From 296c98be74fc01721b6e8a97f257e173bf5496da Mon Sep 17 00:00:00 2001
From: "Vladimir V. Saveliev" <vs@namesys.com>
Date: Tue, 27 Jun 2006 02:53:57 -0700
Subject: [PATCH] --- yaml --- r: 30751 b: refs/heads/master c:
 6527c2bdf1f833cc18e8f42bd97973d583e4aa83 h: refs/heads/master i:   30749:
 487986847d880d71bc54b8a5a13872622e46fd1b   30747:
 1f17bd17bdca5142390dc31493db7c47182a3883   30743:
 31f9214090901348d674f9950312f5075eca8051   30735:
 3b728a53fd2d3cd3009f5740bbbc21cda7d28a5a   30719:
 9991833e64508655770c042b36e7664ece7b545d v: v3

---
 [refs]             |  2 +-
 trunk/mm/filemap.c | 18 +++++++++++-------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/[refs] b/[refs]
index dfb84aa950f8..621d0e76137a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1c0f16e5cdff59f3b132a1b0c0d44a941f8813d2
+refs/heads/master: 6527c2bdf1f833cc18e8f42bd97973d583e4aa83
diff --git a/trunk/mm/filemap.c b/trunk/mm/filemap.c
index 9c7334bafda8..d504d6e98886 100644
--- a/trunk/mm/filemap.c
+++ b/trunk/mm/filemap.c
@@ -2095,14 +2095,21 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 	do {
 		unsigned long index;
 		unsigned long offset;
-		unsigned long maxlen;
 		size_t copied;
 
 		offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
 		index = pos >> PAGE_CACHE_SHIFT;
 		bytes = PAGE_CACHE_SIZE - offset;
-		if (bytes > count)
-			bytes = count;
+
+		/* Limit the size of the copy to the caller's write size */
+		bytes = min(bytes, count);
+
+		/*
+		 * 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);
 
 		/*
 		 * Bring in the user page that we will copy from _first_.
@@ -2110,10 +2117,7 @@ generic_file_buffered_write(struct kiocb *iocb, const struct iovec *iov,
 		 * same page as we're writing to, without it being marked
 		 * up-to-date.
 		 */
-		maxlen = cur_iov->iov_len - iov_base;
-		if (maxlen > bytes)
-			maxlen = bytes;
-		fault_in_pages_readable(buf, maxlen);
+		fault_in_pages_readable(buf, bytes);
 
 		page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec);
 		if (!page) {