[Qemu-devel] [PATCH v2 19/32] qcow2: Update qcow2_alloc_cluster_link_l2() to support L2 slices

Alberto Garcia posted 32 patches 8 years, 1 month ago
There is a newer version of this series
[Qemu-devel] [PATCH v2 19/32] qcow2: Update qcow2_alloc_cluster_link_l2() to support L2 slices
Posted by Alberto Garcia 8 years, 1 month ago
There's a loop in this function that iterates over the L2 entries in a
table, so now we need to assert that it remains within the limits of
an L2 slice.

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>
---
 block/qcow2-cluster.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index f167bb6336..f8c22ca2be 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -931,7 +931,7 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
 {
     BDRVQcow2State *s = bs->opaque;
     int i, j = 0, l2_index, ret;
-    uint64_t *old_cluster, *l2_table;
+    uint64_t *old_cluster, *l2_slice;
     uint64_t cluster_offset = m->alloc_offset;
 
     trace_qcow2_cluster_link_l2(qemu_coroutine_self(), m->nb_clusters);
@@ -958,13 +958,13 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
                                    s->refcount_block_cache);
     }
 
-    ret = get_cluster_table(bs, m->offset, &l2_table, &l2_index);
+    ret = get_cluster_table(bs, m->offset, &l2_slice, &l2_index);
     if (ret < 0) {
         goto err;
     }
-    qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_table);
+    qcow2_cache_entry_mark_dirty(s->l2_table_cache, l2_slice);
 
-    assert(l2_index + m->nb_clusters <= s->l2_size);
+    assert(l2_index + m->nb_clusters <= s->l2_slice_size);
     for (i = 0; i < m->nb_clusters; i++) {
         /* if two concurrent writes happen to the same unallocated cluster
          * each write allocates separate cluster and writes data concurrently.
@@ -972,16 +972,16 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
          * cluster the second one has to do RMW (which is done above by
          * perform_cow()), update l2 table with its cluster pointer and free
          * old cluster. This is what this loop does */
-        if (l2_table[l2_index + i] != 0) {
-            old_cluster[j++] = l2_table[l2_index + i];
+        if (l2_slice[l2_index + i] != 0) {
+            old_cluster[j++] = l2_slice[l2_index + i];
         }
 
-        l2_table[l2_index + i] = cpu_to_be64((cluster_offset +
+        l2_slice[l2_index + i] = cpu_to_be64((cluster_offset +
                     (i << s->cluster_bits)) | QCOW_OFLAG_COPIED);
      }
 
 
-    qcow2_cache_put(s->l2_table_cache, (void **) &l2_table);
+    qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
 
     /*
      * If this was a COW, we need to decrease the refcount of the old cluster.
-- 
2.11.0


Re: [Qemu-devel] [PATCH v2 19/32] qcow2: Update qcow2_alloc_cluster_link_l2() to support L2 slices
Posted by Eric Blake 8 years ago
On 12/15/2017 06:53 AM, Alberto Garcia wrote:
> There's a loop in this function that iterates over the L2 entries in a
> table, so now we need to assert that it remains within the limits of
> an L2 slice.
> 
> 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>
> ---
>  block/qcow2-cluster.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
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