Messages in this thread | | | Date | Fri, 31 Oct 2008 12:24:58 +0800 | From | "Bryan Wu" <> | Subject | Re: 2.6.28-rc2: (mtd)block/partitions BUG with kobject reference count |
| |
On Fri, Oct 31, 2008 at 7:47 AM, Kay Sievers <kay.sievers@vrfy.org> wrote: > On Thu, Oct 30, 2008 at 22:51, Kay Sievers <kay.sievers@vrfy.org> wrote: >> On Thu, Oct 30, 2008 at 00:28, Peter Korsgaard <jacmet@sunsite.dk> wrote: >>>>>>>> "Rafael" == Rafael J Wysocki <rjw@sisk.pl> writes: >>> >>> Rafael> On Wednesday, 29 of October 2008, Peter Korsgaard wrote: >>> >> Hi, >>> >> >>> >> I'm seing what looks like a kobject reference count issue with >>> >> mtdblock_ro + mtd_dataflash + mtd partitions and repeated unbind/bind. >>> >> I'm on 2.6.28-rc2, but I can reproduce the problem on 2.6.27 as well. >>> >>> Rafael> Is it reproducible with 2.6.26 too? >>> >>> Sorry, I haven't backported my platform support code to such "old" >>> kernel. I can do it though, if you think it will help pinpoint the >>> issue. >> >> This sounds like a possible reason for the problem: >> "After digging into the mtd code, this bug is not related to our driver. It >> should be a subtle bug in mtd core code. >> >> In add_mtd_partition, for 2 partitions, 2 gendisk structures will be >> allocated. But these 2 gendisk->queue will be set to the same >> request_queue. Then when unregistering the 1st partition, from the >> same request_queue->backing_dev_info, the bdi struct will be set to >> NULL. So for the 2nd partition (bdi == NULL), the sysfs dir of 2nd >> partition will not be removed. Finally, when modprobe the module >> again, the 2nd partition won't be added" >> https://blackfin.uclinux.org/gf/tracker/4463 > > Looks like a bdi issue: > http://lkml.org/lkml/2008/10/30/519 > > Peter, if I do this (whitespace mangled, just pasted in here), the > error goes away for me. Can you try this? > > Thanks, > Kay > > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -515,7 +515,8 @@ void add_disk(struct gendisk *disk) > blk_register_queue(disk); > > bdi = &disk->queue->backing_dev_info; > - bdi_register_dev(bdi, disk_devt(disk)); > + if (!bdi->dev) > + bdi_register_dev(bdi, disk_devt(disk)); > retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj, > "bdi"); > WARN_ON(retval);
IMHO, this is a workaround, right? I think the final solution should provide every 'gendisk' a dedicated 'bdi'. So they won't mess up and overwrite.
-Bryan
| |