From: Trond Myklebust <trond.myklebust@fys.uio.no>
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Close some potential scheduler races in rpciod.
Cheers,
Trond
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--=-HT9F/x8+F4NM0LHwrnu+--
---
25-akpm/net/sunrpc/sched.c | 31 ++++++++++++++++++++++++-------
1 files changed, 24 insertions(+), 7 deletions(-)
diff -puN net/sunrpc/sched.c~nfs-07-rpc_fixes net/sunrpc/sched.c
--- 25/net/sunrpc/sched.c~nfs-07-rpc_fixes 2004-03-14 15:12:40.725539248 -0800
+++ 25-akpm/net/sunrpc/sched.c 2004-03-14 15:12:40.727538944 -0800
@@ -786,21 +786,22 @@ __rpc_schedule(void)
dprintk("RPC: rpc_schedule enter\n");
while (1) {
- spin_lock_bh(&rpc_queue_lock);
task_for_first(task, &schedq.tasks[0]) {
__rpc_remove_wait_queue(task);
spin_unlock_bh(&rpc_queue_lock);
__rpc_execute(task);
+ spin_lock_bh(&rpc_queue_lock);
} else {
- spin_unlock_bh(&rpc_queue_lock);
break;
}
if (++count >= 200 || need_resched()) {
count = 0;
+ spin_unlock_bh(&rpc_queue_lock);
schedule();
+ spin_lock_bh(&rpc_queue_lock);
}
}
dprintk("RPC: rpc_schedule leave\n");
@@ -1114,27 +1115,41 @@ rpciod(void *ptr)
allow_signal(SIGKILL);
dprintk("RPC: rpciod starting (pid %d)\n", rpciod_pid);
+ spin_lock_bh(&rpc_queue_lock);
while (rpciod_users) {
+ DEFINE_WAIT(wait);
if (signalled()) {
+ spin_unlock_bh(&rpc_queue_lock);
rpciod_killall();
flush_signals(current);
+ spin_lock_bh(&rpc_queue_lock);
}
__rpc_schedule();
- if (current->flags & PF_FREEZE)
+ if (current->flags & PF_FREEZE) {
+ spin_unlock_bh(&rpc_queue_lock);
refrigerator(PF_IOTHREAD);
+ spin_lock_bh(&rpc_queue_lock);
+ }
if (++rounds >= 64) { /* safeguard */
+ spin_unlock_bh(&rpc_queue_lock);
schedule();
rounds = 0;
+ spin_lock_bh(&rpc_queue_lock);
}
- if (!rpciod_task_pending()) {
- dprintk("RPC: rpciod back to sleep\n");
- wait_event_interruptible(rpciod_idle, rpciod_task_pending());
- dprintk("RPC: switch to rpciod\n");
+ dprintk("RPC: rpciod back to sleep\n");
+ prepare_to_wait(&rpciod_idle, &wait, TASK_INTERRUPTIBLE);
+ if (!rpciod_task_pending() && !signalled()) {
+ spin_unlock_bh(&rpc_queue_lock);
+ schedule();
rounds = 0;
+ spin_lock_bh(&rpc_queue_lock);
}
+ finish_wait(&rpciod_idle, &wait);
+ dprintk("RPC: switch to rpciod\n");
}
+ spin_unlock_bh(&rpc_queue_lock);
dprintk("RPC: rpciod shutdown commences\n");
if (!list_empty(&all_tasks)) {
@@ -1158,7 +1173,9 @@ rpciod_killall(void)
while (!list_empty(&all_tasks)) {
clear_thread_flag(TIF_SIGPENDING);
rpc_killall_tasks(NULL);
+ spin_lock_bh(&rpc_queue_lock);
__rpc_schedule();
+ spin_unlock_bh(&rpc_queue_lock);
if (!list_empty(&all_tasks)) {
dprintk("rpciod_killall: waiting for tasks to exit\n");
yield();
_