NTFS: - Fix bug in fs/ntfs/attrib.c::ntfs_find_vcn_nolock() where after
        dropping the read lock and taking the write lock we were not checking
        whether someone else did not already do the work we wanted to do.
      - Rename ntfs_find_vcn_nolock() to ntfs_attr_find_vcn_nolock().
      - Tidy up some comments in fs/ntfs/runlist.c.
      - Add LCN_ENOMEM and LCN_EIO definitions to fs/ntfs/runlist.h.

Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
diff --git a/fs/ntfs/lcnalloc.c b/fs/ntfs/lcnalloc.c
index f2b7f85..6e584ab 100644
--- a/fs/ntfs/lcnalloc.c
+++ b/fs/ntfs/lcnalloc.c
@@ -850,7 +850,7 @@
 
 	/* This returns with ni->runlist locked for reading on success. */
 	down_read(&ni->runlist.lock);
-	rl = ntfs_find_vcn_nolock(ni, start_vcn, FALSE);
+	rl = ntfs_attr_find_vcn_nolock(ni, start_vcn, FALSE);
 	if (IS_ERR(rl)) {
 		if (!is_rollback)
 			ntfs_error(vol->sb, "Failed to find first runlist "
@@ -904,7 +904,7 @@
 
 			/* Attempt to map runlist. */
 			vcn = rl->vcn;
-			rl = ntfs_find_vcn_nolock(ni, vcn, FALSE);
+			rl = ntfs_attr_find_vcn_nolock(ni, vcn, FALSE);
 			if (IS_ERR(rl)) {
 				err = PTR_ERR(rl);
 				if (!is_rollback)