f2fs: add inline_data recovery routine

This patch adds a inline_data recovery routine with the following policy.

[prev.] [next] of inline_data flag
   o       o  -> recover inline_data
   o       x  -> remove inline_data, and then recover data blocks
   x       o  -> remove inline_data, and then recover inline_data
   x       x  -> recover data blocks

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 68dd7bf..c77ad4d 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -251,7 +251,7 @@
 	f2fs_put_page(page, 1);
 }
 
-static int truncate_blocks(struct inode *inode, u64 from)
+int truncate_blocks(struct inode *inode, u64 from)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	unsigned int blocksize = inode->i_sb->s_blocksize;