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>

2 files changed, 19 insertions, 4 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 28a0a3cbd3b7..360114ae8b82 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -164,17 +164,16 @@ static void nfs_zap_caches_locked(struct inode *inode)
         if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)) {
                 nfs_fscache_invalidate(inode);
                 nfsi->cache_validity |= NFS_INO_INVALID_ATTR
-                                        | NFS_INO_INVALID_LABEL
                                         | NFS_INO_INVALID_DATA
                                         | NFS_INO_INVALID_ACCESS
                                         | NFS_INO_INVALID_ACL
                                         | NFS_INO_REVAL_PAGECACHE;
         } else
                 nfsi->cache_validity |= NFS_INO_INVALID_ATTR
-                                        | NFS_INO_INVALID_LABEL
                                         | NFS_INO_INVALID_ACCESS
                                         | NFS_INO_INVALID_ACL
                                         | NFS_INO_REVAL_PAGECACHE;
+        nfs_zap_label_cache_locked(nfsi);
 }
 
 void nfs_zap_caches(struct inode *inode)
@@ -266,6 +265,13 @@ nfs_init_locked(struct inode *inode, void *opaque)
 }
 
 #ifdef CONFIG_NFS_V4_SECURITY_LABEL
+static void nfs_clear_label_invalid(struct inode *inode)
+{
+        spin_lock(&inode->i_lock);
+        NFS_I(inode)->cache_validity &= ~NFS_INO_INVALID_LABEL;
+        spin_unlock(&inode->i_lock);
+}
+
 void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
                                         struct nfs4_label *label)
 {
@@ -283,6 +289,7 @@ void nfs_setsecurity(struct inode *inode, struct nfs_fattr *fattr,
                                         __func__,
                                         (char *)label->label,
                                         label->len, error);
+                nfs_clear_label_invalid(inode);
         }
 }
 
@@ -1648,7 +1655,7 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                 inode->i_blocks = fattr->du.nfs2.blocks;
 
         /* Update attrtimeo value if we're out of the unstable period */
-        if (invalid & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_LABEL)) {
+        if (invalid & NFS_INO_INVALID_ATTR) {
                 nfs_inc_stats(inode, NFSIOS_ATTRINVALIDATE);
                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
                 nfsi->attrtimeo_timestamp = now;
@@ -1661,7 +1668,6 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
                 }
         }
         invalid &= ~NFS_INO_INVALID_ATTR;
-        invalid &= ~NFS_INO_INVALID_LABEL;
         /* Don't invalidate the data if we were to blame */
         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
                                 || S_ISLNK(inode->i_mode)))
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 */