RE: [PATCH] pstore/ram: Clarify resource reservation labels

[Luck, Tony]

> If the filesystem existed on the namespace before the user specified
> the ramoops command line then ramoops will clobber the filesystem and
> the user will only find out when mount later fails. All the kernel
> will say is:
>
>     dev_warn(dev, "could not reserve region %pR\n", res);
>
> ...from the pmem driver, and then the only way to figure who the
> conflict is with is to look at /proc/iomem, but the damage is already
> likely done by that point.

When you set up a ramoops region in pmem, write a magic header block
at the start of the area.  Then when pstore/ramoops goes to find the
region, it checks for the magic header.  Not there? Don't write to the
region. Problem solved.

-Tony