NFSv4: Don't use the delegation->inode in nfs_mark_return_delegation()
nfs_mark_return_delegation() is usually called without any locking, and
so it is not safe to dereference delegation->inode. Since the inode is
only used to discover the nfs_client anyway, it makes more sense to
have the callers pass a valid pointer to the nfs_server as a parameter.
Reported-by: Ian Kent <raven@themaw.net>
Cc: stable@kernel.org
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index dd25c2a..321a66b 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -398,12 +398,11 @@
return err;
}
-static void nfs_mark_return_delegation(struct nfs_delegation *delegation)
+static void nfs_mark_return_delegation(struct nfs_server *server,
+ struct nfs_delegation *delegation)
{
- struct nfs_client *clp = NFS_SERVER(delegation->inode)->nfs_client;
-
set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
- set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
+ set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
}
/**
@@ -441,7 +440,7 @@
if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
continue;
if (delegation->type & flags)
- nfs_mark_return_delegation(delegation);
+ nfs_mark_return_delegation(server, delegation);
}
}
@@ -508,7 +507,7 @@
list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
continue;
- nfs_mark_return_delegation(delegation);
+ nfs_mark_return_delegation(server, delegation);
}
}
@@ -539,7 +538,8 @@
int nfs_async_inode_return_delegation(struct inode *inode,
const nfs4_stateid *stateid)
{
- struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
+ struct nfs_server *server = NFS_SERVER(inode);
+ struct nfs_client *clp = server->nfs_client;
struct nfs_delegation *delegation;
rcu_read_lock();
@@ -549,7 +549,7 @@
rcu_read_unlock();
return -ENOENT;
}
- nfs_mark_return_delegation(delegation);
+ nfs_mark_return_delegation(server, delegation);
rcu_read_unlock();
nfs_delegation_run_state_manager(clp);