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authorNick Piggin <npiggin@suse.de>2007-10-16 01:24:59 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 09:42:55 -0700
commit2f718ffc16c43a435d12919c75dbfad518abd056 (patch)
tree55588cb2815d844e9d0b2404cf8ceafe98b5c55d /include
parent08291429cfa6258c4cd95d8833beb40f828b194e (diff)
mm: buffered write iterator
Add an iterator data structure to operate over an iovec. Add usercopy operators needed by generic_file_buffered_write, and convert that function over. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/fs.h33
1 files changed, 33 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 500ffc0e4ac7..86ce27c72554 100644
--- 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 *);