1 files changed, 20 insertions, 0 deletions
diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index fac90f3fba8..af103be491b 100644
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -246,3 +246,23 @@ int ext4_data_block_valid(struct ext4_sb_info *sbi, ext4_fsblk_t start_blk,
 	return 1;
 }
 
+int ext4_check_blockref(const char *function, unsigned int line,
+			struct inode *inode, __le32 *p, unsigned int max)
+{
+	struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
+	__le32 *bref = p;
+	unsigned int blk;
+
+	while (bref < p+max) {
+		blk = le32_to_cpu(*bref++);
+		if (blk &&
+		    unlikely(!ext4_data_block_valid(EXT4_SB(inode->i_sb),
+						    blk, 1))) {
+			es->s_last_error_block = cpu_to_le64(blk);
+			ext4_error_inode(inode, function, line, blk,
+					 "invalid block");
+			return -EIO;
+		}
+	}
+	return 0;
+}