block/export: Move writable to BlockExportOptions

[mirror_qemu.git] / block / backup.c

diff --git a/block/backup.c b/block/backup.c
index 7430ca5883006acf9f856f6ba9386fd571daf59c..9afa0bf3b41229536a5b9e67df8d2965c734406f 100644 (file)
--- a/block/backup.c
+++ b/block/backup.c
@@ -126,11 +126,7 @@ static void backup_abort(Job *job)
 static void backup_clean(Job *job)
 {
     BackupBlockJob *s = container_of(job, BackupBlockJob, common.job);
-    AioContext *aio_context = bdrv_get_aio_context(s->backup_top);
-
-    aio_context_acquire(aio_context);
     bdrv_backup_top_drop(s->backup_top);
-    aio_context_release(aio_context);
 }
 
 void backup_do_checkpoint(BlockJob *job, Error **errp)
@@ -301,6 +297,7 @@ static int64_t backup_calculate_cluster_size(BlockDriverState *target,
 {
     int ret;
     BlockDriverInfo bdi;
+    bool target_does_cow = bdrv_backing_chain_next(target);
 
     /*
      * If there is no backing file on the target, we cannot rely on COW if our
@@ -308,7 +305,7 @@ static int64_t backup_calculate_cluster_size(BlockDriverState *target,
      * targets with a backing file, try to avoid COW if possible.
      */
     ret = bdrv_get_info(target, &bdi);
-    if (ret == -ENOTSUP && !target->backing) {
+    if (ret == -ENOTSUP && !target_does_cow) {
         /* Cluster size is not defined */
         warn_report("The target block device doesn't provide "
                     "information about the block size and it doesn't have a "
@@ -317,14 +314,14 @@ static int64_t backup_calculate_cluster_size(BlockDriverState *target,
                     "this default, the backup may be unusable",
                     BACKUP_CLUSTER_SIZE_DEFAULT);
         return BACKUP_CLUSTER_SIZE_DEFAULT;
-    } else if (ret < 0 && !target->backing) {
+    } else if (ret < 0 && !target_does_cow) {
         error_setg_errno(errp, -ret,
             "Couldn't determine the cluster size of the target image, "
             "which has no backing file");
         error_append_hint(errp,
             "Aborting, since this may create an unusable destination image\n");
         return ret;
-    } else if (ret < 0 && target->backing) {
+    } else if (ret < 0 && target_does_cow) {
         /* Not fatal; just trudge on ahead. */
         return BACKUP_CLUSTER_SIZE_DEFAULT;
     }
@@ -344,7 +341,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
                   BlockCompletionFunc *cb, void *opaque,
                   JobTxn *txn, Error **errp)
 {
-    int64_t len;
+    int64_t len, target_len;
     BackupBlockJob *job = NULL;
     int64_t cluster_size;
     BdrvRequestFlags write_flags;
@@ -375,7 +372,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
         return NULL;
     }
 
-    if (compress && !block_driver_can_compress(target->drv)) {
+    if (compress && !bdrv_supports_compressed_writes(target)) {
         error_setg(errp, "Compression is not supported for this drive %s",
                    bdrv_get_device_name(target));
         return NULL;
@@ -404,8 +401,20 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
 
     len = bdrv_getlength(bs);
     if (len < 0) {
-        error_setg_errno(errp, -len, "unable to get length for '%s'",
-                         bdrv_get_device_name(bs));
+        error_setg_errno(errp, -len, "Unable to get length for '%s'",
+                         bdrv_get_device_or_node_name(bs));
+        goto error;
+    }
+
+    target_len = bdrv_getlength(target);
+    if (target_len < 0) {
+        error_setg_errno(errp, -target_len, "Unable to get length for '%s'",
+                         bdrv_get_device_or_node_name(bs));
+        goto error;
+    }
+
+    if (target_len != len) {
+        error_setg(errp, "Source and target image have different sizes");
         goto error;
     }