fs,security: Add sb_delete hook

The sb_delete security hook is called when shutting down a superblock,
which may be useful to release kernel objects tied to the superblock's
lifetime (e.g. inodes).

This new hook is needed by Landlock to release (ephemerally) tagged
struct inodes.  This comes from the unprivileged nature of Landlock
described in the next commit.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210422154123.13086-7-mic@digikod.net
Signed-off-by: James Morris <jamorris@linux.microsoft.com>
This commit is contained in:
Mickaël Salaün
2021-04-22 17:41:16 +02:00
committed by James Morris
parent cb2c7d1a17
commit 83e804f0bf
5 changed files with 14 additions and 0 deletions

View File

@@ -108,6 +108,9 @@
* allocated.
* @sb contains the super_block structure to be modified.
* Return 0 if operation was successful.
* @sb_delete:
* Release objects tied to a superblock (e.g. inodes).
* @sb contains the super_block structure being released.
* @sb_free_security:
* Deallocate and clear the sb->s_security field.
* @sb contains the super_block structure to be modified.