diff options
| author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2010-11-24 13:08:03 +0000 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2010-11-24 17:31:06 +0100 |
| commit | 5cbdebe39e08caf5a373ef1c03a0292d5af955ce (patch) | |
| tree | 457ca9726bc8756c6808e876b012d34db1228432 /hw/xen_disk.c | |
| parent | 9fbef1ac7cc888f29435e9f636b5dd14cd3260df (diff) | |
qemu and qemu-xen: support empty write barriers in xen_disk
This patch can be applied to both qemu-xen and qemu and adds support
for empty write barriers to xen_disk.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'hw/xen_disk.c')
| -rw-r--r-- | hw/xen_disk.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/hw/xen_disk.c b/hw/xen_disk.c index 134ac3388e..85a1c85524 100644 --- a/hw/xen_disk.c +++ b/hw/xen_disk.c @@ -181,6 +181,10 @@ static int ioreq_parse(struct ioreq *ioreq) ioreq->prot = PROT_WRITE; /* to memory */ break; case BLKIF_OP_WRITE_BARRIER: + if (!ioreq->req.nr_segments) { + ioreq->presync = 1; + return 0; + } if (!syncwrite) ioreq->presync = ioreq->postsync = 1; /* fall through */ @@ -305,7 +309,7 @@ static int ioreq_runio_qemu_sync(struct ioreq *ioreq) int i, rc, len = 0; off_t pos; - if (ioreq_map(ioreq) == -1) + if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) goto err; if (ioreq->presync) bdrv_flush(blkdev->bs); @@ -329,6 +333,8 @@ static int ioreq_runio_qemu_sync(struct ioreq *ioreq) break; case BLKIF_OP_WRITE: case BLKIF_OP_WRITE_BARRIER: + if (!ioreq->req.nr_segments) + break; pos = ioreq->start; for (i = 0; i < ioreq->v.niov; i++) { rc = bdrv_write(blkdev->bs, pos / BLOCK_SIZE, @@ -386,7 +392,7 @@ static int ioreq_runio_qemu_aio(struct ioreq *ioreq) { struct XenBlkDev *blkdev = ioreq->blkdev; - if (ioreq_map(ioreq) == -1) + if (ioreq->req.nr_segments && ioreq_map(ioreq) == -1) goto err; ioreq->aio_inflight++; @@ -403,6 +409,8 @@ static int ioreq_runio_qemu_aio(struct ioreq *ioreq) case BLKIF_OP_WRITE: case BLKIF_OP_WRITE_BARRIER: ioreq->aio_inflight++; + if (!ioreq->req.nr_segments) + break; bdrv_aio_writev(blkdev->bs, ioreq->start / BLOCK_SIZE, &ioreq->v, ioreq->v.size / BLOCK_SIZE, qemu_aio_complete, ioreq); |