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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.c150
1 files changed, 99 insertions, 51 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 258bc2ae2885..2aafafca2b13 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -2,6 +2,7 @@
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
+#include <linux/smp_lock.h>
#include <linux/hdreg.h>
#include <linux/virtio.h>
#include <linux/virtio_blk.h>
@@ -65,13 +66,18 @@ static void blk_done(struct virtqueue *vq)
break;
}
- if (blk_pc_request(vbr->req)) {
+ switch (vbr->req->cmd_type) {
+ case REQ_TYPE_BLOCK_PC:
vbr->req->resid_len = vbr->in_hdr.residual;
vbr->req->sense_len = vbr->in_hdr.sense_len;
vbr->req->errors = vbr->in_hdr.errors;
- }
- if (blk_special_request(vbr->req))
+ break;
+ case REQ_TYPE_SPECIAL:
vbr->req->errors = (error != 0);
+ break;
+ default:
+ break;
+ }
__blk_end_request_all(vbr->req, error);
list_del(&vbr->list);
@@ -94,36 +100,35 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
return false;
vbr->req = req;
- switch (req->cmd_type) {
- case REQ_TYPE_FS:
- vbr->out_hdr.type = 0;
- vbr->out_hdr.sector = blk_rq_pos(vbr->req);
- vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
- break;
- case REQ_TYPE_BLOCK_PC:
- vbr->out_hdr.type = VIRTIO_BLK_T_SCSI_CMD;
- vbr->out_hdr.sector = 0;
- vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
- break;
- case REQ_TYPE_SPECIAL:
- vbr->out_hdr.type = VIRTIO_BLK_T_GET_ID;
+
+ if (req->cmd_flags & REQ_FLUSH) {
+ vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH;
vbr->out_hdr.sector = 0;
vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
- break;
- case REQ_TYPE_LINUX_BLOCK:
- if (req->cmd[0] == REQ_LB_OP_FLUSH) {
- vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH;
+ } else {
+ switch (req->cmd_type) {
+ case REQ_TYPE_FS:
+ vbr->out_hdr.type = 0;
+ vbr->out_hdr.sector = blk_rq_pos(vbr->req);
+ vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
+ break;
+ case REQ_TYPE_BLOCK_PC:
+ vbr->out_hdr.type = VIRTIO_BLK_T_SCSI_CMD;
+ vbr->out_hdr.sector = 0;
+ vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
+ break;
+ case REQ_TYPE_SPECIAL:
+ vbr->out_hdr.type = VIRTIO_BLK_T_GET_ID;
vbr->out_hdr.sector = 0;
vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
break;
+ default:
+ /* We don't put anything else in the queue. */
+ BUG();
}
- /*FALLTHRU*/
- default:
- /* We don't put anything else in the queue. */
- BUG();
}
- if (blk_barrier_rq(vbr->req))
+ if (vbr->req->cmd_flags & REQ_HARDBARRIER)
vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER;
sg_set_buf(&vblk->sg[out++], &vbr->out_hdr, sizeof(vbr->out_hdr));
@@ -134,12 +139,12 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
* block, and before the normal inhdr we put the sense data and the
* inhdr with additional status information before the normal inhdr.
*/
- if (blk_pc_request(vbr->req))
+ if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC)
sg_set_buf(&vblk->sg[out++], vbr->req->cmd, vbr->req->cmd_len);
num = blk_rq_map_sg(q, vbr->req, vblk->sg + out);
- if (blk_pc_request(vbr->req)) {
+ if (vbr->req->cmd_type == REQ_TYPE_BLOCK_PC) {
sg_set_buf(&vblk->sg[num + out + in++], vbr->req->sense, 96);
sg_set_buf(&vblk->sg[num + out + in++], &vbr->in_hdr,
sizeof(vbr->in_hdr));
@@ -190,12 +195,6 @@ static void do_virtblk_request(struct request_queue *q)
virtqueue_kick(vblk->vq);
}
-static void virtblk_prepare_flush(struct request_queue *q, struct request *req)
-{
- req->cmd_type = REQ_TYPE_LINUX_BLOCK;
- req->cmd[0] = REQ_LB_OP_FLUSH;
-}
-
/* return id (s/n) string for *disk to *id_str
*/
static int virtblk_get_id(struct gendisk *disk, char *id_str)
@@ -219,22 +218,12 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str)
return blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
}
-static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
+static int virtblk_locked_ioctl(struct block_device *bdev, fmode_t mode,
unsigned cmd, unsigned long data)
{
struct gendisk *disk = bdev->bd_disk;
struct virtio_blk *vblk = disk->private_data;
- if (cmd == 0x56424944) { /* 'VBID' */
- void __user *usr_data = (void __user *)data;
- char id_str[VIRTIO_BLK_ID_BYTES];
- int err;
-
- err = virtblk_get_id(disk, id_str);
- if (!err && copy_to_user(usr_data, id_str, VIRTIO_BLK_ID_BYTES))
- err = -EFAULT;
- return err;
- }
/*
* Only allow the generic SCSI ioctls if the host can support it.
