From e3a41a5ba9c2ab988b9f1442925109dca2382fd9 Mon Sep 17 00:00:00 2001
From: Johannes Weiner <jweiner@redhat.com>
Date: Tue, 10 Jan 2012 15:07:55 -0800
Subject: [PATCH] btrfs: pass __GFP_WRITE for buffered write page allocations

Tell the page allocator that pages allocated for a buffered write are
expected to become dirty soon.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 fs/btrfs/file.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 97fbe93..20375e6 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1081,7 +1081,7 @@ static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
 again:
 	for (i = 0; i < num_pages; i++) {
 		pages[i] = find_or_create_page(inode->i_mapping, index + i,
-					       mask);
+					       mask | __GFP_WRITE);
 		if (!pages[i]) {
 			faili = i - 1;
 			err = -ENOMEM;
-- 
2.7.4