NFS: Avoid unnecessary rescanning of the per-server delegation list

If the call to nfs_delegation_grab_inode() fails, we will not have
dropped any locks that require us to rescan the list.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index d5edb3b3eeef0d5e1b1aaba7817d5958e9155a5c..20cb2008f9e4696b05284eab6a0fa578eaa39626 100644 (file)
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -647,6 +647,9 @@ restart:
                                prev = delegation;
                        continue;
                }
+               inode = nfs_delegation_grab_inode(delegation);
+               if (inode == NULL)
+                       continue;
 
                if (prev) {
                        struct inode *tmp = nfs_delegation_grab_inode(prev);
@@ -657,12 +660,6 @@ restart:
                        }
                }
 
-               inode = nfs_delegation_grab_inode(delegation);
-               if (inode == NULL) {
-                       rcu_read_unlock();
-                       iput(to_put);
-                       goto restart;
-               }
                delegation = nfs_start_delegation_return_locked(NFS_I(inode));
                rcu_read_unlock();
 
@@ -1184,7 +1181,6 @@ static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
        struct inode *inode;
 restart:
        rcu_read_lock();
-restart_locked:
        list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
                if (test_bit(NFS_DELEGATION_INODE_FREEING,
                                        &delegation->flags) ||
@@ -1195,7 +1191,7 @@ restart_locked:
                        continue;
                inode = nfs_delegation_grab_inode(delegation);
                if (inode == NULL)
-                       goto restart_locked;
+                       continue;
                delegation = nfs_start_delegation_return_locked(NFS_I(inode));
                rcu_read_unlock();
                if (delegation != NULL) {
@@ -1318,7 +1314,6 @@ static int nfs_server_reap_expired_delegations(struct nfs_server *server,
 
 restart:
        rcu_read_lock();
-restart_locked:
        list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
                if (test_bit(NFS_DELEGATION_INODE_FREEING,
                                        &delegation->flags) ||
@@ -1330,7 +1325,7 @@ restart_locked:
                        continue;
                inode = nfs_delegation_grab_inode(delegation);
                if (inode == NULL)
-                       goto restart_locked;
+                       continue;
                spin_lock(&delegation->lock);
                cred = get_cred_rcu(delegation->cred);
                nfs4_stateid_copy(&stateid, &delegation->stateid);