diff options
Diffstat (limited to 'drivers/block/virtio_blk.c')
| -rw-r--r-- | drivers/block/virtio_blk.c | 112 |
1 files changed, 92 insertions, 20 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 0d39f2f4294..c0bbeb47075 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -21,17 +21,12 @@ struct workqueue_struct *virtblk_wq; struct virtio_blk { - spinlock_t lock; - struct virtio_device *vdev; struct virtqueue *vq; /* The disk structure for the kernel. */ struct gendisk *disk; - /* Request tracking. */ - struct list_head reqs; - mempool_t *pool; /* Process context for config space updates */ @@ -55,7 +50,6 @@ struct virtio_blk struct virtblk_req { - struct list_head list; struct request *req; struct virtio_blk_outhdr out_hdr; struct virtio_scsi_inhdr in_hdr; @@ -69,7 +63,7 @@ static void blk_done(struct virtqueue *vq) unsigned int len; unsigned long flags; - spin_lock_irqsave(&vblk->lock, flags); + spin_lock_irqsave(vblk->disk->queue->queue_lock, flags); while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) { int error; @@ -99,12 +93,11 @@ static void blk_done(struct virtqueue *vq) } __blk_end_request_all(vbr->req, error); - list_del(&vbr->list); mempool_free(vbr, vblk->pool); } /* In case queue is stopped waiting for more buffers. */ blk_start_queue(vblk->disk->queue); - spin_unlock_irqrestore(&vblk->lock, flags); + spin_unlock_irqrestore(vblk->disk->queue->queue_lock, flags); } static bool do_req(struct request_queue *q, struct virtio_blk *vblk, @@ -184,7 +177,6 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk, return false; } - list_add_tail(&vbr->list, &vblk->reqs); return true; } @@ -403,6 +395,83 @@ static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) return 0; } +static int virtblk_get_cache_mode(struct virtio_device *vdev) +{ + u8 writeback; + int err; + + err = virtio_config_val(vdev, VIRTIO_BLK_F_CONFIG_WCE, + offsetof(struct virtio_blk_config, wce), + &writeback); + if (err) + writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE); + + return writeback; +} + +static void virtblk_update_cache_mode(struct virtio_device *vdev) +{ + u8 writeback = virtblk_get_cache_mode(vdev); + struct virtio_blk *vblk = vdev->priv; + + if (writeback) + blk_queue_flush(vblk->disk->queue, REQ_FLUSH); + else + blk_queue_flush(vblk->disk->queue, 0); + + revalidate_disk(vblk->disk); +} + +static const char *const virtblk_cache_types[] = { + "write through", "write back" +}; + +static ssize_t +virtblk_cache_type_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct gendisk *disk = dev_to_disk(dev); + struct virtio_blk *vblk = disk->private_data; + struct virtio_device *vdev = vblk->vdev; + int i; + u8 writeback; + + BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); + for (i = ARRAY_SIZE(virtblk_cache_types); --i >= 0; ) + if (sysfs_streq(buf, virtblk_cache_types[i])) + break; + + if (i < 0) + return -EINVAL; + + writeback = i; + vdev->config->set(vdev, + offsetof(struct virtio_blk_config, wce), + &writeback, sizeof(writeback)); + + virtblk_update_cache_mode(vdev); + return count; +} + +static ssize_t +virtblk_cache_type_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct gendisk *disk = dev_to_disk(dev); + struct virtio_blk *vblk = disk->private_data; + u8 writeback = virtblk_get_cache_mode(vblk->vdev); + + BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); + return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]); +} + +static const struct device_attribute dev_attr_cache_type_ro = + __ATTR(cache_type, S_IRUGO, + virtblk_cache_type_show, NULL); +static const struct device_attribute dev_attr_cache_type_rw = + __ATTR(cache_type, S_IRUGO|S_IWUSR, + virtblk_cache_type_show, virtblk_cache_type_store); + static int __devinit virtblk_probe(struct virtio_device *vdev) { struct virtio_blk *vblk; @@ -437,8 +506,6 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) goto out_free_index; } - INIT_LIST_HEAD(&vblk->reqs); - spin_lock_init(&vblk->lock); vblk->vdev = vdev; vblk->sg_elems = sg_elems; sg_init_table(vblk->sg, vblk->sg_elems); @@ -463,7 +530,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) goto out_mempool; } - q = vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock); + q = vblk->disk->queue = blk_init_queue(do_virtblk_request, NULL); if (!q) { err = -ENOMEM; goto out_put_disk; @@ -481,8 +548,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) vblk->index = index; /* configure queue flush support */ - if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH)) - blk_queue_flush(q, REQ_FLUSH); + virtblk_update_cache_mode(vdev); /* If disk is read-only in the host, the guest should obey */ if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) @@ -560,6 +626,14 @@ static int __devinit virtblk_probe(struct virtio_device *vdev) if (err) goto out_del_disk; + if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) + err = device_create_file(disk_to_dev(vblk->disk), + &dev_attr_cache_type_rw); + else + err = device_create_file(disk_to_dev(vblk->disk), + &dev_attr_cache_type_ro); + if (err) + goto out_del_disk; return 0; out_del_disk: @@ -589,16 +663,14 @@ static void __devexit virtblk_remove(struct virtio_device *vdev) vblk->config_enable = false; mutex_unlock(&vblk->config_lock); - /* Nothing should be pending. */ - BUG_ON(!list_empty(&vblk->reqs)); + del_gendisk(vblk->disk); + blk_cleanup_queue(vblk->disk->queue); /* Stop all the virtqueues. */ vdev->config->reset(vdev); flush_work(&vblk->config_work); - del_gendisk(vblk->disk); - blk_cleanup_queue(vblk->disk->queue); put_disk(vblk->disk); mempool_destroy(vblk->pool); vdev->config->del_vqs(vdev); @@ -654,7 +726,7 @@ static const struct virtio_device_id id_table[] = { static unsigned int features[] = { VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI, - VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY + VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE }; /* |