From f39d8d56b3cf31f293465bd912ae623ada8152c0 Mon Sep 17 00:00:00 2001 From: Max Reitz Date: Tue, 7 Jan 2014 21:57:15 +0100 Subject: [PATCH 10/14] qcow2: Free only newly allocated clusters on error RH-Author: Max Reitz Message-id: <1389131839-12920-11-git-send-email-mreitz@redhat.com> Patchwork-id: 56546 O-Subject: [RHEL-7.0 qemu-kvm PATCH v2 10/14] qcow2: Free only newly allocated clusters on error Bugzilla: 1033490 RH-Acked-by: Kevin Wolf RH-Acked-by: Fam Zheng RH-Acked-by: Stefan Hajnoczi BZ: 1033490 In expand_zero_clusters_in_l1, a new cluster is only allocated if it was not already preallocated. On error, such preallocated clusters should not be freed, but only the newly allocated ones. Signed-off-by: Max Reitz Signed-off-by: Kevin Wolf (cherry picked from commit 320c70666687db4dd4df8165f9fe6960de782ca9) Signed-off-by: Max Reitz --- block/qcow2-cluster.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) Signed-off-by: Miroslav Rezanina --- block/qcow2-cluster.c | 16 ++++++++++------ 1 files changed, 10 insertions(+), 6 deletions(-) diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c index bfdc83a..79c3ae0 100644 --- a/block/qcow2-cluster.c +++ b/block/qcow2-cluster.c @@ -1552,6 +1552,7 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, uint64_t l2_entry = be64_to_cpu(l2_table[j]); int64_t offset = l2_entry & L2E_OFFSET_MASK, cluster_index; int cluster_type = qcow2_get_cluster_type(l2_entry); + bool preallocated = offset != 0; if (cluster_type == QCOW2_CLUSTER_NORMAL) { cluster_index = offset >> s->cluster_bits; @@ -1577,8 +1578,7 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, continue; } - if (!offset) { - /* not preallocated */ + if (!preallocated) { if (!bs->backing_hd) { /* not backed; therefore we can simply deallocate the * cluster */ @@ -1596,16 +1596,20 @@ static int expand_zero_clusters_in_l1(BlockDriverState *bs, uint64_t *l1_table, ret = qcow2_pre_write_overlap_check(bs, 0, offset, s->cluster_size); if (ret < 0) { - qcow2_free_clusters(bs, offset, s->cluster_size, - QCOW2_DISCARD_ALWAYS); + if (!preallocated) { + qcow2_free_clusters(bs, offset, s->cluster_size, + QCOW2_DISCARD_ALWAYS); + } goto fail; } ret = bdrv_write_zeroes(bs->file, offset / BDRV_SECTOR_SIZE, s->cluster_sectors, 0); if (ret < 0) { - qcow2_free_clusters(bs, offset, s->cluster_size, - QCOW2_DISCARD_ALWAYS); + if (!preallocated) { + qcow2_free_clusters(bs, offset, s->cluster_size, + QCOW2_DISCARD_ALWAYS); + } goto fail; } -- 1.7.1