The 'block-commit' QMP command is implemented internally using two different drivers. If the source image is the active layer then the mirror driver is used (commit_active_start()), otherwise the commit driver is used (commit_start()).
In both cases the destination image must be put temporarily in read-write mode. This is done correctly in the latter case, but what commit_active_start() does is copy all flags instead. This patch replaces the bdrv_reopen() calls in that function with bdrv_reopen_set_read_only() so that only the read-only status is changed. A similar change is made in mirror_exit(), which is also used by the 'drive-mirror' and 'blockdev-mirror' commands. Signed-off-by: Alberto Garcia <be...@igalia.com> Reviewed-by: Max Reitz <mre...@redhat.com> --- block/mirror.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/block/mirror.c b/block/mirror.c index 56d9ef7474..41b6cbaad6 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -672,9 +672,10 @@ static int mirror_exit_common(Job *job) if (s->should_complete && !abort) { BlockDriverState *to_replace = s->to_replace ?: src; + bool ro = bdrv_is_read_only(to_replace); - if (bdrv_get_flags(target_bs) != bdrv_get_flags(to_replace)) { - bdrv_reopen(target_bs, bdrv_get_flags(to_replace), NULL); + if (ro != bdrv_is_read_only(target_bs)) { + bdrv_reopen_set_read_only(target_bs, ro, NULL); } /* The mirror job has no requests in flight any more, but we need to @@ -1692,13 +1693,15 @@ void commit_active_start(const char *job_id, BlockDriverState *bs, BlockCompletionFunc *cb, void *opaque, bool auto_complete, Error **errp) { - int orig_base_flags; + bool base_read_only; Error *local_err = NULL; - orig_base_flags = bdrv_get_flags(base); + base_read_only = bdrv_is_read_only(base); - if (bdrv_reopen(base, bs->open_flags, errp)) { - return; + if (base_read_only) { + if (bdrv_reopen_set_read_only(base, false, errp) < 0) { + return; + } } mirror_start_job(job_id, bs, creation_flags, base, NULL, speed, 0, 0, @@ -1717,6 +1720,8 @@ void commit_active_start(const char *job_id, BlockDriverState *bs, error_restore_flags: /* ignore error and errp for bdrv_reopen, because we want to propagate * the original error */ - bdrv_reopen(base, orig_base_flags, NULL); + if (base_read_only) { + bdrv_reopen_set_read_only(base, true, NULL); + } return; } -- 2.11.0