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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2008-05-16 11:17:03 +0200 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2008-05-30 15:09:44 +1000 |
| commit | 3ef536095446552823fc488fec1c5451aab1260d (patch) | |
| tree | 9d525f24f2bd07ce1b82f8b60673062e05c41c2e | |
| parent | a16ffe93c46dfca211434d00453ebb695025978b (diff) | |
| download | linux-3ef536095446552823fc488fec1c5451aab1260d.tar.gz linux-3ef536095446552823fc488fec1c5451aab1260d.tar.bz2 linux-3ef536095446552823fc488fec1c5451aab1260d.zip | |
virtio_blk: allow read-only disks
Hello Rusty,
sometimes it is useful to share a disk (e.g. usr). To avoid file system
corruption, the disk should be mounted read-only in that case. This patch
adds a new feature flag, that allows the host to specify, if the disk should
be considered read-only.
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 | 6 | ||||
| -rw-r--r-- | include/linux/virtio_blk.h | 1 |
2 files changed, 6 insertions, 1 deletions
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index c4804f3465db..dd7ea203f940 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -260,6 +260,10 @@ static int virtblk_probe(struct virtio_device *vdev) if (virtio_has_feature(vdev, VIRTIO_BLK_F_BARRIER)) blk_queue_ordered(vblk->disk->queue, QUEUE_ORDERED_TAG, NULL); + /* If disk is read-only in the host, the guest should obey */ + if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) + set_disk_ro(vblk->disk, 1); + /* Host must always specify the capacity. */ vdev->config->get(vdev, offsetof(struct virtio_blk_config, capacity), &cap, sizeof(cap)); @@ -326,7 +330,7 @@ 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_GEOMETRY, VIRTIO_BLK_F_RO, }; static struct virtio_driver virtio_blk = { diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h index d4695a3356d0..b80919fad0ef 100644 --- a/include/linux/virtio_blk.h +++ b/include/linux/virtio_blk.h @@ -10,6 +10,7 @@ #define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */ #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 */ struct virtio_blk_config { |