> I ended up working on this a bit today, and managed to cobble together 
> something that somewhat works -- please see the patch below.

Just some quick observations:

> +     ctx->ctx_file = anon_inode_getfile("[aio]", &aio_ctx_fops, ctx, O_RDWR);
> +     if (IS_ERR(ctx->ctx_file)) {
> +             ctx->ctx_file = NULL;
> +             return -EAGAIN;
> +     }

It's too bad that aio contexts will now be accounted against the filp
limits (get_empty_filp -> files_stat.max_files, etc). 

> +     for (i=0; i<nr_pages; i++) {
> +             struct page *page;
> +             void *ptr;
> +             page = find_or_create_page(ctx->ctx_file->f_inode->i_mapping,
> +                                        i, GFP_KERNEL);
> +             if (!page) {
> +                     break;
> +             }
> +             ptr = kmap(page);
> +             clear_page(ptr);
> +             kunmap(page);
> +             SetPageUptodate(page);
> +             SetPageDirty(page);
> +             unlock_page(page);
> +     }

If they're GFP_KERNEL then you don't need to kmap them.  But we probably
want to allocate with GFP_HIGHUSER and then use clear_user_highpage() to
zero them?

- z
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to