Commit e7569c18 authored by Paolo Bonzini's avatar Paolo Bonzini Committed by Fam Zheng
Browse files

qed: move tail of qed_aio_write_main to qed_aio_write_{cow, alloc} 



This part is never called for in-place writes, move it away to avoid
the "backwards" coding style typical of callback-based code.

Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170629132749.997-7-pbonzini@redhat.com>
Signed-off-by: default avatarFam Zheng <famz@redhat.com>
parent 254aee4d

block/qed.c

+32 −38
Original line number Diff line number Diff line
@@ -982,40 +982,12 @@ static int coroutine_fn qed_aio_write_main(QEDAIOCB *acb) 
    BDRVQEDState *s = acb_to_s(acb);

    uint64_t offset = acb->cur_cluster +

                      qed_offset_into_cluster(s, acb->cur_pos);

    int ret;



    trace_qed_aio_write_main(s, acb, 0, offset, acb->cur_qiov.size);



    BLKDBG_EVENT(s->bs->file, BLKDBG_WRITE_AIO);

    ret = bdrv_co_pwritev(s->bs->file, offset, acb->cur_qiov.size,

    return bdrv_co_pwritev(s->bs->file, offset, acb->cur_qiov.size,

                           &acb->cur_qiov, 0);

    if (ret < 0) {

        return ret;

    }



    if (acb->find_cluster_ret != QED_CLUSTER_FOUND) {

        if (s->bs->backing) {

            /*

             * Flush new data clusters before updating the L2 table

             *

             * This flush is necessary when a backing file is in use.  A crash

             * during an allocating write could result in empty clusters in the

             * image.  If the write only touched a subregion of the cluster,

             * then backing image sectors have been lost in the untouched

             * region.  The solution is to flush after writing a new data

             * cluster and before updating the L2 table.

             */

            ret = bdrv_co_flush(s->bs->file->bs);

            if (ret < 0) {

                return ret;

            }

        }

        ret = qed_aio_write_l2_update(acb, acb->cur_cluster);

        if (ret < 0) {

            return ret;

        }

    }

    return 0;

}



/**
@@ -1050,7 +1022,29 @@ static int coroutine_fn qed_aio_write_cow(QEDAIOCB *acb) 
        return ret;

    }



    return qed_aio_write_main(acb);

    ret = qed_aio_write_main(acb);

    if (ret < 0) {

        return ret;

    }



    if (s->bs->backing) {

        /*

         * Flush new data clusters before updating the L2 table

         *

         * This flush is necessary when a backing file is in use.  A crash

         * during an allocating write could result in empty clusters in the

         * image.  If the write only touched a subregion of the cluster,

         * then backing image sectors have been lost in the untouched

         * region.  The solution is to flush after writing a new data

         * cluster and before updating the L2 table.

         */

        ret = bdrv_co_flush(s->bs->file->bs);

        if (ret < 0) {

            return ret;

        }

    }



    return 0;

}



/**
@@ -1103,6 +1097,7 @@ static int coroutine_fn qed_aio_write_alloc(QEDAIOCB *acb, size_t len) 
        if (acb->find_cluster_ret == QED_CLUSTER_ZERO) {

            return 0;

        }

        acb->cur_cluster = 1;

    } else {

        acb->cur_cluster = qed_alloc_clusters(s, acb->cur_nclusters);

    }
@@ -1115,15 +1110,14 @@ static int coroutine_fn qed_aio_write_alloc(QEDAIOCB *acb, size_t len) 
        }

    }



    if (acb->flags & QED_AIOCB_ZERO) {

        ret = qed_aio_write_l2_update(acb, 1);

    } else {

    if (!(acb->flags & QED_AIOCB_ZERO)) {

        ret = qed_aio_write_cow(acb);

    }

        if (ret < 0) {

            return ret;

        }

    return 0;

    }



    return qed_aio_write_l2_update(acb, acb->cur_cluster);

}



/**