Re: [PATCH] fork: Use helper function mapping_allow_writable() in dup_mmap()

[Eric W. Biederman]

Miaohe Lin <linmiaohe@xxxxxxxxxx> writes:

> Use helper function mapping_allow_writable() to atomic_inc
> i_mmap_writable.

Why?


> Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
> ---
>  kernel/fork.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 4b328aecabb2..a0586716e327 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -558,7 +558,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
>  				atomic_dec(&inode->i_writecount);
>  			i_mmap_lock_write(mapping);
>  			if (tmp->vm_flags & VM_SHARED)
> -				atomic_inc(&mapping->i_mmap_writable);
> +				mapping_allow_writable(mapping);
>  			flush_dcache_mmap_lock(mapping);
>  			/* insert tmp into the share list, just after mpnt */
>  			vma_interval_tree_insert_after(tmp, mpnt,