SUNRPC: Fix up task signalling

The RPC_TASK_KILLED flag should really not be set from another context
because it can clobber data in the struct task when task->tk_flags is
changed non-atomically.
Let's therefore swap out RPC_TASK_KILLED with an atomic flag, and add
a function to set that flag and safely wake up the task.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index d219159b98af..f7494be8dbe2 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -1032,7 +1032,7 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback
                  * the submission code will error out, so we don't need to
                  * handle that case here.
                  */
-                if (task->tk_flags & RPC_TASK_KILLED)
+                if (RPC_SIGNALLED(task))
                         goto need_restart;
 
                 return true;
@@ -1081,7 +1081,7 @@ static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback
         dprintk("%s: freed slot, new seqid=%d\n", __func__,
                 clp->cl_cb_session->se_cb_seq_nr);
 
-        if (task->tk_flags & RPC_TASK_KILLED)
+        if (RPC_SIGNALLED(task))
                 goto need_restart;
 out:
         return ret;