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Re: [Qemu-devel] [PATCHv4 2/2] iscsi: add .bdrv_co_is_allocated
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCHv4 2/2] iscsi: add .bdrv_co_is_allocated |
Date: |
Thu, 18 Jul 2013 12:36:16 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 |
Il 18/07/2013 10:19, Peter Lieven ha scritto:
> this patch adds a coroutine for .bdrv_co_is_allocated as well as
> a generic framework that can be used to build coroutines in block/iscsi.
This conflicts with my bdrv_get_block_status patches.
Paolo
> Signed-off-by: Peter Lieven <address@hidden>
> ---
> block/iscsi.c | 130
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 130 insertions(+)
>
> diff --git a/block/iscsi.c b/block/iscsi.c
> index ab42f1e..56dedff 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -55,6 +55,15 @@ typedef struct IscsiLun {
> struct scsi_inquiry_block_limits bl;
> } IscsiLun;
>
> +typedef struct IscsiTask {
> + int status;
> + int complete;
> + int retries;
> + int do_retry;
> + struct scsi_task *task;
> + Coroutine *co;
> +} IscsiTask;
> +
> typedef struct IscsiAIOCB {
> BlockDriverAIOCB common;
> QEMUIOVector *qiov;
> @@ -110,6 +119,41 @@ iscsi_schedule_bh(IscsiAIOCB *acb)
> qemu_bh_schedule(acb->bh);
> }
>
> +static void
> +iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
> + void *command_data, void *opaque)
> +{
> + struct IscsiTask *iTask = opaque;
> + struct scsi_task *task = command_data;
> +
> + iTask->complete = 1;
> + iTask->status = status;
> + iTask->do_retry = 0;
> + iTask->task = task;
> +
> + if (iTask->retries-- > 0 && status == SCSI_STATUS_CHECK_CONDITION
> + && task->sense.key == SCSI_SENSE_UNIT_ATTENTION) {
> + iTask->do_retry = 1;
> + goto out;
> + }
> +
> + if (status != SCSI_STATUS_GOOD) {
> + error_report("iSCSI: Failure. %s", iscsi_get_error(iscsi));
> + }
> +
> +out:
> + if (iTask->co) {
> + qemu_coroutine_enter(iTask->co, NULL);
> + }
> +}
> +
> +static void iscsi_co_init_iscsitask(IscsiLun *iscsilun, struct IscsiTask
> *iTask)
> +{
> + *iTask = (struct IscsiTask) {
> + .co = qemu_coroutine_self(),
> + .retries = ISCSI_CMD_RETRIES,
> + };
> +}
>
> static void
> iscsi_abort_task_cb(struct iscsi_context *iscsi, int status, void
> *command_data,
> @@ -804,6 +848,90 @@ iscsi_getlength(BlockDriverState *bs)
> return len;
> }
>
> +static int coroutine_fn iscsi_co_is_allocated(BlockDriverState *bs,
> + int64_t sector_num,
> + int nb_sectors, int *pnum)
> +{
> + IscsiLun *iscsilun = bs->opaque;
> + struct scsi_get_lba_status *lbas = NULL;
> + struct scsi_lba_status_descriptor *lbasd = NULL;
> + struct IscsiTask iTask;
> + int ret;
> +
> + /* default to all sectors allocated */
> + ret = 1;
> + *pnum = nb_sectors;
> +
> + /* LUN does not support logical block provisioning */
> + if (iscsilun->lbpme == 0) {
> + goto out;
> + }
> +
> + iscsi_co_init_iscsitask(iscsilun, &iTask);
> +
> +retry:
> + if (iscsi_get_lba_status_task(iscsilun->iscsi, iscsilun->lun,
> + sector_qemu2lun(sector_num, iscsilun),
> + 8 + 16, iscsi_co_generic_cb,
> + &iTask) == NULL) {
> + ret = 0;
> + *pnum = 0;
> + goto out;
> + }
> +
> + while (!iTask.complete) {
> + iscsi_set_events(iscsilun);
> + qemu_coroutine_yield();
> + }
> +
> + if (iTask.do_retry) {
> + if (iTask.task != NULL) {
> + scsi_free_scsi_task(iTask.task);
> + iTask.task = NULL;
> + }
> + goto retry;
> + }
> +
> + if (iTask.status != SCSI_STATUS_GOOD) {
> + /* 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 */
> + goto out;
> + }
> +
> + lbas = scsi_datain_unmarshall(iTask.task);
> + if (lbas == NULL) {
> + ret = 0;
> + *pnum = 0;
> + goto out;
> + }
> +
> + lbasd = &lbas->descriptors[0];
> +
> + if (sector_qemu2lun(sector_num, iscsilun) != lbasd->lba) {
> + ret = 0;
> + *pnum = 0;
> + goto out;
> + }
> +
> + *pnum = lbasd->num_blocks * (iscsilun->block_size / BDRV_SECTOR_SIZE);
> + if (*pnum > nb_sectors) {
> + *pnum = nb_sectors;
> + }
> +
> + if (lbasd->provisioning == SCSI_PROVISIONING_TYPE_DEALLOCATED ||
> + lbasd->provisioning == SCSI_PROVISIONING_TYPE_ANCHORED) {
> + ret = 0;
> + }
> +
> +out:
> + if (iTask.task != NULL) {
> + scsi_free_scsi_task(iTask.task);
> + }
> + return ret;
> +}
> +
> static int parse_chap(struct iscsi_context *iscsi, const char *target)
> {
> QemuOptsList *list;
> @@ -1345,6 +1473,8 @@ 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,
>