From 62fa2331e97ceb85616fc3d67fe75247d9e74f3a Mon Sep 17 00:00:00 2001 Message-Id: <62fa2331e97ceb85616fc3d67fe75247d9e74f3a.1429902956.git.jen@redhat.com> In-Reply-To: <67968bc615637394c3ef7dfefa360dab90f33d5d.1429902956.git.jen@redhat.com> References: <67968bc615637394c3ef7dfefa360dab90f33d5d.1429902956.git.jen@redhat.com> From: Max Reitz Date: Wed, 18 Mar 2015 19:22:13 -0500 Subject: [CHANGE 30/42] qcow2: Fix refcount blocks beyond image end To: rhvirt-patches@redhat.com, jen@redhat.com RH-Author: Max Reitz Message-id: <1426706542-30384-31-git-send-email-mreitz@redhat.com> Patchwork-id: 64496 O-Subject: [RHEL-6.7 qemu-kvm PATCH v2 30/39] qcow2: Fix refcount blocks beyond image end Bugzilla: 1129892 RH-Acked-by: Jeffrey Cody RH-Acked-by: Kevin Wolf RH-Acked-by: Stefan Hajnoczi BZ: 1129892 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 Signed-off-by: Kevin Wolf (cherry picked from commit 001c158defb65e88e6c50c85d6f20501f7149ddd) Signed-off-by: Max Reitz --- block/qcow2-refcount.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 63 insertions(+), 4 deletions(-) Signed-off-by: Jeff E. Nelson --- 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 79f9da5..76a6f8f 100644 --- a/block/qcow2-refcount.c +++ b/block/qcow2-refcount.c @@ -1390,7 +1390,7 @@ 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++) { @@ -1407,9 +1407,68 @@ 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; } -- 2.1.0