On Mon, 4 Jun 2012 13:36:11 +0800 majianpeng <majianpeng@xxxxxxxxx> wrote:
> On Sun, 3 Jun 2012 20:49:05 -0700,neil wrote:
> >On Thu, 31 May 2012 15:41:22 +0800 "majianpeng" <majianpeng@xxxxxxxxx> wrote:
> >
> >> When raid takeovered, it used old personality to set task->comm.
> >>
> >> Signed-off-by: majianpeng <majianpeng@xxxxxxxxx>
> >> ---
> >> drivers/md/md.c | 15 +++++++++++++++
> >> 1 files changed, 15 insertions(+), 0 deletions(-)
> >>
> >> diff --git a/drivers/md/md.c b/drivers/md/md.c
> >> index 1c2f904..93e20ea 100644
> >> --- a/drivers/md/md.c
> >> +++ b/drivers/md/md.c
> >> @@ -32,6 +32,7 @@
> >> Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
> >> */
> >>
> >> +#include <linux/sched.h>
> >> #include <linux/kthread.h>
> >> #include <linux/blkdev.h>
> >> #include <linux/sysctl.h>
> >> @@ -3513,6 +3514,7 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
> >> long level;
> >> void *priv;
> >> struct md_rdev *rdev;
> >> + char *tmp;
> >>
> >> if (mddev->pers == NULL) {
> >> if (len == 0)
> >> @@ -3674,6 +3676,19 @@ level_store(struct mddev *mddev, const char *buf, size_t len)
> >> del_timer_sync(&mddev->safemode_timer);
> >> }
> >> pers->run(mddev);
> >> + /*
> >> + * when raid takeover using old personality,so mddev->thread->tsk
> >> + * name is wrong.
> >> + * if kzalloc error, only using wrong name.
> >> + */
> >> + len = strlen(mdname(mddev)) + strlen(mddev->pers->name);
> >> + tmp = kzalloc(len + 2, GFP_KERNEL);
> >> + if (tmp) {
> >> + sprintf(tmp, "%s_%s", mdname(mddev), mddev->pers->name);
> >> + set_task_comm(mddev->thread->tsk, tmp);
> >> + kfree(tmp);
> >> + }
> >> +
> >> set_bit(MD_CHANGE_DEVS, &mddev->flags);
> >> mddev_resume(mddev);
> >> sysfs_notify(&mddev->kobj, NULL, "level");
> >
> >Thanks. However:
> >
> > 1/ as a task name is limited to TASK_COMM_LEN, there is little point using
> > kzalloc. Just declare a local variable of that size.
> > 2/ No all levels have a thread. You should check that mddev->thread is not
> > NULL.
> >
> >If you resubmit with those fixes I'll apply the patch.
> >
> >Thanks,
> >NeilBrown
> >
> >
> Neil, There maybe had anthor issue.
> set_task_comm() is not export.So when compile md is module, it will be error.
> So I think it will be rewrite.It should rename in function call md_register_thread().
> How about this way?
good point.
If you change all calls to "md_register_thread" that pass NULL as the last
argument to instead pass the name of the personality as the last arg,
then it should get it right.
Thanks,
NeilBrown
Attachment:
signature.asc
Description: PGP signature
