Re: [PATCH 2/6] qmp: expose block-dirty-bitmap-populate

[Vladimir Sementsov-Ogievskiy]

25.02.2020 3:56, John Snow wrote:
> This is a new job-creating command.
>
> Signed-off-by: John Snow <address@hidden>
> ---
>   qapi/block-core.json  | 18 ++++++++++
>   qapi/transaction.json |  2 ++
>   blockdev.c            | 78 +++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 98 insertions(+)
>
> diff --git a/qapi/block-core.json b/qapi/block-core.json
> index df1797681a..a8be1fb36b 100644
> --- a/qapi/block-core.json
> +++ b/qapi/block-core.json
> @@ -2293,6 +2293,24 @@
>               '*auto-finalize': 'bool',
>               '*auto-dismiss': 'bool' } }
>   
> +##
> +# @block-dirty-bitmap-populate:
> +#
> +# Creates a new job that writes a pattern into a dirty bitmap.
> +#
> +# Since: 5.0
> +#
> +# Example:
> +#
> +# -> { "execute": "block-dirty-bitmap-populate",
> +#      "arguments": { "node": "drive0", "target": "bitmap0",
> +#                     "job-id": "job0", "pattern": "allocate-top" } }
> +# <- { "return": {} }
> +#
> +##
> +{ 'command': 'block-dirty-bitmap-populate', 'boxed': true,
> +  'data': 'BlockDirtyBitmapPopulate' }
> +
>   ##
>   # @BlockDirtyBitmapSha256:
>   #
> diff --git a/qapi/transaction.json b/qapi/transaction.json
> index 04301f1be7..28521d5c7f 100644
> --- a/qapi/transaction.json
> +++ b/qapi/transaction.json
> @@ -50,6 +50,7 @@
>   # - @block-dirty-bitmap-enable: since 4.0
>   # - @block-dirty-bitmap-disable: since 4.0
>   # - @block-dirty-bitmap-merge: since 4.0
> +# - @block-dirty-bitmap-populate: since 5.0
>   # - @blockdev-backup: since 2.3
>   # - @blockdev-snapshot: since 2.5
>   # - @blockdev-snapshot-internal-sync: since 1.7
> @@ -67,6 +68,7 @@
>          'block-dirty-bitmap-enable': 'BlockDirtyBitmap',
>          'block-dirty-bitmap-disable': 'BlockDirtyBitmap',
>          'block-dirty-bitmap-merge': 'BlockDirtyBitmapMerge',
> +       'block-dirty-bitmap-populate': 'BlockDirtyBitmapPopulate',
>          'blockdev-backup': 'BlockdevBackup',
>          'blockdev-snapshot': 'BlockdevSnapshot',
>          'blockdev-snapshot-internal-sync': 'BlockdevSnapshotInternal',
> diff --git a/blockdev.c b/blockdev.c
> index 011dcfec27..33c0e35399 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -2314,6 +2314,67 @@ static void 
> block_dirty_bitmap_remove_commit(BlkActionState *common)
>       bdrv_release_dirty_bitmap(state->bitmap);
>   }
>   
> +static void block_dirty_bitmap_populate_prepare(BlkActionState *common, Error **errp)

over80 line (not the only)

> +{
> +    BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, 
> common);

At first glance using *Backup* looks like a mistake. May be rename it, or at 
least add a comment.

> +    BlockDirtyBitmapPopulate *bitpop;
> +    BlockDriverState *bs;
> +    AioContext *aio_context;
> +    BdrvDirtyBitmap *bmap = NULL;
> +    int job_flags = JOB_DEFAULT;
> +
> +    assert(common->action->type == 
> TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_POPULATE);
> +    bitpop = common->action->u.block_dirty_bitmap_populate.data;
> +
> +    bs = bdrv_lookup_bs(bitpop->node, bitpop->node, errp);
> +    if (!bs) {
> +        return;
> +    }
> +
> +    aio_context = bdrv_get_aio_context(bs);
> +    aio_context_acquire(aio_context);
> +    state->bs = bs;
> +
> +    bmap = bdrv_find_dirty_bitmap(bs, bitpop->name);

Could we use block_dirty_bitmap_lookup ?

> +    if (!bmap) {
> +        error_setg(errp, "Bitmap '%s' could not be found", bitpop->name);
> +        return;

aio context lock leaked

> +    }
> +
> +    /* Paired with .clean() */
> +    bdrv_drained_begin(state->bs);
> +
> +    if (!bitpop->has_on_error) {
> +        bitpop->on_error = BLOCKDEV_ON_ERROR_REPORT;
> +    }
> +    if (!bitpop->has_auto_finalize) {
> +        bitpop->auto_finalize = true;
> +    }
> +    if (!bitpop->has_auto_dismiss) {
> +        bitpop->auto_dismiss = true;
> +    }
> +
> +    if (!bitpop->auto_finalize) {
> +        job_flags |= JOB_MANUAL_FINALIZE;
> +    }
> +    if (!bitpop->auto_dismiss) {
> +        job_flags |= JOB_MANUAL_DISMISS;
> +    }
> +
> +    state->job = bitpop_job_create(
> +        bitpop->job_id,
> +        bs,
> +        bmap,
> +        bitpop->pattern,
> +        bitpop->on_error,
> +        job_flags,
> +        NULL, NULL,
> +        common->block_job_txn,
> +        errp);
> +
> +    aio_context_release(aio_context);
> +}
> +
>   static void abort_prepare(BlkActionState *common, Error **errp)
>   {
>       error_setg(errp, "Transaction aborted using Abort action");
> @@ -2397,6 +2458,13 @@ static const BlkActionOps actions[] = {
>           .commit = block_dirty_bitmap_remove_commit,
>           .abort = block_dirty_bitmap_remove_abort,
>       },
> +    [TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_POPULATE] = {
> +        .instance_size = sizeof(BlockdevBackupState),
> +        .prepare = block_dirty_bitmap_populate_prepare,
> +        .commit = blockdev_backup_commit,
> +        .abort = blockdev_backup_abort,
> +        .clean = blockdev_backup_clean,
> +    },
>       /* Where are transactions for MIRROR, COMMIT and STREAM?
>        * Although these blockjobs use transaction callbacks like the backup job,
>        * these jobs do not necessarily adhere to transaction semantics.
> @@ -3225,6 +3293,16 @@ void qmp_block_dirty_bitmap_merge(const char *node, 
> const char *target,
>       do_block_dirty_bitmap_merge(node, target, bitmaps, NULL, errp);
>   }
>   
> +void qmp_block_dirty_bitmap_populate(BlockDirtyBitmapPopulate *bitpop,
> +                                     Error **errp)
> +{
> +    TransactionAction action = {
> +        .type = TRANSACTION_ACTION_KIND_BLOCK_DIRTY_BITMAP_POPULATE,
> +        .u.block_dirty_bitmap_populate.data = bitpop,
> +    };
> +    blockdev_do_action(&action, errp);
> +}
> +
>   BlockDirtyBitmapSha256 *qmp_x_debug_block_dirty_bitmap_sha256(const char 
> *node,
>                                                                 const char 
> *name,
>                                                                 Error **errp)


--
Best regards,
Vladimir