Re: [PATCH] add_partition silently ignored errors

From: Cornelia Huck
Date: Mon Oct 29 2007 - 09:07:54 EST


On Mon, 29 Oct 2007 05:22:11 -0700,
Dirk Hohndel <hohndel@xxxxxxxxxxxxxxx> wrote:

<only commenting on the kobject part...>

> @@ -390,20 +390,31 @@ void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len,
> p->kobj.parent = &disk->kobj;
> p->kobj.ktype = &ktype_part;
> kobject_init(&p->kobj);
> - kobject_add(&p->kobj);
> + if (kobject_add(&p->kobj))
> + return -1;
> if (!disk->part_uevent_suppress)
> kobject_uevent(&p->kobj, KOBJ_ADD);
> - sysfs_create_link(&p->kobj, &block_subsys.kobj, "subsystem");
> + if(sysfs_create_link(&p->kobj, &block_subsys.kobj, "subsystem")) {
> + kobject_del(&p->kobj);
> + kfree(p);
> + return -1;
> + }


- This is missing a KOBJ_DEL uevent if you did a KOBJ_ADD uevent.
- Calling kfree() after you already registered the kobject via
kobject_add() is wrong, since someone else might already have obtained
a reference. You must drop your reference after kobject_del() and let
the release mechanism take care of it.

<I think I'm having some kind of deja vu, since it seems I've already
pointed that out a couple of times to different people :) >

> if (flags & ADDPART_FLAG_WHOLEDISK) {
> static struct attribute addpartattr = {
> .name = "whole_disk",
> .mode = S_IRUSR | S_IRGRP | S_IROTH,
> };
>
> - sysfs_create_file(&p->kobj, &addpartattr);
> + if (sysfs_create_file(&p->kobj, &addpartattr)) {
> + kobject_del(&p->kobj);
> + kfree(p);
> + return -1;
> + }

Same here. You should probably also delete the link you created above.

> }
> partition_sysfs_add_subdir(p);
> disk->part[part-1] = p;
> +
> + return 0;
> }
>
> static char *make_block_name(struct gendisk *disk)
-
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