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

[John Snow]

On 2/27/20 5:44 AM, Vladimir Sementsov-Ogievskiy wrote:
> 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)
> 

OK, will fix all instances.

>> +{
>> +    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.
> 

You're right, it's tricky. A rename would be helpful.

>> +    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 ?
> 

Yes.

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

Good spot.

>> +    }
>> +
>> +    /* 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)
>>
> 
> 

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—js