[Qemu-devel] [PATCH v3 25/39] qcow2: Update zero_single_l2() to support L2 slices

Alberto Garcia posted 39 patches 8 years ago
There is a newer version of this series
[Qemu-devel] [PATCH v3 25/39] qcow2: Update zero_single_l2() to support L2 slices
Posted by Alberto Garcia 8 years ago
zero_single_l2() limits the number of clusters to be zeroed to the
amount that fits inside an L2 table. Since we'll be loading L2 slices
instead of full tables we need to update that limit.

Apart from that, this function doesn't need any additional changes, so
this patch simply updates the variable name from l2_table to l2_slice.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 block/qcow2-cluster.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index fd1bf5d093..e13f8f2f14 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1753,33 +1753,33 @@ fail:
 
 /*
  * This zeroes as many clusters of nb_clusters as possible at once (i.e.
- * all clusters in the same L2 table) and returns the number of zeroed
+ * all clusters in the same L2 slice) and returns the number of zeroed
  * clusters.
  */
 static int zero_single_l2(BlockDriverState *bs, uint64_t offset,
                           uint64_t nb_clusters, int flags)
 {
     BDRVQcow2State *s = bs->opaque;
-    uint64_t *l2_table;
+    uint64_t *l2_slice;
     int l2_index;
     int ret;
     int i;
     bool unmap = !!(flags & BDRV_REQ_MAY_UNMAP);
 
-    ret = get_cluster_table(bs, offset, &l2_table, &l2_index);
+    ret = get_cluster_table(bs, offset, &l2_slice, &l2_index);
     if (ret < 0) {
         return ret;
     }
 
-    /* Limit nb_clusters to one L2 table */
-    nb_clusters = MIN(nb_clusters, s->l2_size - l2_index);
+    /* Limit nb_clusters to one L2 slice */
+    nb_clusters = MIN(nb_clusters, s->l2_slice_size - l2_index);
     assert(nb_clusters <= INT_MAX);
 
     for (i = 0; i < nb_clusters; i++) {
         uint64_t old_offset;
         QCow2ClusterType cluster_type;
 
-        old_offset = be64_to_cpu(l2_table[l2_index + i]);
+        old_offset = be64_to_cpu(l2_slice[l2_index + i]);
 
         /*
          * Minimize L2 changes if the cluster already reads back as
@@ -1791,16 +1791,16 @@ static int zero_single_l2(BlockDriverState *bs, uint64_t offset,
             continue;
         }
 
-        qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table);
+        qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice);
         if (cluster_type == QCOW2_CLUSTER_COMPRESSED || unmap) {
-            l2_table[l2_index + i] = cpu_to_be64(QCOW_OFLAG_ZERO);
+            l2_slice[l2_index + i] = cpu_to_be64(QCOW_OFLAG_ZERO);
             qcow2_free_any_clusters(bs, old_offset, 1, QCOW2_DISCARD_REQUEST);
         } else {
-            l2_table[l2_index + i] |= cpu_to_be64(QCOW_OFLAG_ZERO);
+            l2_slice[l2_index + i] |= cpu_to_be64(QCOW_OFLAG_ZERO);
         }
     }
 
-    qcow2_cache_put(s->l2_table_cache, (void **) &l2_table);
+    qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
 
     return nb_clusters;
 }
-- 
2.11.0


Re: [Qemu-devel] [PATCH v3 25/39] qcow2: Update zero_single_l2() to support L2 slices
Posted by Max Reitz 8 years ago
On 2018-01-26 15:59, Alberto Garcia wrote:
> zero_single_l2() limits the number of clusters to be zeroed to the
> amount that fits inside an L2 table. Since we'll be loading L2 slices
> instead of full tables we need to update that limit.

Same as last patch, maybe we should rename the function now.

> Apart from that, this function doesn't need any additional changes, so
> this patch simply updates the variable name from l2_table to l2_slice.
> 
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> ---
>  block/qcow2-cluster.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)

Also again:

Reviewed-by: Max Reitz <mreitz@redhat.com>