[Qemu-devel] [PATCH v3 6/7] xen_disk: simplify blk_disconnect with refcnt
We call bdrv_attach_dev when initializing whether or not bs is created locally, so call bdrv_detach_dev and let the refcnt handle the lifecycle. Signed-off-by: Fam Zheng --- hw/block/xen_disk.c | 11 +-- 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c index 99537e8..39757d9 100644 --- a/hw/block/xen_disk.c +++ b/hw/block/xen_disk.c @@ -812,6 +812,9 @@ static int blk_connect(struct XenDevice *xendev) /* setup via qemu cmdline -> already setup for us */ xen_be_printf(&blkdev->xendev, 2, "get configured bdrv (cmdline setup)\n"); blkdev->bs = blkdev->dinfo->bdrv; +/* blkdev->bs is not create by us, we get a reference + * so we can bdrv_unref() unconditionally */ +bdrv_ref(blkdev->bs); } bdrv_attach_dev_nofail(blkdev->bs, blkdev); blkdev->file_size = bdrv_getlength(blkdev->bs); @@ -910,12 +913,8 @@ static void blk_disconnect(struct XenDevice *xendev) struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev); if (blkdev->bs) { -if (!blkdev->dinfo) { -/* close/delete only if we created it ourself */ -bdrv_close(blkdev->bs); -bdrv_detach_dev(blkdev->bs, blkdev); -bdrv_unref(blkdev->bs); -} +bdrv_detach_dev(blkdev->bs, blkdev); +bdrv_unref(blkdev->bs); blkdev->bs = NULL; } xen_be_unbind_evtchn(&blkdev->xendev); -- 1.8.3.4
Re: [Qemu-devel] [PATCH v3 6/7] xen_disk: simplify blk_disconnect with refcnt
Better to split it into two patches: 1 bugfix: always call bdrv_detach_dev(). 2 use refcnt to manage lifecycle. > We call bdrv_attach_dev when initializing whether or not bs is created > locally, so call bdrv_detach_dev and let the refcnt handle the > lifecycle. > > Signed-off-by: Fam Zheng > --- > hw/block/xen_disk.c | 11 +-- > 1 file changed, 5 insertions(+), 6 deletions(-) > > diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c > index 99537e8..39757d9 100644 > --- a/hw/block/xen_disk.c > +++ b/hw/block/xen_disk.c > @@ -812,6 +812,9 @@ static int blk_connect(struct XenDevice *xendev) > /* setup via qemu cmdline -> already setup for us */ > xen_be_printf(&blkdev->xendev, 2, "get configured bdrv (cmdline > setup)\n"); > blkdev->bs = blkdev->dinfo->bdrv; > +/* blkdev->bs is not create by us, we get a reference > + * so we can bdrv_unref() unconditionally */ > +bdrv_ref(blkdev->bs); > } > bdrv_attach_dev_nofail(blkdev->bs, blkdev); > blkdev->file_size = bdrv_getlength(blkdev->bs); > @@ -910,12 +913,8 @@ static void blk_disconnect(struct XenDevice *xendev) > struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, > xendev); > > if (blkdev->bs) { > -if (!blkdev->dinfo) { > -/* close/delete only if we created it ourself */ > -bdrv_close(blkdev->bs); > -bdrv_detach_dev(blkdev->bs, blkdev); > -bdrv_unref(blkdev->bs); > -} > +bdrv_detach_dev(blkdev->bs, blkdev); > +bdrv_unref(blkdev->bs); > blkdev->bs = NULL; > } > xen_be_unbind_evtchn(&blkdev->xendev); > -- Best Regards Wenchao Xia