NFSv4: Save the owner/group name string when doing open

...so that we can do the uid/gid mapping outside the asynchronous RPC
context.
This fixes a bug in the current NFSv4 atomic open code where the client
isn't able to determine what the true uid/gid fields of the file are,
(because the asynchronous nature of the OPEN call denies it the ability
to do an upcall) and so fills them with default values, marking the
inode as needing revalidation.
Unfortunately, in some cases, the VFS will do some additional sanity
checks on the file, and may override the server's decision to allow
the open because it sees the wrong owner/group fields.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/nfs_idmap.h b/include/linux/nfs_idmap.h
index ae7d6a380dae..308c18877018 100644
--- a/include/linux/nfs_idmap.h
+++ b/include/linux/nfs_idmap.h
@@ -66,6 +66,8 @@ struct idmap_msg {
 /* Forward declaration to make this header independent of others */
 struct nfs_client;
 struct nfs_server;
+struct nfs_fattr;
+struct nfs4_string;
 
 #ifdef CONFIG_NFS_USE_NEW_IDMAPPER
 
@@ -97,6 +99,12 @@ void nfs_idmap_delete(struct nfs_client *);
 
 #endif /* CONFIG_NFS_USE_NEW_IDMAPPER */
 
+void nfs_fattr_init_names(struct nfs_fattr *fattr,
+                struct nfs4_string *owner_name,
+                struct nfs4_string *group_name);
+void nfs_fattr_free_names(struct nfs_fattr *);
+void nfs_fattr_map_and_free_names(struct nfs_server *, struct nfs_fattr *);
+
 int nfs_map_name_to_uid(const struct nfs_server *, const char *, size_t, __u32 *);
 int nfs_map_group_to_gid(const struct nfs_server *, const char *, size_t, __u32 *);
 int nfs_map_uid_to_name(const struct nfs_server *, __u32, char *, size_t);