[PATCH -mm] UBI: one less BUG usage

[Randy Dunlap]

Artem Bityutskiy wrote:
> On Tue, 26 Jun 2007, Randy Dunlap wrote:
> 
>> From: Randy Dunlap <randy.dunlap at oracle.com>
>>
>> Eliminate one BUG() usage.  The callers of major_to_device() already
>> handle and report errors.  This is just another error to return.
> 
> Why is this just an error? It must never happen unles there is a bug in 
> the code. Or is there a campaign against BUG() calls?
> 
> Artem.

There's always a campaign against unneeded BUG() calls.
However, if you say this one is needed, then so be it.

However(2), ubi_cdev_ioctl() calls major_to_device() and allows it
to return an error [although major_to_device() currently cannot
return such an error]:

	ubi = major_to_device(imajor(inode));
	if (IS_ERR(ubi))
		return PTR_ERR(ubi);

so part of cdev.c allows and handles error returns from major_to_device().

All my patch does is allow and handle error returns from major_to_device()
in vol_cdev_open().  vol_cdev_open() already handles errors by returning
the error to its caller.

-- 
~Randy
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