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authorMatthew Wilcox <willy@linux.intel.com>2014-08-01 09:27:22 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2014-10-09 02:39:03 -0400
commitc35e02480014f7a86e264a2fda39a568690163da (patch)
tree6b1f1afc1c19bcbfc9c96f707c93627b0f4acbf3 /include/linux/uio.h
parent475d0db742e3755c6b267f48577ff7cbb7dfda0d (diff)
downloadop-kernel-dev-c35e02480014f7a86e264a2fda39a568690163da.zip
op-kernel-dev-c35e02480014f7a86e264a2fda39a568690163da.tar.gz
Add copy_to_iter(), copy_from_iter() and iov_iter_zero()
For DAX, we want to be able to copy between iovecs and kernel addresses that don't necessarily have a struct page. This is a fairly simple rearrangement for bvec iters to kmap the pages outside and pass them in, but for user iovecs it gets more complicated because we might try various different ways to kmap the memory. Duplicating the existing logic works out best in this case. We need to be able to write zeroes to an iovec for reads from unwritten ranges in a file. This is performed by the new iov_iter_zero() function, again patterned after the existing code that handles iovec iterators. [AV: and export the buggers...] Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include/linux/uio.h')
-rw-r--r--include/linux/uio.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/uio.h b/include/linux/uio.h
index 290fbf0..9b15814 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -80,6 +80,9 @@ size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i);
size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes,
struct iov_iter *i);
+size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i);
+size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
+size_t iov_iter_zero(size_t bytes, struct iov_iter *);
unsigned long iov_iter_alignment(const struct iov_iter *i);
void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov,
unsigned long nr_segs, size_t count);
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