aboutsummaryrefslogtreecommitdiff
path: root/drivers/block/virtio_blk.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2008-12-30 17:37:25 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2008-12-30 17:37:25 -0800
commitab70537c32a3245325b48774664da588904e47f2 (patch)
treefdb4447e520bd34dd8696fdd3b976075414d8555 /drivers/block/virtio_blk.c
parent14a3c4ab0e58d143c7928c9eb2f2610205e13bf2 (diff)
parentbda53cd510b6777ced652ba279020bb7b414b744 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: lguest: struct device - replace bus_id with dev_name() lguest: move the initial guest page table creation code to the host kvm-s390: implement config_changed for virtio on s390 virtio_console: support console resizing virtio: add PCI device release() function virtio_blk: fix type warning virtio: block: dynamic maximum segments virtio: set max_segment_size and max_sectors to infinite. virtio: avoid implicit use of Linux page size in balloon interface virtio: hand virtio ring alignment as argument to vring_new_virtqueue virtio: use KVM_S390_VIRTIO_RING_ALIGN instead of relying on pagesize virtio: use LGUEST_VRING_ALIGN instead of relying on pagesize virtio: Don't use PAGE_SIZE for vring alignment in virtio_pci. virtio: rename 'pagesize' arg to vring_init/vring_size virtio: Don't use PAGE_SIZE in virtio_pci.c virtio: struct device - replace bus_id with dev_name(), dev_set_name() virtio-pci queue allocation not page-aligned
Diffstat (limited to 'drivers/block/virtio_blk.c')
-rw-r--r--drivers/block/virtio_blk.c41
1 files changed, 28 insertions, 13 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index f151592ecf7..5d34764c8a8 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -6,7 +6,6 @@
#include <linux/virtio_blk.h>
#include <linux/scatterlist.h>
-#define VIRTIO_MAX_SG (3+MAX_PHYS_SEGMENTS)
#define PART_BITS 4
static int major, index;
@@ -26,8 +25,11 @@ struct virtio_blk
mempool_t *pool;
+ /* What host tells us, plus 2 for header & tailer. */
+ unsigned int sg_elems;
+
/* Scatterlist: can be too big for stack. */
- struct scatterlist sg[VIRTIO_MAX_SG];
+ struct scatterlist sg[/*sg_elems*/];
};
struct virtblk_req
@@ -97,8 +99,6 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
if (blk_barrier_rq(vbr->req))
vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER;
- /* This init could be done at vblk creation time */
- sg_init_table(vblk->sg, VIRTIO_MAX_SG);
sg_set_buf(&vblk->sg[0], &vbr->out_hdr, sizeof(vbr->out_hdr));
num = blk_rq_map_sg(q, vbr->req, vblk->sg+1);
sg_set_buf(&vblk->sg[num+1], &vbr->status, sizeof(vbr->status));
@@ -130,7 +130,7 @@ static void do_virtblk_request(struct request_queue *q)
while ((req = elv_next_request(q)) != NULL) {
vblk = req->rq_disk->private_data;
- BUG_ON(req->nr_phys_segments > ARRAY_SIZE(vblk->sg));
+ BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
/* If this request fails, stop queue and wait for something to
finish to restart it. */
@@ -196,12 +196,22 @@ static int virtblk_probe(struct virtio_device *vdev)
int err;
u64 cap;
u32 v;
- u32 blk_size;
+ u32 blk_size, sg_elems;
if (index_to_minor(index) >= 1 << MINORBITS)
return -ENOSPC;
- vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
+ /* We need to know how many segments before we allocate. */
+ err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
+ offsetof(struct virtio_blk_config, seg_max),
+ &sg_elems);
+ if (err)
+ sg_elems = 1;
+
+ /* We need an extra sg elements at head and tail. */
+ sg_elems += 2;
+ vdev->priv = vblk = kmalloc(sizeof(*vblk) +
+ sizeof(vblk->sg[0]) * sg_elems, GFP_KERNEL);
if (!vblk) {
err = -ENOMEM;
goto out;
@@ -210,6 +220,8 @@ static int virtblk_probe(struct virtio_device *vdev)
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);
/* We expect one virtqueue, for output. */
vblk->vq = vdev->config->find_vq(vdev, 0, blk_done);
@@ -279,6 +291,13 @@ static int virtblk_probe(struct virtio_device *vdev)
}
set_capacity(vblk->disk, cap);
+ /* We can handle whatever the host told us to handle. */
+ blk_queue_max_phys_segments(vblk->disk->queue, vblk->sg_elems-2);
+ blk_queue_max_hw_segments(vblk->disk->queue, vblk->sg_elems-2);
+
+ /* No real sector limit. */
+ blk_queue_max_sectors(vblk->disk->queue, -1U);
+
/* Host can optionally specify maximum segment size and number of
* segments. */
err = virtio_config_val(vdev, VIRTIO_BLK_F_SIZE_MAX,
@@ -286,12 +305,8 @@ static int virtblk_probe(struct virtio_device *vdev)
&v);
if (!err)
blk_queue_max_segment_size(vblk->disk->queue, 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
+ blk_queue_max_segment_size(vblk->disk->queue, -1U);
/* Host can optionally specify the block size of the device */
err = virtio_config_val(vdev, VIRTIO_BLK_F_BLK_SIZE,