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Re: [Qemu-block] [PATCH v7] qemu-img info lists bitmap directory entries
From: |
Andrey Shinkevich |
Subject: |
Re: [Qemu-block] [PATCH v7] qemu-img info lists bitmap directory entries |
Date: |
Sun, 30 Dec 2018 20:16:47 +0000 |
Ping / Note
Dear colleagues,
Kindly remind you to complete reviewing of this simple series.
Happy New Year!
On 13/12/2018 13:59, Andrey Shinkevich wrote:
> In the 'Format specific information' section of the 'qemu-img info'
> command output, the supplemental information about existing QCOW2
> bitmaps will be shown, such as a bitmap name, flags and granularity:
>
> image: /vz/vmprivate/VM1/harddisk.hdd
> file format: qcow2
> virtual size: 64G (68719476736 bytes)
> disk size: 3.0M
> cluster_size: 1048576
> Format specific information:
> compat: 1.1
> lazy refcounts: true
> bitmaps:
> [0]:
> flags:
> [0]: in-use
> [1]: auto
> name: back-up1
> unknown flags: 4
> granularity: 65536
> [1]:
> flags:
> [0]: in-use
> [1]: auto
> name: back-up2
> unknown flags: 8
> granularity: 65536
> refcount bits: 16
> corrupt: false
>
> Signed-off-by: Andrey Shinkevich <address@hidden>
> Reviewed-by: Vladimir Sementsov-Ogievskiy <address@hidden>
> Reviewed-by: Eric Blake <address@hidden>
> ---
> v7:
> A description was added to the function qcow2_get_bitmap_info_list().
> In the function qcow2_get_specific_info(), the comment was modified
> so that we ignore any error in obtaining the list of bitmaps to
> pass the rest of QCOW2 specific information to a caller.
>
> v6:
> '[PATCH v6] qemu-img info lists bitmap directory entries'.
> The error handling logic for the bitmaps empty list was reversed.
>
> v5:
> '[PATCH v5] qemu-img info lists bitmap directory entries'.
> The error handling logic for the bitmaps empty list was fixed and documented.
>
> v4:
> '[PATCH v4] qemu-img info lists bitmap directory entries'.
> Unknown flags are checked with the mask BME_RESERVED_FLAGS.
> The code minor refactoring was made.
>
> v3:
> '[PATCH v3] qemu-img info lists bitmap directory entries'.
> Now, qcow2_get_bitmap_info_list() is invoked under the condition of QCOW
> version #3 to avoid memory leaks in case of QCOW version #2.
> Furthermore, qcow2_get_bitmap_info_list() checks the number of existing
> bitmaps.
> So, if no bitmap exists, no bitmap error message is printed in the output.
> The data type of the bitmap 'granularity' parameter was left as 'uint32'
> because bitmap_list_load() returns error if granularity_bits is grater than
> 31.
>
> v2:
> '[PATCH v2] qemu-img info lists bitmap directory entries'.
> The targeted version of the release at 'Since' word of the comments to the new
> structures changed to 4.0 in the file qapi/block-core.json.
> A comment to the 'bitmaps' new member was supplied.
> The 'unknown flags' parameter was introduced to indicate presence of QCOW2
> bitmap unknown flags, if any.
> The word 'dirty' was removed from the code and from the comments as we list
> all
> the bitmaps.
> The 'bitmaps' printed parameter was removed for the release versions earlier
> than 3.x.
> The example of the output was moved above the 'Signed-off-by' line.
>
> The first version was '[PATCH] qemu-img info lists bitmap directory entries'.
