Messages in this thread Patch in this message |  | | | Date | Fri, 31 Oct 2008 00:47:18 +0100 | | From | "Kay Sievers" <> | | Subject | Re: 2.6.28-rc2: (mtd)block/partitions BUG with kobject reference count |
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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);
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