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path: root/block/qcow2-snapshot.c
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Diffstat (limited to 'block/qcow2-snapshot.c')
-rw-r--r--block/qcow2-snapshot.c25
1 files changed, 20 insertions, 5 deletions
diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
index bdc33ba94c..4134bbc253 100644
--- a/block/qcow2-snapshot.c
+++ b/block/qcow2-snapshot.c
@@ -68,6 +68,7 @@ int qcow2_read_snapshots(BlockDriverState *bs)
int i, id_str_size, name_size;
int64_t offset;
uint32_t extra_data_size;
+ int ret;
if (!s->nb_snapshots) {
s->snapshots = NULL;
@@ -77,10 +78,15 @@ int qcow2_read_snapshots(BlockDriverState *bs)
offset = s->snapshots_offset;
s->snapshots = g_malloc0(s->nb_snapshots * sizeof(QCowSnapshot));
+
for(i = 0; i < s->nb_snapshots; i++) {
+ /* Read statically sized part of the snapshot header */
offset = align_offset(offset, 8);
- if (bdrv_pread(bs->file, offset, &h, sizeof(h)) != sizeof(h))
+ ret = bdrv_pread(bs->file, offset, &h, sizeof(h));
+ if (ret < 0) {
goto fail;
+ }
+
offset += sizeof(h);
sn = s->snapshots + i;
sn->l1_table_offset = be64_to_cpu(h.l1_table_offset);
@@ -94,25 +100,34 @@ int qcow2_read_snapshots(BlockDriverState *bs)
id_str_size = be16_to_cpu(h.id_str_size);
name_size = be16_to_cpu(h.name_size);
+ /* Skip extra data */
offset += extra_data_size;
+ /* Read snapshot ID */
sn->id_str = g_malloc(id_str_size + 1);
- if (bdrv_pread(bs->file, offset, sn->id_str, id_str_size) != id_str_size)
+ ret = bdrv_pread(bs->file, offset, sn->id_str, id_str_size);
+ if (ret < 0) {
goto fail;
+ }
offset += id_str_size;
sn->id_str[id_str_size] = '\0';
+ /* Read snapshot name */
sn->name = g_malloc(name_size + 1);
- if (bdrv_pread(bs->file, offset, sn->name, name_size) != name_size)
+ ret = bdrv_pread(bs->file, offset, sn->name, name_size);
+ if (ret < 0) {
goto fail;
+ }
offset += name_size;
sn->name[name_size] = '\0';
}
+
s->snapshots_size = offset - s->snapshots_offset;
return 0;
- fail:
+
+fail:
qcow2_free_snapshots(bs);
- return -1;
+ return ret;
}
/* add at the end of the file a new list of snapshots */