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[Qemu-devel] [PULL 17/32] qcow2: Fix refcount blocks beyond image end
From: |
Kevin Wolf |
Subject: |
[Qemu-devel] [PULL 17/32] qcow2: Fix refcount blocks beyond image end |
Date: |
Thu, 23 Oct 2014 22:42:24 +0200 |
From: Max Reitz <address@hidden>
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>
Signed-off-by: Kevin Wolf <address@hidden>
---
block/qcow2-refcount.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 63 insertions(+), 4 deletions(-)
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index c92e1fc..b87eafc 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1575,7 +1575,7 @@ 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++) {
@@ -1592,9 +1592,68 @@ 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;
+ uint16_t *new_refcount_table;
+
+ if (offset > INT64_MAX - s->cluster_size) {
+ 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);
+
+ new_refcount_table = g_try_realloc(*refcount_table,
+ *nb_clusters *
+ sizeof(**refcount_table));
+ if (!new_refcount_table) {
+ *nb_clusters = old_nb_clusters;
+ res->check_errors++;
+ return -ENOMEM;
+ }
+ *refcount_table = new_refcount_table;
+
+ memset(*refcount_table + old_nb_clusters, 0,
+ (*nb_clusters - old_nb_clusters) *
+ sizeof(**refcount_table));
+
+ if (cluster >= *nb_clusters) {
+ ret = -EINVAL;
+ goto resize_fail;
+ }
+
+ res->corruptions_fixed++;
+ ret = inc_refcounts(bs, res, refcount_table, nb_clusters,
+ offset, s->cluster_size);
+ if (ret < 0) {
+ return ret;
+ }
+ /* 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;
}
--
1.8.3.1
- [Qemu-devel] [PULL 08/32] qcow2: Fix leaks in dirty images, (continued)
- [Qemu-devel] [PULL 08/32] qcow2: Fix leaks in dirty images, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 07/32] qcow2: Calculate refcount block entry count, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 09/32] qcow2: Split qcow2_check_refcounts(), Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 10/32] qcow2: Use sizeof(**refcount_table), Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 11/32] qcow2: Pull check_refblocks() up, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 13/32] qcow2: Split fail code in L1 and L2 checks, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 12/32] qcow2: Use int64_t for in-memory reftable size, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 14/32] qcow2: Let inc_refcounts() return -errno, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 16/32] qcow2: Reuse refcount table in calculate_refcounts(), Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 15/32] qcow2: Let inc_refcounts() resize the reftable, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 17/32] qcow2: Fix refcount blocks beyond image end,
Kevin Wolf <=
- [Qemu-devel] [PULL 18/32] qcow2: Do not perform potentially damaging repairs, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 20/32] qcow2: Clean up after refcount rebuild, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 19/32] qcow2: Rebuild refcount structure during check, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 21/32] iotests: Fix test outputs, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 22/32] iotests: Add test for potentially damaging repairs, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 23/32] qcow2: Drop REFCOUNT_SHIFT, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 24/32] docs/qcow2: Correct refcount_block_entries, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 25/32] docs/qcow2: Limit refcount_order to [0, 6], Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 27/32] qemu-io: Respect early image end for map, Kevin Wolf, 2014/10/23
- [Qemu-devel] [PULL 28/32] iotests: Add test for map commands, Kevin Wolf, 2014/10/23