Re: [BUG 2.6.17-git] kmem_cache_create: duplicate cache scsi_cmd_cache

Linus Torvalds
2006-05-12T22:15:37Z

On Fri, 12 May 2006, Russell King wrote:
>
> From: Todd Blumer <todd@sdgsystems.com>
> On a PXA27x handheld (iPAQ hx4700), when we eject a mounted SD memory
> card, we get a kernel panic (kernel trying to clean up non-existent
> device). One hack patch to avoid the panic is:
>
> --- fs/partitions/check.c 10 Apr 2006 22:57:27 -0000 1.15
> +++ fs/partitions/check.c 4 May 2006 20:30:15 -0000
> @@ -491,6 +491,7 @@
> kfree(disk_name);
> }
> put_device(disk->driverfs_dev);
> + disk->driverfs_dev = 0; /* HACK - what's the right solution? */
> }
> kobject_uevent(&disk->kobj, KOBJ_REMOVE);
> kobject_del(&disk->kobj);

Btw, on the face it of, I really think that this patch is correct
regardless of any other issues.

We're clearly getting rid of "disk->driverfs_dev" (that's what the
"put_device()" does). So we should clear it out - using
"disk->driverfs_dev" afterwards is clearly not _valid_, because we've
dropped the reference.

Of course, we shouldn't assign zero to it. We should assign NULL.
Alternatively, we could poison it (so that anybody who tries to use it
gets a nice oops ASAP).

Now, regardless of whether that is correct or not, it might not be the
only problem, of course. It sounds like there is something else going on
here too.

Linus