Commit f7f9a0c8 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

iov_iter: Map the page later in copy_page_from_iter_atomic() 



Remove a couple of calls to kunmap_atomic() in the rare error cases.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
parent 6eaae198

lib/iov_iter.c

+8 −8
Original line number Diff line number Diff line
@@ -569,20 +569,20 @@ EXPORT_SYMBOL(iov_iter_zero); 
size_t copy_page_from_iter_atomic(struct page *page, unsigned offset, size_t bytes,

				  struct iov_iter *i)

{

	char *kaddr = kmap_atomic(page), *p = kaddr + offset;

	if (!page_copy_sane(page, offset, bytes)) {

		kunmap_atomic(kaddr);

	char *p;



	if (!page_copy_sane(page, offset, bytes))

		return 0;

	}

	if (WARN_ON_ONCE(!i->data_source)) {

		kunmap_atomic(kaddr);

	if (WARN_ON_ONCE(!i->data_source))

		return 0;

	}



	p = kmap_atomic(page) + offset;

	iterate_and_advance(i, bytes, base, len, off,

		copyin(p + off, base, len),

		memcpy_from_iter(i, p + off, base, len)

	)

	kunmap_atomic(kaddr);

	kunmap_atomic(p);



	return bytes;

}

EXPORT_SYMBOL(copy_page_from_iter_atomic);