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authorAndriy Skulysh <andriy_skulysh@xyratex.com>2013-01-06 17:12:15 -0500
committerJ. Bruce Fields <bfields@redhat.com>2013-01-23 18:17:39 -0500
commit35525b79786b2ba58ef13822198ce22c497bc7a2 (patch)
tree2aaefaf2b21a3b3b133b29b711c811be0e335c11
parent624ab4644819948e9dc87c114201e98f2e52490f (diff)
sunrpc: Fix lockd sleeping until timeout
There is a race in enqueueing thread to a pool and waking up a thread. lockd doesn't wake up on reception of lock granted callback if svc_wake_up() is called before lockd's thread is added to a pool. Signed-off-by: Andriy Skulysh <Andriy_Skulysh@xyratex.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
-rw-r--r--include/linux/sunrpc/svc.h1
-rw-r--r--net/sunrpc/svc_xprt.c9
2 files changed, 9 insertions, 1 deletions
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 676ddf53b3ee..1f0216b9a6c9 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -50,6 +50,7 @@ struct svc_pool {
50 unsigned int sp_nrthreads; /* # of threads in pool */ 50 unsigned int sp_nrthreads; /* # of threads in pool */
51 struct list_head sp_all_threads; /* all server threads */ 51 struct list_head sp_all_threads; /* all server threads */
52 struct svc_pool_stats sp_stats; /* statistics on pool operation */ 52 struct svc_pool_stats sp_stats; /* statistics on pool operation */
53 int sp_task_pending;/* has pending task */
53} ____cacheline_aligned_in_smp; 54} ____cacheline_aligned_in_smp;
54 55
55/* 56/*
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index b8e47fac7315..5a9d40c5a9f3 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -499,7 +499,8 @@ void svc_wake_up(struct svc_serv *serv)
499 rqstp->rq_xprt = NULL; 499 rqstp->rq_xprt = NULL;
500 */ 500 */
501 wake_up(&rqstp->rq_wait); 501 wake_up(&rqstp->rq_wait);
502 } 502 } else
503 pool->sp_task_pending = 1;
503 spin_unlock_bh(&pool->sp_lock); 504 spin_unlock_bh(&pool->sp_lock);
504 } 505 }
505} 506}
@@ -634,7 +635,13 @@ struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout)
634 * long for cache updates. 635 * long for cache updates.
635 */ 636 */
636 rqstp->rq_chandle.thread_wait = 1*HZ; 637 rqstp->rq_chandle.thread_wait = 1*HZ;
638 pool->sp_task_pending = 0;
637 } else { 639 } else {
640 if (pool->sp_task_pending) {
641 pool->sp_task_pending = 0;
642 spin_unlock_bh(&pool->sp_lock);
643 return ERR_PTR(-EAGAIN);
644 }
638 /* No data pending. Go to sleep */ 645 /* No data pending. Go to sleep */
639 svc_thread_enqueue(pool, rqstp); 646 svc_thread_enqueue(pool, rqstp);
640 647