qcow2: Drop l2meta.cluster_offset

There's no real reason to have an l2meta for normal requests that don't
allocate anything. Before we can get rid of it, we must return the host
cluster offset in a different way.

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

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 94b7f136fa7f05e7bbd0e1f700a8bac11e9c5269..c4752ee81224a0dcc245d0b60f7e305be6a5928b 100644 (file)
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -856,7 +856,7 @@ static int do_alloc_cluster_offset(BlockDriverState *bs, uint64_t guest_offset,
  * Return 0 on success and -errno in error cases
  */
 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
-    int n_start, int n_end, int *num, QCowL2Meta *m)
+    int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta *m)
 {
     BDRVQcowState *s = bs->opaque;
     int l2_index, ret, sectors;
@@ -929,7 +929,6 @@ again:
 
     /* If there is something left to allocate, do that now */
     *m = (QCowL2Meta) {
-        .cluster_offset     = cluster_offset,
         .nb_clusters        = 0,
     };
     qemu_co_queue_init(&m->dependent_requests);
@@ -977,9 +976,11 @@ again:
             int alloc_n_start = keep_clusters == 0 ? n_start : 0;
             int nb_sectors = MIN(requested_sectors, avail_sectors);
 
+            if (keep_clusters == 0) {
+                cluster_offset = alloc_cluster_offset;
+            }
+
             *m = (QCowL2Meta) {
-                .cluster_offset = keep_clusters == 0 ?
-                                  alloc_cluster_offset : cluster_offset,
                 .alloc_offset   = alloc_cluster_offset,
                 .offset         = alloc_offset & ~(s->cluster_size - 1),
                 .nb_clusters    = nb_clusters,
@@ -1007,6 +1008,7 @@ again:
 
     assert(sectors > n_start);
     *num = sectors - n_start;
+    *host_offset = cluster_offset;
 
     return 0;
 

diff --git a/block/qcow2.c b/block/qcow2.c
index 71f870d8294eb546abc53835a1acfcac67699cf6..66ca12f94e9c37630f31746568c86ea2f9b6414e 100644 (file)
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -799,7 +799,7 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,
         }
 
         ret = qcow2_alloc_cluster_offset(bs, sector_num << 9,
-            index_in_cluster, n_end, &cur_nr_sectors, l2meta);
+            index_in_cluster, n_end, &cur_nr_sectors, &cluster_offset, l2meta);
         if (ret < 0) {
             goto fail;
         }
@@ -809,7 +809,6 @@ static coroutine_fn int qcow2_co_writev(BlockDriverState *bs,
             qcow2_mark_dirty(bs);
         }
 
-        cluster_offset = l2meta->cluster_offset;
         assert((cluster_offset & 511) == 0);
 
         qemu_iovec_reset(&hd_qiov);
@@ -1132,6 +1131,7 @@ static int preallocate(BlockDriverState *bs)
 {
     uint64_t nb_sectors;
     uint64_t offset;
+    uint64_t host_offset = 0;
     int num;
     int ret;
     QCowL2Meta meta;
@@ -1139,18 +1139,18 @@ static int preallocate(BlockDriverState *bs)
     nb_sectors = bdrv_getlength(bs) >> 9;
     offset = 0;
     qemu_co_queue_init(&meta.dependent_requests);
-    meta.cluster_offset = 0;
 
     while (nb_sectors) {
         num = MIN(nb_sectors, INT_MAX >> 9);
-        ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num, &meta);
+        ret = qcow2_alloc_cluster_offset(bs, offset, 0, num, &num,
+                                         &host_offset, &meta);
         if (ret < 0) {
             return ret;
         }
 
         ret = qcow2_alloc_cluster_link_l2(bs, &meta);
         if (ret < 0) {
-            qcow2_free_any_clusters(bs, meta.cluster_offset, meta.nb_clusters);
+            qcow2_free_any_clusters(bs, meta.alloc_offset, meta.nb_clusters);
             return ret;
         }
 
@@ -1169,10 +1169,10 @@ static int preallocate(BlockDriverState *bs)
      * all of the allocated clusters (otherwise we get failing reads after
      * EOF). Extend the image to the last allocated sector.
      */
-    if (meta.cluster_offset != 0) {
+    if (host_offset != 0) {
         uint8_t buf[512];
         memset(buf, 0, 512);
-        ret = bdrv_write(bs->file, (meta.cluster_offset >> 9) + num - 1, buf, 1);
+        ret = bdrv_write(bs->file, (host_offset >> 9) + num - 1, buf, 1);
         if (ret < 0) {
             return ret;
         }

diff --git a/block/qcow2.h b/block/qcow2.h
index 1106b3320683d45dbf3c9670bc1909c20282f6dc..24f100125c43bbb3df91400906bcf6f4d8c47419 100644 (file)
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -213,9 +213,6 @@ typedef struct QCowL2Meta
     /** Guest offset of the first newly allocated cluster */
     uint64_t offset;
 
-    /** Host offset of the first cluster of the request */
-    uint64_t cluster_offset;
-
     /** Host offset of the first newly allocated cluster */
     uint64_t alloc_offset;
 
@@ -336,7 +333,7 @@ void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
     int *num, uint64_t *cluster_offset);
 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
-    int n_start, int n_end, int *num, QCowL2Meta *m);
+    int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta *m);
 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
                                          uint64_t offset,
                                          int compressed_size);