From: Marc Eshel <eshel@xxxxxxxxxxxxxxx>
FIXME: bhalevy: I think this patch should be dropped.
First, dp->dl_client is correctly refcounted while in do_recall and
should protect dp->dl_client->cl_callback.cb_client from going away.
Second, the rpc_clnt isn't dereferenced on the error-free path so
apparently this patch introduces a leak.
Signed-off-by: Benny Halevy <bhalevy@xxxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 13 +++++++++++++
net/sunrpc/clnt.c | 1 +
2 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 0b45680..55fd003 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1810,6 +1810,7 @@ static
void nfsd_break_deleg_cb(struct file_lock *fl)
{
struct nfs4_delegation *dp= (struct nfs4_delegation *)fl->fl_owner;
+ struct rpc_clnt *clnt;
struct task_struct *t;
int did_lock;
@@ -1817,6 +1818,17 @@ void nfsd_break_deleg_cb(struct file_lock *fl)
if (!dp)
return;
+ did_lock = nfs4_lock_state_nested();
+ clnt = dp->dl_client->cl_callback.cb_client;
+ if (!atomic_read(&dp->dl_client->cl_callback.cb_set) || !clnt) {
+ if (did_lock)
+ nfs4_unlock_state();
+ return;
+ }
+ kref_get(&clnt->cl_kref);
+ if (did_lock)
+ nfs4_unlock_state();
+
/* We're assuming the state code never drops its reference
* without first removing the lease. Since we're in this lease
* callback (and since the lease code is serialized by the kernel
@@ -1846,6 +1858,7 @@ void nfsd_break_deleg_cb(struct file_lock *fl)
printk(KERN_INFO "NFSD: Callback thread failed for "
"for client (clientid %08x/%08x)\n",
clp->cl_clientid.cl_boot, clp->cl_clientid.cl_id);
+ rpc_release_client(clnt);
did_lock = nfs4_lock_state_nested();
put_nfs4_client(dp->dl_client);
nfs4_put_delegation(dp);
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 5e8fba0..144f3bd 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -464,6 +464,7 @@ rpc_release_client(struct rpc_clnt *clnt)
wake_up(&destroy_wait);
kref_put(&clnt->cl_kref, rpc_free_auth);
}
+EXPORT_SYMBOL_GPL(rpc_release_client);
/**
* rpc_bind_new_program - bind a new RPC program to an existing client
--
1.6.0.2
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