[Qemu-devel] [RFC V8 15/24] qcow2: Extract qcow2_set_incompat_feature and qcow2_clear_incompat_feature.

["Benoît Canet" <benoit@irqsave.net>]

Also change callers.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
 block/qcow2-cluster.c |    2 +-
 block/qcow2.c         |   43 ++++++++++++++++++++++---------------------
 block/qcow2.h         |    7 ++++---
 3 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 41c4bc2..7cd6e75 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -672,7 +672,7 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
 
     /* Update L2 table. */
     if (s->use_lazy_refcounts) {
-        qcow2_mark_dirty(bs);
+        qcow2_set_incompat_feature(bs, QCOW2_INCOMPAT_DIRTY);
     }
     if (qcow2_need_accurate_refcounts(s)) {
         qcow2_cache_set_dependency(bs, s->l2_table_cache,
diff --git a/block/qcow2.c b/block/qcow2.c
index 3cd1051..58e6236 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -250,56 +250,57 @@ static void report_unsupported_feature(BlockDriverState *bs,
 }
 
 /*
- * Sets the dirty bit and flushes afterwards if necessary.
+ * Sets the an incompatible feature bit and flushes afterwards if necessary.
  *
  * The incompatible_features bit is only set if the image file header was
  * updated successfully.  Therefore it is not required to check the return
  * value of this function.
  */
-int qcow2_mark_dirty(BlockDriverState *bs)
+int qcow2_set_incompat_feature(BlockDriverState *bs,
+                               QCow2IncompatibleFeature feature)
 {
     BDRVQcowState *s = bs->opaque;
     uint64_t val;
-    int ret;
+    int ret = 0;
 
     assert(s->qcow_version >= 3);
 
-    if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
-        return 0; /* already dirty */
+    if (s->incompatible_features & feature) {
+        return 0; /* already added */
     }
 
-    val = cpu_to_be64(s->incompatible_features | QCOW2_INCOMPAT_DIRTY);
+    val = cpu_to_be64(s->incompatible_features | feature);
     ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, incompatible_features),
                       &val, sizeof(val));
     if (ret < 0) {
         return ret;
     }
-    ret = bdrv_flush(bs->file);
-    if (ret < 0) {
-        return ret;
-    }
 
-    /* Only treat image as dirty if the header was updated successfully */
-    s->incompatible_features |= QCOW2_INCOMPAT_DIRTY;
+    /* Only treat image as having the feature if the header was updated
+     * successfully
+     */
+    s->incompatible_features |= feature;
     return 0;
 }
 
 /*
- * Clears the dirty bit and flushes before if necessary.  Only call this
- * function when there are no pending requests, it does not guard against
- * concurrent requests dirtying the image.
+ * Clears an incompatible feature bit and flushes before if necessary.
+ * Only call this function when there are no pending requests, it does not
+ * guard against concurrent requests adding a feature to the image.
  */
-static int qcow2_mark_clean(BlockDriverState *bs)
+static int qcow2_clear_incompat_feature(BlockDriverState *bs,
+                                        QCow2IncompatibleFeature feature)
 {
     BDRVQcowState *s = bs->opaque;
+    int ret = 0;
 
-    if (s->incompatible_features & QCOW2_INCOMPAT_DIRTY) {
-        int ret = bdrv_flush(bs);
+    if (s->incompatible_features & feature) {
+        ret = bdrv_flush(bs);
         if (ret < 0) {
             return ret;
         }
 
-        s->incompatible_features &= ~QCOW2_INCOMPAT_DIRTY;
+        s->incompatible_features &= ~feature;
         return qcow2_update_header(bs);
     }
     return 0;
@@ -314,7 +315,7 @@ static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result,
     }
 
     if (fix && result->check_errors == 0 && result->corruptions == 0) {
-        return qcow2_mark_clean(bs);
+        return qcow2_clear_incompat_feature(bs, QCOW2_INCOMPAT_DIRTY);
     }
     return ret;
 }
@@ -949,7 +950,7 @@ static void qcow2_close(BlockDriverState *bs)
     qcow2_cache_flush(bs, s->l2_table_cache);
     qcow2_cache_flush(bs, s->refcount_block_cache);
 
-    qcow2_mark_clean(bs);
+    qcow2_clear_incompat_feature(bs, QCOW2_INCOMPAT_DIRTY);
 
     qcow2_cache_destroy(bs, s->l2_table_cache);
     qcow2_cache_destroy(bs, s->refcount_block_cache);
diff --git a/block/qcow2.h b/block/qcow2.h
index ff26e81..720131d 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -290,14 +290,14 @@ enum {
 };
 
 /* Incompatible feature bits */
-enum {
+typedef enum {
     QCOW2_INCOMPAT_DIRTY_BITNR   = 0,
     QCOW2_INCOMPAT_DIRTY         = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
     QCOW2_INCOMPAT_DEDUP_BITNR   = 1,
     QCOW2_INCOMPAT_DEDUP         = 1 << QCOW2_INCOMPAT_DEDUP_BITNR,
 
     QCOW2_INCOMPAT_MASK          = QCOW2_INCOMPAT_DIRTY | QCOW2_INCOMPAT_DEDUP,
-};
+} QCow2IncompatibleFeature;
 
 /* Compatible feature bits */
 enum {
@@ -543,7 +543,8 @@ static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
 int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
                   int64_t sector_num, int nb_sectors);
 
-int qcow2_mark_dirty(BlockDriverState *bs);
+int qcow2_set_incompat_feature(BlockDriverState *bs,
+                               QCow2IncompatibleFeature feature);
 int qcow2_update_header(BlockDriverState *bs);
 int qcow2_read_cluster_data(BlockDriverState *bs,
                             uint8_t *data,
-- 
1.7.10.4