NFSv4: Allow entries in the idmap cache to expire

 If someone changes the uid/gid mapping in userland, then we do eventually
 want those changes to be propagated to the kernel. Currently the kernel
 assumes that it may cache entries forever.

 Add an expiration time + garbage collector for idmap entries.

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

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/nfs_idmap.h b/include/linux/nfs_idmap.h
index a0f1f25e0ead..102e56094296 100644
--- a/include/linux/nfs_idmap.h
+++ b/include/linux/nfs_idmap.h
@@ -71,6 +71,8 @@ int nfs_map_name_to_uid(struct nfs4_client *, const char *, size_t, __u32 *);
 int nfs_map_group_to_gid(struct nfs4_client *, const char *, size_t, __u32 *);
 int nfs_map_uid_to_name(struct nfs4_client *, __u32, char *);
 int nfs_map_gid_to_group(struct nfs4_client *, __u32, char *);
+
+extern unsigned int nfs_idmap_cache_timeout;
 #endif /* __KERNEL__ */
 
 #endif /* NFS_IDMAP_H */