Il 03/12/2012 20:35, Peter Lieven ha scritto:
> This patch adds support for directly passing the iovec
> array from QEMUIOVector if libiscsi supports it.
Thanks, one question below.
> Signed-off-by: Peter Lieven <p...@kamp.de>
> ---
> block/iscsi.c | 31 +++++++++++++++++++++++++++++++
> 1 file changed, 31 insertions(+)
>
> diff --git a/block/iscsi.c b/block/iscsi.c
> index c0b70b3..6f3ee4a 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -55,7 +55,9 @@ typedef struct IscsiAIOCB {
> QEMUBH *bh;
> IscsiLun *iscsilun;
> struct scsi_task *task;
> +#if !defined(LIBISCSI_FEATURE_IOVECTOR)
> uint8_t *buf;
> +#endif
> int status;
> int canceled;
> size_t read_size;
> @@ -192,7 +194,9 @@ iscsi_aio_write16_cb(struct iscsi_context *iscsi, int
> status,
>
> trace_iscsi_aio_write16_cb(iscsi, status, acb, acb->canceled);
>
> +#if !defined(LIBISCSI_FEATURE_IOVECTOR)
> g_free(acb->buf);
> +#endif
>
> if (acb->canceled != 0) {
> return;
> @@ -225,7 +229,9 @@ iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num,
> size_t size;
> uint32_t num_sectors;
> uint64_t lba;
> +#if !defined(LIBISCSI_FEATURE_IOVECTOR)
> struct iscsi_data data;
> +#endif
>
> acb = qemu_aio_get(&iscsi_aiocb_info, bs, cb, opaque);
> trace_iscsi_aio_writev(iscsi, sector_num, nb_sectors, opaque, acb);
> @@ -240,8 +246,11 @@ iscsi_aio_writev(BlockDriverState *bs, int64_t
> sector_num,
> /* XXX we should pass the iovec to write16 to avoid the extra copy */
> /* this will allow us to get rid of 'buf' completely */
> size = nb_sectors * BDRV_SECTOR_SIZE;
> +
> +#if !defined(LIBISCSI_FEATURE_IOVECTOR)
> acb->buf = g_malloc(size);
> qemu_iovec_to_buf(acb->qiov, 0, acb->buf, size);
> +#endif
>
> acb->task = malloc(sizeof(struct scsi_task));
> if (acb->task == NULL) {
> @@ -262,6 +271,17 @@ iscsi_aio_writev(BlockDriverState *bs, int64_t
> sector_num,
> *(uint32_t *)&acb->task->cdb[10] = htonl(num_sectors);
> acb->task->expxferlen = size;
>
> +#if defined(LIBISCSI_FEATURE_IOVECTOR)
> + if (iscsi_scsi_command_async(iscsi, iscsilun->lun, acb->task,
> + iscsi_aio_write16_cb,
> + NULL,
> + acb) != 0) {
> + scsi_free_scsi_task(acb->task);
> + qemu_aio_release(acb);
> + return NULL;
> + }
> + scsi_task_set_iov_out(acb->task, (struct scsi_iovec*) acb->qiov->iov,
> acb->qiov->niov);
Are you sure that scsi_task_set_iov_out must be called _after_
submitting the command?
> +#else
> data.data = acb->buf;
> data.size = size;
>
> @@ -274,6 +294,7 @@ iscsi_aio_writev(BlockDriverState *bs, int64_t sector_num,
> qemu_aio_release(acb);
> return NULL;
> }
> +#endif
>
> iscsi_set_events(iscsilun);
>
> @@ -312,7 +333,9 @@ iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
> struct iscsi_context *iscsi = iscsilun->iscsi;
> IscsiAIOCB *acb;
> size_t qemu_read_size;
> +#if !defined(LIBISCSI_FEATURE_IOVECTOR)
> int i;
> +#endif
> uint64_t lba;
> uint32_t num_sectors;
>
> @@ -328,7 +351,9 @@ iscsi_aio_readv(BlockDriverState *bs, int64_t sector_num,
> acb->bh = NULL;
> acb->status = -EINPROGRESS;
> acb->read_size = qemu_read_size;
> +#if !defined(LIBISCSI_FEATURE_IOVECTOR)
> acb->buf = NULL;
> +#endif
>
> /* If LUN blocksize is bigger than BDRV_BLOCK_SIZE a read from QEMU
> * may be misaligned to the LUN, so we may need to read some extra
> @@ -383,11 +408,15 @@ iscsi_aio_readv(BlockDriverState *bs, int64_t
> sector_num,
> return NULL;
> }
>
> +#if defined(LIBISCSI_FEATURE_IOVECTOR)
> + scsi_task_set_iov_in(acb->task, (struct scsi_iovec*) acb->qiov->iov,
> acb->qiov->niov);
> +#else
> for (i = 0; i < acb->qiov->niov; i++) {
> scsi_task_add_data_in_buffer(acb->task,
> acb->qiov->iov[i].iov_len,
> acb->qiov->iov[i].iov_base);
> }
> +#endif
>
> iscsi_set_events(iscsilun);
>
> @@ -557,7 +586,9 @@ static BlockDriverAIOCB *iscsi_aio_ioctl(BlockDriverState
> *bs,
> acb->canceled = 0;
> acb->bh = NULL;
> acb->status = -EINPROGRESS;
> +#if !defined(LIBISCSI_FEATURE_IOVECTOR)
> acb->buf = NULL;
> +#endif
> acb->ioh = buf;
>
> acb->task = malloc(sizeof(struct scsi_task));
>
