From: Jens Axboe <jens.axboe@oracle.com>
Date: Sat, 26 Sep 2009 15:34:25 +0000 (+0200)
Subject: Make lock_page_async() accept the wait queue
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=81433ee666e5620b534fe50412196b54966f590f;p=linux-block.git

Make lock_page_async() accept the wait queue

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 59fc8999e9f0..6b55e4cffffb 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -325,17 +325,19 @@ static inline void lock_page_nosync(struct page *page)
  * lock_page(). If that happens, this helper may also return fatal signals
  * terminating the wait, even if the page isn't locked yet.
  */
-static inline int lock_page_async(struct page *page)
+static inline int lock_page_async(struct page *page, struct wait_bit_queue *wq)
 {
 	might_sleep();
 
 	if (!trylock_page(page)) {
-		struct wait_bit_queue *wq;
 		DEFINE_WAIT_BIT(wq_stack, &page->flags, PG_locked);
 		
-		wq = current->io_wait;
 		if (!wq)
 			wq = &wq_stack;
+		else {
+			wq->key.flags = &page->flags;
+			wq->key.bit_nr = PG_locked;
+		}
 
 		return __lock_page_async(page, wq);
 	}
@@ -348,12 +350,8 @@ static inline int lock_page_async(struct page *page)
  */
 static inline void lock_page(struct page *page)
 {
-	might_sleep();
-
-	if (!trylock_page(page)) {
-		int ret = __lock_page_async(page, NULL);
-		WARN_ON(ret);
-	}
+	WARN_ON(current->io_wait);
+	lock_page_async(page, NULL);
 }
 
 /*
diff --git a/mm/filemap.c b/mm/filemap.c
index 24124388e8d4..91d24ff03324 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -623,14 +623,10 @@ EXPORT_SYMBOL(end_page_writeback);
  */
 int __lock_page_async(struct page *page, struct wait_bit_queue *wq)
 {
-	int (*fn)(void *);
+	int (*fn)(void *) = sync_page;
 
-	if (wq) {
-		wq->key.flags = &page->flags;
-		wq->key.bit_nr = PG_locked;
+	if (!is_sync_wait_bit_queue(wq))
 		fn = sync_page_killable;
-	} else
-		fn = sync_page;
 
 	return __wait_on_bit_lock(page_waitqueue(page), wq, fn,
  							TASK_UNINTERRUPTIBLE);
@@ -1126,7 +1122,7 @@ page_ok:
 
 page_not_up_to_date:
 		/* Get exclusive access to the page ... */
-		error = lock_page_async(page);
+		error = lock_page_async(page, current->io_wait);
 		if (unlikely(error))
 			goto readpage_error;
 
@@ -1157,7 +1153,7 @@ readpage:
 		}
 
 		if (!PageUptodate(page)) {
-			error = lock_page_async(page);
+			error = lock_page_async(page, current->io_wait);
 			if (unlikely(error))
 				goto readpage_error;
 			if (!PageUptodate(page)) {