Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[linux.git] / include / linux / uio.h

diff --git a/include/linux/uio.h b/include/linux/uio.h
index c55ce243cc0985c450786e4cb63f8ed3c8e5c53b..199bcc34241ba0155a367f11d05edf5d9c138a02 100644 (file)
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -9,14 +9,23 @@
 #ifndef __LINUX_UIO_H
 #define __LINUX_UIO_H
 
+#include <linux/kernel.h>
 #include <uapi/linux/uio.h>
 
+struct page;
 
 struct kvec {
        void *iov_base; /* and that should *never* hold a userland pointer */
        size_t iov_len;
 };
 
+struct iov_iter {
+       const struct iovec *iov;
+       unsigned long nr_segs;
+       size_t iov_offset;
+       size_t count;
+};
+
 /*
  * Total number of bytes covered by an iovec.
  *
@@ -34,8 +43,51 @@ static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
        return ret;
 }
 
+static inline struct iovec iov_iter_iovec(const struct iov_iter *iter)
+{
+       return (struct iovec) {
+               .iov_base = iter->iov->iov_base + iter->iov_offset,
+               .iov_len = min(iter->count,
+                              iter->iov->iov_len - iter->iov_offset),
+       };
+}
+
+#define iov_for_each(iov, iter, start)                         \
+       for (iter = (start);                                    \
+            (iter).count &&                                    \
+            ((iov = iov_iter_iovec(&(iter))), 1);              \
+            iov_iter_advance(&(iter), (iov).iov_len))
+
 unsigned long iov_shorten(struct iovec *iov, unsigned long nr_segs, size_t to);
 
+size_t iov_iter_copy_from_user_atomic(struct page *page,
+               struct iov_iter *i, unsigned long offset, size_t bytes);
+size_t iov_iter_copy_from_user(struct page *page,
+               struct iov_iter *i, unsigned long offset, size_t bytes);
+void iov_iter_advance(struct iov_iter *i, size_t bytes);
+int iov_iter_fault_in_readable(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);
+
+static inline void iov_iter_init(struct iov_iter *i,
+                       const struct iovec *iov, unsigned long nr_segs,
+                       size_t count, size_t written)
+{
+       i->iov = iov;
+       i->nr_segs = nr_segs;
+       i->iov_offset = 0;
+       i->count = count + written;
+
+       iov_iter_advance(i, written);
+}
+
+static inline size_t iov_iter_count(struct iov_iter *i)
+{
+       return i->count;
+}
+
 int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len);
 int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len);
+
 #endif