On Wed, Mar 30, 2016 at 9:53 PM, Luis de Bethencourt <lui...@osg.samsung.com> wrote: > Since mixed block groups accounting isn't byte-accurate and f_bree is an > unsigned integer, it could overflow. Avoid this. > > Signed-off-by: Luis de Bethencourt <lui...@osg.samsung.com> > Suggested-by: David Sterba <dste...@suse.com> > --- > fs/btrfs/super.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c > index bdca79c..93376d0 100644 > --- a/fs/btrfs/super.c > +++ b/fs/btrfs/super.c > @@ -2101,6 +2101,11 @@ static int btrfs_statfs(struct dentry *dentry, struct > kstatfs *buf) > /* Account global block reserve as used, it's in logical size already > */ > spin_lock(&block_rsv->lock); > buf->f_bfree -= block_rsv->size >> bits;
You forgot to remove the line above, didn't you? > + /* Mixed block groups accounting is not byte-accurate, avoid overflow > */ > + if (buf->f_bfree >= block_rsv->size >> bits) > + buf->f_bfree -= block_rsv->size >> bits; > + else > + buf->f_bfree = 0; > spin_unlock(&block_rsv->lock); > > buf->f_bavail = div_u64(total_free_data, factor); > -- > 2.5.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Filipe David Manana, "Reasonable men adapt themselves to the world. Unreasonable men adapt the world to themselves. That's why all progress depends on unreasonable men."
