From dda27be251d01939fc39c6cd07a1dd64888b1ba9 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Wed, 5 Sep 2012 16:06:56 +0200
Subject: [PATCH] --- yaml --- r: 329784 b: refs/heads/master c:
 3f6bba823767e3c78efcf1bea5b6fdf98ad80e3b h: refs/heads/master v: v3

---
 [refs]              |  2 +-
 trunk/fs/udf/file.c | 35 +++++++++++++++++++++++++++++------
 2 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/[refs] b/[refs]
index e3b7f70cce67..8d838c5db8a3 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 76f59b3bf5af41c2fb60f05f5d5ec51e8138e996
+refs/heads/master: 3f6bba823767e3c78efcf1bea5b6fdf98ad80e3b
diff --git a/trunk/fs/udf/file.c b/trunk/fs/udf/file.c
index 7f3f7ba3df6e..d1c6093fd3d3 100644
--- a/trunk/fs/udf/file.c
+++ b/trunk/fs/udf/file.c
@@ -39,20 +39,24 @@
 #include "udf_i.h"
 #include "udf_sb.h"
 
-static int udf_adinicb_readpage(struct file *file, struct page *page)
+static void __udf_adinicb_readpage(struct page *page)
 {
 	struct inode *inode = page->mapping->host;
 	char *kaddr;
 	struct udf_inode_info *iinfo = UDF_I(inode);
 
-	BUG_ON(!PageLocked(page));
-
 	kaddr = kmap(page);
-	memset(kaddr, 0, PAGE_CACHE_SIZE);
 	memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr, inode->i_size);
+	memset(kaddr + inode->i_size, 0, PAGE_CACHE_SIZE - inode->i_size);
 	flush_dcache_page(page);
 	SetPageUptodate(page);
 	kunmap(page);
+}
+
+static int udf_adinicb_readpage(struct file *file, struct page *page)
+{
+	BUG_ON(!PageLocked(page));
+	__udf_adinicb_readpage(page);
 	unlock_page(page);
 
 	return 0;
@@ -77,6 +81,25 @@ static int udf_adinicb_writepage(struct page *page,
 	return 0;
 }
 
+static int udf_adinicb_write_begin(struct file *file,
+			struct address_space *mapping, loff_t pos,
+			unsigned len, unsigned flags, struct page **pagep,
+			void **fsdata)
+{
+	struct page *page;
+
+	if (WARN_ON_ONCE(pos >= PAGE_CACHE_SIZE))
+		return -EIO;
+	page = grab_cache_page_write_begin(mapping, 0, flags);
+	if (!page)
+		return -ENOMEM;
+	*pagep = page;
+
+	if (!PageUptodate(page) && len != PAGE_CACHE_SIZE)
+		__udf_adinicb_readpage(page);
+	return 0;
+}
+
 static int udf_adinicb_write_end(struct file *file,
 			struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned copied,
@@ -98,8 +121,8 @@ static int udf_adinicb_write_end(struct file *file,
 const struct address_space_operations udf_adinicb_aops = {
 	.readpage	= udf_adinicb_readpage,
 	.writepage	= udf_adinicb_writepage,
-	.write_begin = simple_write_begin,
-	.write_end = udf_adinicb_write_end,
+	.write_begin	= udf_adinicb_write_begin,
+	.write_end	= udf_adinicb_write_end,
 };
 
 static ssize_t udf_file_aio_write(struct kiocb *iocb, const struct iovec *iov,