From 98bf67db979927a5c7bbdc4a17c35d60b5f38e71 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 3 Jun 2020 16:03:24 +0100 Subject: [PATCH 25/26] mirror: Make sure that source and target size match RH-Author: Kevin Wolf Message-id: <20200603160325.67506-11-kwolf@redhat.com> Patchwork-id: 97110 O-Subject: [RHEL-AV-8.2.1 qemu-kvm PATCH v2 10/11] mirror: Make sure that source and target size match Bugzilla: 1778593 RH-Acked-by: Eric Blake RH-Acked-by: Max Reitz RH-Acked-by: Stefano Garzarella If the target is shorter than the source, mirror would copy data until it reaches the end of the target and then fail with an I/O error when trying to write past the end. If the target is longer than the source, the mirror job would complete successfully, but the target wouldn't actually be an accurate copy of the source image (it would contain some additional garbage at the end). Fix this by checking that both images have the same size when the job starts. Signed-off-by: Kevin Wolf Reviewed-by: Eric Blake Message-Id: <20200511135825.219437-4-kwolf@redhat.com> Reviewed-by: Max Reitz Reviewed-by: Vladimir Sementsov-Ogievskiy Signed-off-by: Kevin Wolf (cherry picked from commit e83dd6808c6e0975970f37b49b27cc37bb54eea8) Signed-off-by: Kevin Wolf Signed-off-by: Danilo C. L. de Paula --- block/mirror.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/block/mirror.c b/block/mirror.c index 5e5a521..0d32fca 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -859,6 +859,7 @@ static int coroutine_fn mirror_run(Job *job, Error **errp) BlockDriverState *target_bs = blk_bs(s->target); bool need_drain = true; int64_t length; + int64_t target_length; BlockDriverInfo bdi; char backing_filename[2]; /* we only need 2 characters because we are only checking for a NULL string */ @@ -874,24 +875,26 @@ static int coroutine_fn mirror_run(Job *job, Error **errp) goto immediate_exit; } + target_length = blk_getlength(s->target); + if (target_length < 0) { + ret = target_length; + goto immediate_exit; + } + /* Active commit must resize the base image if its size differs from the * active layer. */ if (s->base == blk_bs(s->target)) { - int64_t base_length; - - base_length = blk_getlength(s->target); - if (base_length < 0) { - ret = base_length; - goto immediate_exit; - } - - if (s->bdev_length > base_length) { + if (s->bdev_length > target_length) { ret = blk_truncate(s->target, s->bdev_length, false, PREALLOC_MODE_OFF, NULL); if (ret < 0) { goto immediate_exit; } } + } else if (s->bdev_length != target_length) { + error_setg(errp, "Source and target image have different sizes"); + ret = -EINVAL; + goto immediate_exit; } if (s->bdev_length == 0) { -- 1.8.3.1