diff options
Diffstat (limited to 'drivers/block/virtio_blk.c')
-rw-r--r-- | drivers/block/virtio_blk.c | 106 |
1 files changed, 65 insertions, 41 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 924ddd8..3b1a68d 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -7,8 +7,10 @@ #include <linux/scatterlist.h> #define VIRTIO_MAX_SG (3+MAX_PHYS_SEGMENTS) +#define PART_BITS 4 + +static int major, index; -static unsigned char virtblk_index = 'a'; struct virtio_blk { spinlock_t lock; @@ -36,7 +38,7 @@ struct virtblk_req struct virtio_blk_inhdr in_hdr; }; -static bool blk_done(struct virtqueue *vq) +static void blk_done(struct virtqueue *vq) { struct virtio_blk *vblk = vq->vdev->priv; struct virtblk_req *vbr; @@ -65,7 +67,6 @@ static bool blk_done(struct virtqueue *vq) /* In case queue is stopped waiting for more buffers. */ blk_start_queue(vblk->disk->queue); spin_unlock_irqrestore(&vblk->lock, flags); - return true; } static bool do_req(struct request_queue *q, struct virtio_blk *vblk, @@ -153,20 +154,37 @@ static int virtblk_ioctl(struct inode *inode, struct file *filp, (void __user *)data); } +/* We provide getgeo only to please some old bootloader/partitioning tools */ +static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) +{ + /* some standard values, similar to sd */ + geo->heads = 1 << 6; + geo->sectors = 1 << 5; + geo->cylinders = get_capacity(bd->bd_disk) >> 11; + return 0; +} + static struct block_device_operations virtblk_fops = { - .ioctl = virtblk_ioctl, - .owner = THIS_MODULE, + .ioctl = virtblk_ioctl, + .owner = THIS_MODULE, + .getgeo = virtblk_getgeo, }; +static int index_to_minor(int index) +{ + return index << PART_BITS; +} + static int virtblk_probe(struct virtio_device *vdev) { struct virtio_blk *vblk; - int err, major; - void *token; - unsigned int len; + int err; u64 cap; u32 v; + if (index_to_minor(index) >= 1 << MINORBITS) + return -ENOSPC; + vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); if (!vblk) { err = -ENOMEM; @@ -178,7 +196,7 @@ static int virtblk_probe(struct virtio_device *vdev) vblk->vdev = vdev; /* We expect one virtqueue, for output. */ - vblk->vq = vdev->config->find_vq(vdev, blk_done); + vblk->vq = vdev->config->find_vq(vdev, 0, blk_done); if (IS_ERR(vblk->vq)) { err = PTR_ERR(vblk->vq); goto out_free_vblk; @@ -190,17 +208,11 @@ static int virtblk_probe(struct virtio_device *vdev) goto out_free_vq; } - major = register_blkdev(0, "virtblk"); - if (major < 0) { - err = major; - goto out_mempool; - } - /* FIXME: How many partitions? How long is a piece of string? */ - vblk->disk = alloc_disk(1 << 4); + vblk->disk = alloc_disk(1 << PART_BITS); if (!vblk->disk) { err = -ENOMEM; - goto out_unregister_blkdev; + goto out_mempool; } vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock); @@ -209,22 +221,32 @@ static int virtblk_probe(struct virtio_device *vdev) goto out_put_disk; } - sprintf(vblk->disk->disk_name, "vd%c", virtblk_index++); + if (index < 26) { + sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26); + } else if (index < (26 + 1) * 26) { + sprintf(vblk->disk->disk_name, "vd%c%c", + 'a' + index / 26 - 1, 'a' + index % 26); + } else { + const unsigned int m1 = (index / 26 - 1) / 26 - 1; + const unsigned int m2 = (index / 26 - 1) % 26; + const unsigned int m3 = index % 26; + sprintf(vblk->disk->disk_name, "vd%c%c%c", + 'a' + m1, 'a' + m2, 'a' + m3); + } + vblk->disk->major = major; - vblk->disk->first_minor = 0; + vblk->disk->first_minor = index_to_minor(index); vblk->disk->private_data = vblk; vblk->disk->fops = &virtblk_fops; + index++; /* If barriers are supported, tell block layer that queue is ordered */ - token = vdev->config->find(vdev, VIRTIO_CONFIG_BLK_F, &len); - if (virtio_use_bit(vdev, token, len, VIRTIO_BLK_F_BARRIER)) + if (vdev->config->feature(vdev, VIRTIO_BLK_F_BARRIER)) blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_TAG, NULL); - err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_CAPACITY, &cap); - if (err) { - dev_err(&vdev->dev, "Bad/missing capacity in config\n"); - goto out_cleanup_queue; - } + /* Host must always specify the capacity. */ + __virtio_config_val(vdev, offsetof(struct virtio_blk_config, capacity), + &cap); /* If capacity is too big, truncate with warning. */ if ((sector_t)cap != cap) { @@ -234,31 +256,25 @@ static int virtblk_probe(struct virtio_device *vdev) } set_capacity(vblk->disk, cap); - err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_SIZE_MAX, &v); + /* Host can optionally specify maximum segment size and number of + * segments. */ + err = virtio_config_val(vdev, VIRTIO_BLK_F_SIZE_MAX, + offsetof(struct virtio_blk_config, size_max), + &v); if (!err) blk_queue_max_segment_size(vblk->disk->queue, v); - else if (err != -ENOENT) { - dev_err(&vdev->dev, "Bad SIZE_MAX in config\n"); - goto out_cleanup_queue; - } - err = virtio_config_val(vdev, VIRTIO_CONFIG_BLK_F_SEG_MAX, &v); + err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX, + offsetof(struct virtio_blk_config, seg_max), + &v); if (!err) blk_queue_max_hw_segments(vblk->disk->queue, v); - else if (err != -ENOENT) { - dev_err(&vdev->dev, "Bad SEG_MAX in config\n"); - goto out_cleanup_queue; - } add_disk(vblk->disk); return 0; -out_cleanup_queue: - blk_cleanup_queue(vblk->disk->queue); out_put_disk: put_disk(vblk->disk); -out_unregister_blkdev: - unregister_blkdev(major, "virtblk"); out_mempool: mempool_destroy(vblk->pool); out_free_vq: @@ -274,12 +290,16 @@ static void virtblk_remove(struct virtio_device *vdev) struct virtio_blk *vblk = vdev->priv; int major = vblk->disk->major; + /* Nothing should be pending. */ BUG_ON(!list_empty(&vblk->reqs)); + + /* Stop all the virtqueues. */ + vdev->config->reset(vdev); + blk_cleanup_queue(vblk->disk->queue); put_disk(vblk->disk); unregister_blkdev(major, "virtblk"); mempool_destroy(vblk->pool); - /* There should be nothing in the queue now, so no need to shutdown */ vdev->config->del_vq(vblk->vq); kfree(vblk); } @@ -299,11 +319,15 @@ static struct virtio_driver virtio_blk = { static int __init init(void) { + major = register_blkdev(0, "virtblk"); + if (major < 0) + return major; return register_virtio_driver(&virtio_blk); } static void __exit fini(void) { + unregister_blkdev(major, "virtblk"); unregister_virtio_driver(&virtio_blk); } module_init(init); |