f2fs: fix to report newly allocate region as extent

Previous get_block in f2fs didn't report the newly allocated region which has
NEW_ADDR.
For reader, it should not report, but fiemap needs this.
So, this patch introduces two get_block sharing core function.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/data.c

@@ -608,8 +608,8 @@ static int __allocate_data_block(struct dnode_of_data *dn)
  *     b. do not use extent cache for better performance
  *     c. give the block addresses to blockdev
  */
-static int get_data_block(struct inode *inode, sector_t iblock,
-			struct buffer_head *bh_result, int create)
+static int __get_data_block(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create, bool fiemap)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	unsigned int blkbits = inode->i_sb->s_blocksize_bits;
@@ -637,7 +637,7 @@ static int get_data_block(struct inode *inode, sector_t iblock,
 			err = 0;
 		goto unlock_out;
 	}
-	if (dn.data_blkaddr == NEW_ADDR)
+	if (dn.data_blkaddr == NEW_ADDR && !fiemap)
 		goto put_out;
 
 	if (dn.data_blkaddr != NULL_ADDR) {
@@ -671,7 +671,7 @@ static int get_data_block(struct inode *inode, sector_t iblock,
 				err = 0;
 			goto unlock_out;
 		}
-		if (dn.data_blkaddr == NEW_ADDR)
+		if (dn.data_blkaddr == NEW_ADDR && !fiemap)
 			goto put_out;
 
 		end_offset = ADDRS_PER_PAGE(dn.node_page, F2FS_I(inode));
@@ -708,10 +708,23 @@ static int get_data_block(struct inode *inode, sector_t iblock,
 	return err;
 }
 
+static int get_data_block(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create)
+{
+	return __get_data_block(inode, iblock, bh_result, create, false);
+}
+
+static int get_data_block_fiemap(struct inode *inode, sector_t iblock,
+			struct buffer_head *bh_result, int create)
+{
+	return __get_data_block(inode, iblock, bh_result, create, true);
+}
+
 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		u64 start, u64 len)
 {
-	return generic_block_fiemap(inode, fieinfo, start, len, get_data_block);
+	return generic_block_fiemap(inode, fieinfo,
+				start, len, get_data_block_fiemap);
 }
 
 static int f2fs_read_data_page(struct file *file, struct page *page)