On Friday 25 May 2007, [EMAIL PROTECTED] wrote:
> +static void ps3disk_scatter_gather(struct ps3_storage_device *dev,
> + struct request *req, int gather)
> +{
> + unsigned int sectors = 0, offset = 0;
> + struct bio *bio;
> + sector_t sector;
> + struct bio_vec *bvec;
> + unsigned int i = 0, j;
> + size_t size;
> + void *buf;
> +
> + rq_for_each_bio(bio, req) {
> + sector = bio->bi_sector;
> + dev_dbg(&dev->sbd.core,
> + "%s:%u: bio %u: %u segs %u sectors from %lu\n",
> + __func__, __LINE__, i, bio_segments(bio),
> + bio_sectors(bio), sector);
> + bio_for_each_segment(bvec, bio, j) {
> + size = bio_cur_sectors(bio)*KERNEL_SECTOR_SIZE;
> + buf = __bio_kmap_atomic(bio, j, KM_USER0);
> + if (gather)
> + memcpy(dev->bounce_buf+offset, buf, size);
> + else
> + memcpy(buf, dev->bounce_buf+offset, size);
> + offset += size;
> + __bio_kunmap_atomic(bio, KM_USER0);
> + }
> + sectors += bio_sectors(bio);
> + i++;
> + }
> +}
So the hypervison uses guest-real addresses here? I would have expected
it to use the kernel page tables, which lets you use vmap() to do
scatter-gather.
> +static int ps3disk_thread(void *data)
> +{
> + struct ps3_storage_device *dev = data;
> + struct ps3disk_private *priv = ps3disk_priv(dev);
> + request_queue_t *q = priv->queue;
> + struct request *req;
> +
> + dev_dbg(&dev->sbd.core, "%s thread init\n", __func__);
> +
> + current->flags |= PF_NOFREEZE;
> +
> + while (!kthread_should_stop()) {
> + spin_lock_irq(&priv->lock);
> + set_current_state(TASK_INTERRUPTIBLE);
> + req = elv_next_request(q);
> + if (!req) {
> + spin_unlock_irq(&priv->lock);
> + schedule();
> + continue;
> + }
> + if (!blk_fs_request(req)) {
> + blk_dump_rq_flags(req, DEVICE_NAME " bad request");
> + end_request(req, 0);
> + spin_unlock_irq(&priv->lock);
> + continue;
> + }
> + spin_unlock_irq(&priv->lock);
> + ps3disk_handle_request_sg(dev, req);
> + }
> +
> + dev_dbg(&dev->sbd.core, "%s thread exit\n", __func__);
> + return 0;
> +}
I don't really understand what the kthread is needed for. You probably
thought about multiple options and ended up with this, but having
a comment in front of it might be helpful.
Arnd <><
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