From 8295df07b4b1c2742bab24dd4d37b204574199a9 Mon Sep 17 00:00:00 2001
From: Nick Piggin <npiggin@suse.de>
Date: Tue, 16 Oct 2007 01:24:53 -0700
Subject: [PATCH] --- yaml --- r: 69619 b: refs/heads/master c:
 41cb8ac025dbbf6782eae10d231e7e2336ad3724 h: refs/heads/master i:   69617:
 12ccc6c5e6c38651ffb055c456c9840d38924ccb   69615:
 0e41831f2690db7faf01d256ceff78caca1012f6 v: v3

---
 [refs]             |  2 +-
 trunk/mm/filemap.c | 32 +++++++++++++-------------------
 2 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/[refs] b/[refs]
index cb9674f4a4a3..49e8143d1d08 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 902aaed0d983dfd459fcb2b678608d4584782200
+refs/heads/master: 41cb8ac025dbbf6782eae10d231e7e2336ad3724
diff --git a/trunk/mm/filemap.c b/trunk/mm/filemap.c
index 7989c44cb293..c504db18ac26 100644
--- a/trunk/mm/filemap.c
+++ b/trunk/mm/filemap.c
@@ -1874,27 +1874,21 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 		/* Limit the size of the copy to the caller's write size */
 		bytes = min(bytes, count);
 
-		/* We only need to worry about prefaulting when writes are from
-		 * user-space.  NFSd uses vfs_writev with several non-aligned
-		 * segments in the vector, and limiting to one segment a time is
-		 * a noticeable performance for re-write
+		/*
+		 * Limit the size of the copy to that of the current segment,
+		 * because fault_in_pages_readable() doesn't know how to walk
+		 * segments.
 		 */
-		if (!segment_eq(get_fs(), KERNEL_DS)) {
-			/*
-			 * Limit the size of the copy to that of the current
-			 * segment, because fault_in_pages_readable() doesn't
-			 * know how to walk segments.
-			 */
-			bytes = min(bytes, cur_iov->iov_len - iov_base);
+		bytes = min(bytes, cur_iov->iov_len - iov_base);
+
+		/*
+		 * Bring in the user page that we will copy from _first_.
+		 * Otherwise there's a nasty deadlock on copying from the
+		 * same page as we're writing to, without it being marked
+		 * up-to-date.
+		 */
+		fault_in_pages_readable(buf, bytes);
 
-			/*
-			 * Bring in the user page that we will copy from
-			 * _first_.  Otherwise there's a nasty deadlock on
-			 * copying from the same page as we're writing to,
-			 * without it being marked up-to-date.
-			 */
-			fault_in_pages_readable(buf, bytes);
-		}
 		page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec);
 		if (!page) {
 			status = -ENOMEM;