block/backup: refactor: split out backup_calculate_cluster_size
Split out cluster_size calculation. Move copy-bitmap creation above
block-job creation, as we are going to share it with upcoming
backup-top filter, which also should be created before actual block job
creation.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190429090842.57910-6-vsementsov@virtuozzo.com
[mreitz: Dropped a paragraph from the commit message that was left over
from a previous version]
Signed-off-by: Max Reitz <mreitz@redhat.com>
diff --git a/block/backup.c b/block/backup.c
index 5b3fc9d..00f4f8a 100644
--- a/block/backup.c
+++ b/block/backup.c
@@ -497,6 +497,42 @@
.drain = backup_drain,
};
+static int64_t backup_calculate_cluster_size(BlockDriverState *target,
+ Error **errp)
+{
+ int ret;
+ BlockDriverInfo bdi;
+
+ /*
+ * If there is no backing file on the target, we cannot rely on COW if our
+ * backup cluster size is smaller than the target cluster size. Even for
+ * targets with a backing file, try to avoid COW if possible.
+ */
+ ret = bdrv_get_info(target, &bdi);
+ if (ret == -ENOTSUP && !target->backing) {
+ /* 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 "
+ "backing file. The default block size of %u bytes is "
+ "used. If the actual block size of the target exceeds "
+ "this default, the backup may be unusable",
+ BACKUP_CLUSTER_SIZE_DEFAULT);
+ return BACKUP_CLUSTER_SIZE_DEFAULT;
+ } else if (ret < 0 && !target->backing) {
+ 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) {
+ /* Not fatal; just trudge on ahead. */
+ return BACKUP_CLUSTER_SIZE_DEFAULT;
+ }
+
+ return MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size);
+}
+
BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs,
BlockDriverState *target, int64_t speed,
MirrorSyncMode sync_mode, BdrvDirtyBitmap *sync_bitmap,
@@ -508,9 +544,10 @@
JobTxn *txn, Error **errp)
{
int64_t len;
- BlockDriverInfo bdi;
BackupBlockJob *job = NULL;
int ret;
+ int64_t cluster_size;
+ HBitmap *copy_bitmap = NULL;
assert(bs);
assert(target);
@@ -572,6 +609,13 @@
goto error;
}
+ cluster_size = backup_calculate_cluster_size(target, errp);
+ if (cluster_size < 0) {
+ goto error;
+ }
+
+ copy_bitmap = hbitmap_alloc(len, ctz32(cluster_size));
+
/* job->len is fixed, so we can't allow resize */
job = block_job_create(job_id, &backup_job_driver, txn, bs,
BLK_PERM_CONSISTENT_READ,
@@ -600,35 +644,9 @@
/* Detect image-fleecing (and similar) schemes */
job->serialize_target_writes = bdrv_chain_contains(target, bs);
-
- /* If there is no backing file on the target, we cannot rely on COW if our
- * backup cluster size is smaller than the target cluster size. Even for
- * targets with a backing file, try to avoid COW if possible. */
- ret = bdrv_get_info(target, &bdi);
- if (ret == -ENOTSUP && !target->backing) {
- /* 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 "
- "backing file. The default block size of %u bytes is "
- "used. If the actual block size of the target exceeds "
- "this default, the backup may be unusable",
- BACKUP_CLUSTER_SIZE_DEFAULT);
- job->cluster_size = BACKUP_CLUSTER_SIZE_DEFAULT;
- } else if (ret < 0 && !target->backing) {
- 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");
- goto error;
- } else if (ret < 0 && target->backing) {
- /* Not fatal; just trudge on ahead. */
- job->cluster_size = BACKUP_CLUSTER_SIZE_DEFAULT;
- } else {
- job->cluster_size = MAX(BACKUP_CLUSTER_SIZE_DEFAULT, bdi.cluster_size);
- }
-
- job->copy_bitmap = hbitmap_alloc(len, ctz32(job->cluster_size));
+ job->cluster_size = cluster_size;
+ job->copy_bitmap = copy_bitmap;
+ copy_bitmap = NULL;
job->use_copy_range = true;
job->copy_range_size = MIN_NON_ZERO(blk_get_max_transfer(job->common.blk),
blk_get_max_transfer(job->target));
@@ -644,6 +662,10 @@
return &job->common;
error:
+ if (copy_bitmap) {
+ assert(!job || !job->copy_bitmap);
+ hbitmap_free(copy_bitmap);
+ }
if (sync_bitmap) {
bdrv_reclaim_dirty_bitmap(bs, sync_bitmap, NULL);
}
