From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:37058) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UN97H-0008Qj-Qd for qemu-devel@nongnu.org; Tue, 02 Apr 2013 17:51:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UN97G-0000J4-HV for qemu-devel@nongnu.org; Tue, 02 Apr 2013 17:51:43 -0400 Sender: fluxion From: Michael Roth Date: Tue, 2 Apr 2013 16:45:23 -0500 Message-Id: <1364939142-30066-19-git-send-email-mdroth@linux.vnet.ibm.com> In-Reply-To: <1364939142-30066-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1364939142-30066-1-git-send-email-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 18/37] qcow2: make is_allocated return true for zero clusters List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org From: Paolo Bonzini Otherwise, live migration of the top layer will miss zero clusters and let the backing file show through. This also matches what is done in qed. QCOW2_CLUSTER_ZERO clusters are invalid in v2 image files. Check this directly in qcow2_get_cluster_offset instead of replicating the test everywhere. Cc: qemu-stable@nongnu.org Signed-off-by: Paolo Bonzini Signed-off-by: Stefan Hajnoczi (cherry picked from commit 381b487d54ba18c73df9db8452028a330058c505) Signed-off-by: Michael Roth --- block/qcow2-cluster.c | 3 +++ block/qcow2.c | 6 +----- 2 files changed, 4 insertions(+), 5 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index 56fccf9..bb04432 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -454,6 +454,9 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, *cluster_offset &= L2E_COMPRESSED_OFFSET_SIZE_MASK; break; case QCOW2_CLUSTER_ZERO: + if (s->qcow_version < 3) { + return -EIO; + } c = count_contiguous_clusters(nb_clusters, s->cluster_size, &l2_table[l2_index], 0, QCOW_OFLAG_COMPRESSED | QCOW_OFLAG_ZERO); diff --git a/block/qcow2.c b/block/qcow2.c index 7610e56..b4c7c54 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -584,7 +584,7 @@ static int coroutine_fn qcow2_co_is_allocated(BlockDriverState *bs, *pnum = 0; } - return (cluster_offset != 0); + return (cluster_offset != 0) || (ret == QCOW2_CLUSTER_ZERO); } /* handle reading after the end of the backing file */ @@ -665,10 +665,6 @@ static coroutine_fn int qcow2_co_readv(BlockDriverState *bs, int64_t sector_num, break; case QCOW2_CLUSTER_ZERO: - if (s->qcow_version < 3) { - ret = -EIO; - goto fail; - } qemu_iovec_memset(&hd_qiov, 0, 0, 512 * cur_nr_sectors); break; -- 1.7.9.5