Re: [PATCH] mm: allow __GFP_RETRY_MAYFAIL in vmalloc

["Vishal Moola (Oracle)" <vishal.moola@gmail.com>]

On Thu, Feb 12, 2026 at 05:33:30PM +0100, Mikulas Patocka wrote:
> The commit 07003531e03c8 ("mm/vmalloc: warn on invalid vmalloc gfp
> flags") breaks the device mapper VDO target. The VDO target calls vmalloc
> with __GFP_RETRY_MAYFAIL and this flag is not in the mask of allowed
> flags.
> 
> There is no reason why vmalloc couldn't support __GFP_RETRY_MAYFAIL, so 
> let's add this flag to GFP_VMALLOC_SUPPORTED.

My only skepticism about this comes from the line in the
vmalloc_node_range() doc: 
"and %__GFP_RETRY_MAYFAIL are not supported."

I myself don't know why that may be. Could you elaborate on if/why the
doc is wrong please?

> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
> Reported-by: Zdenek Kabelac <zkabelac@redhat.com>
> Fixes: 07003531e03c ("mm/vmalloc: warn on invalid vmalloc gfp flags")
> Cc: stable@vger.kernel.org	# v6.19
> 
> ---
>  mm/vmalloc.c |    1 +
>  1 file changed, 1 insertion(+)
> 
> Index: linux-2.6/mm/vmalloc.c
> ===================================================================
> --- linux-2.6.orig/mm/vmalloc.c
> +++ linux-2.6/mm/vmalloc.c
> @@ -3928,6 +3928,7 @@ fail:
>   */
>  #define GFP_VMALLOC_SUPPORTED (GFP_KERNEL | GFP_ATOMIC | GFP_NOWAIT |\
>  				__GFP_NOFAIL |  __GFP_ZERO | __GFP_NORETRY |\
> +				__GFP_RETRY_MAYFAIL |\
>  				GFP_NOFS | GFP_NOIO | GFP_KERNEL_ACCOUNT |\
>  				GFP_USER | __GFP_NOLOCKDEP)
>  
>