f2fs: fix to truncate inline data in inode page when setattr

Previous we do not truncate inline data in inode page when setattr, so following
case could still read the inline data which has already truncated:

1.write inline data
2.ftruncate size to 0
3.ftruncate size to max inline data size
4.read from offset 0

This patch introduces truncate_inline_data() to fix this problem.

change log from v1:
 o fix a bug and do not truncate first page data after truncate inline data.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index 3258c7cf00d..d215dbb09f0 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -176,6 +176,24 @@ int f2fs_write_inline_data(struct inode *inode,
 	return 0;
 }
 
+void truncate_inline_data(struct inode *inode, u64 from)
+{
+	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+	struct page *ipage;
+
+	if (from >= MAX_INLINE_DATA)
+		return;
+
+	ipage = get_node_page(sbi, inode->i_ino);
+	if (IS_ERR(ipage))
+		return;
+
+	zero_user_segment(ipage, INLINE_DATA_OFFSET + from,
+				INLINE_DATA_OFFSET + MAX_INLINE_DATA);
+	set_page_dirty(ipage);
+	f2fs_put_page(ipage, 1);
+}
+
 int recover_inline_data(struct inode *inode, struct page *npage)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);