Commit 922a2c78 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring/rsrc: cleanup io_pin_pages() 



This function is overly convoluted with a goto error path, and checks
under the mmap_read_lock() that don't need to be at all. Rearrange it
a bit so the checks and errors fall out naturally, rather than needing
to jump around for it.

Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 93b8cc60

io_uring/rsrc.c

+17 −20
Original line number Diff line number Diff line
@@ -1037,39 +1037,36 @@ struct page **io_pin_pages(unsigned long ubuf, unsigned long len, int *npages) 
{

	unsigned long start, end, nr_pages;

	struct page **pages = NULL;

	int pret, ret = -ENOMEM;

	int ret;



	end = (ubuf + len + PAGE_SIZE - 1) >> PAGE_SHIFT;

	start = ubuf >> PAGE_SHIFT;

	nr_pages = end - start;

	WARN_ON(!nr_pages);



	pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);

	if (!pages)

		goto done;

		return ERR_PTR(-ENOMEM);



	ret = 0;

	mmap_read_lock(current->mm);

	pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,

			      pages);

	if (pret == nr_pages)

	ret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM, pages);

	mmap_read_unlock(current->mm);



	/* success, mapped all pages */

	if (ret == nr_pages) {

		*npages = nr_pages;

	else

		ret = pret < 0 ? pret : -EFAULT;

		return pages;

	}



	mmap_read_unlock(current->mm);

	if (ret) {

	/* partial map, or didn't map anything */

	if (ret >= 0) {

		/* if we did partial map, release any pages we did get */

		if (pret > 0)

			unpin_user_pages(pages, pret);

		goto done;

		if (ret)

			unpin_user_pages(pages, ret);

		ret = -EFAULT;

	}

	ret = 0;

done:

	if (ret < 0) {

	kvfree(pages);

		pages = ERR_PTR(ret);

	}

	return pages;

	return ERR_PTR(ret);

}



static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,