Re: [PATCH 3.12-rc7] KVM: Fix modprobe failure for kvm_intel/kvm_amd

Linus Torvalds
2013-10-29T19:33:40Z

On Tue, Oct 29, 2013 at 12:27 PM, Raghavendra K T
<raghavendra.kt@linux.vnet.ibm.com> wrote:
>
> Could one solution be cascading actual error
> that is lost in fs/debugfs/inode.c:__create_file(), so that we could
> take correct action in case of failure of debugfs_create_dir()?
>
> (ugly side is we increase total number of params for __create_file to
> 6). or I hope there could be some better solution.

The solution to this would be to simply return an error-pointer. See
<linux/err.h>. That's what we do for most complex subsystems that
return a pointer to a struct: rather than returning "NULL" as an
error, return the actual error number encoded in the pointer itself.

But that would require every user of debugfs_create_dir() to be
updated to check errors using IS_ERR() instead of checking against
NULL, and there's quite a few of them.

So I think just making the error be EEXIST is a simpler solution right now.

Linus