SUNRPC: Handle low memory situations in call_status()

stable inclusion
from stable-v5.10.111
commit 9a45e08636bba2949819cbf4d9ee0b974dd5c7a6
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5GL1Z

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9a45e08636bba2949819cbf4d9ee0b974dd5c7a6

--------------------------------

[ Upstream commit 9d82819d ]

We need to handle ENFILE, ENOBUFS, and ENOMEM, because
xprt_wake_pending_tasks() can be called with any one of these due to
socket creation failures.

Fixes: b61d59ff ("SUNRPC: xs_tcp_connect_worker{4,6}: merge common code")
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>

net/sunrpc/clnt.c

@@ -2342,6 +2342,11 @@ call_status(struct rpc_task *task)
 	case -EPIPE:
 	case -EAGAIN:
 		break;
+	case -ENFILE:
+	case -ENOBUFS:
+	case -ENOMEM:
+		rpc_delay(task, HZ>>2);
+		break;
 	case -EIO:
 		/* shutdown or soft timeout */
 		goto out_exit;