NFSv4: Fix revalidation of dentries with delegations

If a dentry was not initially looked up while we were holding a
delegation, then we do still need to revalidate that it still holds
the same name. If there are multiple hard links to the same file,
then all the hard links need validation.

Reported-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@redhat.com>
Tested-by: Benjamin Coddington <bcodding@redhat.com>
[Anna: Put nfs_unset_verifier_delegated() under CONFIG_NFS_V4]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 6 insertions, 20 deletions

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index a5f8f03ecd59..5d5b91e54f73 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -337,35 +337,17 @@ static inline int nfs_server_capable(struct inode *inode, int cap)
 	return NFS_SERVER(inode)->caps & cap;
 }
 
-static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
-{
-	dentry->d_time = verf;
-}
-
 /**
  * nfs_save_change_attribute - Returns the inode attribute change cookie
  * @dir - pointer to parent directory inode
- * The "change attribute" is updated every time we finish an operation
- * that will result in a metadata change on the server.
+ * The "cache change attribute" is updated when we need to revalidate
+ * our dentry cache after a directory was seen to change on the server.
  */
 static inline unsigned long nfs_save_change_attribute(struct inode *dir)
 {
 	return NFS_I(dir)->cache_change_attribute;
 }
 
-/**
- * nfs_verify_change_attribute - Detects NFS remote directory changes
- * @dir - pointer to parent directory inode
- * @chattr - previously saved change attribute
- * Return "false" if the verifiers doesn't match the change attribute.
- * This would usually indicate that the directory contents have changed on
- * the server, and that any dentries need revalidating.
- */
-static inline int nfs_verify_change_attribute(struct inode *dir, unsigned long chattr)
-{
-	return chattr == NFS_I(dir)->cache_change_attribute;
-}
-
 /*
  * linux/fs/nfs/inode.c
  */
@@ -495,6 +477,10 @@ extern const struct file_operations nfs_dir_operations;
 extern const struct dentry_operations nfs_dentry_operations;
 
 extern void nfs_force_lookup_revalidate(struct inode *dir);
+extern void nfs_set_verifier(struct dentry * dentry, unsigned long verf);
+#if IS_ENABLED(CONFIG_NFS_V4)
+extern void nfs_clear_verifier_delegated(struct inode *inode);
+#endif /* IS_ENABLED(CONFIG_NFS_V4) */
 extern struct dentry *nfs_add_or_obtain(struct dentry *dentry,
 			struct nfs_fh *fh, struct nfs_fattr *fattr,
 			struct nfs4_label *label);