Add the equivalent of iov_iter_fault_in_readable(), but for pages that will be
written to.
While at it, fix an indentation error in iov_iter_fault_in_readable().
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
---
include/linux/uio.h | 1 +
lib/iov_iter.c | 20 +++++++++++++++++++-
2 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/include/linux/uio.h b/include/linux/uio.h
index d3ec87706d75..6811eb6ac6e3 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -124,6 +124,7 @@ size_t iov_iter_copy_from_user_atomic(struct page *page,
void iov_iter_advance(struct iov_iter *i, size_t bytes);
void iov_iter_revert(struct iov_iter *i, size_t bytes);
int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes);
+int iov_iter_fault_in_writeable(struct iov_iter *i, size_t bytes);
size_t iov_iter_single_seg_count(const struct iov_iter *i);
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i);
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index c701b7a187f2..317c94eac907 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -480,13 +480,31 @@ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes)
iterate_iovec(i, bytes, v, iov, skip, ({
err = fault_in_pages_readable(v.iov_base, v.iov_len);
if (unlikely(err))
- return err;
+ return err;
0;}))
}
return 0;
}
EXPORT_SYMBOL(iov_iter_fault_in_readable);
+int iov_iter_fault_in_writeable(struct iov_iter *i, size_t bytes)
+{
+ size_t skip = i->iov_offset;
+ const struct iovec *iov;
+ int err;
+ struct iovec v;
+
+ if (!(i->type & (ITER_BVEC|ITER_KVEC))) {
+ iterate_iovec(i, bytes, v, iov, skip, ({
+ err = fault_in_pages_writeable(v.iov_base, v.iov_len);
+ if (unlikely(err))
+ return err;
+ 0;}))
+ }
+ return 0;
+}
+EXPORT_SYMBOL(iov_iter_fault_in_writeable);
+
void iov_iter_init(struct iov_iter *i, unsigned int direction,
const struct iovec *iov, unsigned long nr_segs,
size_t count)
--
2.26.3
