NFS: Always call nfs_inode_find_state_and_recover() when revoking a delegation

Don't rely on nfs_inode_detach_delegation() succeeding. That can race...

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 094e0efe6a82da57c6e24c4b8f03fe1b38975d64..dff600ae0d7477333a3e41749cffe58ad77c7e3a 100644 (file)
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -662,18 +662,24 @@ static bool nfs_revoke_delegation(struct inode *inode,
                const nfs4_stateid *stateid)
 {
        struct nfs_delegation *delegation;
+       nfs4_stateid tmp;
        bool ret = false;
 
        rcu_read_lock();
        delegation = rcu_dereference(NFS_I(inode)->delegation);
        if (delegation == NULL)
                goto out;
-       if (stateid && !nfs4_stateid_match(stateid, &delegation->stateid))
+       if (stateid == NULL) {
+               nfs4_stateid_copy(&tmp, &delegation->stateid);
+               stateid = &tmp;
+       } else if (!nfs4_stateid_match(stateid, &delegation->stateid))
                goto out;
        nfs_mark_delegation_revoked(NFS_SERVER(inode), delegation);
        ret = true;
 out:
        rcu_read_unlock();
+       if (ret)
+               nfs_inode_find_state_and_recover(inode, stateid);
        return ret;
 }
 
@@ -685,10 +691,8 @@ void nfs_remove_bad_delegation(struct inode *inode,
        if (!nfs_revoke_delegation(inode, stateid))
                return;
        delegation = nfs_inode_detach_delegation(inode);
-       if (delegation) {
-               nfs_inode_find_state_and_recover(inode, &delegation->stateid);
+       if (delegation)
                nfs_free_delegation(delegation);
-       }
 }
 EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);