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Re: [Qemu-devel] [PATCH v1 3/3] qcow2: check for NULL l2meta
From: |
Hu Tao |
Subject: |
Re: [Qemu-devel] [PATCH v1 3/3] qcow2: check for NULL l2meta |
Date: |
Tue, 21 Jan 2014 14:02:55 +0800 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Tue, Jan 21, 2014 at 11:33:18AM +0800, Hu Tao wrote:
> On Mon, Jan 20, 2014 at 04:17:16PM +0100, Kevin Wolf wrote:
> > Am 20.01.2014 um 04:04 hat Hu Tao geschrieben:
> > > On Sun, Jan 19, 2014 at 05:18:05PM +0100, Max Reitz wrote:
> > > > On 30.12.2013 06:29, Hu Tao wrote:
> > > > >In case of do preallocating metadata with a large cluster size,
> > > > >qcow2_alloc_cluster_offset() can allocate nothing and returns
> > > > >a NULL l2meta. This patch checks for it and link2 l2 with only
> > > > >valid l2meta.
> > > > >
> > > > >Signed-off-by: Hu Tao <address@hidden>
> > > > >---
> > > > > block/qcow2.c | 14 ++++++++------
> > > > > 1 file changed, 8 insertions(+), 6 deletions(-)
> > > > >
> > > > >diff --git a/block/qcow2.c b/block/qcow2.c
> > > > >index 46860d5..380c240 100644
> > > > >--- a/block/qcow2.c
> > > > >+++ b/block/qcow2.c
> > > > >@@ -1399,18 +1399,20 @@ static int preallocate(BlockDriverState *bs)
> > > > > offset = 0;
> > > > > while (nb_sectors) {
> > > > >- num = MIN(nb_sectors, INT_MAX >> 9);
> > > > >+ num = MIN(nb_sectors, INT_MAX >> BDRV_SECTOR_BITS);
> > > >
> > > > Well, if you're already adjusting this here, you could also replace
> > > > the other occurrences of 9 and 512 in this function. ;-)
> > > >
> > > > > ret = qcow2_alloc_cluster_offset(bs, offset, &num,
> > > > > &host_offset, &meta);
> > > > > if (ret < 0) {
> > > > > return ret;
> > > > > }
> > > > >- ret = qcow2_alloc_cluster_link_l2(bs, meta);
> > > > >- if (ret < 0) {
> > > > >- qcow2_free_any_clusters(bs, meta->alloc_offset,
> > > > >meta->nb_clusters,
> > > > >- QCOW2_DISCARD_NEVER);
> > > > >- return ret;
> > > > >+ if (meta) {
> > > > >+ ret = qcow2_alloc_cluster_link_l2(bs, meta);
> > > > >+ if (ret < 0) {
> > > > >+ qcow2_free_any_clusters(bs, meta->alloc_offset,
> > > > >+ meta->nb_clusters,
> > > > >QCOW2_DISCARD_NEVER);
> > > > >+ return ret;
> > > > >+ }
> > > > > }
> > > > > /* There are no dependent requests, but we need to remove
> > > > > our request
> > > >
> > > > But this doesn't make this patch wrong, so:
> > > >
> > > > Reviewed-by: Max Reitz <address@hidden>
> > >
> > > Max,
> > >
> > > Thanks for all of you comments!
> >
> > The series looks good in general, but I think the comments are worth
> > addressing before we merge it. I would also love to see an qemu-iotests
> > case that tests the cases that would previously crash.
Should I add the test case into an existing file or create a new file?