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path: root/drivers/block/virtio_blk.c
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Diffstat (limited to 'drivers/block/virtio_blk.c')
-rw-r--r--drivers/block/virtio_blk.c106
1 files changed, 65 insertions, 41 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 924ddd8bccd2..3b1a68d6eddb 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);