Re: [Qemu-devel] [PATCH 2/8] iscsi: add bdrv_co_is_allocated

[Paolo Bonzini <pbonzini@redhat.com>]

Il 22/06/2013 22:58, Peter Lieven ha scritto:
> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>  block/iscsi.c |  103 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 103 insertions(+)
> 
> diff --git a/block/iscsi.c b/block/iscsi.c
> index a38a1bf..98be71e 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -56,6 +56,15 @@ typedef struct IscsiLun {
>      uint8_t lbpws10;
>  } IscsiLun;
>  
> +typedef struct IscsiTask {
> +    IscsiLun *iscsilun;
> +    BlockDriverState *bs;
> +    int status;
> +    int complete;
> +    Coroutine *co;
> +    struct scsi_lba_status_descriptor lbasd;
> +} IscsiTask;
> +
>  typedef struct IscsiAIOCB {
>      BlockDriverAIOCB common;
>      QEMUIOVector *qiov;
> @@ -805,6 +814,98 @@ iscsi_getlength(BlockDriverState *bs)
>      return len;
>  }
>  
> +static void
> +iscsi_co_is_allocated_cb(struct iscsi_context *iscsi, int status,
> +                        void *command_data, void *opaque)
> +{
> +    struct IscsiTask *iTask = opaque;
> +    struct scsi_task *task = command_data;
> +    struct scsi_get_lba_status *lbas = NULL;
> +
> +    iTask->complete = 1;
> +
> +    if (status != 0) {
> +        error_report("iSCSI: Failed to get_lba_status on iSCSI lun. %s",
> +                     iscsi_get_error(iscsi));
> +        iTask->status   = 1;
> +        goto out;
> +    }
> +
> +    lbas = scsi_datain_unmarshall(task);
> +    if (lbas == NULL) {
> +        iTask->status   = 1;
> +        goto out;
> +    }
> +
> +    memcpy(&iTask->lbasd, &lbas->descriptors[0],
> +           sizeof(struct scsi_lba_status_descriptor));
> +
> +    iTask->status   = 0;
> +
> +out:
> +    scsi_free_scsi_task(task);
> +
> +    if (iTask->co) {
> +        qemu_coroutine_enter(iTask->co, NULL);
> +    }
> +}
> +
> +static int coroutine_fn iscsi_co_is_allocated(BlockDriverState *bs,
> +                                              int64_t sector_num,
> +                                              int nb_sectors, int *pnum)
> +{
> +    IscsiLun *iscsilun = bs->opaque;
> +    struct IscsiTask iTask;
> +    int ret;
> +
> +    *pnum = nb_sectors;
> +
> +    if (iscsilun->lbpme == 0) {
> +        return 1;
> +    }
> +
> +    iTask.iscsilun = iscsilun;
> +    iTask.status = 0;
> +    iTask.complete = 0;
> +    iTask.bs = bs;
> +
> +    if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun,
> +                                  sector_qemu2lun(sector_num, iscsilun),
> +                                  8 + 16, iscsi_co_is_allocated_cb,
> +                                  &iTask) == NULL) {
> +        *pnum = 0;
> +        return 0;
> +    }
> +
> +    while (!iTask.complete) {
> +        iscsi_set_events(iscsilun);
> +        iTask.co = qemu_coroutine_self();
> +        qemu_coroutine_yield();
> +    }
> +
> +    if (iTask.status != 0) {
> +        /* in case the get_lba_status_callout fails (i.e.
> +         * because the device is busy or the cmd is not
> +         * supported) we pretend all blocks are allocated
> +         * for backwards compatiblity */
> +        return 1;
> +    }
> +
> +    if (sector_qemu2lun(sector_num, iscsilun) != iTask.lbasd.lba) {
> +        *pnum = 0;
> +        return 0;
> +    }
> +
> +    *pnum = iTask.lbasd.num_blocks * (iscsilun->block_size / BDRV_SECTOR_SIZE);
> +    if (*pnum > nb_sectors) {
> +        *pnum = nb_sectors;
> +    }
> +
> +    return (iTask.lbasd.provisioning == SCSI_PROVISIONING_TYPE_MAPPED) ? 1 : 0;
> +
> +    return ret;
> +}
> +
>  static int parse_chap(struct iscsi_context *iscsi, const char *target)
>  {
>      QemuOptsList *list;
> @@ -1315,6 +1416,8 @@ static BlockDriver bdrv_iscsi = {
>      .bdrv_getlength  = iscsi_getlength,
>      .bdrv_truncate   = iscsi_truncate,
>  
> +    .bdrv_co_is_allocated = iscsi_co_is_allocated,
> +
>      .bdrv_aio_readv  = iscsi_aio_readv,
>      .bdrv_aio_writev = iscsi_aio_writev,
>      .bdrv_aio_flush  = iscsi_aio_flush,
> 

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>