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[Qemu-devel] [PATCH v4 05/10] qcow2: Fix refcount blocks beyond image en
From: |
Max Reitz |
Subject: |
[Qemu-devel] [PATCH v4 05/10] qcow2: Fix refcount blocks beyond image end |
Date: |
Wed, 27 Aug 2014 22:18:21 +0200 |
If the qcow2 check function detects a refcount block located beyond the
image end, grow the image appropriately. This cannot break anything and
is the logical fix for such a case.
Signed-off-by: Max Reitz <address@hidden>
---
block/qcow2-refcount.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 58 insertions(+), 4 deletions(-)
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index babe6cb..394a402 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1505,7 +1505,8 @@ static int check_refblocks(BlockDriverState *bs,
BdrvCheckResult *res,
int64_t *nb_clusters)
{
BDRVQcowState *s = bs->opaque;
- int64_t i;
+ int64_t i, size;
+ int ret;
for(i = 0; i < s->refcount_table_size; i++) {
uint64_t offset, cluster;
@@ -1521,9 +1522,62 @@ static int check_refblocks(BlockDriverState *bs,
BdrvCheckResult *res,
}
if (cluster >= *nb_clusters) {
- fprintf(stderr, "ERROR refcount block %" PRId64
- " is outside image\n", i);
- res->corruptions++;
+ fprintf(stderr, "%s refcount block %" PRId64 " is outside image\n",
+ fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR", i);
+
+ if (fix & BDRV_FIX_ERRORS) {
+ int64_t old_nb_clusters = *nb_clusters;
+
+ if (offset + s->cluster_size < offset ||
+ offset + s->cluster_size > INT64_MAX)
+ {
+ ret = -EINVAL;
+ goto resize_fail;
+ }
+
+ ret = bdrv_truncate(bs->file, offset + s->cluster_size);
+ if (ret < 0) {
+ goto resize_fail;
+ }
+ size = bdrv_getlength(bs->file);
+ if (size < 0) {
+ ret = size;
+ goto resize_fail;
+ }
+
+ *nb_clusters = size_to_clusters(s, size);
+ assert(*nb_clusters >= old_nb_clusters);
+
+ *refcount_table = g_try_realloc(*refcount_table,
+ *nb_clusters * sizeof(uint16_t));
+ if (!*refcount_table) {
+ res->check_errors++;
+ return -ENOMEM;
+ }
+
+ memset(*refcount_table + old_nb_clusters, 0,
+ (*nb_clusters - old_nb_clusters) * sizeof(uint16_t));
+
+ if (cluster >= *nb_clusters) {
+ ret = -EINVAL;
+ goto resize_fail;
+ }
+
+ res->corruptions_fixed++;
+ inc_refcounts(bs, res, *refcount_table, *nb_clusters,
+ offset, s->cluster_size);
+ /* No need to check whether the refcount is now greater than 1:
+ * This area was just allocated and zeroed, so it can only be
+ * exactly 1 after inc_refcounts() */
+ continue;
+
+resize_fail:
+ res->corruptions++;
+ fprintf(stderr, "ERROR could not resize image: %s\n",
+ strerror(-ret));
+ } else {
+ res->corruptions++;
+ }
continue;
}
--
2.1.0
- [Qemu-devel] [PATCH v4 00/10] qcow2: Fix image repairing, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 01/10] qcow2: Fix leaks in dirty images, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 02/10] qcow2: Split qcow2_check_refcounts(), Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 03/10] qcow2: Pull check_refblocks() up, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 04/10] qcow2: Reuse refcount table in calculate_refcounts(), Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 05/10] qcow2: Fix refcount blocks beyond image end,
Max Reitz <=
- [Qemu-devel] [PATCH v4 06/10] qcow2: Do not perform potentially damaging repairs, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 07/10] qcow2: Rebuild refcount structure during check, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 08/10] qcow2: Clean up after refcount rebuild, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 09/10] iotests: Fix test outputs, Max Reitz, 2014/08/27
- [Qemu-devel] [PATCH v4 10/10] iotests: Add test for potentially damaging repairs, Max Reitz, 2014/08/27