fs: rcu-walk aware d_revalidate method
Require filesystems be aware of .d_revalidate being called in rcu-walk
mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning
-ECHILD from all implementations.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 3be5ed7..e3ffc5e 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -43,6 +43,9 @@
static int vfat_revalidate(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
/* This is not negative dentry. Always valid. */
if (dentry->d_inode)
return 1;
@@ -51,6 +54,9 @@
static int vfat_revalidate_ci(struct dentry *dentry, struct nameidata *nd)
{
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
/*
* This is not negative dentry. Always valid.
*