qcow2: Use negated overflow check mask

In qcow2_check_metadata_overlap and qcow2_pre_write_overlap_check,
change the parameter signifying the checks to perform from its current
positive form to a negative one, i.e., it will no longer explicitly
specify every check to perform but rather a mask of checks not to
perform.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 10 insertions, 12 deletions

diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 4ef689996f..988644a281 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -1311,9 +1311,8 @@ static int check_oflag_copied(BlockDriverState *bs, BdrvCheckResult *res,
         }
 
         if (l2_dirty) {
-            ret = qcow2_pre_write_overlap_check(bs,
-                    QCOW2_OL_DEFAULT & ~QCOW2_OL_ACTIVE_L2, l2_offset,
-                    s->cluster_size);
+            ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_ACTIVE_L2,
+                                                l2_offset, s->cluster_size);
             if (ret < 0) {
                 fprintf(stderr, "ERROR: Could not write L2 table; metadata "
                         "overlap check failed: %s\n", strerror(-ret));
@@ -1354,8 +1353,7 @@ static int write_reftable_entry(BlockDriverState *bs, int rt_index)
         buf[i] = cpu_to_be64(s->refcount_table[rt_start_index + i]);
     }
 
-    ret = qcow2_pre_write_overlap_check(bs,
-            QCOW2_OL_DEFAULT & ~QCOW2_OL_REFCOUNT_TABLE,
+    ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_REFCOUNT_TABLE,
             s->refcount_table_offset + rt_start_index * sizeof(uint64_t),
             sizeof(buf));
     if (ret < 0) {
@@ -1406,8 +1404,7 @@ static int64_t realloc_refcount_block(BlockDriverState *bs, int reftable_index,
 
     /* new block has not yet been entered into refcount table, therefore it is
      * no refcount block yet (regarding this check) */
-    ret = qcow2_pre_write_overlap_check(bs, QCOW2_OL_DEFAULT, new_offset,
-            s->cluster_size);
+    ret = qcow2_pre_write_overlap_check(bs, 0, new_offset, s->cluster_size);
     if (ret < 0) {
         fprintf(stderr, "Could not write refcount block; metadata overlap "
                 "check failed: %s\n", strerror(-ret));
@@ -1639,8 +1636,8 @@ fail:
  * looking for overlaps with important metadata sections (L1/L2 tables etc.),
  * i.e. a sanity check without relying on the refcount tables.
  *
- * The chk parameter specifies exactly what checks to perform (being a bitmask
- * of QCow2MetadataOverlap values).
+ * The ign parameter specifies what checks not to perform (being a bitmask of
+ * QCow2MetadataOverlap values), i.e., what sections to ignore.
  *
  * Returns:
  * - 0 if writing to this offset will not affect the mentioned metadata
@@ -1648,10 +1645,11 @@ fail:
  * - a negative value (-errno) indicating an error while performing a check,
  *   e.g. when bdrv_read failed on QCOW2_OL_INACTIVE_L2
  */
-int qcow2_check_metadata_overlap(BlockDriverState *bs, int chk, int64_t offset,
+int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
                                  int64_t size)
 {
     BDRVQcowState *s = bs->opaque;
+    int chk = QCOW2_OL_DEFAULT & ~ign;
     int i, j;
 
     if (!size) {
@@ -1767,10 +1765,10 @@ static const char *metadata_ol_names[] = {
  * Returns 0 if there were neither overlaps nor errors while checking for
  * overlaps; or a negative value (-errno) on error.
  */
-int qcow2_pre_write_overlap_check(BlockDriverState *bs, int chk, int64_t offset,
+int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
                                   int64_t size)
 {
-    int ret = qcow2_check_metadata_overlap(bs, chk, offset, size);
+    int ret = qcow2_check_metadata_overlap(bs, ign, offset, size);
 
     if (ret < 0) {
         return ret;