update Documentation/filesystems/ regarding the follow_link/put_link changes
Signed-off-by: Al Viro <[email protected]>
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index e69274d..3eae250 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -483,3 +483,20 @@
--
[mandatory]
->aio_read/->aio_write are gone. Use ->read_iter/->write_iter.
+---
+[recommended]
+ for embedded ("fast") symlinks just set inode->i_link to wherever the
+ symlink body is and use simple_follow_link() as ->follow_link().
+--
+[mandatory]
+ calling conventions for ->follow_link() have changed. Instead of returning
+ cookie and using nd_set_link() to store the body to traverse, we return
+ the body to traverse and store the cookie using explicit void ** argument.
+ nameidata isn't passed at all - nd_jump_link() doesn't need it and
+ nd_[gs]et_link() is gone.
+--
+[mandatory]
+ calling conventions for ->put_link() have changed. It gets inode instead of
+ dentry, it does not get nameidata at all and it gets called only when cookie
+ is non-NULL. Note that link body isn't available anymore, so if you need it,
+ store it as cookie.
