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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2008-05-29 11:08:26 +0200 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2008-07-25 12:06:05 +1000 |
| commit | 066f4d82a67f621ddd547bfa4b9c94631d8457b0 (patch) | |
| tree | 96bdeadd9af5b16476186df0ea8056175bc16cbb | |
| parent | e962fa660d391fc9b90988e6538c94c858c099f9 (diff) | |
| download | linux-3.10-066f4d82a67f621ddd547bfa4b9c94631d8457b0.tar.gz linux-3.10-066f4d82a67f621ddd547bfa4b9c94631d8457b0.tar.bz2 linux-3.10-066f4d82a67f621ddd547bfa4b9c94631d8457b0.zip | |
virtio_blk: check for hardsector size from host
Currently virtio_blk assumes a 512 byte hard sector size. This can cause
trouble / performance issues if the backing has a different block size
(like a file on an ext3 file system formatted with 4k block size or a dasd).
Lets add a feature flag that tells the guest to use a different hard sector
size than 512 byte.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| -rw-r--r-- | drivers/block/virtio_blk.c | 10 | ||||
| -rw-r--r-- | include/linux/virtio_blk.h | 3 |
2 files changed, 12 insertions, 1 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index dd7ea203f94..42251095134 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -196,6 +196,7 @@ static int virtblk_probe(struct virtio_device *vdev) int err; u64 cap; u32 v; + u32 blk_size; if (index_to_minor(index) >= 1 << MINORBITS) return -ENOSPC; @@ -290,6 +291,13 @@ static int virtblk_probe(struct virtio_device *vdev) if (!err) blk_queue_max_hw_segments(vblk->disk->queue, v); + /* Host can optionally specify the block size of the device */ + err = virtio_config_val(vdev, VIRTIO_BLK_F_BLK_SIZE, + offsetof(struct virtio_blk_config, blk_size), + &blk_size); + if (!err) + blk_queue_hardsect_size(vblk->disk->queue, blk_size); + add_disk(vblk->disk); return 0; @@ -330,7 +338,7 @@ static struct virtio_device_id id_table[] = { static unsigned int features[] = { VIRTIO_BLK_F_BARRIER, VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, - VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, + VIRTIO_BLK_F_GEOMETRY, VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, }; static struct virtio_driver virtio_blk = { diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h index 6a66c7f30bc..c1aef85243b 100644 --- a/include/linux/virtio_blk.h +++ b/include/linux/virtio_blk.h @@ -13,6 +13,7 @@ #define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */ #define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */ #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */ +#define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/ struct virtio_blk_config { @@ -28,6 +29,8 @@ struct virtio_blk_config __u8 heads; __u8 sectors; } geometry; + /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ + __u32 blk_size; } __attribute__((packed)); /* These two define direction. */ |