NFS: Do not set NFS_INO_INVALID_LABEL unless server supports labeled NFS

Commit aa9c2669626c (NFS: Client implementation of Labeled-NFS) introduces
a performance regression. When nfs_zap_caches_locked is called, it sets
the NFS_INO_INVALID_LABEL flag irrespectively of whether or not the
NFS server supports security labels. Since that flag is never cleared,
it means that all calls to nfs_revalidate_inode() will now trigger
an on-the-wire GETATTR call.

This patch ensures that we never set the NFS_INO_INVALID_LABEL unless the
server advertises support for labeled NFS.
It also causes nfs_setsecurity() to clear NFS_INO_INVALID_LABEL when it
has successfully set the security label for the inode.
Finally it gets rid of the NFS_INO_INVALID_LABEL cruft from nfs_update_inode,
which has nothing to do with labeled NFS.

Reported-by: Neil Brown <neilb@suse.de>
Cc: stable@vger.kernel.org # 3.11+
Tested-by: Neil Brown <neilb@suse.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 8b5cc04a8611..fafdddac8271 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -279,9 +279,18 @@ static inline void nfs4_label_free(struct nfs4_label *label)
         }
         return;
 }
+
+static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
+{
+        if (nfs_server_capable(&nfsi->vfs_inode, NFS_CAP_SECURITY_LABEL))
+                nfsi->cache_validity |= NFS_INO_INVALID_LABEL;
+}
 #else
 static inline struct nfs4_label *nfs4_label_alloc(struct nfs_server *server, gfp_t flags) { return NULL; }
 static inline void nfs4_label_free(void *label) {}
+static inline void nfs_zap_label_cache_locked(struct nfs_inode *nfsi)
+{
+}
 #endif /* CONFIG_NFS_V4_SECURITY_LABEL */
 
 /* proc.c */