1 files changed, 21 insertions, 0 deletions

diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index fac90f3fba80..8efb2f0a3447 100644
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -246,3 +246,24 @@ 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;
+}
+