From: Tejun Heo <tj@xxxxxxxxxx>
Remove now unused REQ_HARDBARRIER support and implement REQ_FLUSH/FUA
support instead. A new feature flag VIRTIO_BLK_F_FUA is added to
indicate the support for FUA.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
drivers/block/virtio_blk.c | 26 ++++++++++++--------------
include/linux/virtio_blk.h | 6 +++++-
2 files changed, 17 insertions(+), 15 deletions(-)
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index d10b635..ed0fb7d 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -128,9 +128,6 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
}
}
- 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));
/*
@@ -157,6 +154,8 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
if (rq_data_dir(vbr->req) == WRITE) {
vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
out += num;
+ if (req->cmd_flags & REQ_FUA)
+ vbr->out_hdr.type |= VIRTIO_BLK_T_FUA;
} else {
vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
in += num;
@@ -307,6 +306,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
{
struct virtio_blk *vblk;
struct request_queue *q;
+ unsigned int flush;
int err;
u64 cap;
u32 v, blk_size, sg_elems, opt_io_size;
@@ -388,15 +388,13 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
vblk->disk->driverfs_dev = &vdev->dev;
index++;
- /*
- * 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; otherwise, we must assume
- * that the host does not perform any kind of volatile write
- * caching.
- */
+ /* configure queue flush support */
+ flush = 0;
if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
- blk_queue_flush(q, REQ_FLUSH);
+ flush |= REQ_FLUSH;
+ if (virtio_has_feature(vdev, VIRTIO_BLK_F_FUA))
+ flush |= REQ_FUA;
+ blk_queue_flush(q, flush);
/* If disk is read-only in the host, the guest should obey */
if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
@@ -515,9 +513,9 @@ static const 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_BLK_SIZE,
- VIRTIO_BLK_F_SCSI, VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY
+ VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
+ VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
+ VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_FUA,
};
/*
diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h
index 167720d..f453f3c 100644
--- a/include/linux/virtio_blk.h
+++ b/include/linux/virtio_blk.h
@@ -16,6 +16,7 @@
#define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */
#define VIRTIO_BLK_F_FLUSH 9 /* Cache flush command support */
#define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */
+#define VIRTIO_BLK_F_FUA 11 /* Forced Unit Access write support */
#define VIRTIO_BLK_ID_BYTES 20 /* ID string length */
@@ -70,7 +71,10 @@ struct virtio_blk_config {
#define VIRTIO_BLK_T_FLUSH 4
/* Get device ID command */
-#define VIRTIO_BLK_T_GET_ID 8
+#define VIRTIO_BLK_T_GET_ID 8
+
+/* FUA command */
+#define VIRTIO_BLK_T_FUA 16
/* Barrier before this op. */
#define VIRTIO_BLK_T_BARRIER 0x80000000
--
1.7.1
--
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