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/nfs/dir.c b/fs/nfs/dir.c
index 37e0a8b..58beace 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -938,7 +938,8 @@
* component of the path.
* We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT.
*/
-static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask)
+static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd,
+ unsigned int mask)
{
if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))
return 0;
@@ -1018,7 +1019,7 @@
* If the parent directory is seen to have changed, we throw out the
* cached dentry and do a new lookup.
*/
-static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
+static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct inode *dir;
struct inode *inode;
@@ -1027,6 +1028,9 @@
struct nfs_fattr *fattr = NULL;
int error;
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
parent = dget_parent(dentry);
dir = parent->d_inode;
nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);