From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Fiona Ebner Date: Thu, 11 Apr 2024 11:29:27 +0200 Subject: [PATCH] backup: add minimum cluster size to performance options Useful to make discard-source work in the context of backup fleecing when the fleecing image has a larger granularity than the backup target. Backup/block-copy will use at least this granularity for copy operations and in particular, discard requests to the backup source will too. If the granularity is too small, they will just be aligned down in cbw_co_pdiscard_snapshot() and thus effectively ignored. Signed-off-by: Fiona Ebner Signed-off-by: Thomas Lamprecht --- block/backup.c | 2 +- block/copy-before-write.c | 2 ++ block/copy-before-write.h | 1 + blockdev.c | 3 +++ qapi/block-core.json | 9 +++++++-- 5 files changed, 14 insertions(+), 3 deletions(-) diff --git a/block/backup.c b/block/backup.c index f19b751fe6..4367278d68 100644 --- a/block/backup.c +++ b/block/backup.c @@ -434,7 +434,7 @@ BlockJob *backup_job_create(const char *job_id, BlockDriverState *bs, } cbw = bdrv_cbw_append(bs, target, filter_node_name, discard_source, - &bcs, errp); + perf->min_cluster_size, &bcs, errp); if (!cbw) { goto error; } diff --git a/block/copy-before-write.c b/block/copy-before-write.c index fbc5aeb9eb..3d5523992c 100644 --- a/block/copy-before-write.c +++ b/block/copy-before-write.c @@ -557,6 +557,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source, BlockDriverState *target, const char *filter_node_name, bool discard_source, + int64_t min_cluster_size, BlockCopyState **bcs, Error **errp) { @@ -575,6 +576,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source, } qdict_put_str(opts, "file", bdrv_get_node_name(source)); qdict_put_str(opts, "target", bdrv_get_node_name(target)); + qdict_put_int(opts, "min-cluster-size", min_cluster_size); top = bdrv_insert_node(source, opts, flags, errp); if (!top) { diff --git a/block/copy-before-write.h b/block/copy-before-write.h index 01af0cd3c4..dc6cafe7fa 100644 --- a/block/copy-before-write.h +++ b/block/copy-before-write.h @@ -40,6 +40,7 @@ BlockDriverState *bdrv_cbw_append(BlockDriverState *source, BlockDriverState *target, const char *filter_node_name, bool discard_source, + int64_t min_cluster_size, BlockCopyState **bcs, Error **errp); void bdrv_cbw_drop(BlockDriverState *bs); diff --git a/blockdev.c b/blockdev.c index e167ad1e54..35ec5d8f0b 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2781,6 +2781,9 @@ static BlockJob *do_backup_common(BackupCommon *backup, if (backup->x_perf->has_max_chunk) { perf.max_chunk = backup->x_perf->max_chunk; } + if (backup->x_perf->has_min_cluster_size) { + perf.min_cluster_size = backup->x_perf->min_cluster_size; + } } if ((backup->sync == MIRROR_SYNC_MODE_BITMAP) || diff --git a/qapi/block-core.json b/qapi/block-core.json index f2fec625cc..48eec4ef29 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -1775,11 +1775,16 @@ # it should not be less than job cluster size which is calculated # as maximum of target image cluster size and 64k. Default 0. # +# @min-cluster-size: Minimum size of blocks used by copy-before-write +# and background copy operations. Has to be a power of 2. No +# effect if smaller than the maximum of the target's cluster size +# and 64 KiB. Default 0. (Since 8.1) +# # Since: 6.0 ## { 'struct': 'BackupPerf', - 'data': { '*use-copy-range': 'bool', - '*max-workers': 'int', '*max-chunk': 'int64' } } + 'data': { '*use-copy-range': 'bool', '*max-workers': 'int', + '*max-chunk': 'int64', '*min-cluster-size': 'uint32' } } ## # @BackupCommon: