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

Pull more vfs updates from Al Viro:
 "In this pile:

   - autofs-namespace series
   - dedupe stuff
   - more struct path constification"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
  ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features
  ocfs2: charge quota for reflinked blocks
  ocfs2: fix bad pointer cast
  ocfs2: always unlock when completing dio writes
  ocfs2: don't eat io errors during _dio_end_io_write
  ocfs2: budget for extent tree splits when adding refcount flag
  ocfs2: prohibit refcounted swapfiles
  ocfs2: add newlines to some error messages
  ocfs2: convert inode refcount test to a helper
  simple_write_end(): don't zero in short copy into uptodate
  exofs: don't mess with simple_write_{begin,end}
  9p: saner ->write_end() on failing copy into non-uptodate page
  fix gfs2_stuffed_write_end() on short copies
  fix ceph_write_end()
  nfs_write_end(): fix handling of short copies
  vfs: refactor clone/dedupe_file_range common functions
  fs: try to clone files first in vfs_copy_file_range
  vfs: misc struct path constification
  namespace.c: constify struct path passed to a bunch of primitives
  quota: constify struct path in quota_on
  ...

1 files changed, 8 insertions, 6 deletions

diff --git a/fs/libfs.c b/fs/libfs.c
index 48826d4da189..76048705d922 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -465,6 +465,8 @@ EXPORT_SYMBOL(simple_write_begin);
  * is not called, so a filesystem that actually does store data in .write_inode
  * should extend on what's done here with a call to mark_inode_dirty() in the
  * case that i_size has changed.
+ *
+ * Use *ONLY* with simple_readpage()
  */
 int simple_write_end(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned copied,
@@ -474,14 +476,14 @@ int simple_write_end(struct file *file, struct address_space *mapping,
 	loff_t last_pos = pos + copied;
 
 	/* zero the stale part of the page if we did a short copy */
-	if (copied < len) {
-		unsigned from = pos & (PAGE_SIZE - 1);
-
-		zero_user(page, from + copied, len - copied);
-	}
+	if (!PageUptodate(page)) {
+		if (copied < len) {
+			unsigned from = pos & (PAGE_SIZE - 1);
 
-	if (!PageUptodate(page))
+			zero_user(page, from + copied, len - copied);
+		}
 		SetPageUptodate(page);
+	}
 	/*
 	 * No need to use i_size_read() here, the i_size
 	 * cannot change under us because we hold the i_mutex.