| Message ID | 4A9F3319.8040509@ds.jp.nec.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Sep 02, 2009 at 11:08:09PM -0400, Munehiro Ikeda wrote: > Hi, > > Vivek Goyal wrote, on 08/28/2009 05:30 PM: > > +static struct io_group *io_find_alloc_group(struct request_queue *q, > > + struct cgroup *cgroup, struct elv_fq_data *efqd, > > + int create) > > +{ > > + struct io_cgroup *iocg = cgroup_to_io_cgroup(cgroup); > > + struct io_group *iog = NULL; > > + /* Note: Use efqd as key */ > > + void *key = efqd; > > + > > + /* > > + * Take a refenrece to css object. Don't want to map a bio to > > + * a group if it has been marked for deletion > > + */ > > + > > + if (!css_tryget(&iocg->css)) > > + return iog; > > cgroup_to_io_cgroup() returns NULL if only blkio subsystem > is mounted but io subsystem is not. It can cause NULL pointer > access. > Good catch Muuhh. Thanks. Applied for next release. Thanks Vivek > Signed-off-by: Munehiro "Muuhh" Ikeda <m-ikeda@ds.jp.nec.com> > --- > block/elevator-fq.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/block/elevator-fq.c b/block/elevator-fq.c > index b723c12..6714e73 100644 > --- a/block/elevator-fq.c > +++ b/block/elevator-fq.c > @@ -1827,7 +1827,7 @@ static struct io_group *io_find_alloc_group(struct request_queue *q, > * a group if it has been marked for deletion > */ > > - if (!css_tryget(&iocg->css)) > + if (!iocg || !css_tryget(&iocg->css)) > return iog; > > iog = io_cgroup_lookup_group(iocg, key); > -- > 1.6.2.5 > > > -- > IKEDA, Munehiro > NEC Corporation of America > m-ikeda@ds.jp.nec.com -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
diff --git a/block/elevator-fq.c b/block/elevator-fq.c index b723c12..6714e73 100644 --- a/block/elevator-fq.c +++ b/block/elevator-fq.c @@ -1827,7 +1827,7 @@ static struct io_group *io_find_alloc_group(struct request_queue *q, * a group if it has been marked for deletion */ - if (!css_tryget(&iocg->css)) + if (!iocg || !css_tryget(&iocg->css)) return iog; iog = io_cgroup_lookup_group(iocg, key);