>
> block/qcow2-bitmap.c | 63
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
> block/qcow2.c | 9 ++++++++
> block/qcow2.h | 2 ++
> qapi/block-core.json | 42 ++++++++++++++++++++++++++++++++++-
> qemu-img.c | 5 +++++
> 5 files changed, 120 insertions(+), 1 deletion(-)
>
> diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
> index accebef..8aedddc 100644
> --- a/block/qcow2-bitmap.c
> +++ b/block/qcow2-bitmap.c
> @@ -1008,6 +1008,69 @@ fail:
> return false;
> }
>
> +static Qcow2BitmapInfoFlagsList *get_bitmap_info_flags(uint32_t flags)
> +{
> + Qcow2BitmapInfoFlagsList *list = NULL;
> + Qcow2BitmapInfoFlagsList **plist = &list;
> +
> + if (flags & BME_FLAG_IN_USE) {
> + Qcow2BitmapInfoFlagsList *entry = g_new0(Qcow2BitmapInfoFlagsList,
> 1);
> + entry->value = QCOW2_BITMAP_INFO_FLAGS_IN_USE;
> + *plist = entry;
> + plist = &entry->next;
> + }
> + if (flags & BME_FLAG_AUTO) {
> + Qcow2BitmapInfoFlagsList *entry = g_new0(Qcow2BitmapInfoFlagsList,
> 1);
> + entry->value = QCOW2_BITMAP_INFO_FLAGS_AUTO;
> + *plist = entry;
> + }
> + return list;
> +}
> +
> +/* qcow2_get_bitmap_info_list()
> + * Returns a list of QCOW2 bitmap details.
> + * In case of no bitmaps, the function returns NULL and
> + * the @errp parameter is not set (for a 0-length list in the QMP).
> + * When bitmap information can not be obtained, the function returns
> + * NULL and the @errp parameter is set (for omitting the list in QMP).
> + */
> +Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
> + Error **errp)
> +{
> + BDRVQcow2State *s = bs->opaque;
> + Qcow2BitmapList *bm_list;
> + Qcow2Bitmap *bm;
> + Qcow2BitmapInfoList *list = NULL;
> + Qcow2BitmapInfoList **plist = &list;
> +
> + if (s->nb_bitmaps == 0) {
> + return NULL;
> + }
> +
> + bm_list = bitmap_list_load(bs, s->bitmap_directory_offset,
> + s->bitmap_directory_size, errp);
> + if (bm_list == NULL) {
> + return NULL;
> + }
> +
> + QSIMPLEQ_FOREACH(bm, bm_list, entry) {
> + Qcow2BitmapInfo *info = g_new0(Qcow2BitmapInfo, 1);
> + Qcow2BitmapInfoList *obj = g_new0(Qcow2BitmapInfoList, 1);
> + info->granularity = 1U << bm->granularity_bits;
> + info->name = g_strdup(bm->name);
> + info->flags = get_bitmap_info_flags(bm->flags);
> + info->unknown_flags = bm->flags & BME_RESERVED_FLAGS;
> + info->has_unknown_flags = !!info->unknown_flags;
> + obj->value = info;
> + *plist = obj;
> + plist = &obj->next;
> + }
> +
> + bitmap_list_free(bm_list);
> +
> + return list;
> +}
> +
> int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated,
> Error **errp)
> {
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 991d6ac..d79f667 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -4270,6 +4270,10 @@ static ImageInfoSpecific
> *qcow2_get_specific_info(BlockDriverState *bs)
> .refcount_bits = s->refcount_bits,
> };
> } else if (s->qcow_version == 3) {
> + Qcow2BitmapInfoList *bitmaps;
> + Error *local_err = NULL;
> +
> + bitmaps = qcow2_get_bitmap_info_list(bs, &local_err);
> *spec_info->u.qcow2.data = (ImageInfoSpecificQCow2){
> .compat = g_strdup("1.1"),
> .lazy_refcounts = s->compatible_features &
> @@ -4279,7 +4283,12 @@ static ImageInfoSpecific
> *qcow2_get_specific_info(BlockDriverState *bs)
> QCOW2_INCOMPAT_CORRUPT,
> .has_corrupt = true,
> .refcount_bits = s->refcount_bits,
