ext4: Fix estimate of # of blocks needed to write indirect-mapped files

http://bugzilla.kernel.org/show_bug.cgi?id=15420

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/inode.c

@@ -1035,7 +1035,7 @@ static int ext4_indirect_calc_metadata_amount(struct inode *inode,
 					      sector_t lblock)
 {
 	struct ext4_inode_info *ei = EXT4_I(inode);
-	int dind_mask = EXT4_ADDR_PER_BLOCK(inode->i_sb) - 1;
+	sector_t dind_mask = ~((sector_t)EXT4_ADDR_PER_BLOCK(inode->i_sb) - 1);
 	int blk_bits;
 
 	if (lblock < EXT4_NDIR_BLOCKS)
@@ -1050,7 +1050,7 @@ static int ext4_indirect_calc_metadata_amount(struct inode *inode,
 	}
 	ei->i_da_metadata_calc_last_lblock = lblock & dind_mask;
 	ei->i_da_metadata_calc_len = 1;
-	blk_bits = roundup_pow_of_two(lblock + 1);
+	blk_bits = order_base_2(lblock);
 	return (blk_bits / EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb)) + 1;
 }