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qcow2: Ignore reserved bits in check_refcounts

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Also don't infer the cluster type directly from the L2 entries, but use
qcow2_get_cluster_type() to keep everything in a single place.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Kevin Wolf 2012-03-27 13:44:56 +02:00
parent 76dc9e0c8f
commit afdf0abe77
1 changed files with 56 additions and 46 deletions
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102
block/qcow2-refcount.c
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@ -940,7 +940,7 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res,
int check_copied)
{
BDRVQcowState *s = bs->opaque;
uint64_t *l2_table, offset;
uint64_t *l2_table, l2_entry;
int i, l2_size, nb_csectors, refcount;
/* Read L2 table from disk */
@ -952,54 +952,64 @@ static int check_refcounts_l2(BlockDriverState *bs, BdrvCheckResult *res,
/* Do the actual checks */
for(i = 0; i < s->l2_size; i++) {
offset = be64_to_cpu(l2_table[i]);
if (offset != 0) {
if (offset & QCOW_OFLAG_COMPRESSED) {
/* Compressed clusters don't have QCOW_OFLAG_COPIED */
if (offset & QCOW_OFLAG_COPIED) {
fprintf(stderr, "ERROR: cluster %" PRId64 ": "
"copied flag must never be set for compressed "
"clusters\n", offset >> s->cluster_bits);
offset &= ~QCOW_OFLAG_COPIED;
res->corruptions++;
l2_entry = be64_to_cpu(l2_table[i]);
switch (qcow2_get_cluster_type(l2_entry)) {
case QCOW2_CLUSTER_COMPRESSED:
/* Compressed clusters don't have QCOW_OFLAG_COPIED */
if (l2_entry & QCOW_OFLAG_COPIED) {
fprintf(stderr, "ERROR: cluster %" PRId64 ": "
"copied flag must never be set for compressed "
"clusters\n", l2_entry >> s->cluster_bits);
l2_entry &= ~QCOW_OFLAG_COPIED;
res->corruptions++;
}
/* Mark cluster as used */
nb_csectors = ((l2_entry >> s->csize_shift) &
s->csize_mask) + 1;
l2_entry &= s->cluster_offset_mask;
inc_refcounts(bs, res, refcount_table, refcount_table_size,
l2_entry & ~511, nb_csectors * 512);
break;
case QCOW2_CLUSTER_NORMAL:
{
/* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
uint64_t offset = l2_entry & L2E_OFFSET_MASK;
if (check_copied) {
refcount = get_refcount(bs, offset >> s->cluster_bits);
if (refcount < 0) {
fprintf(stderr, "Can't get refcount for offset %"
PRIx64 ": %s\n", l2_entry, strerror(-refcount));
goto fail;
}
/* Mark cluster as used */
nb_csectors = ((offset >> s->csize_shift) &
s->csize_mask) + 1;
offset &= s->cluster_offset_mask;
inc_refcounts(bs, res, refcount_table, refcount_table_size,
offset & ~511, nb_csectors * 512);
} else {
/* QCOW_OFLAG_COPIED must be set iff refcount == 1 */
if (check_copied) {
uint64_t entry = offset;
offset &= ~QCOW_OFLAG_COPIED;
refcount = get_refcount(bs, offset >> s->cluster_bits);
if (refcount < 0) {
fprintf(stderr, "Can't get refcount for offset %"
PRIx64 ": %s\n", entry, strerror(-refcount));
goto fail;
}
if ((refcount == 1) != ((entry & QCOW_OFLAG_COPIED) != 0)) {
fprintf(stderr, "ERROR OFLAG_COPIED: offset=%"
PRIx64 " refcount=%d\n", entry, refcount);
res->corruptions++;
}
}
/* Mark cluster as used */
offset &= ~QCOW_OFLAG_COPIED;
inc_refcounts(bs, res, refcount_table,refcount_table_size,
offset, s->cluster_size);
/* Correct offsets are cluster aligned */
if (offset & (s->cluster_size - 1)) {
fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not "
"properly aligned; L2 entry corrupted.\n", offset);
if ((refcount == 1) != ((l2_entry & QCOW_OFLAG_COPIED) != 0)) {
fprintf(stderr, "ERROR OFLAG_COPIED: offset=%"
PRIx64 " refcount=%d\n", l2_entry, refcount);
res->corruptions++;
}
}
/* Mark cluster as used */
inc_refcounts(bs, res, refcount_table,refcount_table_size,
offset, s->cluster_size);
/* Correct offsets are cluster aligned */
if (offset & (s->cluster_size - 1)) {
fprintf(stderr, "ERROR offset=%" PRIx64 ": Cluster is not "
"properly aligned; L2 entry corrupted.\n", offset);
res->corruptions++;
}
break;
}
case QCOW2_CLUSTER_UNALLOCATED:
break;
default:
abort();
}
}
@ -1070,7 +1080,7 @@ static int check_refcounts_l1(BlockDriverState *bs,
}
/* Mark L2 table as used */
l2_offset &= ~QCOW_OFLAG_COPIED;
l2_offset &= L1E_OFFSET_MASK;
inc_refcounts(bs, res, refcount_table, refcount_table_size,
l2_offset, s->cluster_size);