Commit 607dbdc4 authored by Vladimir Sementsov-Ogievskiy's avatar Vladimir Sementsov-Ogievskiy Committed by Kevin Wolf
Browse files

block/backup: use buffer-based io 



Signed-off-by: default avatarVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent a4072543

block/backup.c

+6 −8
Original line number Diff line number Diff line
@@ -107,7 +107,6 @@ static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job, 
                                                      void **bounce_buffer)

{

    int ret;

    QEMUIOVector qiov;

    BlockBackend *blk = job->common.blk;

    int nbytes;

    int read_flags = is_write_notifier ? BDRV_REQ_NO_SERIALISING : 0;
@@ -118,9 +117,8 @@ static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job, 
    if (!*bounce_buffer) {

        *bounce_buffer = blk_blockalign(blk, job->cluster_size);

    }

    qemu_iovec_init_buf(&qiov, *bounce_buffer, nbytes);



    ret = blk_co_preadv(blk, start, qiov.size, &qiov, read_flags);

    ret = blk_co_pread(blk, start, nbytes, *bounce_buffer, read_flags);

    if (ret < 0) {

        trace_backup_do_cow_read_fail(job, start, ret);

        if (error_is_read) {
@@ -129,12 +127,12 @@ static int coroutine_fn backup_cow_with_bounce_buffer(BackupBlockJob *job, 
        goto fail;

    }



    if (qemu_iovec_is_zero(&qiov)) {

    if (buffer_is_zero(*bounce_buffer, nbytes)) {

        ret = blk_co_pwrite_zeroes(job->target, start,

                                   qiov.size, write_flags | BDRV_REQ_MAY_UNMAP);

                                   nbytes, write_flags | BDRV_REQ_MAY_UNMAP);

    } else {

        ret = blk_co_pwritev(job->target, start,

                             qiov.size, &qiov, write_flags |

        ret = blk_co_pwrite(job->target, start,

                            nbytes, *bounce_buffer, write_flags |

                            (job->compress ? BDRV_REQ_WRITE_COMPRESSED : 0));

    }

    if (ret < 0) {