Commit 5b7bfe51 authored by Sergio Lopez's avatar Sergio Lopez Committed by Kevin Wolf
Browse files

blockdev: unify qmp_blockdev_backup and blockdev-backup transaction paths 



Issuing a blockdev-backup from qmp_blockdev_backup takes a slightly
different path than when it's issued from a transaction. In the code,
this is manifested as some redundancy between do_blockdev_backup() and
blockdev_backup_prepare().

This change unifies both paths, merging do_blockdev_backup() and
blockdev_backup_prepare(), and changing qmp_blockdev_backup() to
create a transaction instead of calling do_backup_common() direcly.

As a side-effect, now qmp_blockdev_backup() is executed inside a
drained section, as it happens when creating a blockdev-backup
transaction. This change is visible from the user's perspective, as
the job gets paused and immediately resumed before starting the actual
work.

Signed-off-by: default avatarSergio Lopez <slp@redhat.com>
Reviewed-by: default avatarMax Reitz <mreitz@redhat.com>
Reviewed-by: default avatarKevin Wolf <kwolf@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 2288ccfa

blockdev.c

+13 −47
Original line number Diff line number Diff line
@@ -1940,16 +1940,13 @@ typedef struct BlockdevBackupState { 
    BlockJob *job;

} BlockdevBackupState;



static BlockJob *do_blockdev_backup(BlockdevBackup *backup, JobTxn *txn,

                                    Error **errp);



static void blockdev_backup_prepare(BlkActionState *common, Error **errp)

{

    BlockdevBackupState *state = DO_UPCAST(BlockdevBackupState, common, common);

    BlockdevBackup *backup;

    BlockDriverState *bs, *target;

    BlockDriverState *bs;

    BlockDriverState *target_bs;

    AioContext *aio_context;

    Error *local_err = NULL;



    assert(common->action->type == TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP);

    backup = common->action->u.blockdev_backup.data;
@@ -1959,8 +1956,8 @@ static void blockdev_backup_prepare(BlkActionState *common, Error **errp) 
        return;

    }



    target = bdrv_lookup_bs(backup->target, backup->target, errp);

    if (!target) {

    target_bs = bdrv_lookup_bs(backup->target, backup->target, errp);

    if (!target_bs) {

        return;

    }
@@ -1971,13 +1968,10 @@ static void blockdev_backup_prepare(BlkActionState *common, Error **errp) 
    /* Paired with .clean() */

    bdrv_drained_begin(state->bs);



    state->job = do_blockdev_backup(backup, common->block_job_txn, &local_err);

    if (local_err) {

        error_propagate(errp, local_err);

        goto out;

    }

    state->job = do_backup_common(qapi_BlockdevBackup_base(backup),

                                  bs, target_bs, aio_context,

                                  common->block_job_txn, errp);



out:

    aio_context_release(aio_context);

}
@@ -3695,41 +3689,13 @@ XDbgBlockGraph *qmp_x_debug_query_block_graph(Error **errp) 
    return bdrv_get_xdbg_block_graph(errp);

}



BlockJob *do_blockdev_backup(BlockdevBackup *backup, JobTxn *txn,

                             Error **errp)

void qmp_blockdev_backup(BlockdevBackup *backup, Error **errp)

{

    BlockDriverState *bs;

    BlockDriverState *target_bs;

    AioContext *aio_context;

    BlockJob *job;



    bs = bdrv_lookup_bs(backup->device, backup->device, errp);

    if (!bs) {

        return NULL;

    }



    target_bs = bdrv_lookup_bs(backup->target, backup->target, errp);

    if (!target_bs) {

        return NULL;

    }



    aio_context = bdrv_get_aio_context(bs);

    aio_context_acquire(aio_context);



    job = do_backup_common(qapi_BlockdevBackup_base(backup),

                           bs, target_bs, aio_context, txn, errp);



    aio_context_release(aio_context);

    return job;

}



void qmp_blockdev_backup(BlockdevBackup *arg, Error **errp)

{

    BlockJob *job;

    job = do_blockdev_backup(arg, NULL, errp);

    if (job) {

        job_start(&job->job);

    }

    TransactionAction action = {

        .type = TRANSACTION_ACTION_KIND_BLOCKDEV_BACKUP,

        .u.blockdev_backup.data = backup,

    };

    blockdev_do_action(&action, errp);

}



/* Parameter check and block job starting for drive mirroring.