diff options
| -rw-r--r-- | block/backup.c | 82 |
1 files changed, 52 insertions, 30 deletions
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 @@ static const BlockJobDriver backup_job_driver = { .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 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, 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 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, 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 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, /* 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 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, 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); } |