vfs: re-introduce MAY_CHDIR
Currently MAY_ACCESS means that filesystems must check the permissions
right then and not rely on cached results or the results of future
operations on the object. This can be because of a call to sys_access() or
because of a call to chdir() which needs to check search without relying on
any future operations inside that dir. I plan to use MAY_ACCESS for other
purposes in the security system, so I split the MAY_ACCESS and the
MAY_CHDIR cases.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 68ca1b0..7d94b72 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -53,6 +53,7 @@
#define MAY_APPEND 8
#define MAY_ACCESS 16
#define MAY_OPEN 32
+#define MAY_CHDIR 64
/*
* flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond