| Message ID | 1389968119-24771-3-git-send-email-kwolf@redhat.com |
|---|---|
| State | New |
| Headers | show |
Le Friday 17 Jan 2014 à 15:14:52 (+0100), Kevin Wolf a écrit : > When there is a format driver between the backend, it's not guaranteed > that exposing the opt_transfer_length for the format driver results in > the optimal requests (because of fragmentation etc.), but it can't make > things worse, so let's just do it. > > Signed-off-by: Kevin Wolf <kwolf@redhat.com> > Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> > Reviewed-by: Max Reitz <mreitz@redhat.com> > --- > block.c | 20 +++++++++++++++++++- > 1 file changed, 19 insertions(+), 1 deletion(-) > > diff --git a/block.c b/block.c > index 99e69da..20f85cb 100644 > --- a/block.c > +++ b/block.c > @@ -485,7 +485,25 @@ static int bdrv_refresh_limits(BlockDriverState *bs) > > memset(&bs->bl, 0, sizeof(bs->bl)); > > - if (drv && drv->bdrv_refresh_limits) { > + if (!drv) { > + return 0; > + } > + > + /* Take some limits from the children as a default */ > + if (bs->file) { > + bdrv_refresh_limits(bs->file); > + bs->bl.opt_transfer_length = bs->file->bl.opt_transfer_length; > + } > + > + if (bs->backing_hd) { > + bdrv_refresh_limits(bs->backing_hd); > + bs->bl.opt_transfer_length = > + MAX(bs->bl.opt_transfer_length, > + bs->backing_hd->bl.opt_transfer_length); > + } > + > + /* Then let the driver override it */ > + if (drv->bdrv_refresh_limits) { > return drv->bdrv_refresh_limits(bs); > } Reviewed-by: Benoît Canet <benoit@irqsave.net> > > -- > 1.8.1.4 > >
diff --git a/block.c b/block.c index 99e69da..20f85cb 100644 --- a/block.c +++ b/block.c @@ -485,7 +485,25 @@ static int bdrv_refresh_limits(BlockDriverState *bs) memset(&bs->bl, 0, sizeof(bs->bl)); - if (drv && drv->bdrv_refresh_limits) { + if (!drv) { + return 0; + } + + /* Take some limits from the children as a default */ + if (bs->file) { + bdrv_refresh_limits(bs->file); + bs->bl.opt_transfer_length = bs->file->bl.opt_transfer_length; + } + + if (bs->backing_hd) { + bdrv_refresh_limits(bs->backing_hd); + bs->bl.opt_transfer_length = + MAX(bs->bl.opt_transfer_length, + bs->backing_hd->bl.opt_transfer_length); + } + + /* Then let the driver override it */ + if (drv->bdrv_refresh_limits) { return drv->bdrv_refresh_limits(bs); }