Re: [PATCH] mm/hugetlb: change ENOSPC to ENOMEM in alloc_hugetlb_folio

[Andrew Morton <akpm@linux-foundation.org>]

On Sun,  1 Dec 2024 03:03:41 +0200 Dafna Hirschfeld <dafna.hirschfeld@intel.com> wrote:

> The error ENOSPC is translated in vmf_error to VM_FAULT_SIGBUS which is
> further translated in EFAULT in i.e. pin/get_user_pages.
> But when running out of pages/hugepages we expect to see ENOMEM and
> not EFAULT.
> 
> ...
>
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -3113,7 +3113,7 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
>  	if (!memcg_charge_ret)
>  		mem_cgroup_cancel_charge(memcg, nr_pages);
>  	mem_cgroup_put(memcg);
> -	return ERR_PTR(-ENOSPC);
> +	return ERR_PTR(-ENOMEM);
>  }
>  
>  int alloc_bootmem_huge_page(struct hstate *h, int nid)

err, yes.  ENOSPC is for disk drives!  I'll slap a cc:stable on this
fix for a decade old bug.