c
+++ b/block/block-copy.c
@@ -109,9 +109,9 @@ BlockCopyState *block_copy_state_new(BdrvChild *source, BdrvChild *target,
         s->use_copy_range = false;
         s->copy_size = cluster_size;
     } else if (write_flags & BDRV_REQ_WRITE_COMPRESSED) {
-        /* Compression is not supported for copy_range */
+        /* Compression supports only cluster-size writes and no copy-range. */
         s->use_copy_range = false;
-        s->copy_size = MAX(cluster_size, BLOCK_COPY_MAX_BUFFER);
+        s->copy_size = cluster_size;
     } else {
         /*
          * copy_range does not respect max_transfer (it's a TODO), so we factor