mirror/freebsd
1
0
Fork 0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-17 10:26:15 +00:00
Code Issues Releases Activity

Only set the barrier flag if the feature was negotiated

Browse Source 
When the VirtIO barrier feature is not negotiated, the driver
must enforce the proper ordering for BIO_ORDERED BIOs. All the
in-flight BIOs must complete before starting the BIO, and the
ordered BIO must complete before subsequent BIOs can start.

Also fix a few whitespace nits.

Reported by:	neel
Approved by:	grehan (mentor)
MFC after:	3 days
This commit is contained in:
Bryan Venteicher 2013-03-05 07:00:05 +00:00
parent facc592d88
commit 4dbc384845
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=247829
1 changed files with 41 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

49
sys/dev/virtio/block/virtio_blk.c
View File

@ -72,6 +72,7 @@ struct vtblk_softc {
#define VTBLK_FLAG_DETACH 0x0004
#define VTBLK_FLAG_SUSPEND 0x0008
#define VTBLK_FLAG_DUMPING 0x0010
#define VTBLK_FLAG_BARRIER 0x0020
struct virtqueue *vtblk_vq;
struct sglist *vtblk_sglist;
@ -81,7 +82,8 @@ struct vtblk_softc {
TAILQ_HEAD(, vtblk_request)
vtblk_req_free;
TAILQ_HEAD(, vtblk_request)
vtblk_req_ready;
vtblk_req_ready;
struct vtblk_request *vtblk_req_ordered;
struct taskqueue *vtblk_tq;
struct task vtblk_intr_task;
@ -278,9 +280,10 @@ vtblk_attach(device_t dev)
if (virtio_with_feature(dev, VIRTIO_RING_F_INDIRECT_DESC))
sc->vtblk_flags |= VTBLK_FLAG_INDIRECT;
if (virtio_with_feature(dev, VIRTIO_BLK_F_RO))
sc->vtblk_flags |= VTBLK_FLAG_READONLY;
if (virtio_with_feature(dev, VIRTIO_BLK_F_BARRIER))
sc->vtblk_flags |= VTBLK_FLAG_BARRIER;
/* Get local copy of config. */
virtio_read_device_config(dev, 0, &blkcfg,
@ -766,25 +769,45 @@ vtblk_bio_request(struct vtblk_softc *sc)
bp->bio_cmd);
}
if (bp->bio_flags & BIO_ORDERED)
req->vbr_hdr.type |= VIRTIO_BLK_T_BARRIER;
return (req);
}
static int
vtblk_execute_request(struct vtblk_softc *sc, struct vtblk_request *req)
{
struct virtqueue *vq;
struct sglist *sg;
struct bio *bp;
int readable, writable, error;
int ordered, readable, writable, error;
vq = sc->vtblk_vq;
sg = sc->vtblk_sglist;
bp = req->vbr_bp;
ordered = 0;
writable = 0;
VTBLK_LOCK_ASSERT(sc);
/*
* Wait until the ordered request completes before
* executing subsequent requests.
*/
if (sc->vtblk_req_ordered != NULL)
return (EBUSY);
if (bp->bio_flags & BIO_ORDERED) {
if ((sc->vtblk_flags & VTBLK_FLAG_BARRIER) == 0) {
/*
* This request will be executed once all
* the in-flight requests are completed.
*/
if (!virtqueue_empty(vq))
return (EBUSY);
ordered = 1;
} else
req->vbr_hdr.type |= VIRTIO_BLK_T_BARRIER;
}
sglist_reset(sg);
sglist_append(sg, &req->vbr_hdr, sizeof(struct virtio_blk_outhdr));
@ -802,10 +825,13 @@ vtblk_execute_request(struct vtblk_softc *sc, struct vtblk_request *req)
writable++;
sglist_append(sg, &req->vbr_ack, sizeof(uint8_t));
readable = sg->sg_nseg - writable;
return (virtqueue_enqueue(sc->vtblk_vq, req, sg, readable, writable));
error = virtqueue_enqueue(vq, req, sg, readable, writable);
if (error == 0 && ordered)
sc->vtblk_req_ordered = req;
return (error);
}
static int
@ -1013,6 +1039,12 @@ vtblk_finish_completed(struct vtblk_softc *sc)
while ((req = virtqueue_dequeue(sc->vtblk_vq, NULL)) != NULL) {
bp = req->vbr_bp;
if (sc->vtblk_req_ordered != NULL) {
/* This should be the only outstanding request. */
MPASS(sc->vtblk_req_ordered == req);
sc->vtblk_req_ordered = NULL;
}
error = vtblk_request_error(req);
if (error)
disk_err(bp, "hard error", -1, 1);
@ -1039,6 +1071,7 @@ vtblk_drain_vq(struct vtblk_softc *sc, int skip_done)
vtblk_enqueue_request(sc, req);
}
sc->vtblk_req_ordered = NULL;
KASSERT(virtqueue_empty(vq), ("virtqueue not empty"));
}