From 99327d29f23e84f9d3d35f523af536a3c1ef65c0 Mon Sep 17 00:00:00 2001
From: Allison Henderson <achender@linux.vnet.ibm.com>
Date: Tue, 6 Sep 2011 21:53:01 -0400
Subject: [PATCH] --- yaml --- r: 273104 b: refs/heads/master c:
 02fac1297eb3f471a27368271aadd285548297b0 h: refs/heads/master v: v3

---
 [refs]                |  2 +-
 trunk/fs/ext4/inode.c | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 24f9df301f7f..928b9691f203 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 189e868fa8fdca702eb9db9d8afc46b5cb9144c9
+refs/heads/master: 02fac1297eb3f471a27368271aadd285548297b0
diff --git a/trunk/fs/ext4/inode.c b/trunk/fs/ext4/inode.c
index f86b149fb8b1..6ecc93979e48 100644
--- a/trunk/fs/ext4/inode.c
+++ b/trunk/fs/ext4/inode.c
@@ -2255,6 +2255,7 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
 	pgoff_t index;
 	struct inode *inode = mapping->host;
 	handle_t *handle;
+	loff_t page_len;
 
 	index = pos >> PAGE_CACHE_SHIFT;
 
@@ -2301,6 +2302,13 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
 		 */
 		if (pos + len > inode->i_size)
 			ext4_truncate_failed_write(inode);
+	} else {
+		page_len = pos & (PAGE_CACHE_SIZE - 1);
+		if (page_len > 0) {
+			ret = ext4_discard_partial_page_buffers_no_lock(handle,
+				inode, page, pos - page_len, page_len,
+				EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED);
+		}
 	}
 
 	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
@@ -2343,6 +2351,7 @@ static int ext4_da_write_end(struct file *file,
 	loff_t new_i_size;
 	unsigned long start, end;
 	int write_mode = (int)(unsigned long)fsdata;
+	loff_t page_len;
 
 	if (write_mode == FALL_BACK_TO_NONDELALLOC) {
 		if (ext4_should_order_data(inode)) {
@@ -2391,6 +2400,16 @@ static int ext4_da_write_end(struct file *file,
 	}
 	ret2 = generic_write_end(file, mapping, pos, len, copied,
 							page, fsdata);
+
+	page_len = PAGE_CACHE_SIZE -
+			((pos + copied - 1) & (PAGE_CACHE_SIZE - 1));
+
+	if (page_len > 0) {
+		ret = ext4_discard_partial_page_buffers_no_lock(handle,
+			inode, page, pos + copied - 1, page_len,
+			EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED);
+	}
+
 	copied = ret2;
 	if (ret2 < 0)
 		ret = ret2;