The function should collect statistics, about used/unused by top-level format driver space (in its .file) and allocation status (data/zero/discarded/after-eof) of corresponding areas in this .file.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com> --- block.c | 16 +++++++++++ include/block/block.h | 3 ++ include/block/block_int.h | 2 ++ qapi/block-core.json | 72 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 93 insertions(+) diff --git a/block.c b/block.c index 50ba264143..7d720ae0c2 100644 --- a/block.c +++ b/block.c @@ -3407,6 +3407,22 @@ int64_t bdrv_get_allocated_file_size(BlockDriverState *bs) } /** + * Collect format allocation info. See BlockFormatAllocInfo definition in + * qapi/block-core.json. + */ +int bdrv_get_format_alloc_stat(BlockDriverState *bs, BlockFormatAllocInfo *bfai) +{ + BlockDriver *drv = bs->drv; + if (!drv) { + return -ENOMEDIUM; + } + if (drv->bdrv_get_format_alloc_stat) { + return drv->bdrv_get_format_alloc_stat(bs, bfai); + } + return -ENOTSUP; +} + +/** * Return number of sectors on success, -errno on error. */ int64_t bdrv_nb_sectors(BlockDriverState *bs) diff --git a/include/block/block.h b/include/block/block.h index 9b355e92d8..646376a772 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -335,6 +335,9 @@ typedef enum { int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix); +int bdrv_get_format_alloc_stat(BlockDriverState *bs, + BlockFormatAllocInfo *bfai); + /* The units of offset and total_work_size may be chosen arbitrarily by the * block driver; total_work_size may change during the course of the amendment * operation */ diff --git a/include/block/block_int.h b/include/block/block_int.h index 8d3724cce6..458c715e99 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -208,6 +208,8 @@ struct BlockDriver { int64_t (*bdrv_getlength)(BlockDriverState *bs); bool has_variable_length; int64_t (*bdrv_get_allocated_file_size)(BlockDriverState *bs); + int (*bdrv_get_format_alloc_stat)(BlockDriverState *bs, + BlockFormatAllocInfo *bfai); int coroutine_fn (*bdrv_co_pwritev_compressed)(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov); diff --git a/qapi/block-core.json b/qapi/block-core.json index ea0b3e8b13..93f6995381 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -139,6 +139,78 @@ '*format-specific': 'ImageInfoSpecific' } } ## +# @BlockFormatAllocInfo: +# +# +# Allocation information of an underlying protocol file, as partitioned by a +# format driver's utilization of said allocations. +# All fields are in bytes. +# +# Regions of the underlying protocol file may be considered used or unused by +# the format driver interpreting these regions. It is at the discretion of the +# format driver (e.g. qcow2) which regions of its backing storage are considered +# in-use or not. +# +# For now, the only format driver supporting this feature is Qcow2 which is a +# cluster based format. Clusters considered in-use by qcow2 are those with a +# non-zero refcount in the format metadata. All other clusters, if present, are +# considered unused. Examples of unused allocations for the Qcow2 format are +# leaked clusters, pre-allocated clusters, and recently freed clusters. +# +# Note: the whole underlying protocol file is described as well as all format +# file allocations, not only virtual disk data (metadata, internal snapshots, +# etc. are included). +# +# For the underlying protocol file there are native block-status types of the +# regions: +# - data: allocated data +# - zero: reported as zero (for example, this type corresponds to holes for +# POSIX files on sparce file-system) +# - discarded: not allocated +# 4th additional type is 'overrun', is data referenced by the format driver +# located beyond EOF of the underlying protocol file. For example, a partially +# allocated cluster at the end of a QCOW2 file, where Qcow2 generally operates +# on complete clusters. +# +# So, the fields are: +# +# @used-data: used by the format file and backed by data in the underlying +# protocol file +# +# @used-zero: used by the format file and backed by zeroes in the underlying +# protocol file; which may be a filesystem hole for POSIX files. +# +# @used-discarded: used by the format file but actually unallocated in the +# underlying protocol file +# +# @used-overrun: used by the format file beyond the end of the underlying +# protocol file +# +# @unused-data: allocated data in the underlying protocol file not used by the +# format file +# +# @unused-zero: reported-as-zero regions in the underlying protocol file not +# used by the format file +# +# @unused-discarded: unallocated areas in the underlying protocol file not used +# by the format file +# +# Note: sum of 6 fields {used,unused}-{data,zero,discarded} is equal to the +# length of the underlying protocol file. +# +# Since: 2.11 +# +## +{ 'struct': 'BlockFormatAllocInfo', + 'data': {'used-data': 'uint64', + 'used-zero': 'uint64', + 'used-discarded': 'uint64', + 'used-overrun': 'uint64', + 'unused-data': 'uint64', + 'unused-zero': 'uint64', + 'unused-discarded': 'uint64' } } + +## # @ImageCheck: # # Information about a QEMU image file check -- 2.11.1