This is a note to let you know that I've just added the patch titled SUNRPC: Set memalloc_nofs_save() for sync tasks to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: sunrpc-set-memalloc_nofs_save-for-sync-tasks.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 96898493deb839afe5fb0f7482ef374d12896e93 Author: Benjamin Coddington <bcodding@xxxxxxxxxx> Date: Wed Mar 3 08:47:16 2021 -0500 SUNRPC: Set memalloc_nofs_save() for sync tasks [ Upstream commit f0940f4b3284a00f38a5d42e6067c2aaa20e1f2e ] We could recurse into NFS doing memory reclaim while sending a sync task, which might result in a deadlock. Set memalloc_nofs_save for sync task execution. Fixes: a1231fda7e94 ("SUNRPC: Set memalloc_nofs_save() on all rpciod/xprtiod jobs") Signed-off-by: Benjamin Coddington <bcodding@xxxxxxxxxx> Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index 7afbf15bcbd9..4beb6d2957c3 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -990,8 +990,11 @@ void rpc_execute(struct rpc_task *task) rpc_set_active(task); rpc_make_runnable(rpciod_workqueue, task); - if (!is_async) + if (!is_async) { + unsigned int pflags = memalloc_nofs_save(); __rpc_execute(task); + memalloc_nofs_restore(pflags); + } } static void rpc_async_schedule(struct work_struct *work)