From: David Howells <dhowells@redhat.com>
Date: Thu, 16 Mar 2017 16:27:49 +0000 (+0000)
Subject: afs: Don't wait for page writeback with the page lock held
X-Git-Tag: v4.14-rc1~1278^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c5051c7bc777dffa5661569dec5997f432b9a34a;p=platform%2Fkernel%2Flinux-rpi.git

afs: Don't wait for page writeback with the page lock held

Drop the page lock before waiting for page writeback.

Signed-off-by: David Howells <dhowells@redhat.com>
---

diff --git a/fs/afs/write.c b/fs/afs/write.c
index e5f150b..2d2fccd 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -518,17 +518,16 @@ static int afs_writepages_region(struct address_space *mapping,
 		 */
 		lock_page(page);
 
-		if (page->mapping != mapping) {
+		if (page->mapping != mapping || !PageDirty(page)) {
 			unlock_page(page);
 			put_page(page);
 			continue;
 		}
 
-		if (wbc->sync_mode != WB_SYNC_NONE)
-			wait_on_page_writeback(page);
-
-		if (PageWriteback(page) || !PageDirty(page)) {
+		if (PageWriteback(page)) {
 			unlock_page(page);
+			if (wbc->sync_mode != WB_SYNC_NONE)
+				wait_on_page_writeback(page);
 			put_page(page);
 			continue;
 		}