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[Qemu-devel] [PATCH] qemu and qemu-xen: support empty write barriers in
From: |
Stefano Stabellini |
Subject: |
[Qemu-devel] [PATCH] qemu and qemu-xen: support empty write barriers in xen_disk |
Date: |
Wed, 24 Nov 2010 13:08:03 +0000 |
User-agent: |
Alpine 2.00 (DEB 1167 2008-08-23) |
Hi all,
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 <address@hidden>
diff --git a/hw/xen_disk.c b/hw/xen_disk.c
index 38b5fbf..94af001 100644
--- a/hw/xen_disk.c
+++ b/hw/xen_disk.c
@@ -182,6 +182,10 @@ 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 */
@@ -306,7 +310,7 @@ 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);
@@ -330,6 +334,8 @@ 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,
@@ -387,7 +393,7 @@ 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++;
@@ -404,6 +410,8 @@ 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);
- [Qemu-devel] [PATCH] qemu and qemu-xen: support empty write barriers in xen_disk,
Stefano Stabellini <=
- Re: [Qemu-devel] [PATCH] qemu and qemu-xen: support empty write barriers in xen_disk, Gerd Hoffmann, 2010/11/24
- Re: [Qemu-devel] [PATCH] qemu and qemu-xen: support empty write barriers in xen_disk, Christoph Hellwig, 2010/11/24
- Re: [Xen-devel] Re: [Qemu-devel] [PATCH] qemu and qemu-xen: support empty write barriers in xen_disk, Jeremy Fitzhardinge, 2010/11/24
- Re: [Xen-devel] Re: [Qemu-devel] [PATCH] qemu and qemu-xen: support empty write barriers in xen_disk, Christoph Hellwig, 2010/11/24
- Re: [Xen-devel] Re: [Qemu-devel] [PATCH] qemu and qemu-xen: support empty write barriers in xen_disk, Stefano Stabellini, 2010/11/24
- Re: [Xen-devel] Re: [Qemu-devel] [PATCH] qemu and qemu-xen: support empty write barriers in xen_disk, Kevin Wolf, 2010/11/26
- Re: [Xen-devel] Re: [Qemu-devel] [PATCH] qemu and qemu-xen: support empty write barriers in xen_disk, Christoph Hellwig, 2010/11/26
- Re: [Xen-devel] Re: [Qemu-devel] [PATCH] qemu and qemu-xen: support empty write barriers in xen_disk, Stefano Stabellini, 2010/11/26