patches/fs-fscache-remove-spin_lock-from-the-condition-in-wh.patch

From d32f5420ac164141683c51e8a8fce666423de492 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed, 3 Apr 2013 12:43:30 +0200
Subject: [PATCH] fs/fscache: remove spin_lock() from the condition in while()

The spinlock() within the condition in while() will cause a compile error
if it is not a function. This is not a problem on mainline but it does not
look pretty and there is no reason to do it that way.
That patch writes it a little differently and avoids the double condition.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 fs/fscache/page.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/fscache/page.c b/fs/fscache/page.c
index ff000e5..c84696c 100644
--- a/fs/fscache/page.c
+++ b/fs/fscache/page.c
@@ -796,11 +796,13 @@ void fscache_invalidate_writes(struct fscache_cookie *cookie)
 
 	_enter("");
 
-	while (spin_lock(&cookie->stores_lock),
-	       n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0,
-					      ARRAY_SIZE(results),
-					      FSCACHE_COOKIE_PENDING_TAG),
-	       n > 0) {
+	spin_lock(&cookie->stores_lock);
+	while (1) {
+		n = radix_tree_gang_lookup_tag(&cookie->stores, results, 0,
+					       ARRAY_SIZE(results),
+					       FSCACHE_COOKIE_PENDING_TAG);
+		if (n == 0)
+			break;
 		for (i = n - 1; i >= 0; i--) {
 			page = results[i];
 			radix_tree_delete(&cookie->stores, page->index);
@@ -810,6 +812,7 @@ void fscache_invalidate_writes(struct fscache_cookie *cookie)
 
 		for (i = n - 1; i >= 0; i--)
 			page_cache_release(results[i]);
+		spin_lock(&cookie->stores_lock);
 	}
 
 	spin_unlock(&cookie->stores_lock);
-- 
1.7.10.4