From 62c3dde0dcd04ce52e761beb66a3ec4aacd007e6 Mon Sep 17 00:00:00 2001 From: John Snow Date: Wed, 18 Jul 2018 22:55:08 +0200 Subject: [PATCH 250/268] nbd/server: Fix dirty bitmap logic regression RH-Author: John Snow Message-id: <20180718225511.14878-33-jsnow@redhat.com> Patchwork-id: 81427 O-Subject: [RHEL-7.6 qemu-kvm-rhev PATCH 32/35] nbd/server: Fix dirty bitmap logic regression Bugzilla: 1207657 RH-Acked-by: Eric Blake RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Fam Zheng From: Eric Blake In my hurry to fix a build failure, I introduced a logic bug. The assertion conditional is backwards, meaning that qemu will now abort instead of reporting dirty bitmap status. The bug can only be tickled by an NBD client using an exported dirty bitmap (which is still an experimental QMP command), so it's not the end of the world for supported usage (and neither 'make check' nor qemu-iotests fails); but it also shows that we really want qemu-io support for reading dirty bitmaps if only so that I can add iotests coverage to prevent future brown-bag-of-shame events like this one. Fixes: 45eb6fb6 Signed-off-by: Eric Blake Message-Id: <20180622153509.375130-1-eblake@redhat.com> (cherry picked from commit 7606c99a0421be7e9d984766fe239f7791a2fd9c) Signed-off-by: John Snow Signed-off-by: Miroslav Rezanina --- nbd/server.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/nbd/server.c b/nbd/server.c index 50ac8bf..e52b76b 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1977,7 +1977,7 @@ static unsigned int bitmap_to_extents(BdrvDirtyBitmap *bitmap, uint64_t offset, bdrv_dirty_bitmap_unlock(bitmap); - assert(offset > end); + assert(offset < end); *length = end - offset; return i; } -- 1.8.3.1