*/
@@ -245,6 +234,18 @@ static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
(void __user *)data);
}
+static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
+ unsigned int cmd, unsigned long param)
+{
+ int ret;
+
+ lock_kernel();
+ ret = virtblk_locked_ioctl(bdev, mode, cmd, param);
+ unlock_kernel();
+
+ return ret;
+}
+
/* We provide getgeo only to please some old bootloader/partitioning tools */
static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
{
@@ -271,7 +272,7 @@ static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
}
static const struct block_device_operations virtblk_fops = {
- .locked_ioctl = virtblk_ioctl,
+ .ioctl = virtblk_ioctl,
.owner = THIS_MODULE,
.getgeo = virtblk_getgeo,
};
@@ -281,6 +282,27 @@ static int index_to_minor(int index)
return index << PART_BITS;
}
+static ssize_t virtblk_serial_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+ int err;
+
+ /* sysfs gives us a PAGE_SIZE buffer */
+ BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
+
+ buf[VIRTIO_BLK_ID_BYTES] = '\0';
+ err = virtblk_get_id(disk, buf);
+ if (!err)
+ return strlen(buf);
+
+ if (err == -EIO) /* Unsupported? Make it empty. */
+ return 0;
+
+ return err;
+}
+DEVICE_ATTR(serial, S_IRUGO, virtblk_serial_show, NULL);
+
static int __devinit virtblk_probe(struct virtio_device *vdev)
{
struct virtio_blk *vblk;
@@ -366,12 +388,31 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
vblk->disk->driverfs_dev = &vdev->dev;
index++;
- /* If barriers are supported, tell block layer that queue is ordered */
- if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
- blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH,
- virtblk_prepare_flush);
- else if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER))
- blk_queue_ordered(q, QUEUE_ORDERED_TAG, NULL);
+ if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH)) {
+ /*
+ * If the FLUSH feature is supported we do have support for
+ * flushing a volatile write cache on the host. Use that
+ * to implement write barrier support.
+ */
+ blk_queue_ordered(q, QUEUE_ORDERED_DRAIN_FLUSH);
+ } else if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER)) {
+ /*
+ * If the BARRIER feature is supported the host expects us
+ * to order request by tags. This implies there is not
+ * volatile write cache on the host, and that the host
+ * never re-orders outstanding I/O. This feature is not
+ * useful for real life scenarious and deprecated.
+ */
+ blk_queue_ordered(q, QUEUE_ORDERED_TAG);
+ } else {
+ /*
+ * If the FLUSH feature is not supported we must assume that
+ * the host does not perform any kind of volatile write
+ * caching. We still need to drain the queue to provider
+ * proper barrier semantics.
+ */
+ blk_queue_ordered(q, QUEUE_ORDERED_DRAIN);
+ }
/* If disk is read-only in the host, the guest should obey */
if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
@@ -445,8 +486,15 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
add_disk(vblk->disk);
+ err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
+ if (err)
+ goto out_del_disk;
+
return 0;
+out_del_disk:
+ del_gendisk(vblk->disk);
+ blk_cleanup_queue(vblk->disk->queue);
out_put_disk:
put_disk(vblk->disk);
out_mempool:
generated by cgit v1.2.3 (git 2.0.4) at 2024-06-14 19:36:58 +0000