parallel lookups machinery, part 2

[mirror_ubuntu-zesty-kernel.git] / Documentation / filesystems / porting

diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 57bb3754a027f53e3df7439fc1e550d54c6d7ae9..8810e2367fe6252cad7c8a4536d0d69a6eb2075b 100644 (file)
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -531,3 +531,11 @@ in your dentry operations instead.
        dentry might be yet to be attached to inode, so do _not_ use its ->d_inode
        in the instances.  Rationale: !@#!@# security_d_instantiate() needs to be
        called before we attach dentry to inode.
+--
+[mandatory]
+       symlinks are no longer the only inodes that do *not* have i_bdev/i_cdev/
+       i_pipe/i_link union zeroed out at inode eviction.  As the result, you can't
+       assume that non-NULL value in ->i_nlink at ->destroy_inode() implies that
+       it's a symlink.  Checking ->i_mode is really needed now.  In-tree we had
+       to fix shmem_destroy_callback() that used to take that kind of shortcut;
+       watch out, since that shortcut is no longer valid.