> + .has_bitmaps = !local_err,
> + .bitmaps = bitmaps,
> };
> + /* If an error occurs in obtaining bitmaps, ignore
> + * it to show other QCOW2 specific information. */
> + error_free(local_err);
> } else {
> /* if this assertion fails, this probably means a new version was
> * added without having it covered here */
> diff --git a/block/qcow2.h b/block/qcow2.h
> index 8662b68..0ec2b3d 100644
> --- a/block/qcow2.h
> +++ b/block/qcow2.h
> @@ -685,6 +685,8 @@ int qcow2_check_bitmaps_refcounts(BlockDriverState *bs,
> BdrvCheckResult *res,
> void **refcount_table,
> int64_t *refcount_table_size);
> bool qcow2_load_dirty_bitmaps(BlockDriverState *bs, Error **errp);
> +Qcow2BitmapInfoList *qcow2_get_bitmap_info_list(BlockDriverState *bs,
> + Error **errp);
> int qcow2_reopen_bitmaps_rw_hint(BlockDriverState *bs, bool *header_updated,
> Error **errp);
> int qcow2_reopen_bitmaps_rw(BlockDriverState *bs, Error **errp);
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index d4fe710..9898baa 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -69,6 +69,10 @@
> # @encrypt: details about encryption parameters; only set if image
> # is encrypted (since 2.10)
> #
> +# @bitmaps: A list of qcow2 bitmap details (possibly empty, such as for
> +# v2 images which do not support bitmaps); absent if bitmap
> +# information could not be obtained (since 4.0)
> +#
> # Since: 1.7
> ##
> { 'struct': 'ImageInfoSpecificQCow2',
> @@ -77,7 +81,8 @@
> '*lazy-refcounts': 'bool',
> '*corrupt': 'bool',
> 'refcount-bits': 'int',
> - '*encrypt': 'ImageInfoSpecificQCow2Encryption'
> + '*encrypt': 'ImageInfoSpecificQCow2Encryption',
> + '*bitmaps': ['Qcow2BitmapInfo']
> } }
>
> ##
> @@ -454,6 +459,41 @@
> 'status': 'DirtyBitmapStatus'} }
>
> ##
> +# @Qcow2BitmapInfoFlags:
> +#
> +# An enumeration of flags that a bitmap can report to the user.
> +#
> +# @in-use: The bitmap was not saved correctly and may be inconsistent.
> +#
> +# @auto: The bitmap must reflect all changes of the virtual disk by any
> +# application that would write to this qcow2 file.
> +#
> +# Since: 4.0
> +##
> +{ 'enum': 'Qcow2BitmapInfoFlags',
> + 'data': ['in-use', 'auto'] }
> +
> +##
> +# @Qcow2BitmapInfo:
> +#
> +# Qcow2 bitmap information.
> +#
> +# @name: the name of the bitmap
> +#
> +# @granularity: granularity of the bitmap in bytes
> +#
> +# @flags: flags of the bitmap
> +#
> +# @unknown-flags: unspecified flags if detected
> +#
> +# Since: 4.0
> +##
> +{ 'struct': 'Qcow2BitmapInfo',
> + 'data': {'name': 'str', 'granularity': 'uint32',
> + 'flags': ['Qcow2BitmapInfoFlags'],
> + '*unknown-flags': 'uint32' } }
> +
> +##
> # @BlockLatencyHistogramInfo:
> #
> # Block latency histogram.
> diff --git a/qemu-img.c b/qemu-img.c
> index ad04f59..144d7b8 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -2601,6 +2601,11 @@ static ImageInfoList *collect_image_info_list(bool
> image_opts,
> blk_unref(blk);
> goto err;
> }
> + if (info->format_specific &&
> + info->format_specific->type == IMAGE_INFO_SPECIFIC_KIND_QCOW2 &&
> + info->format_specific->u.qcow2.data->has_bitmaps == false) {
> + warn_report("Failed to load bitmap list");
> + }
>
> elem = g_new0(ImageInfoList, 1);
> elem->value = info;
>
--
With the best regards,
Andrey Shinkevich