Merge remote branch 'spice/submit.6' into staging

[mirror_qemu.git] / block / qcow2-cluster.c

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index 5760ad6d26a737318b8419641a395e647def0401..fb4224a669ebeeff8e8b6545008aaf93fd6e2f0f 100644 (file)
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -60,12 +60,13 @@ int qcow2_grow_l1_table(BlockDriverState *bs, int min_size)
         qemu_free(new_l1_table);
         return new_l1_table_offset;
     }
+    bdrv_flush(bs->file);
 
     BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_WRITE_TABLE);
     for(i = 0; i < s->l1_size; i++)
         new_l1_table[i] = cpu_to_be64(new_l1_table[i]);
-    ret = bdrv_pwrite(bs->file, new_l1_table_offset, new_l1_table, new_l1_size2);
-    if (ret != new_l1_size2)
+    ret = bdrv_pwrite_sync(bs->file, new_l1_table_offset, new_l1_table, new_l1_size2);
+    if (ret < 0)
         goto fail;
     for(i = 0; i < s->l1_size; i++)
         new_l1_table[i] = be64_to_cpu(new_l1_table[i]);
@@ -74,8 +75,8 @@ int qcow2_grow_l1_table(BlockDriverState *bs, int min_size)
     BLKDBG_EVENT(bs->file, BLKDBG_L1_GROW_ACTIVATE_TABLE);
     cpu_to_be32w((uint32_t*)data, new_l1_size);
     cpu_to_be64w((uint64_t*)(data + 4), new_l1_table_offset);
-    ret = bdrv_pwrite(bs->file, offsetof(QCowHeader, l1_size), data,sizeof(data));
-    if (ret != sizeof(data)) {
+    ret = bdrv_pwrite_sync(bs->file, offsetof(QCowHeader, l1_size), data,sizeof(data));
+    if (ret < 0) {
         goto fail;
     }
     qemu_free(s->l1_table);
@@ -87,7 +88,7 @@ int qcow2_grow_l1_table(BlockDriverState *bs, int min_size)
  fail:
     qemu_free(new_l1_table);
     qcow2_free_clusters(bs, new_l1_table_offset, new_l1_size2);
-    return ret < 0 ? ret : -EIO;
+    return ret;
 }
 
 void qcow2_l2_cache_reset(BlockDriverState *bs)
@@ -207,7 +208,7 @@ static int write_l1_entry(BlockDriverState *bs, int l1_index)
     }
 
     BLKDBG_EVENT(bs->file, BLKDBG_L1_UPDATE);
-    ret = bdrv_pwrite(bs->file, s->l1_table_offset + 8 * l1_start_index,
+    ret = bdrv_pwrite_sync(bs->file, s->l1_table_offset + 8 * l1_start_index,
         buf, sizeof(buf));
     if (ret < 0) {
         return ret;
@@ -243,6 +244,7 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
     if (l2_offset < 0) {
         return l2_offset;
     }
+    bdrv_flush(bs->file);
 
     /* allocate a new entry in the l2 cache */
 
@@ -263,7 +265,7 @@ static int l2_allocate(BlockDriverState *bs, int l1_index, uint64_t **table)
     }
     /* write the l2 table to the file */
     BLKDBG_EVENT(bs->file, BLKDBG_L2_ALLOC_WRITE);
-    ret = bdrv_pwrite(bs->file, l2_offset, l2_table,
+    ret = bdrv_pwrite_sync(bs->file, l2_offset, l2_table,
         s->l2_size * sizeof(uint64_t));
     if (ret < 0) {
         goto fail;
@@ -348,6 +350,8 @@ static int qcow_read(BlockDriverState *bs, int64_t sector_num,
     BDRVQcowState *s = bs->opaque;
     int ret, index_in_cluster, n, n1;
     uint64_t cluster_offset;
+    struct iovec iov;
+    QEMUIOVector qiov;
 
     while (nb_sectors > 0) {
         n = nb_sectors;
@@ -362,7 +366,11 @@ static int qcow_read(BlockDriverState *bs, int64_t sector_num,
         if (!cluster_offset) {
             if (bs->backing_hd) {
                 /* read from the base image */
-                n1 = qcow2_backing_read1(bs->backing_hd, sector_num, buf, n);
+                iov.iov_base = buf;
+                iov.iov_len = n * 512;
+                qemu_iovec_init_external(&qiov, &iov, 1);
+
+                n1 = qcow2_backing_read1(bs->backing_hd, &qiov, sector_num, n);
                 if (n1 > 0) {
                     BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING);
                     ret = bdrv_read(bs->backing_hd, sector_num, buf, n1);
@@ -414,7 +422,7 @@ static int copy_sectors(BlockDriverState *bs, uint64_t start_sect,
     }
     BLKDBG_EVENT(bs->file, BLKDBG_COW_WRITE);
     ret = bdrv_write(bs->file, (cluster_offset >> 9) + n_start,
-                     s->cluster_data, n);
+        s->cluster_data, n);
     if (ret < 0)
         return ret;
     return 0;
@@ -631,10 +639,10 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 
     BLKDBG_EVENT(bs->file, BLKDBG_L2_UPDATE_COMPRESSED);
     l2_table[l2_index] = cpu_to_be64(cluster_offset);
-    if (bdrv_pwrite(bs->file,
+    if (bdrv_pwrite_sync(bs->file,
                     l2_offset + l2_index * sizeof(uint64_t),
                     l2_table + l2_index,
-                    sizeof(uint64_t)) != sizeof(uint64_t))
+                    sizeof(uint64_t)) < 0)
         return 0;
 
     return cluster_offset;
@@ -712,15 +720,30 @@ int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m)
                     (i << s->cluster_bits)) | QCOW_OFLAG_COPIED);
      }
 
+    /*
+     * Before we update the L2 table to actually point to the new cluster, we
+     * need to be sure that the refcounts have been increased and COW was
+     * handled.
+     */
+    bdrv_flush(bs->file);
+
     ret = write_l2_entries(bs, l2_table, l2_offset, l2_index, m->nb_clusters);
     if (ret < 0) {
         qcow2_l2_cache_reset(bs);
         goto err;
     }
 
-    for (i = 0; i < j; i++)
-        qcow2_free_any_clusters(bs,
-            be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED, 1);
+    /*
+     * If this was a COW, we need to decrease the refcount of the old cluster.
+     * Also flush bs->file to get the right order for L2 and refcount update.
+     */
+    if (j != 0) {
+        bdrv_flush(bs->file);
+        for (i = 0; i < j; i++) {
+            qcow2_free_any_clusters(bs,
+                be64_to_cpu(old_cluster[i]) & ~QCOW_OFLAG_COPIED, 1);
+        }
+    }
 
     ret = 0;
 err: