mm: buffered write iterator

[net-next-2.6.git] / include / linux / fs.h

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 500ffc0e4ac7856f4cd9487794f2cdd9ed35195e..86ce27c725540244d0e2c09303d67b169a8848aa 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -401,6 +401,39 @@ struct page;
 struct address_space;
 struct writeback_control;
 
+struct iov_iter {
+       const struct iovec *iov;
+       unsigned long nr_segs;
+       size_t iov_offset;
+       size_t count;
+};
+
+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 iov_iter_single_seg_count(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;
+}
+
+
 struct address_space_operations {
        int (*writepage)(struct page *page, struct writeback_control *wbc);
        int (*readpage)(struct file *, struct page *);